Radio communication apparatus

The present invention relates to a digital modulation method used for wireless communication.

[0002] In a digital mobile wireless communication system, transmission / reception between a base station device and a communication terminal device is affected by a radio wave propagation environment, and the radio wave propagation environment has reception quality and reception sensitivity characteristics on the receiving side. Affects. Therefore, conventionally, as a method of improving the reception sensitivity characteristic of the receiving device by devising the signal point position of the pilot symbol, a method relating to the signal point position of the pilot symbol when performing quadrature detection is described in the literature (for land mobile communication). 16QAM Fading Strain Compensation Method) Sampei, IEICE Journal B-II Vol.J-72-B-II No.1 pp.7-15 Described in January 1989. FIG. 35 shows the signal point arrangement of the 16QAM and pilot symbols in the in-phase-quadrature plane (IQ plane). In FIG. 35, reference numeral 3501 indicates a signal point of 16QAM in the IQ plane, and the signal point of the pilot symbol is arranged at any of reference numeral 3502, reference numeral 3503, reference numeral 3504, and reference numeral 3505. In addition, a method is known in which a signal point having the maximum amplitude among 16QAM signal points is used as a pilot signal to perform quadrature detection.

[0003] However, in the conventional arrangement of pilot symbols, the signal point having the maximum signal point amplitude of the signal point in one modulation method is set as the signal point of the pilot symbol, but the receiving device Considering the reception sensitivity of, this point is not always the optimum position as the signal point of the pilot symbol. Further, increasing the transmission power of the transmission device and increasing the maximum signal point amplitude shown in FIG. 35 in order to improve the reception sensitivity characteristic of the reception device increases the transmission power for all the symbols to be transmitted. It is nothing but increasing the power consumption of the transmitter.

[0004] The present invention has been made in view of this point, and the signal points of the pilot symbols are arranged while keeping the average transmission power of the transmitting device at a certain level to improve the receiving sensitivity characteristics of the receiving device. With the goal.

[Means for Solving the Problems] The wireless communication device of the present invention includes a plurality of signal generation means for generating orthogonal baseband signals by different modulation methods, and signals output from the plurality of signal generation means. Of the switching means for selecting only the target signal, the radio means for performing predetermined radio processing on the orthogonal baseband signal selected by the switching means, and the power of the transmission signal output from the radio means are amplified. The transmission power of the symbol for demodulation is provided so that the average transmission output power of the transmission signal by each of the modulation methods is equal to each other and the operating range of the power amplification means becomes a predetermined value. Take a configuration to adjust.

[0006] The wireless communication device of the present invention adopts a configuration in which a predetermined value is the same value for each modulation method.

[0007] The wireless communication device of the present invention selects only a target signal from a plurality of signal generation means for generating orthogonal baseband signals by different modulation methods and signals output from the plurality of signal generation means. It includes a switching means, a radio means that performs predetermined radio processing on the orthogonal baseband signal selected by the switching means, and a power amplification means that amplifies the power of the transmission signal output from the radio means. The configuration is adopted in which the transmission power of the symbol for demodulation is adjusted so that the average transmission output power of the transmission signals by each of the modulation methods is equal to each other and the reception sensitivity becomes an optimum value.

[0008] According to these configurations, it is possible to maintain the average transmission power of the transmission device at a certain level, adjust the transmission power of the symbol for demodulation, and improve the reception sensitivity characteristic of the reception device. Examples of symbols for demodulation include pilot symbols, unique words, preambles, and the like.

[0009] In the wireless communication device of the present invention, only a plurality of signal generation means for generating a serial signal of transmission digital signals by different modulation methods and a target signal among the serial signals output from the plurality of signal generation means. A switching means for selecting the above, a serial-parallel conversion means for converting the serial signal output from the switching means into a parallel signal, a discrete inverse Fourier conversion means for performing discrete inverse Fourier conversion on the serial-parallel converted parallel signal, and a discrete inverse Fourier conversion means. A radio means that performs predetermined radio processing on a Fourier-converted signal and a power amplification means that amplifies the power of the transmission signal output from the radio means are provided, and the average transmission output of the transmission signal by each of the modulation methods is provided. A configuration is adopted in which the transmission power of the symbol for demodulation is adjusted so that the powers are equal to each other and the operating range in the power amplification means becomes a predetermined value.

[0010] The wireless communication device of the present invention adopts a configuration in which a predetermined value is the same value for each modulation method.

[0011] The wireless communication device of the present invention includes only a plurality of signal generation means for generating serial signals of transmitted digital signals by different modulation methods, and a target signal among the serial signals output from the plurality of signal generation means. A switching means for selecting the above, a serial-parallel conversion means for converting the serial signal output from the switching means into a parallel signal, a discrete inverse Fourier conversion means for performing discrete inverse Fourier conversion on the serial-parallel converted parallel signal, and a discrete inverse Fourier conversion means. A radio means that performs predetermined radio processing on a Fourier-converted signal and a power amplification means that amplifies the power of the transmission signal output from the radio means are provided, and the average transmission output of the transmission signal by each of the modulation methods is provided. A configuration is adopted in which the transmission power of the symbol for demodulation is adjusted so that the powers are equal to each other and the reception sensitivity is the optimum value.

[0012] According to these configurations, even in the OFDM method, the average transmission power of the transmitter is maintained at a certain level, the transmission power of the symbol for demodulation is adjusted, and the reception sensitivity characteristic of the receiver is improved. be able to.

[0013] In the wireless communication device of the present invention, the correction value is determined from the ratio of the signal point amplitude of the symbol for demodulation received from the wireless communication device according to any one of the above to the maximum signal point amplitude of each modulation method. , The transmission line distortion estimation signal that estimates the distortion due to the transmission line is multiplied by the correction value to perform detection.

[0014] According to this configuration, the accuracy of the fading estimation signal can be improved, and the reception sensitivity characteristic of the receiving device can be improved.

[0015] The wireless communication device of the present invention has a configuration in which, when a signal transmitted by a communication partner is received by a plurality of incoming waves, the communication partner is required to have a modulation method having strong error tolerance or an error correction method having the strongest correction capability. take.

[0016] When the wireless communication device of the present invention receives information from a communication partner that it has been received by a plurality of incoming waves, it adopts a configuration in which a modulation method having strong error tolerance or an error correction method having the strongest correction capability is selected.

[0017] According to these configurations, when a plurality of incoming waves are received, the receiving device cannot demodulate the signal, so that this can be prevented.

[0018] The wireless communication device of the present invention adopts a configuration in which the modulation method having the highest resistance to noise is selected from the switchable modulation methods as the modulation method selected at the start of communication.

[0019] The wireless communication device of the present invention adopts a configuration in which an error correction method having the most error correction capability is selected from among the switchable error correction methods as the error correction method selected at the start of communication.

[0020] According to these configurations, it is possible to improve the data reception quality even when the radio wave propagation environment cannot be estimated at the start of communication.

[0021] The wireless communication device of the present invention estimates a radio wave propagation environment based on a signal transmitted from a communication partner, and based on the estimated radio wave propagation environment, a signal transmitted to the communication partner at the start of communication. A configuration is used to determine the modulation method.

The wireless communication device of the present invention estimates the radio wave propagation environment based on the signal transmitted from the communication partner, and based on the estimated radio wave propagation environment, the signal transmitted to the communication partner at the start of communication. Adopt a configuration that determines the error correction method.

[0023] The wireless communication device of the present invention constantly transmits a predetermined signal, and the communication partner receiving the predetermined signal estimates the radio wave propagation environment based on the predetermined signal, and the estimated radio wave propagation environment. A configuration is adopted in which information is transmitted and the modulation method of the signal to be transmitted to the communication partner at the start of communication is determined based on the radio wave propagation environment information.

[0024] The wireless communication device of the present invention constantly transmits a predetermined signal, and the communication partner receiving the predetermined signal estimates the radio wave propagation environment based on the predetermined signal, and the estimated radio wave propagation environment. A configuration is adopted in which information is transmitted and an error correction method for a signal to be transmitted to the communication partner at the start of communication is determined based on the radio wave propagation environment information.

[0025] According to these configurations, the signal to be transmitted at the start of communication is determined by the modulation method and the error correction method according to the radio wave propagation environment, so that the data reception quality can be improved.

[0026] The wireless communication device of the present invention receives a predetermined signal constantly transmitted from a communication partner, estimates a radio wave propagation environment based on the predetermined signal, and transmits the estimated radio wave propagation environment information. Take the composition.

[0027] The wireless communication device of the present invention adopts a configuration in which the radio wave propagation environment information includes information on a modulation method or an error correction method suitable for the estimated radio wave propagation environment.

[0028] According to these configurations, since the modulation method and the error correction method are determined according to the radio wave propagation environment, it is possible to improve the data reception quality.

[0029] In CDMA wireless communication, the wireless communication device of the present invention constantly transmits a signal of a predetermined channel, and a communication partner receiving the signal of the predetermined channel is based on the signal of the predetermined channel. A configuration is adopted in which the radio wave propagation environment is estimated, the estimated radio wave propagation environment information is transmitted, and the modulation method of the signal to be transmitted to the communication partner at the start of communication is determined based on the radio wave propagation environment information.

[0030] In CDMA wireless communication, the wireless communication device of the present invention constantly transmits a signal of a predetermined channel, and a communication partner receiving the signal of the predetermined channel is based on the signal of the predetermined channel. A configuration is adopted in which the radio wave propagation environment is estimated, the estimated radio wave propagation environment information is transmitted, and the error correction method of the signal transmitted to the communication partner at the start of communication is determined based on the radio wave propagation environment information.

[0031] According to these configurations, in the CDMA system, the signal to be transmitted at the start of communication is determined to be a modulation method and an error correction method according to the radio wave propagation environment, so that the data reception quality can be improved. ..

[0032] The wireless communication device of the present invention receives a signal of a predetermined channel constantly transmitted from a communication partner in CDMA wireless communication, and estimates a radio wave propagation environment based on the signal of the predetermined channel. At the same time, a configuration is adopted in which the estimated radio wave propagation environment information is transmitted.

[0033] The wireless communication device of the present invention adopts a configuration in which the radio wave propagation environment information includes information on a modulation method or an error correction method suitable for the estimated radio wave propagation environment.

[0034] According to this configuration, in the CDMA system, the modulation method and the error correction method according to the radio wave propagation environment are determined, so that the data reception quality can be improved.

[0035] The wireless communication device of the present invention adopts a configuration in which information on a modulation method of a signal to be transmitted is transmitted to a communication partner via a control channel in CDMA wireless communication.

