Wireless communication apparatus and subcarrier allocation method

The present invention relates to a wireless communication device and a subcarrier allocation method, and more particularly to a communication terminal device and a transmission method that combine adaptive modulation and frequency scheduling.

The multi-user adaptive modulation OFDM system is a system that efficiently schedules the entire system according to the propagation environment of each mobile station. Specifically, the base station equipment allocates an appropriate number of subcarriers to each user based on the line quality (frequency division user multiplexing), and the appropriate modulation coding schemes (hereinafter, hereinafter) for each subcarrier. It is a system that selects "MCS; Modulation Coding Schemes"). That is, based on the line quality, the base station apparatus assigns each user a subcarrier that can satisfy the desired communication quality (for example, minimum transmission rate, error rate) and has the highest frequency utilization efficiency, and throughput to each subcarrier. By selecting the MCS that maximizes the data transmission, high-speed data communication can be performed by multiple users. In such a multi-user adaptive modulation OFDM system, for example, Non-Patent Document 1 proposes a notification method for notifying line quality information from each mobile station to a base station apparatus.

A predetermined MCS selection table is used for MCS selection. The MCS selection table includes reception quality such as CIR (Carrier to Interference Ratio) and packet error rate (hereinafter referred to as "PER; Packet Error Rate") for each MCS modulation method and error coding method. It shows the correspondence with the error rate such as (described) or bit error rate (hereinafter referred to as "BER; Bit Error Rate"), and when selecting MCS, it is based on the measured reception quality. Select the fastest MCS that can meet the desired error rate.

By the way, conventionally, in frequency division user multiplexing, each mobile station notifies the base station apparatus of line quality information of all subcarriers. FIG. 1 shows a signal-to-noise ratio (hereinafter referred to as SNR; Signal to Noise Ratio) notification format of line quality information notified from a conventional mobile station to a base station device, and FIG. 2 shows a notification format. It shows the relationship between the SNR report bit and the modulation method. As shown in FIG. 1, the base station device allocates and adapts subcarriers by receiving notification of SNR report bits for each subcarrier in the order of subcarriers from each communication terminal device for all subcarriers in the communication band. Perform modulation. In such a case, the base station apparatus selects the 1st or 5th subcarrier having an SNR report bit of 3 when transmission by 64QAM is required as a modulation method that satisfies the desired transmission rate and PER. Then, the packet data using 64QAM is assigned to the 1st or 5th subcarrier.

<p><nplcit num="1"><text>"MC-CDM method using frequency scheduling" Shingaku Giho, RCS2002-129, published in July 2002, pp. 61-66</text></nplcit></p>

<p> However, in the conventional base station apparatus and subcarrier allocation method, although each mobile station uses only a part of all the subcarriers in the communication band, each mobile station uses all the subcarriers. Since the line quality information of the subcarriers is notified to the base station apparatus, the amount of line quality control information becomes enormous as the number of mobile stations and the number of subcarriers increases, so that there is a problem that the communication efficiency is lowered.</p><p> The present invention has been made in view of this point, and an object of the present invention is to provide a communication terminal device and a transmission method capable of improving communication efficiency by reducing the amount of control information to be transmitted.</p>

<p> According to one embodiment of the present invention, the communication terminal device transmits the CQIs of all the subcarriers, or the first information indicating the positions of the plurality of subcarriers and the second regarding the CQIs of the plurality of subcarriers. A receiver that receives information indicating whether to transmit the first information and the second information, wherein the total data amount with the information of the above is smaller than the total data amount of the CQI of all the subcarriers, and the above. It includes a transmission unit that transmits CQIs of all the subcarriers based on the information, or transmits the first information and the second information.</p><p> According to another embodiment of the present invention, the transmission method transmits the CQIs of all the subcarriers, or the first information indicating the positions of the plurality of subcarriers and the second regarding the CQIs of the plurality of subcarriers. The total amount of data with the information of the above is smaller than the total amount of data of CQI of all the subcarriers, and the information indicating whether to transmit the first information and the second information is received, and based on the information. Therefore, the CQIs of all the subcarriers are transmitted, or the first information and the second information are transmitted.</p>