[0036] In CDMA wireless communication, the wireless communication device of the present invention constantly transmits a signal of a predetermined channel, and a communication partner receiving the signal of the predetermined channel is based on the signal of the predetermined channel. A modulation method that estimates the radio wave propagation environment, transmits the estimated radio wave propagation environment information, determines the modulation method of the signal to be transmitted to the communication partner based on the radio wave propagation environment information, and determines via the control channel. Adopt a configuration in which information is transmitted to the communication partner.

[0037] The wireless communication device of the present invention adopts a configuration in which information of an error correction method of a signal to be transmitted is transmitted to a communication partner via a control channel in CDMA wireless communication.

[0038] In CDMA wireless communication, the wireless communication device of the present invention constantly transmits a signal of a predetermined channel, and a communication partner receiving the signal of the predetermined channel is based on the signal of the predetermined channel. An error determined by estimating the radio wave propagation environment, transmitting the estimated radio wave propagation environment information, determining an error correction method for a signal transmitted to the communication partner based on the radio wave propagation environment information, and determining via a control channel. A configuration is adopted in which the correction method is transmitted to the communication partner.

[0039] According to these configurations, in the CDMA system, the modulation method and the error correction method according to the radio wave propagation environment are determined, so that the data reception quality can be improved.

[0040] The wireless communication device of the present invention adopts a configuration for performing wireless communication in the OFDM system.

[0041] According to this configuration, the wireless communication device of the present invention can be applied to the OFDM system.

[Embodiment of the Invention] The gist of the present invention is that in a wireless communication system that performs adaptive modulation, the reception sensitivity of the receiving device is the best while maintaining the average transmission output power of the transmitting device at a certain level. In this way, the signal points of the pilot symbol are arranged on the in-phase-quadrature plane (IQ plane). Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 shows an example of a frame configuration according to the present embodiment. Hereinafter, the modulation method will be described by taking three types of combinations of QPSK, 16QAM, and 64QAM as an example.

[0044] In FIG. 1, the preamble 101, the pilot symbol 103, and the unique word 104 are control information, and the preamble 101 includes information on the selected modulation method, indicating any of QPSK, 16QAM, and 64QAM. Contains information. Data symbol 102 contains data information. The pilot symbol 103 is used for estimating the radio wave propagation environment and performing synchronous detection, and the unique word 104 is a signal for the receiving device to synchronize with the transmitting device in time. It should be noted that these control information requires more reliability than data symbols.

[0045] FIG. 2 shows the configuration of the transmission device according to the present embodiment. In FIG. 2, when the modulation method information included in the control signal among the input transmission digital signal and the control signal is QPSK, the QPSK signal generation unit 201 generates an orthogonal baseband signal according to the frame configuration of FIG. The generated in-phase component of the QPSK orthogonal baseband signal is output to the in-phase component switching unit 204, and the orthogonal component of the QPSK orthogonal baseband signal is output to the orthogonal component switching unit 205.

[0046] When the modulation method information included in the control signal is 16QAM among the input transmission digital signal and the control signal, the 16QAM signal generation unit 202 generates an orthogonal baseband signal according to the frame configuration of FIG. Then, the in-phase component of the 16QAM orthogonal baseband signal is output to the in-phase component switching unit 204, and the orthogonal component of the 16QAM orthogonal baseband signal is output to the orthogonal component switching unit 205.

[0047] The 64QAM signal generation unit 203 generates an orthogonal baseband signal according to the frame configuration of FIG. 1 in the case of the modulation method information 64QAM included in the control signal among the input transmission digital signal and the control signal. , The in-phase component of the 64QAM system orthogonal baseband signal is output to the in-phase component switching unit 204, and the orthogonal component of the 64QAM system orthogonal baseband signal is output to the orthogonal component switching unit 205.

[0048] The in-phase component switching unit 204 is routed differently from the orthogonal baseband signal in-phase component input by either the QPSK signal generation unit 201, the 16QAM signal generation unit 202, or the 64QAM signal generation unit 203. Of the input control signals, the input portion is switched so as to input the orthogonal baseband signal in-phase component of the specified modulation method based on the information of the modulation method included in the control signal, and the input orthogonal baseband signal in-phase is input. The component is output to the radio unit 206.

The orthogonal component switching unit 205 uses a different route from the orthogonal baseband signal orthogonal component input by either the QPSK signal generation unit 201, the 16QAM signal generation unit 202, or the 64QAM signal generation unit 203. Of the input control signals, the input portion is switched so that the transmission orthogonal baseband signal orthogonal component of the specified modulation method is input based on the information of the modulation method included in the control signal, and the input orthogonal baseband signal is input. The orthogonal component is output to the radio unit 206.

[0050] The radio unit 206 performs predetermined radio processing on the transmission orthogonal baseband signal in-phase component output from the in-phase component switching unit 204 and the transmission orthogonal baseband signal orthogonal component output from the orthogonal component switching unit 205. , Output to the transmission power amplification unit 207. The transmission power amplification unit 207 amplifies the signal wirelessly processed by the radio unit 206, and transmits the amplified transmission signal via the transmission antenna 208.

FIG. 3 shows the configuration of the receiving device according to the present embodiment. In FIG. 3, the receiving radio unit 302 performs predetermined radio processing on the signal (received signal) received via the receiving antenna 301, and synchronizes the receiving quadrature baseband signal in-phase component and the receiving quadrature baseband signal quadrature component. Outputs to the modulation method determination unit 303, fading distortion estimation unit 304, frequency offset estimation unit 305, QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308, respectively.

[0052] The synchronization / modulation method determination unit 303 detects and detects the unique word 104 in FIG. 1 from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 302. Synchronize with the transmitter based on the unique word. It also detects the preamble and identifies the modulation method information contained in the preamble. A control signal including these two pieces of information is output to each of the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308.

[0053] The fading distortion estimation unit 304 uses the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 302 and the control signal output from the synchronization / modulation method determination unit 303. Then, the distortion due to fading is estimated from the pilot symbol in FIG. 1, and the fading distortion estimation signal is output to each of the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308.

[0054] The frequency offset estimation unit 305 uses the reception quadrature baseband signal in-phase component and quadrature component output from the reception radio unit 302, and the control signal output from the synchronization / modulation method determination unit 303 to use the pilot in FIG. The frequency offset is estimated from the symbol 103, and the frequency offset estimation signal is output to each of the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308.

When the modulation method information included in the control signal output from the synchronization / modulation method determination unit 303 indicates QPSK, the QPSK detection unit 306 outputs a reception orthogonal baseband signal from the reception radio unit 302. In-phase component and received orthogonal baseband signal The fading distortion and frequency offset in the orthogonal component are removed by using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305. , Demodulate and output the QPSK received digital signal.

[0056] The 16QAM detection unit 307 receives the reception orthogonal baseband signal output from the reception radio unit 302 when the modulation method information included in the control signal output from the synchronization / modulation method determination unit 303 indicates 16QAM. In-phase component and received orthogonal baseband signal The fading distortion and frequency offset in the orthogonal component are removed by using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305. , Demodulates and outputs a 16QAM received digital signal.

When the modulation method information included in the control signal output from the synchronization / modulation method determination unit 303 indicates 64QAM, the 64QAM detection unit 308 indicates the reception orthogonal baseband signal output from the reception radio unit 302. In-phase component and received orthogonal baseband signal The fading distortion and frequency offset in the orthogonal component are removed by using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305. , Demodulates and outputs 64QAM received digital signal 308.

Next, the operation of the transmitting device and the receiving device having the above configuration will be described. First, the transmission digital signal and the control signal shown in FIG. 2 are input to the QPSK signal generation unit 201, the 16QAM signal generation unit 202, and the 64QAM signal generation unit 203, and are signal generation units that match the modulation method information of the control signal. Only is operated, and the orthogonal baseband signal is generated by the signal generation unit of the corresponding modulation method, and the orthogonal baseband signal in-phase component is output to the in-phase component switching unit 204, and the orthogonal baseband signal orthogonal component is output to the orthogonal component switching unit 205. Will be done.

The orthogonal baseband signal in-phase component output from the modulation method signal generation unit is switched by the in-phase component switching unit 204 to the input unit corresponding to the modulation method indicated by the control signal, and is output to the radio unit 206. Further, the orthogonal baseband signal orthogonal component output from the modulation method generation unit is switched by the orthogonal component switching unit 205 to the input unit corresponding to the modulation method indicated by the control signal, and is output to the radio unit 206.

[0060] The transmission orthogonal baseband signal in-phase component output from the in-phase component switching unit 204 and the transmission orthogonal baseband signal orthogonal component output from the orthogonal component switching unit 205 are subjected to predetermined radio processing by the radio unit 206. , The transmission signal is output to the transmission power amplification unit 207. The transmission signal output from the radio unit 206 is power-amplified by the transmission power amplification unit 207 and transmitted to the receiving device via the transmission antenna 208.

The signal transmitted by the transmitting device is received by the receiving device via the antenna 301 shown in FIG. In FIG. 3, the signal (received signal) received via the antenna 301 is subjected to predetermined radio processing by the receiving radio unit 302, and the receiving quadrature baseband signal in-phase component and the receiving quadrature baseband signal quadrature component are synchronized. -It is output to the modulation method determination unit 303, the fading distortion estimation unit 304, the frequency offset estimation unit 305, the QPSK detection unit 306, the 16QAM detection unit 307, and the 64QAM detection unit 308, respectively.

[0062] The reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 302 are detected by detecting the unique word 104 shown in FIG. 1 by the synchronization / modulation method determination unit 303. Time synchronization with the transmitter is taken based on the unique word 104. In addition, the preamble is detected, and the modulation method information included in the preamble is identified. A control signal including these two pieces of information is generated and output to the fading distortion estimation unit 304, the frequency offset estimation unit 305, the QPSK detection unit 306, the 16QAM detection unit 307, and the 64QAM detection unit 308, respectively.

[0063] The reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 302 and the control signal output from the synchronization / modulation method determination unit 303 are generated by the fading distortion estimation unit 304. Distortion due to fading is estimated from the pilot symbol 103 shown in FIG. 1, and the fading distortion estimation signal is output to the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308, respectively.

[0064] Further, the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 302 and the control signal output from the synchronization / modulation method determination unit 303 are the frequency offset estimation unit 305. The frequency offset is estimated from the pilot symbol 103 shown in FIG. 1, and the frequency offset estimation signal is output to the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308, respectively.