<p> According to the present invention, communication efficiency can be improved by reducing the amount of control information to be transmitted.</p>

<figref num="1">Diagram showing the traditional SNR notification format</figref><figref num="2">Diagram showing the relationship between the SNR report bit and the modulation method</figref><figref num="3">A block diagram showing a configuration of a wireless communication device according to a first embodiment of the present invention.</figref><figref num="4">A block diagram showing a configuration of a communication terminal device according to a first embodiment of the present invention.</figref><figref num="5">A flow chart showing a method of allocating subcarriers according to the first embodiment of the present invention.</figref><figref num="6">The figure which shows the SNR notification format which concerns on Embodiment 1 of this invention.</figref><figref num="7">A block diagram showing a configuration of a wireless communication device according to a second embodiment of the present invention.</figref><figref num="8">A flow chart showing a method of allocating subcarriers according to the second embodiment of the present invention.</figref>

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 3 is a block diagram showing a configuration of the wireless communication device 100 according to the first embodiment of the present invention.

The reception RF unit 102 down-converts the reception signal received by the antenna 101 from the radio frequency to the baseband frequency and outputs the signal to the line quality information extraction unit 103.

The line quality information extraction unit 103 extracts line quality information CQI (Channel Quality Indicator) from the reception signal input from the reception RF unit 102 and outputs it to the allocation control unit 104. Further, the line quality information extraction unit 103 extracts the subcarrier identification information indicating the subcarrier selected by each communication terminal device from the received signal and outputs the subcarrier identification information to the allocation control unit 104.

The allocation control unit 104 is among all the subcarriers within a predetermined communication band for the CQI input from the line quality information extraction unit 103 and the transmission information to each communication terminal device input from the user information storage unit 106 described later. A part of the subcarriers are assigned from, and the modulation method of the assigned subcarriers is selected for each subcarrier. That is, the allocation control unit 104 selects the subcarrier and the modulation method for each communication terminal device so as to be equal to or higher than the required transmission rate, and each communication terminal device is set to be equal to or lower than a predetermined PER value for each subcarrier. Subcarriers and modulation methods are assigned to. Then, the allocation control unit 104 outputs the allocation information of the allocated subcarriers to the subcarrier allocation unit 110, and outputs the modulation method information of the selected modulation method to the modulation units 111-1 to 111-N.

The request subcarrier number determination unit 105, which is a means for determining the number of subcarriers, obtains the number of subcarriers that can be assigned to each communication terminal device from the user information of the communication terminal device of each user input from the user information storage unit 106. .. That is, the request subcarrier number determination unit 105 determines the number of subcarriers so as to be equal to or higher than the request transmission rate for each user's communication terminal device. At this time, the request subcarrier number determination unit 105 determines the number of subcarriers with a slight margin with respect to the request transmission rate in preparation for deterioration of reception quality due to fading fluctuation. Further, when the total data amount of the CQI and the subcarrier number information for the obtained number of subcarriers is less than or equal to the total data amount of only the CQI of all the subcarriers, the request subcarrier number determination unit 105 has obtained the subcarrier. The number of carriers is output as the number of subcarriers information to the request subcarrier number information generation unit 107, and the total amount of data of the obtained number of subcarriers CQI and subcarrier number information is the total amount of data only for the CQI of all subcarriers. If it is larger than, the total number of subcarriers (for example, 64) in the communication band is output to the request subcarrier number information generation unit 107 as the number of subcarriers information.

The user information storage unit 106 stores user information such as the required transmission rate and data type together with the data to be transmitted to each communication terminal device, and the allocation control unit 104 and the request subcarrier number determination unit 105 as necessary. And output to the subcarrier allocation unit 110. Here, the required transmission rate information is, for example, information on the ratio of the amount of data per unit time requested by one user's communication terminal device to the amount of data per unit time requested by all communication terminal devices. The user information storage unit 106 can update the stored user information by inputting the user information from a control unit (not shown in the figure) at a predetermined timing.

The request subcarrier number information generation unit 107 generates the subcarrier number information input from the request subcarrier number determination unit 105 as control channel information and outputs it to the control information multiplexing unit 109.

The allocation information generation unit 108 generates control information in which identification information indicating each subcarrier input from the allocation control unit 104 and modulation method information of each subcarrier are paired, and the generated control information is used as a control information multiplexing unit. Output to 109.

The control information multiplexing unit 109 multiplexes and multiplexes the control information of the number of subcarriers input from the request subcarrier number information generation unit 107 and the control information of the allocation information and the modulation method information input from the allocation information generation unit 108. The control information for each subcarrier is output to the switching unit 112. The control information multiplexing unit 109 can also multiplex control information other than the number of subcarriers information, the allocation information, and the modulation method information.

From the allocation information input from the allocation control unit 104 and the user information input from the user information storage unit 106, the subcarrier allocation unit 110 transmits packet data to each user's communication terminal device for all subcarriers in the communication band. Allocate and output the packet data assigned to each subcarrier to the modulation units 111-1 to 111-N that perform modulation by the modulation method selected for each subcarrier.

The modulation units 111-1 to 111-N are provided in the same number as the number of subcarriers, and the packet data input from the subcarrier allocation unit 110 is modulated by the modulation method of the modulation method information input from the allocation control unit 104. And output to the switching unit 112.

The switching unit 112 switches between the control information output from the control information multiplexing unit 109 and modulated by the modulation unit (not shown) and then input, and the packet data modulated by the modulation units 111-1 to 111-N, and reverse high speed. Output to the Fourier transform (hereinafter referred to as "IFFT; Inverse Fast Fourier Transform") section 113.

The IFFT unit 113 IFFTs the control information for each subcarrier or the packet data for each subcarrier input from the switching unit 112 and outputs it to the guard interval (hereinafter referred to as GI) insertion unit 114.

The GI insertion unit 114 inserts the GI into the control information or packet data input from the IFFT unit 113 and outputs the GI to the transmission RF unit 115.

The transmission RF unit 115 up-converts the control information or packet data input from the GI insertion unit 114 from the baseband frequency to the radio frequency and transmits the control information or packet data from the antenna 101.

Next, the configuration of the communication terminal device 200 will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the communication terminal device 200.

The receiving RF unit 202 down-converts the received signal received by the antenna 201 from the radio frequency to the baseband frequency and outputs it to the GI removing unit 203.

The GI removing unit 203 removes the GI from the received signal input from the receiving RF unit 202 and outputs the GI to the fast Fourier transform (hereinafter referred to as FFT; Fast Fourier Transform) unit 204.

The FFT unit 204 converts the received signal input from the GI removal unit 203 from the serial data format to the parallel data format, then despreads each data converted into the parallel data format by a spreading code, and further performs FFT, etc. Output to the chemical device 207, the line estimation unit 206, and the line quality estimation unit 205.

The line quality estimation unit 205 estimates the line quality from the FFT received signal input from the FFT unit 204, and outputs the estimation result to the subcarrier selection unit 214 and the line quality information forming unit 215. The line quality estimation unit 205 uses, for example, SIR (Signal to Interferer Ratio) as the estimation result. The estimation result is not limited to SIR, and any estimation result such as CIR (Carrier to Interferer Ratio) can be used.

The line estimation unit 206 performs channel estimation from the received signal after FFT input from the FFT unit 204, and outputs the estimation result to the equalizer 207.

The equalizer 207 corrects the amplitude and phase distortion of the received signal after FFT input from the FFT unit 204 using the estimation result input from the line estimation unit 206, and outputs the signal to the separation unit 208.

The separation unit 208 separates the reception signal input from the equalizer 207 into a control channel signal and a data channel signal, outputs the control channel signal to the control information extraction unit 211, and is used for the data channel. The signal is output to the demodulators 201-1 to 209-N.

The demodulation units 2091 to 209-N adaptively modulate the received signal input from the separation unit 208 according to the modulation method information for each subcarrier input from the allocation information extraction unit 212, and perform parallel / serial (hereinafter, P / S). It is output to the conversion unit 210.