[0065] Output from the receiving radio unit 302 in each detection unit corresponding to the modulation method information of the control signal output from the synchronization / modulation method determination unit 303, that is, the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308. Received orthogonal baseband signal The fading distortion and frequency offset in the in-phase component and the orthogonal component are measured by using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305. , Removal and demodulation are performed, and the received digital signal corresponding to each modulation method is output.

[0066] The operation of the transmission power amplification unit in the wireless communication system of the present embodiment and the arrangement of signal points of the pilot symbols in each modulation method will be described. In the present embodiment, the signal point amplitude of the pilot symbol represents the transmission power on the IQ plane, and increasing the transmission power increases the signal point amplitude of the pilot symbol.

FIG. 4 shows the input / output relationship of the conventional transmission power amplification unit. In FIG. 4, reference numeral 401 indicates that it is the average transmission output power at the operating point of the transmission power amplification unit. Reference numeral 402, reference numeral 403, and reference numeral 404 are operating ranges of QPSK, 16QAM, and 64QAM, respectively (level ranges in which signals input to the power amplification unit can be input), and their respective modulation methods are selected. The operating range of the transmission power amplification unit at this time is shown. As shown in Fig. 4, the operating range is the largest when the modulation method is 64QAM. As described above, conventionally, the operating range has been determined by the modulation method.

However, since the transmission power amplification unit uses a transmission power amplifier capable of linearly amplifying the signal of the 64QAM modulation method, the operating range does not exceed the operating range of 64QAM when the modulation method is QPSK or 16QAM. Therefore, linear amplification is possible even if the operating range is expanded.

[0069] Therefore, in the wireless communication system for adaptive modulation according to the present embodiment, the reception sensitivity characteristic of the receiving device is the highest within the range not exceeding the operating range of the modulation method having the widest operating range of the transmission power amplification unit. In order to improve the method, the signal point of the pilot symbol is arranged on the IQ plane. That is, when the modulation method is QPSK or 16QAM, the input level of the pilot symbol is increased within the operating range of 64QAM to improve the receiving sensitivity characteristic of the receiving device. Hereinafter, this method will be described.

[0070] FIG. 5 shows the arrangement of the QPSK symbol and the pilot symbol signal point in the IQ plane according to the present embodiment. Reference numeral 501 is a QPSK modulation signal point, and reference numeral 502 is a pilot symbol signal point. Then, the pilot symbol signal point amplitude is r_pilotThen r_pilotIncreasing the value increases the resistance of the pilot symbol to noise in the receiving device, improving the estimation accuracy of the fading distortion in the fading distortion estimation unit 304 of the receiving device in FIG. 3 and the estimation accuracy of the frequency offset estimation unit 305, resulting in high accuracy. Since various detection processes can be performed, the reception sensitivity characteristics of the receiving device are improved.

Further, FIG. 6 shows the arrangement of the 16QAM symbol and the pilot symbol signal point in the IQ plane according to the present embodiment, where reference numeral 601 is the 16QAM signal point and reference numeral 602 is the pilot symbol signal point. .. Then, the pilot symbol signal point amplitude is r_pilotThen r_pilotIncreasing the value increases the resistance of the pilot symbol to noise in the receiving device, improving the estimation accuracy of the fading distortion in the fading distortion estimation unit 304 of the receiving device in FIG. 3 and the estimation accuracy of the frequency offset estimation unit 305, resulting in high accuracy. Since various detection processes can be performed, the reception sensitivity characteristics of the receiving device are improved. The same applies to 64QAM.

Next, the operating range of two types of transmission power amplification units having different input / output characteristics will be described. FIG. 7 shows the input / output relationship of the two types of transmission power amplification units according to the present embodiment. Here, in order to attempt a general explanation, two types of transmission power amplification units are referred to as transmission power amplification unit A and transmission power amplification unit B. In FIG. 7, reference numeral 701 indicates an input / output relationship of the transmission power amplification unit A, and reference numeral 702 indicates an input / output relationship of the transmission power amplification unit B. When the input level is within the operating range of reference numeral 703, both the transmission power amplification unit A and the transmission power amplification unit B can handle the operation range. However, when the input level is in the operating range of reference numeral 704, there is a range that cannot be handled by the transmission power amplification unit A. For example, considering a communication device in which it is sufficient to use a modulation method up to 16QAM, if the transmission power amplification unit having the input / output characteristics of reference code 701 can be used, it has the input / output characteristics of reference code 702. The power consumption can be suppressed to be smaller than that of using the transmission power amplification unit. However, assuming that the transmission power amplification unit indicated by reference numeral 702 must be used in order to correspond to 64QAM used in the present embodiment, an operating range wider than the operating range indicated by reference numeral 703 should be secured. Can be done. That is, when applying the QPSK or 16QAM modulation method, if the transmission power of the pilot symbol is increased within the operating range indicated by the reference code 704, the fading distortion estimation accuracy and the frequency offset estimation accuracy in the receiving device are improved, and the receiving device is used. The reception sensitivity characteristics are improved.

[0073] In the present embodiment, the operating range of the transmission power amplification unit has the largest operating range of 64QAM. Therefore, r_pilotR_QPSKAs a result of making it larger, the operating range in the transmission power amplification unit becomes larger, but if it is within the operating range of the 64QAM method, amplification is possible even when QPSK is selected. The same can be said for 16QAM.

[0074] Considering the above, it is possible to establish the input / output relationship of the transmission power amplification unit as shown in FIG. FIG. 8 is a diagram showing the input / output relationship of the transmission power amplification unit according to the present embodiment. Reference numeral 801 is the operating point of the transmission power amplification unit, and reference numeral 802 is the signal point amplitude of the pilot symbol. QPSK operating range when the maximum signal point amplitude of conventional QPSK modulation is larger, reference code 803 is 16QAM operating range when the signal point amplitude of the pilot symbol is larger than the maximum signal point amplitude of 16QAM, reference code 804. Is the 64QAM operating range. However, the operating range of reference numeral 802 and the operating range of reference numeral 803 shall be smaller than the operating range of 64QAM. At this time, compared to the case where the transmission power amplification unit was used as shown in FIG. 4, in FIG. 8, the QPSK operating range and the 16QAM operating range are larger, but amplification is possible, and each modulation method is used. It is also possible to set the operating range to the same range. On the other hand, in the receiving device, the noise immunity of the pilot symbol becomes stronger at QPSK and 16QAM. However, it is not always necessary to increase the amplitude of the pilot symbol, and it will be explained with reference to FIG. 9 that there is an optimum amplitude.

[0075] FIG. 9 shows a pilot symbol of QPSK modulation according to the present embodiment, a signal point power ratio, and a bit error rate of 10.^-4、10^-6The graph of the desired carrier power to noise power ratio required for is shown. Reference code 901 has a bit error rate of 10.^-4The desired carrier power to noise power ratio required for reference code 902 is a bit error rate of 10.^-6The desired carrier power to noise power ratio required for Focusing on the reference code 901, the bit error rate is 10.^-4The horizontal axis of the lowest desired wave power to noise power ratio (r)²_pilot/ r²_QPSK) Is 2, and even if the amplitude of the pilot signal increases, the desired carrier power to noise power ratio does not decrease. Bit error rate indicated by reference numeral 902 10^-6The same can be said for the case of, and it can be said that there is an optimum amplitude of the pilot signal.

[0076] In the present embodiment, the single carrier method has been described, but the multiplexing method, the CDMA method, and the OFDM (Orthogonal Frequency Division Multiplexing) method may be used in the same manner.

[0077] Hereinafter, it will be described with reference to FIG. 10 that it can also be applied to common amplification. FIG. 10 shows the configuration of a transmission device that performs common amplification according to the present embodiment. The f1 modulation unit 1001 digitally modulates the digital signal for frequency f1 and outputs the transmission signal of frequency f1 to the addition unit 1004. The f2 modulation unit 1002 digitally modulates the digital signal for frequency f2 and outputs the transmission signal of frequency f2 to the addition unit 1004. The fn modulation unit 1003 digitally modulates the digital signal for frequency fn, and outputs the transmission signal of frequency fn to the addition unit 1004.

[0078] The addition unit 1004 adds the transmission signal of frequency f1, the transmission signal of frequency f2, and the transmission signal of frequency fn, and outputs the added transmission signal to the transmission power amplification unit 1005. The transmission power amplification unit 1005 amplifies the added transmission signal and transmits the amplified transmission signal via the transmission antenna 1006.

[0079] As described above, according to the present embodiment, in the wireless communication system that performs adaptive modulation, IQ is performed so as to maximize the reception sensitivity of the receiving device while keeping the average transmission output power of the transmitting device constant. By arranging the signal points of the pilot symbol on the plane, the reception sensitivity characteristic of the receiving device can be improved.

[0080] Although the modulation method has been described by giving an example of a combination of three types of QPSK, 16QAM, and 64QAM, it is not limited to this modulation method, and it is not limited to switching of the three types of modulation methods. Absent.

[0081] In the present embodiment, a signal point known as a pilot symbol has been described as an example, but the present invention is not limited to this, and for example, a PSK modulated signal may be used as the pilot symbol.

[0082] Further, in the present embodiment, the pilot symbol is used for fading distortion estimation and frequency offset estimation in the receiving device, but it is also possible to use other control information such as the preamble and the unique word in FIG. is there.

[0083] Then, with respect to the control information using the channel control information excluding the data as an example, it is possible to carry out the same implementation as the pilot symbol in the present embodiment. At this time, the control information has a characteristic of being error-tolerant to noise, particularly as compared with the data.

(Embodiment 2) In the second embodiment, in the wireless communication system, the transmitting device, and the receiving device using the method described in the first embodiment, a communication method for switching the modulation method according to the radio wave propagation environment and the communication traffic. The method of determining the modulation method of the above will be described.

[0085] FIG. 11 is a diagram showing an example of a frame configuration transmitted by the communication terminal according to the present embodiment. In FIG. 11, the same reference numerals are given to those common to those in FIG. 1, and detailed description thereof will be omitted. In FIG. 11, reference numeral 1101 is a preamble and includes control information. Reference numeral 1102 is radio wave propagation environment estimation information, which is a symbol for the communication terminal to estimate the radio wave propagation environment of the signal transmitted by the base station and notify the base station as radio wave propagation environment information.

[0086] Next, the configuration of the receiving device of the base station will be described. FIG. 12 shows the configuration of the receiving device of the base station according to the present embodiment. In FIG. 12, the receiving radio unit 1202 performs predetermined radio processing on the signal (received signal) received via the antenna 1201 to synchronize the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal orthogonal component with the synchronous unit 1203. Is output to the detection unit 1204.

[0087] The synchronization unit 1203 detects the 104 unique words in FIG. 11 from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1202, and the detected unique words 104. The time is synchronized with the communication terminal based on the above, and the signal is output to the detection unit 1204 as a synchronization signal.

[0088] The detection unit 1204 converts the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1202, and the synchronization signal output from the synchronization unit 1203 into a signal transmitted by the communication terminal. It performs detection processing and outputs the received digital signal to the data detection unit 1205.

[0089] The data detection unit 1205 outputs the radio wave propagation environment information from the received digital signal output from the detection unit 1204 to the transmission data generation unit 1206 based on the frame configuration of FIG. 11, and also outputs the received data. To do.

[0090] The transmission data generation unit 1206 determines a modulation method based on the radio wave propagation environment information among the radio wave propagation environment information output from the data detection unit 1205 and the input transmission data, and responds to the determined modulation method. It outputs a transmission digital signal having the information bit and a control signal for notifying the base station of the determined modulation method. If the data detection unit 1205 determines that there are multiple incoming waves, the transmission data generation unit 1206 selects QPSK with strong error tolerance and communicates without being affected by other parameters indicating the radio wave propagation environment. Request to the terminal. This is to prevent the receiving device from demodulating this signal when receiving a plurality of incoming waves.

FIG. 13 shows an example of a frame configuration transmitted by the base station according to the present embodiment. In FIG. 13, the same reference numerals are given to those common to FIG. 11, and detailed description thereof will be omitted. In FIG. 13, 1301 is modulation method information, which is a symbol for notifying the communication terminal of the modulation method of the base station.

Next, the configuration of the transmission device of the communication terminal device will be described. FIG. 14 shows the configuration of the transmission device of the communication terminal according to the present embodiment. In FIG. 14, the transmission data generation unit 1401 generates a transmission digital signal according to the frame configuration of FIG. 11 from the transmission data and the radio wave propagation environment estimation signal, and outputs the transmission digital signal to the orthogonal baseband signal generation unit 1402.

The orthogonal baseband signal generation unit 1402 generates a transmission orthogonal baseband signal in-phase component and a transmission orthogonal baseband signal orthogonal component from the transmission digital signal output from the transmission data generation unit 1401 to the transmission radio unit 1403. Output.

[0094] The transmission radio unit 1403 performs predetermined radio processing on the transmission orthogonal baseband signal in-phase component and the transmission orthogonal baseband signal orthogonal component generated by the transmission orthogonal baseband signal generation unit 1402, and amplifies the transmission power of the transmission signal. Output to part 1404. The transmission power amplification unit 1404 amplifies the transmission signal output from the transmission radio unit 1403, and outputs the amplified transmission signal to the base station via the transmission antenna 1405.

[0095] FIG. 15 shows the configuration of the receiving device in the communication terminal according to the present embodiment. In FIG. 15, the receiving radio unit 1502 performs a predetermined radio reception process on the signal (received signal) received via the receiving antenna 1501 and outputs a receiving orthogonal baseband signal in-phase component and a receiving orthogonal baseband signal orthogonal component. ..

[0096] The synchronization / modulation method determination unit 1506 is a unique word having a frame configuration transmitted by the base station of FIG. 13 from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1502. 104 is detected and time-synchronized with the base station, modulation method information 1301 is detected, the modulation method is estimated, and the synchronization signal and the modulation method information are output to each modulation method detection unit.

[0097] The QPSK detection unit 1503 demodulates the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal, the synchronization signal, and the modulation method information when the modulation method information indicates QPSK, and demodulates the received digital to detect QPSK. Output a signal.

[0098] The 16QAM detection unit 1504 demodulates the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal, the synchronization signal, and the modulation method information when the modulation method information indicates 16QAM, and detects the 16QAM received digital. Output a signal.

[0099] The 64QAM detection unit 1505 demodulates the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal, the synchronization signal, and the modulation method information when the modulation method information indicates 64QAM, and the received digital detected by 64QAM. Output a signal.

[0100] The interfering wave intensity estimation unit 1507 receives the interfering wave intensity from the modulated signal, the unique word, or the pilot symbol among the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal orthogonal component output from the receiving radio unit 1502. Is estimated, and the interference wave intensity estimation signal is output to the radio wave propagation environment estimation unit 1511.

[0101] The electric field strength estimation unit 1508 receives a received electric field strength or a carrier wave from a modulated signal, a unique word, or a pilot symbol among the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal orthogonal component output from the receiving radio unit 1502. The power-to-noise power ratio is estimated, and the electric field strength estimation signal is output to the radio wave propagation environment estimation unit 1511.

[0102] The multipath estimation unit 1509 determines the multipath status from the modulated signal, unique word, or pilot symbol among the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal orthogonal component output from the receiving radio unit 1502. Estimate and output the multipath estimation signal to the radio wave propagation environment estimation unit 1511.

[0103] The Doppler frequency estimation unit 1510 estimates the Doppler frequency from the modulated signal, the unique word, or the pilot symbol among the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal output from the receiving radio unit 1502, and the Doppler frequency is estimated. The frequency estimation signal is output to the radio wave propagation environment estimation unit 1511.

[0104] The radio wave propagation environment estimation unit 1511 receives a plurality of arrivals from the interference wave intensity estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal, for example, when the electric field strength is weak or when the Doppler frequency is large. When there is a wave, QPSK is selected when the interference wave intensity is strong, and the modulation method required for the base station is determined and output. If the multipath estimation unit 1509 determines that there are multiple incoming waves, the radio wave propagation environment estimation unit 1511 is not affected by other parameters indicating the radio wave propagation environment, and the radio wave propagation environment estimation unit 1511 is a modulation method with strong error tolerance (this). In the embodiment, QPSK) is selected and requested to the communication terminal. This is to prevent the receiving device from demodulating the signal when a plurality of incoming waves are received. Alternatively, the radio wave propagation environment estimation unit 1511 may output the interference wave estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal itself.

Next, the operation of the base station and the communication terminal having the above configuration will be described. First, in the transmission device of the communication terminal shown in FIG. 14, the transmission data and the radio wave propagation environment estimation signal are generated by the transmission data generation unit 1401 as a transmission digital signal according to the frame configuration of FIG. 11, and an orthogonal baseband signal is generated. It is output to part 1402.

The transmission digital signal output from the transmission data raw unit 1401 is generated by the orthogonal baseband signal generation unit 1402 as a transmission orthogonal baseband signal in-phase component and a transmission orthogonal baseband signal orthogonal component, and is generated by the transmission radio unit 1403. It is output.

[0107] The orthogonal baseband signal in-phase component and the orthogonal component of the orthogonal baseband signal output from the orthogonal baseband signal generation unit 1402 are subjected to predetermined radio processing by the transmission radio unit 1403, and the transmission signal is amplified in transmission power. It is output to part 1404.

[0108] The transmission signal subjected to the predetermined radio processing by the transmission radio unit is power-amplified by the transmission power amplification unit 1404 and transmitted via the transmission antenna 1405.

The signal transmitted by the communication terminal is received by the base station shown in FIG. In FIG. 12, the signal (received signal) received via the receiving antenna 1201 is subjected to predetermined radio processing by the radio unit 1202, and the receiving orthogonal baseband signal in-phase component and the receiving orthogonal baseband signal orthogonal component are synchronized with each other. It is output to 1203 and the detection unit 1204.

[0110] The reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1202 have a unique word detected by the synchronization unit 1203, and the communication terminal and the communication terminal are based on the detected unique word. The time is synchronized, a synchronization signal is generated, and it is output to the detection unit 1204.

[0111] The reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1202 are detected by the detection unit 1204 based on the synchronization signal output from the synchronization unit 1203. Then, the received digital signal is output to the data detection unit 1205.

[0112] In the received digital signal output from the detection unit 1204, radio wave propagation environment information is generated by the data detection unit 1205 and output to the transmission data generation unit 1206. In addition, the received data is output.

[0113] The radio wave propagation environment information output from the data detection unit 1205 is generated by the transmission data generation unit 1206 according to the radio wave propagation environment, for example, when the electric field strength is weak, when the Doppler frequency is large, and a plurality of incoming waves are generated. In some cases, the modulation method is determined, such as selecting QPSK when the interference wave intensity is strong, the transmission data is modulated by the modulation method, and the transmission digital signal is output. In addition, a control signal modulated by the determined modulation method is output.

Next, the signal transmitted from the transmitting device of the base station (using FIG. 1) is received by the receiving device of the communication terminal shown in FIG. In FIG. 15, the signal (received signal) received via the receiving antenna 1501 is subjected to predetermined reception processing in the receiving radio unit 1502, and the receiving orthogonal baseband signal in-phase component and the receiving orthogonal baseband signal orthogonal component are formed. Output to interference wave intensity estimation unit 1507, electric field strength estimation unit 1508, multipath estimation unit 1509, Doppler frequency estimation unit 1510, QPSK detection unit 1503, 16QAM detection unit 1504, 64QAM detection unit 1505, synchronization / modulation method determination unit 1506. To.

[0115] A unique word is detected by the synchronization / modulation method determination unit 1506 for the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1502, and the unique word is based on the detected unique word. The time is synchronized with the base station. Further, the modulation method information is detected, the modulation method is estimated, and the synchronization signal and the modulation method information are output to each modulation method detection unit.

[0116] The reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1502 are the synchronization signal and modulation output from the synchronization / modulation method determination unit 1506 in each modulation method detection unit. Based on the system information, it is demodulated and the corresponding received digital signal is output.

[0117] For the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 1502, parameters for estimating the propagation environment are estimated in each estimation unit, and the estimated signal is the radio wave propagation environment. It is output to the estimation unit 1511.

[0118] With respect to the estimated signal output from each estimation unit, the radio wave propagation environment estimation unit 1511 comprehensively determines the radio wave propagation environment, and the radio wave propagation environment information to be notified to the base station is estimated and output.

[0119] Next, a modulation method selected at the initial stage of the transmission signal transmitted by the base station will be described. For example, when a wireless communication system as in the present embodiment is constructed, the modulation method adopted at the initial stage of the transmission signal transmitted by the base station becomes a problem. In this case, since the base station has never transmitted the transmission signal to the communication terminal, the communication terminal cannot estimate the radio wave propagation environment. Therefore, the base station must determine the modulation method to be initially adopted by the base station. For example, if 16QAM or 64QAM is used as the initial modulation method, data quality cannot be obtained at the communication terminal when the radio wave propagation environment is poor. Considering this, it is better to select QPSK modulation.