The P / S conversion unit 210 converts the reception signal input from the demodulation units 2091 to 209-N from the parallel data format to the serial data format to obtain the received data.

The control information extraction unit 211 extracts control information from the received signal input from the separation unit 208 and outputs the control information to the allocation information extraction unit 212 and the subcarrier number information extraction unit 213.

The allocation information extraction unit 212 extracts the modulation method information and the subcarrier number information from the control information input from the control information extraction unit 211, and corresponds to the modulation method information of each subcarrier by referring to the subcarrier number information. Output to demodulation section 2091 to 209-N.

The subcarrier number information extraction unit 213 extracts the subcarrier number information from the control information input from the control information extraction unit 211 and outputs it to the subcarrier selection unit 214.

The subcarrier selection unit 214 inputs the subcarriers for the number of subcarriers instructed by the base station device from the subcarrier number information input from the subcarrier number information extraction unit 213 from the line quality estimation unit 205, and the SIR measurement result. Select in order of better line quality. Then, the subcarrier selection unit 214 outputs the information of the selected subcarrier to the line quality information forming unit 215.

The line quality information forming unit 215, which is a line quality information generating means, holds a reference table that stores line quality selection information in which SIR and CQI are related, and is a subcarrier input from the subcarrier selection unit 214. From the information, for each selected subcarrier, CQI is selected by referring to the line quality selection information using the SIR input from the line quality estimation unit 205. Then, the line quality information forming unit 215 outputs the CQI for each selected subcarrier to the transmitting RF unit 216.

The transmission RF unit 216 up-converts the transmission signal including the CQI input from the line quality information formation unit 215 from the baseband frequency to the radio frequency and transmits it from the antenna 201.

Next, a method of allocating subcarriers will be described with reference to FIG. FIG. 5 is a flow chart showing a method of allocating subcarriers.

First, the request subcarrier number determination unit 105 allocates the number of subcarriers S to each communication terminal device 200 based on the user information._kDetermine (k is the user number and any natural number greater than or equal to 2) (step ST301). The request subcarrier number determination unit 105 uses the following equation (1) or equation (2) to determine the number of subcarriers S._kCan be sought.<maths num="1"><img file="JP4872012B2_D0001.tif" /></maths>However, S_k: Number of subcarriers (k is a user number and is a natural number of 2 or more), α: constant, R_k: Required transmission rate of communication terminal device 200-k (k is a user number and is a natural number of 2 or more), r: The transmission rate of one subcarrier when using the modulation coding schemes with the highest transmission rate, or the average signal-to-noise ratio plus the constant γ (eg, γ = 0 to 3 dB constant). The transmission rate of one subcarrier when using modulation coding schemes that satisfy the requested packet error rate rather than the line quality value of the value,<maths num="2"><img file="JP4872012B2_D0002.tif" /></maths>Greater integer.<maths num="3"><img file="JP4872012B2_D0003.tif" /></maths>However, S_k: Number of subcarriers (k is a user number and is a natural number of 2 or more), β: Constant (for example, β = 2.0 ~ 4.0), R_k: Required transmission rate of communication terminal device 200-k (k is a user number and is a natural number of 2 or more), N: Total number of subcarriers,<maths num="4"><img file="JP4872012B2_D0004.tif" /></maths> Greater integer.

Equation (1) determines the number of subcarriers using the required transmission rate of each communication terminal device and the transmission rate per subcarrier when the modulation method and coding rate that can maximize the transmission rate are used. Or, the number of subcarriers using the required transmission rate of each communication terminal device and the transmission rate per subcarrier when a modulation method and coding rate that satisfy the required error rate in the average reception quality of each communication terminal device are used. Is what determines. In addition, equation (2) determines the number of subcarriers by using the ratio of all the number of subcarriers in the band, the required transmission rate of each communication terminal device, and the total of the required transmission rates of all communication partners. is there.