[0120] As described above, the modulation method selected at the initial stage is the modulation method that is most resistant to noise among the switchable modulation methods, so that the data quality is improved in the communication terminal. become. The initial setting of this modulation method is not limited to the present embodiment, and can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like.

[0121] Similarly, in a communication method characterized in that the error correction method is changed depending on the radio wave propagation environment, the initial error correction method of the transmitted signal to be transmitted can be similarly considered. The error correction method selected at the initial stage is the error correction method having the most error correction capability among the switchable error correction methods, so that the quality of the data is improved. The initial setting of this error correction method is not limited to the present embodiment, and can be applied to a communication method characterized by switching the error correction method depending on the radio wave propagation environment, communication traffic, and the like.

[0122] When the modulation method is variable, it is assumed that the base station constantly transmits the preamble 1101, the unique word 104, and the pilot symbol 103 excluding the data symbol 102 in FIG. The communication terminal uses these signals transmitted by the base station to estimate the radio wave propagation environment, and when starting communication with the base station, the base station transmits information on the radio wave propagation environment to the base station. Data quality can be obtained by determining the initial modulation method of the data symbol 102 based on the radio wave propagation environment information transmitted from the communication terminal. At this time, the information of the modulation method can be included in the radio wave propagation environment information. The initial setting of the modulation method by this method is not limited to the present embodiment, and can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like. Further, as the signal that is constantly transmitted, the preamble, the unique word, and the pilot symbol have been described, but the present invention is not limited to this, and a dedicated symbol for estimating the radio wave propagation environment may be inserted.

Similarly, in a communication method characterized in that the error correction method is changed depending on the radio wave propagation environment, for example, an initial error correction method of a transmission signal to be transmitted can be similarly considered, and in a communication terminal, a base station is used. When estimating the radio wave propagation environment from the signal that is constantly transmitted and starting communication with the base station, information on the radio wave propagation environment is transmitted to the base station, and the base station information on the radio wave propagation environment transmitted from the communication terminal. The quality of the data can be obtained by determining the error correction method of the data symbol based on the above. At this time, the information of the error correction method can be included in the radio wave propagation environment information. The initial setting of the modulation method by this method is not limited to the present embodiment, and can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like.

[0124] As described above, it is possible to configure a wireless communication system, a transmitting device, and a receiving device using the method described in the first embodiment, thereby improving the receiving sensitivity characteristics of the receiving device. It becomes. At this time, the modulation method has described the combination of three types of QPSK, 16QAM, and 64QAM, but the present invention is not limited to this, and the modulation method is not limited to the switching of the three types of modulation methods. Further, in FIGS. 2 and 12, for example, information on communication traffic may be input and the modulation method may be determined in consideration of this. Further, as the parameters of the radio wave propagation environment, the jamming wave strength, the electric field strength, the multipath situation, and the Doppler frequency have been described as examples, but the present invention is not limited to these.

(Embodiment 3) In the third embodiment, the initial setting and the setting method when the modulation method of each channel adaptively changes the modulation method depending on the radio wave propagation environment, communication traffic, etc. in the CDMA system will be described. To do. At this time, the primary modulation (data modulation) of the base station is a communication method that can be switched to QPSK modulation, 16QAM, and 64QAM depending on the radio wave propagation environment, communication traffic, and the like.

FIG. 16 shows an example of a frame configuration of a signal transmitted by a base station in the CDMA system according to the present embodiment, and the control channel frame includes channel A modulation method information 1601 and channel A transmission power. It consists of control information 1602, channel Z modulation method information 1603, channel Z transmission power control information 1604, and so on. The channel A frame configuration is composed of channel A data symbol 1605, and the primary modulation of channel A data symbol 1605 shall be one of QPSK, 16QAM, and 64QAM. The channel Z frame configuration is composed of channel Z data symbol 1606, and the primary modulation of channel Z data symbol 1606 shall be one of QPSK, 16QAM, and 64QAM.

[0127] FIG. 17 shows a configuration of a base station transmitter in the CDMA system according to the present embodiment. The spectrum diffusion modulation unit 1701 of channel A QPSK-modulates the transmitted digital signal of channel A to the transmitted digital signal of channel A, 16QAM, based on the modulation method information of channel A among the input digital signal of channel A and the modulation method information of channel A. Performs any primary modulation of 64QAM and outputs the transmission quadrature baseband signal of channel A to the adder 1703.

[0128] The channel Z spectrum diffusion modulation unit 1702 QPSK-modulates the channel Z transmission digital signal based on the channel Z modulation method information among the input channel Z transmission digital signal and channel Z modulation method information. , 16QAM, or 64QAM is subjected to primary modulation, and the transmission quadrature baseband signal of channel Z is output to the adder 1703.

[0129] The addition unit 1703 includes a transmission quadrature baseband signal of the input pilot channel, a transmission quadrature baseband signal of the control channel, a transmission quadrature baseband signal output from the spectrum diffusion modulation unit 1701 of the channel A, and a channel Z. The transmission orthogonal baseband signal output from the spectrum diffusion modulation unit 1702 is added, and the added transmission orthogonal baseband signal is output to the transmission radio unit 1704.

[0130] The transmission radio unit 1704 performs predetermined radio processing on the added transmission orthogonal baseband signal output from the addition unit 1703, and outputs the transmission signal.

[0131] The transmission power amplification unit 1705 amplifies the transmission signal output from the transmission radio unit 1704, and outputs the amplified transmission signal via the antenna 1706.

[0132] FIG. 18 shows a configuration of a base station receiving device in the CDMA system according to the present embodiment. The receiving radio unit 1802 performs predetermined radio processing on the signal (received signal) received via the antenna 1801 and outputs the received orthogonal baseband signal to the channel A detection unit 1803 and the channel Z detection unit 1804.

[0133] The channel A detection unit 1803 performs detection processing on the reception orthogonal baseband signal output from the reception radio unit 1802, and outputs the reception digital signal of channel A to the channel A data detection unit 1805. Further, the channel Z detection unit 1804 performs detection processing on the reception orthogonal baseband signal output from the reception radio unit 1802, and outputs the reception digital signal of the channel Z to the channel Z data detection unit 1806.

[0134] The channel A data detection unit 1805 generates radio wave propagation environment information estimated by the communication terminal of channel A from the received digital signal of channel A output from the channel A detection unit 1803, and is a channel A modulation method determination unit. Output to 1807. It also outputs the received data of channel A.

[0135] The channel Z data detection unit 1806 generates radio wave propagation environment information estimated by the communication terminal of channel Z from the received digital signal of channel Z output from the channel Z detection unit 1804, and the channel Z modulation method determination unit. Output to 1808. It also outputs the received data of channel Z.

[0136] The channel A modulation method determination unit 1807 uses the input communication traffic information and the channel A radio wave propagation environment information output from the channel A data detection unit 1805 to obtain the data quality and data of the channel A communication terminal. A modulation method that achieves both transmission speeds is selected from QPSK, 16QAM, and 64QAM, and output to the control channel transmission signal generation unit 1809 as modulation method information for channel A.

[0137] The channel Z modulation method determination unit 1808 uses the input communication traffic information and the channel Z radio wave propagation environment information output from the channel Z data detection unit 1806 to obtain the data quality and data of the channel Z communication terminal. A modulation method that achieves both transmission speeds is selected from QPSK, 16QAM, and 64QAM, and output to the control channel transmission signal generator 1809 as channel Z modulation method information.

[0138] The control channel transmission signal generation unit 1809 uses the modulation method information of channel A output from the channel A modulation method determination unit 1807 and the modulation method information of channel Z output from the channel Z modulation method determination unit 1808. , Generates and outputs a control channel signal based on the control channel frame configuration of FIG. 16 including the modulation method information of channel A and the modulation method information of channel Z.

FIG. 19 shows an example of a frame configuration of a signal transmitted by a communication terminal in the CDMA system according to the present embodiment, and reference numeral 1901 communicates a radio wave propagation environment of a signal transmitted from a base station. This is radio wave propagation environment information that the terminal estimates and notifies the base station. Reference numeral 1902 is a data symbol.

[0140] FIG. 20 shows a configuration of a transmission device of a communication terminal in the CDMA system according to the present embodiment, and a transmission data generation unit 2001 transmits digital transmission data from input transmission data and a radio wave propagation environment estimation signal. A signal is generated and output to the spread spectrum modulation unit 2002.

[0141] The spectrum diffusion modulation unit 2002 spreads the spectrum of the transmission digital signal output from the transmission data generation unit 2001, and outputs the transmission orthogonal baseband signal according to the frame configuration of FIG. 23 to the transmission radio unit 2003.

[0142] The transmission radio unit 2003 performs predetermined radio processing on the transmission orthogonal baseband signal output from the spectrum diffusion modulation unit 2002, and outputs the transmission signal to the transmission power amplification unit 2004.

[0143] The transmission power amplification unit 2004 amplifies the transmission signal output from the transmission radio unit 2003, and transmits the amplified transmission signal via the antenna 2005.

[0144] FIG. 21 shows a configuration of a receiving device of a communication terminal in the CDMA system according to the present embodiment. In FIG. 21, the signal (received signal) received via the receiving antenna 2101 is subjected to predetermined reception processing by the receiving radio unit 2102, and the receiving orthogonal baseband signal in-phase component and the receiving orthogonal baseband signal orthogonal component are formed. Output to the jamming wave intensity estimation unit 2104, electric field strength estimation unit 2105, multipath estimation unit 2106, and Doppler frequency estimation 2107.

[0145] The detection unit 2103 performs detection processing on the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2102, and outputs the detection processing.

[0146] The interfering wave intensity estimation unit 2104 uses the interfering wave from the pilot channel component and the control channel component among the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal orthogonal component output from the receiving radio unit 2102. The intensity is estimated, and the interference wave intensity estimation signal is output to the radio wave propagation environment estimation unit 2108.

[0147] The electric field strength estimation unit 2105 receives the received electric field strength from the pilot channel component and the control channel component among the received orthogonal baseband signal in-phase component and the received orthogonal baseband signal orthogonal component output from the receiving radio unit 2102. Is estimated, and the electric field strength estimation signal is output to the radio wave propagation environment estimation unit 2108.

[0148] The multipath estimation unit 2106 determines the multipath status from the pilot channel component and the control channel component among the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2102. Is estimated, and the multipath estimation signal is output to the radio wave propagation environment estimation unit 2108.

[0149] The Doppler frequency estimation unit 2107 calculates the Doppler frequency from the pilot channel component and the control channel component among the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2102. Estimate and output the Doppler frequency estimation signal to the radio wave propagation environment estimation unit 2108.

[0150] As described above, by inserting the information of the modulation method transmitted by the base station into the control channel, the base station can transmit the modulation method of the transmission signal transmitted to the communication terminal. Is. In particular, the communication terminal uses the pilot channel and control channel transmitted by the base station to estimate the radio wave propagation environment, so that the base station does not transmit the data symbol to the communication terminal. , The communication terminal can estimate the radio wave propagation environment.

[0151] By taking the above means, in the CDMA system, it is possible to configure a wireless communication system in which the modulation method of each channel is adapted to the radio wave propagation environment, communication traffic, and the like to switch the modulation method. Similarly, it is also possible to configure a wireless communication system in which the error correction method of each channel is variable according to the radio wave propagation environment, communication traffic, and the like.

[0152] Next, in the CDMA system, an initial setting method of a modulation method in which the modulation method of each channel is variable depending on the radio wave propagation environment, communication traffic, and the like will be described. For example, when a wireless communication system as in the present embodiment is constructed, the modulation method adopted at the initial stage of the transmission signal transmitted by the base station becomes a problem. In this case, for example, if 16QAM or 64QAM is used as the initial modulation method, the data quality cannot be obtained at the communication terminal when the radio wave propagation environment is poor. Considering this, it is better to select QPSK modulation.

[0153] As described above, the modulation method selected at the initial stage is the modulation method that is most resistant to noise among the switchable modulation methods, so that the data quality is improved in the communication terminal. become.

[0154] Similarly, in a communication method in which the error correction method for each channel is variable depending on the radio wave propagation environment, communication traffic, etc., the initial error correction method for the transmitted signal to be transmitted is also considered and initially selected. By using the error correction method having the most error correction capability among the switchable error correction methods, the quality of the data will be improved.

[0155] In the CDMA system, an initial setting method when the modulation method of each channel is adapted to the radio wave propagation environment, communication traffic, and the like to switch the modulation method will be described. In this method, the communication terminal is constantly transmitting data even when the base station is not communicating data. For example, the radio wave propagation environment is estimated from the signals of the pilot channel and the control channel. Then, when the communication terminal starts data communication with the base station, the communication terminal first transmits the radio wave propagation environment information estimated from the signals of the pilot channel and the control channel to the base station, and the base station first transmits the radio wave propagation environment information. After receiving, select QPSK as the modulation method of the transmission signal transmitted by the base station, for example, when the electric field strength is weak, the Doppler frequency is large, there are multiple incoming waves, or the interference wave strength is strong. To decide. As a result, the quality of the initial data transmitted by the base station is improved in the communication terminal.

[0156] Similarly, for example, it is possible to implement a communication method in which the error correction method is variable depending on the modulation method of each channel, the radio wave propagation environment, the communication traffic, and the like. The communication terminal estimates the radio wave propagation environment from the pilot channel and control channel that the base station constantly transmits, and when starting communication with the base station, the base station transmits information on the radio wave propagation environment to the base station. Based on the radio wave propagation environment information transmitted from the communication terminal, for example, if the electric field strength is weak, the Doppler frequency is large, there are multiple incoming waves, or the jamming wave strength is strong, the error correction capability is strong. Data quality can be obtained by determining the error correction method of the data symbol, such as selecting the method. However, in the description of the CDMA system, the pilot channel and the control channel have been described as an example of the signal that is constantly transmitted, but the present invention is not limited to this, and any signal that is constantly transmitted may be used. Further, although the modulation method of the transmission signal transmitted by the base station has been described as variable, the present invention is not limited to this, and the modulation method of the transmission signal transmitted by the communication terminal may be variable.

[0157] As described above, it is possible to configure a wireless communication system, a transmitting device, and a receiving device using the method described in the first embodiment, thereby improving the receiving sensitivity characteristics of the receiving device. It becomes. At this time, the modulation method has described the combination of three types of QPSK, 16QAM, and 64QAM, but the present invention is not limited to this, and the modulation method is not limited to the switching of the three types of modulation methods. Further, in FIGS. 2 and 12, for example, information on communication traffic may be input and the modulation method may be determined in consideration of this. Further, as the parameters of the radio wave propagation environment, the jamming wave strength, the electric field strength, the multipath situation, and the Doppler frequency have been described as examples, but the present invention is not limited to these.

(Embodiment 4) In the fourth embodiment, a wireless communication system, a transmitting device, and a receiving device using the method described in the first embodiment will be described.

[0159] For the configuration of the transmission device of the base station in the present embodiment, FIG. 1 is incorporated, and detailed description thereof will be omitted. FIG. 22 shows the configuration of the receiving device of the base station according to the present embodiment. The reception radio unit 2202 performs predetermined radio processing on the signal received via the antenna 2201 and outputs a reception orthogonal baseband signal in-phase component and a reception orthogonal baseband signal orthogonal component.

[0160] The synchronization unit 2203 synchronizes the time with the communication terminal based on the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2202, and detects as a synchronization signal in the detection unit 2204. Output to.

[0161] The detection unit 2204 performs detection processing from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2202, and the synchronization signal output from the synchronization unit 2203, and receives digital. Output a signal.

[0162] The interference wave intensity estimation unit 2205 estimates the interference wave intensity from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2202, and modulates the interference wave intensity estimation signal. Output to the method determination unit 2209.

[0163] The electric field strength estimation unit 2206 estimates the electric field strength from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2202, and the electric field strength estimation signal is a modulation method determination unit. Output to 2209.

[0164] The multipath estimation unit 2207 estimates the multipath situation from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2202, and modulates the multipath estimation signal. Output to the determination unit 2209.

[0165] The Doppler frequency estimation unit 2208 estimates the Doppler frequency from the reception orthogonal baseband signal in-phase component and the reception orthogonal baseband signal orthogonal component output from the reception radio unit 2202, and modulates the Doppler frequency estimation signal with the modulation method determination unit. Output to 2209.

[0166] The modulation method determination unit 2209 is a base station based on the interference wave intensity estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal obtained based on the signal transmitted by the communication terminal. Determines the modulation method of the signal transmitted by, for example, when the electric field strength is weak, when the Doppler frequency is large, when there are multiple incoming waves, and when the interfering wave strength is strong, QPSK is selected, and the control signal is selected. Output.

Next, the modulation method selected at the initial stage of the transmission signal transmitted by the base station will be described. For example, when a wireless communication system as in the present embodiment is constructed, first, the communication terminal transmits a transmission signal, the base station receives the transmission signal transmitted by the communication terminal, and estimates the radio wave propagation environment. For example, the modulation method is determined such that the electric field strength is weak, the Doppler frequency is large, there are a plurality of incoming waves, and QPSK is selected when the interference wave strength is strong. By determining the initial modulation method in this way, the data quality is improved in the communication terminal. The initial setting of this modulation method is not limited to the present embodiment, and can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like.

Similarly, in a communication method characterized in that the error correction method is changed depending on the radio wave propagation environment, for example, the initial error correction method of the transmitted signal to be transmitted can be similarly considered, and the error correction initially selected is also considered. First, the communication terminal transmits a transmission signal. For example, if the electric field strength is weak, the Doppler frequency is large, there are multiple incoming waves, or the interference wave strength is strong, the error correction capability is strong. The base station may receive the transmission signal transmitted by the communication terminal, estimate the radio wave propagation environment, determine the error correction method, and determine the error correction method of the signal transmitted by the base station.

[0169] As described above, by determining the initial error correction method, the data quality of the communication terminal is improved. The initial setting of this error correction method is not limited to the present embodiment, and can be applied to a communication method characterized by switching the error correction method depending on the radio wave propagation environment, communication traffic, and the like.

[0170] As described above, it is possible to configure the wireless communication system, the transmitting device, and the receiving device using the method described in the first embodiment, thereby improving the receiving sensitivity characteristic of the receiving device. It will be possible. Further, in FIGS. 2 and 22, for example, information on communication traffic may be input and the modulation method may be determined in consideration of this. Further, as the parameters of the radio wave propagation environment, the jamming wave strength, the electric field strength, the multipath situation, and the Doppler frequency have been described as examples, but the present invention is not limited to these.

[0171] In the present embodiment, the CDMA system and the OFDM system may be used in the same manner regardless of the multiplexing system.

[Embodiment 5] In the fifth embodiment, the configuration of the transmission device and the reception device of the wireless communication system of the present invention will be described.

FIG. 23 shows an example of the frame configuration according to the present embodiment. Reference numeral 2301 is a preamble with respect to the time on the horizontal axis, and is a symbol for the receiving device to synchronize with the transmitting device in time. is there. Reference numeral 2302 is a data symbol, and the modulation method is variable. Reference numeral 2303 is a pilot symbol, which is a symbol for estimating transmission line distortion and frequency offset. Reference numeral 2304 is a symbol for control, and is a symbol for system control such as system information and cell information.

FIG. 24 shows the signal point arrangement of the QPSK symbol and the pilot symbol in the IQ plane according to the present embodiment, reference numeral 2401 is the signal point of the data symbol 2302 in FIG. 23, and reference numeral 2402 is the preamble. 2301, the signal point of the control symbol 2304, and the reference code 2403 indicate the signal point of the pilot symbol 2303. It is assumed that the signal point amplitudes of reference numerals 2402 and reference numeral 2403, that is, the distance from the origin, are larger than the signal point amplitudes of reference numerals 2401. As a result, in the receiving device, the estimation accuracy of the transmission line distortion by the pilot symbol and the estimation accuracy of the frequency offset are improved. In addition, the noise immunity of the control symbol becomes stronger. However, the signal point arrangement shall be performed so that it can be used by the method of using the transmission power amplifier described in the first embodiment.

FIG. 25 shows the signal point arrangement of the 16QAM symbol and the pilot symbol in the IQ plane, reference numeral 2501 being the signal point of the data symbol 2302 in FIG. 23, reference numeral 2502 being the preamble 2301 and the control symbol 2304. The signal point, 2503, indicates the signal point of the pilot symbol 2303. It is assumed that the signal point amplitudes of reference numerals 2502 and reference numeral 2503, that is, the distance from the origin, are larger than the maximum signal point amplitude of reference numeral 2501. As a result, in the receiving device, the estimation accuracy of the transmission line distortion by the pilot symbol and the estimation accuracy of the frequency offset are improved. In addition, the noise immunity of the control symbol becomes stronger. However, the signal point arrangement shall be performed so that it can be used by the method of using the transmission power amplifier described in the first embodiment.