Next, the request subcarrier number determination unit 105 calculates the total data amount of the CQI and subcarrier number information of the selected subcarrier for each communication terminal device 200, and totals the CQI and subcarrier number information of the selected subcarrier. It is determined whether or not the amount of data is larger than the total amount of CQI data of all the subcarriers (for example, 64 subcarriers) in the predetermined communication band (step ST302). That is, the request subcarrier number determination unit 105 determines whether or not the equation (3) holds. S_k&gt; (Q × N) / (Q + log₂N) (3) Here, Q: the number of coding bits required to quantize the SNR information, N: Total number of subcarriers.

When the total amount of CQI and subcarrier number information of the selected subcarrier is not larger than the total amount of CQI of all subcarriers within the predetermined communication band (when equation (3) does not hold) , The request subcarrier number determination unit 105 determines the number of subcarriers S._kIs determined as information on the number of subcarriers to be transmitted to the communication terminal device 200-k. Then, the request subcarrier number information generation unit 107 requests the number of subcarriers S._kIs generated as the number of subcarriers information, and the number of subcarriers information is transmitted to the communication terminal device 200-k to be notified (step ST303).

Next, in the communication terminal device 200-k that has received the subcarrier number information, the subcarrier number information extraction unit 213 extracts the subcarrier number information from the received signal, and the line quality information forming unit 215 has good reception quality. S in order_kOne subcarrier is selected (step ST304).

On the other hand, in step ST302, when the total data amount of the CQI and the subcarrier number information of the selected subcarrier is larger than the total data amount of the CQI of all the subcarriers in the predetermined communication band (Equation (3) holds. In the case), the request subcarrier number determination unit 105 decides to have the communication terminal device 200-k send the CQIs of all the subcarriers, and decides to select the total number of subcarriers. Then, the request subcarrier number information generation unit 107 generates subcarrier number information for selecting all subcarriers, and the subcarrier number information is notified to the communication terminal device 200-k (step ST305).

Next, the line quality information forming unit 215 of the communication terminal device 200 generates a CQI for each selected subcarrier or all subcarriers (step ST306).

Next, the communication terminal device 200 transmits the generated CQI and the generated subcarrier number information of the CQI to the wireless communication device 100 in the SNR notification format as shown in FIG. 6 (step ST307). Figure 6 shows the SNR report bits and subcarrier number information for the two subcarriers. As shown in FIG. 6, the first subcarrier has an SNR report bit of "3" and the subcarrier number information is "0", and the second subcarrier has an SNR report bit of "3" and The subcarrier number information is "4".

Next, the line quality information extraction unit 103 of the wireless communication device 100 extracts the CQI from the received signal, and the allocation control unit 104 allocates a subcarrier to the communication terminal device 200-k (step ST308).

As described above, according to the first embodiment, the base station apparatus determines the number of subcarriers to be allocated to each communication terminal apparatus based on the required transmission rate of each communication terminal apparatus, and communicates the determined subcarrier number information. Since it is transmitted to the terminal device, the communication terminal device need only generate and transmit CQIs for the number of subcarriers allocated from the base station device. As a result, the amount of control information can be reduced, so that communication efficiency can be improved.

Further, according to the first embodiment, in the base station apparatus, the total amount of data of the CQI and the subcarrier number information in the number of subcarriers assigned to the communication terminal apparatus of each user is the CQI of all the subcarriers. If the amount of data is larger than the total amount of data in, the communication terminal device is requested to transmit only the CQI of all subcarriers. The amount of transmission can be reduced.

Further, according to the first embodiment, the communication terminal device selects the number of subcarriers instructed by the base station device based on the number of subcarriers information in the order of good line quality and notifies the base station device. Since the base station apparatus can allocate the packet data to the subcarriers having good reception quality, the user diversity effect can be obtained, the throughput of the entire system can be improved, and the frequency utilization efficiency can be improved.

(Embodiment 2) FIG. 7 is a block diagram showing a configuration of the wireless communication device 500 according to the second embodiment of the present invention. In FIG. 7, the same reference numerals are given to the parts having the same configuration as that in FIG. 3, and the description thereof will be omitted. Further, since the configuration of the communication terminal device is the same as that shown in FIG. 4, the description thereof will be omitted.