[0176] FIG. 26 shows the signal point arrangement of the 64QAM symbol in the IQ plane according to the present embodiment, reference numeral 2601 shows the signal point of the data symbol 2302 in FIG. 23, and the preamble 2301 and the pilot. Symbol 2303 and control symbol 2304 shall take any signal point having the maximum amplitude indicated by reference numeral 2602 in FIG.

[0177] FIG. 27 shows the configuration of the transmission device according to the present embodiment. In FIG. 27, the parts common to FIG. 2 are designated by the same reference numerals as those in FIG. 2, and detailed description thereof will be omitted. The radio unit 2701 is output from the transmission orthogonal baseband signal in-phase component output from the in-phase component switching unit 204 and the orthogonal component switching unit 205 based on the information of the selected modulation method included in the input control signal. The gain of the received orthogonal baseband signal orthogonal component is controlled, and the transmitted signal is output to the transmission power amplification unit 207.

FIG. 28 shows the internal configuration of the signal generation unit, which is the QPSK signal generation unit 201 of FIG. 2, the 16QAM signal generation unit 202, the 64QAM signal generation unit 203, and the QPSK signal generation unit of FIG. 27. The detailed configuration of the signal generation unit 202 for 201 and 16QAM and the signal generation unit 203 for 64QAM is shown.

[0179] In FIG. 28, the frame timing control unit 2801 inputs the frame timing signal for controlling the frame timing to the modulation signal generation unit 2802, the control signal generation unit 2803, the preamble signal generation unit 2804, the pilot signal generation unit 2805, and the signal selection. Output to each of parts 2806.

[0180] The modulation signal generation unit 2802 generates a modulation signal based on the frame configuration of the frame timing signal among the input transmission digital signal and the frame timing signal output from the frame timing control unit 2801, and generates a modulation signal of the data symbol. The transmission orthogonal baseband signal is output to the signal selection unit 2806.

[0181] The control signal generation unit 2803 generates a control signal based on the frame configuration of the frame timing signal among the input control digital signal and the frame timing signal output from the frame timing control unit 2801, and the control signal is generated. The orthogonal baseband signal of is output to the signal selection unit 2806.

[0182] The preamble signal generation unit 2804 generates a preamble based on the frame configuration of the frame timing signal output from the frame timing control unit 2801, and outputs the transmission orthogonal baseband signal of the preamble to the signal selection unit 2806.

[0183] The pilot signal generation unit 2805 generates a pilot signal based on the frame configuration of the frame timing signal output from the frame timing control unit 2801, and outputs the transmission orthogonal baseband signal of the pilot signal to the signal selection unit 2806. ..

[0184] The signal selection unit 2806 is a transmission orthogonal baseband signal of the data symbol output from the modulation signal generation unit 2802, a transmission orthogonal baseband signal of the control signal output from the control signal generation unit 2803, and a preamble signal generation unit 2804. The frame of the frame timing signal among the transmission orthogonal baseband signal of the preamble output, the transmission orthogonal baseband signal of the pilot signal output from the pilot signal generation unit 2805, and the frame timing signal output from the frame timing control unit 2801. The transmission orthogonal baseband signal to be output is selected based on the configuration, and the selected transmission direct baseband signal is output.

Next, the fading distortion estimation unit 304 shown in FIG. 3 outputs a fading distortion estimation signal according to the modulation method from the ratio of the signal point amplitude of the pilot symbol to the maximum signal point amplitude of each modulation method. This detailed configuration will be described with reference to FIG. FIG. 29 shows the configuration of the receiving device according to the present embodiment. In FIG. 29, the parts common to FIG. 3 are designated by the same reference numerals as those in FIG. 3, and detailed description thereof will be omitted.

[0186] The correction unit 2901 calculates a correction value based on the modulation method information of the control signal among the fading distortion estimation signal output from the fading distortion estimation unit 304 and the input control signal, and the fading distortion estimation signal. Is multiplied by the correction value, and the corrected fading distortion estimation signal is output to the QPSK detection unit 306, 16QAM detection unit 307, and 64QAM detection unit 308. At this time, the correction value is a value determined from the ratio of the signal point amplitude of the pilot symbol and the maximum signal point amplitude of each modulation method. As a result, the estimation accuracy of the fading distortion estimation signal is improved, and the reception sensitivity characteristic in the receiving device is improved.

[0187] As described above, according to the present embodiment, the common power amplification unit can amplify the modulation signals of a plurality of modulation methods, and the receiving device side can receive with high sensitivity.

[Embodiment 6] FIG. 30 shows an example of a frame configuration of a signal transmitted by a base station according to the sixth embodiment. In FIG. 30, reference numeral 3001 is a data symbol with respect to the time and frequency axes, and it is possible to select, for example, QPSK, 16QAM, or 64QAM as the modulation method. Reference numeral 3002 is a pilot symbol, and it is assumed that the signal point amplitude of the pilot symbol in the IQ plane is variable by the modulation method of the data symbol 3001 as described in the first embodiment.

[0189] FIG. 31 shows the configuration of the transmission device of the base station according to the present embodiment. In FIG. 31, the modulation unit 3101 applies the modulation of the selected modulation method to the input transmission digital signal based on the information of the modulation method and frame configuration in the input control signal, and converts the serial signal into a serial-parallel conversion unit. Output to 3102.

[0190] The serial parallel conversion unit 3102 converts the serial signal output from the modulation unit 3101 in parallel, and outputs the parallel signal to the discrete inverse Fourier transform unit 3103. The discrete inverse Fourier transform unit 3103 performs discrete inverse Fourier transform on the parallel signal output from the serial parallel transform unit 3102, and outputs the signal after the discrete inverse Fourier transform to the radio unit 3104.

[0191] The radio unit 3104 performs predetermined radio processing on the signal output from the discrete inverse Fourier transform unit 3103, and outputs the transmission signal to the transmission power amplification unit 3105. The transmission power amplification unit 3105 amplifies the transmission signal output from the radio unit 3104, and transmits the amplified transmission signal to the communication terminal via the antenna 3106.

[0192] FIG. 32 shows the configuration of the receiving device of the communication terminal according to the present embodiment. In FIG. 32, the radio unit 3202 performs predetermined radio processing on the signal (received signal) received via the antenna 3201 and outputs the signal to the Fourier transform unit 3203. The Fourier transform unit 3203 performs a Fourier transform on the signal output from the radio unit 3202, and outputs a parallel signal to the parallel serial conversion unit 3204.

[0193] The parallel serial conversion unit 3204 performs parallel serial conversion of the parallel signal output from the Fourier transform unit 3203, and outputs the serial signal. The interfering wave intensity estimation unit 3205 estimates the interfering wave intensity based on the serial signal output from the parallel serial conversion unit 3204 (for example, from the pilot symbol), and outputs the interfering wave intensity estimation signal to the radio wave propagation environment estimation unit 3209. To do.

[0194] The electric field strength estimation unit 3206 estimates the electric field strength based on the serial signal output from the parallel serial conversion unit 3204 (for example, from the pilot symbol), and outputs the electric field strength estimation signal to the radio wave propagation environment estimation unit 3209. To do. The multipath estimation unit 3207 estimates the number of incoming waves based on the serial signal output from the parallel serial conversion unit 3204 (for example, from the pilot symbol), and outputs the multipath estimation signal to the radio wave propagation environment estimation unit 3209.

[0195] The Doppler frequency estimation unit 3208 estimates the Doppler frequency based on the serial signal output from the parallel serial conversion unit 3204 (for example, from the pilot symbol), and outputs the Doppler frequency estimation signal to the radio wave propagation environment estimation unit 3209. To do.

[0196] The radio wave propagation environment estimation unit 3209 determines the requirement of the modulation method of the transmission signal transmitted by the base station based on the interference wave intensity estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal. , Output as a radio wave propagation environment estimation signal. Alternatively, the interference wave intensity estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal itself are output as the radio wave propagation environment estimation signal. Then, the information of the radio wave propagation environment estimation signal is transmitted from the transmission device of the communication terminal to the base station, and the modulation method of the transmission signal transmitted by the base station is changed. However, when the interference wave intensity estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal itself are output as the radio wave propagation environment estimation signal, the modulation method is determined by the base station. ..

[0197] The distortion estimation unit 3210 estimates the distortion generated by the transmission line based on the serial signal output from the parallel serial conversion unit 3204 (for example, from the pilot symbol), and outputs the distortion estimation signal to the correction unit 3211. .. The correction unit 3211 corrects the distortion estimation signal output from the distortion estimation unit 3210 by multiplying it as a correction value by a value in which the amplitude of the pilot symbol 3002 in the IQ plane is variable by the modulation method of the data symbol 3001 in FIG. The generated distortion estimation signal is output to the demodulation unit 3212. The demodulation unit 3212 demodulates the serial signal output from the parallel serial conversion unit 3204 based on the corrected distortion estimation signal output from the correction unit 3211, and outputs a received digital signal.

[0198] FIG. 33 shows the internal configuration of the modulation unit 3101 in FIG. 31. In FIG. 33, the QPSK serial signal generator 3301 generates a serial signal according to the frame configuration of FIG. 30 when the modulation method information included in the control signal among the input transmission digital signal and control signal is QPSK. Then, the QPSK serial signal is output to the serial signal selection unit 3304.

[0199] When the modulation method information included in the control signal among the input transmission digital signal and the control signal is 16QAM, the serial signal generation unit 3302 for 16QAM generates a serial signal according to the frame configuration of FIG. , 16QAM serial signal is output to serial signal selection unit 3304.

[0200] The 64QAM serial signal generator 3303 generates a serial signal according to the frame configuration of FIG. 30 when the modulation method information included in the control signal among the input transmission digital signal and control signal is 64QAM. , 64QAM serial signal is output to serial signal selection unit 3304.

[0201] The serial signal selection unit 3304 inputs a QPSK serial signal, a 16QAM serial signal, a 64QAM serial signal, and a control signal, and selects a serial signal of a specified modulation method based on the modulation method information included in the control signal. And it is output as the selected serial signal. The serial signal selected at this time corresponds to the serial signal output from the modulation unit 3101 of FIG. 31.

[0202] However, in the QPSK serial signal generation unit 3301, the 16QAM serial signal generation unit 3302, and the 64QAM serial signal generation unit 3303, the average power of each transmission signal is constant as in the first embodiment. Further, in the transmission power amplification unit 3105, the signal point amplitude of the pilot symbol in the in-phase-quadrature plane is arranged so that the operating range does not change even if the modulation method is switched. Further, in the transmission power amplification unit 3105, the signal point amplitude of the pilot symbol in the IQ plane may be arranged so as to maximize the reception sensitivity of the communication partner within a range in which distortion does not occur.

[0203] FIG. 34 shows the configuration of the transmission device of the base station according to the present embodiment. In FIG. 34, the difference from FIG. 31 is that the control signal is input to the radio unit 3404. The radio unit 3401 has a function of adjusting the average transmission power of the transmission signal to be the same in all the modulation methods based on the information of the modulation method included in the input control signal.

[0204] As described above, the embodiments described in the first embodiment, the second embodiment, and the fifth embodiment can also be implemented in the OFDM method.

[Effect of the Invention] As described above, according to the present invention, in the wireless communication method for performing adaptive modulation, the average transmission power of the transmitting device is maintained at a certain level, and the receiving sensitivity characteristic of the receiving device is maximized. By adopting a method in which the signal points of the pilot symbols are arranged on the IQ plane so as to be improved, the reception sensitivity characteristics of the receiving device can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS [FIG. 1] FIG. 1 is a diagram showing an example of a frame configuration according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a transmission device according to the first embodiment of the present invention. 3 Block diagram showing the configuration of the receiving device according to the first embodiment of the present invention [Fig. 4] Input / output relationship diagram of the conventional transmission power amplification unit [Fig. 5] In the IQ plane according to the first embodiment of the present invention. QPSK symbol and pilot symbol signal point arrangement diagram [Fig. 6] 16QAM symbol and pilot symbol signal point arrangement diagram on the IQ plane according to the first embodiment of the present invention [Fig. 7] Two types of 16QAM symbol and pilot symbol signal point arrangement diagram according to the first embodiment of the present invention. Input / output relationship diagram of the transmission power amplification unit [Fig. 8] Input / output relationship diagram of the transmission power amplification unit according to the first embodiment of the present invention [Fig. 9] A pilot symbol of QPSK modulation according to the first embodiment of the present invention. Power ratio of signal points, bit error rate 10^-4、10^-6Graph of desired carrier power to noise power ratio required for FIG. 10 [Fig. 10] Block diagram showing a configuration of a transmission device for performing common amplification according to the first embodiment of the present invention [Fig. 11] Fig. 11 according to the second embodiment of the present invention. FIG. 12 is a diagram showing an example of a frame configuration of a signal transmitted by a communication terminal. FIG. 12 is a block diagram showing a configuration of a receiving device in a base station according to the second embodiment of the present invention. FIG. 14 is a diagram showing an example of a frame configuration of a signal transmitted by the base station. FIG. 14 is a block diagram showing a configuration of a transmission device of a communication terminal according to the second embodiment of the present invention. FIG. FIG. 16 is a block diagram showing a configuration of a receiving device of a communication terminal according to the present invention. FIG. 16 is a diagram showing an example of a frame configuration of a signal transmitted by a base station in the CDMA system according to the third embodiment of the present invention. FIG. 18 is a block diagram showing a configuration of a base station transmitting device in the CDMA system according to the third embodiment. FIG. 18 is a block diagram showing a configuration of a base station receiving device in the CDMA system according to the third embodiment of the present invention. FIG. 20 shows an example of a frame configuration of a signal transmitted by a communication terminal in the CDMA system according to the third embodiment of the present invention. FIG. 20 is a configuration of a transmission device of the communication terminal in the CDMA system according to the third embodiment of the present invention. FIG. 21 is a block diagram showing the fruit of the present invention.Block diagram showing the configuration of the receiving device of the communication terminal in the CDMA system according to the third embodiment [FIG. 22] Block diagram showing the configuration of the receiving device of the base station according to the fourth embodiment of the present invention [FIG. 23] FIG. 24 is a diagram showing an example of the frame configuration according to the fifth embodiment of the present invention. FIG. 24 is an arrangement diagram of QPSK symbols and pilot symbol signal points on the IQ plane according to the fifth embodiment of the present invention. [FIG. 25] Embodiment 5 of the present invention. 16QAM symbol and pilot symbol signal point arrangement diagram in the IQ plane according to FIG. 26 [FIG. 26] 64QAM symbol signal point arrangement diagram in the IQ plane according to the fifth embodiment of the present invention [Fig. 27] Transmission according to the fifth embodiment of the present invention. Block diagram showing the configuration of the device [FIG. 28] Block diagram showing the configuration of the quadrature baseband signal generation unit according to the fifth embodiment of the present invention [FIG. 29] The configuration of the receiving device according to the fifth embodiment of the present invention. FIG. 30 is a diagram showing an example of a frame configuration of a signal transmitted by the base station according to the sixth embodiment of the present invention. FIG. 31 is a configuration of a transmission device of the base station according to the sixth embodiment of the present invention. FIG. 32 is a block diagram showing a configuration of a receiving device of a communication terminal according to a sixth embodiment of the present invention. FIG. 33 is a block diagram showing an internal configuration of a modulation unit according to the sixth embodiment of the present invention. FIG. 34 is a block diagram showing a configuration of a transmission device of a base station according to a sixth embodiment of the present invention. FIG. 35 is a 16QAM symbol and pilot symbol signal point arrangement diagram on an IQ plane. [Description of reference numerals] Signal generation for 201 QPSK. Unit 202 16QAM signal generation unit 203 64QAM signal generation unit 204 Quadrature component switching unit 205 Quadrature component switching unit 207, 1005, 1404, 1705, 2004, 3105 Transmission power amplification unit 306, 1503 QPSK detection unit 307, 1504 16QAM detection unit 308, 1505 64QAM detection unit 303, 1506 synchronization / modulation method determination unit 304 phasing distortion estimation unit 305 frequency offset estimation unit 1001 f1 modulation unit 1002 f2 modulation unit 1003 fn modulation unit 1004, 1703Addition unit 1203, 2203 Synchronization unit 1204, 2103, 2204 Detection unit 1205 Data detection unit 1206, 1401, 2001 Transmission data generation unit 1402 Orthogonal baseband signal generation unit, 1507, 2104, 2205, 3205 Interference wave intensity estimation unit 1508, 2105 , 2206, 3206 Electric field strength estimation unit 1509, 2106, 2207, 3207 Multipath estimation unit 1510, 2107, 2208, 3208 Doppler frequency estimation unit 1511, 3209 Radio wave propagation environment estimation unit 1618 Modulation method determination unit 1701 Channel A spectrum diffusion modulation Part 1702 Channel Z spectrum diffusion Modulation unit 1803 Channel A detection unit 1804 Channel Z detection unit 1805 Channel A data detection unit 1806 Channel Z data detection unit 1807 Channel A modulation method determination unit 1808 Channel Z modulation method determination unit 1809 Control channel transmission signal Generation unit 2002 Spectral diffusion modulation unit 2801 Frame timing control unit 2802 Modulation signal generation unit 2803 Control signal generation unit 2804 Preamble signal generation unit 2805 Pilot signal generation unit 2806 Signal selection unit 2901, 3211 Correction unit 3101 Modulation unit 3102 Serial parallel conversion unit 3103 Discrete inverse Fourier conversion unit 3203 Fourier conversion unit 3204 Parallel serial conversion unit 3210 Distortion estimation unit 3212 Demodulation unit 3301 Serial signal generation unit for QPSK 3302 16 Serial signal generation unit for QAM 3303 64 Serial signal generation unit for QAM 3304 Serial signal selection unitMultipath estimation unit 1510, 2107, 2208, 3208 Doppler frequency estimation unit 1511, 3209 Radio wave propagation environment estimation unit 1618 Modulation method determination unit 1701 Channel A spectrum diffusion modulation unit 1702 Channel Z spectrum diffusion modulation unit 1803 Channel A detection unit 1804 Channel Z detection unit 1805 Channel A data detection unit 1806 Channel Z data detection unit 1807 Channel A modulation method determination unit 1808 Channel Z modulation method determination unit 1809 Control channel transmission signal generation unit 2002 Spectrum diffusion modulation unit 2801 Frame timing control unit 2802 Modulation signal Generation unit 2803 Control signal generation unit 2804 Preamble signal generation unit 2805 Pilot signal generation unit 2806 Signal selection unit 2901, 3211 Correction unit 3101 Modulation unit 3102 Serial parallel conversion unit 3103 Discrete inverse Fourier conversion unit 3203 Fourier conversion unit 3204 Parallel serial conversion unit 3210 Distortion estimation unit 3212 Demodulation unit 3301 QPSK serial signal generation unit 3302 16QAM serial signal generation unit 3303 64QAM serial signal generation unit 3304 Serial signal selection unitMultipath estimation unit 1510, 2107, 2208, 3208 Doppler frequency estimation unit 1511, 3209 Radio wave propagation environment estimation unit 1618 Modulation method determination unit 1701 Channel A spectrum diffusion modulation unit 1702 Channel Z spectrum diffusion modulation unit 1803 Channel A detection unit 1804 Channel Z detection unit 1805 Channel A data detection unit 1806 Channel Z data detection unit 1807 Channel A modulation method determination unit 1808 Channel Z modulation method determination unit 1809 Control channel transmission signal generation unit 2002 Spectrum diffusion modulation unit 2801 Frame timing control unit 2802 Modulation signal Generation unit 2803 Control signal generation unit 2804 Preamble signal generation unit 2805 Pilot signal generation unit 2806 Signal selection unit 2901, 3211 Correction unit 3101 Modulation unit 3102 Serial parallel conversion unit 3103 Discrete inverse Fourier conversion unit 3203 Fourier conversion unit 3204 Parallel serial conversion unit 3210 Distortion estimation unit 3212 Demodulation unit 3301 QPSK serial signal generation unit 3302 16QAM serial signal generation unit 3303 64QAM serial signal generation unit 3304 Serial signal selection unitSignal selection unit 2901, 3211 Correction unit 3101 Modulation unit 3102 Serial parallel conversion unit 3103 Discrete inverse Fourier conversion unit 3203 Fourier conversion unit 3204 Parallel serial conversion unit 3210 Distortion estimation unit 3212 Demodulation unit 3301 Serial signal generation unit for QPSK 3302 16 Serial signal for QAM Generation unit 3303 64QAM serial signal generation unit 3304 Serial signal selection unitSignal selection unit 2901, 3211 Correction unit 3101 Modulation unit 3102 Serial parallel conversion unit 3103 Discrete inverse Fourier conversion unit 3203 Fourier conversion unit 3204 Parallel serial conversion unit 3210 Distortion estimation unit 3212 Demodulation unit 3301 Serial signal generation unit for QPSK 3302 16 Serial signal for QAM Generation unit 3303 64QAM serial signal generation unit 3304 Serial signal selection unit