The allocation control unit 104 allocates a subcarrier to each user's communication terminal device from the CQI input from the line quality information extraction unit 103 and the user information of each user's communication terminal device input from the user information storage unit 106. , Select the modulation method for each subcarrier. Then, the allocation control unit 104 outputs the allocation information of the allocated subcarriers to the subcarrier allocation unit 110, and outputs the modulation method information of the selected modulation method to the modulation units 111-1 to 111-N. The allocation control unit 104 allocates the subcarrier and the modulation method to each communication partner so that the PER value is equal to or less than the predetermined PER value for each subcarrier. Further, the allocation control unit 104 outputs the information on the number of subcarriers in the communication terminal device of each user who has actually allocated the packet data to the request subcarrier number determination unit 105 in frame units.

The request subcarrier number determination unit 105 is a sub that is actually assigned by the allocation control unit 104 input from the allocation control unit 104 for the communication terminal device to which the subcarrier is assigned in the frame immediately before the current frame. The number of subcarriers is determined using the carrier number information, and the determined subcarrier number information is output to the request subcarrier number information generation unit 107. On the other hand, the request subcarrier number determination unit 105 uses the user information of each communication terminal device input from the user information storage unit 106 for the communication terminal device to which the subcarrier was not assigned in the frame immediately before the current frame. , The number of subcarriers that can be assigned is determined, and the determined subcarrier number information is output to the request subcarrier number information generation unit 107.

Next, a method of allocating subcarriers will be described with reference to FIG. FIG. 8 is a flow chart showing a method of allocating subcarriers.

First, the allocation control unit 104 determines whether or not a subcarrier is allocated in the immediately preceding frame immediately before the current frame (step ST601).

If a subcarrier is assigned in the immediately preceding frame, the number of subcarriers in the number of subcarriers information transmitted in the current frame by Eq. (4) S_kDetermine (t) (step ST602). S_k(t) = δ × S _k(t-1) (4) Where S_k(t): Number of subcarriers in the current frame, S'_k(t-1): The number of subcarriers actually assigned to the communication terminal device 200-k in the frame immediately before the current frame, δ: A constant (where 2.0 δ).

When the communication terminal device is stationary or the amount of movement of the communication terminal device is small, it can be estimated that the fluctuation of the line quality is small. Therefore, the number of subcarriers is used on the communication terminal device side using equation (4). Can be determined.

On the other hand, in step ST601, if no subcarrier is assigned in the immediately preceding frame, the number of subcarriers S of the number of subcarriers information transmitted in the current frame by the equation (1) or (2)._kDetermine (t) (step ST603).

Next, the request subcarrier number information generation unit 107 determines the number of subcarriers S._k(t) is generated as the number of subcarriers information, and the number of subcarriers information is notified to the communication terminal device 200-k in the current frame (step ST604).

Next, in the communication terminal device 200-k that has received the subcarrier number information, the subcarrier number information extraction unit 213 extracts the subcarrier number information from the received signal, and the line quality information forming unit 215 has good reception quality. S in order_kOne subcarrier is selected (step ST605).

Next, the line quality information forming unit 215 of the communication terminal device 200 generates a CQI for each selected subcarrier or all subcarriers (step ST606).

Next, the communication terminal device 200 transmits the generated CQI and the generated subcarrier number information of the CQI to the wireless communication device 500 in the SNR notification format as shown in FIG. 6 (step ST607).

Next, the line quality information extraction unit 103 of the wireless communication device 500 extracts the CQI from the received signal, and the allocation control unit 104 allocates a subcarrier to the communication terminal device 200-k (step ST608).

As described above, according to the second embodiment, the base station apparatus determines the number of subcarriers to be assigned to each communication terminal apparatus of each user based on the required transmission rate of each communication terminal apparatus, and the determined number of subcarriers. Since the information is transmitted to the communication terminal device, the communication terminal device need only generate and transmit CQIs for the number of subcarriers allocated from the base station device. As a result, the amount of control information can be reduced, so that communication efficiency can be improved.

Further, according to the second embodiment, the base station apparatus can determine the number of subcarriers by a simple method of multiplying the number of subcarriers of the frame immediately before the current frame by a constant. When the moving speed of the communication terminal device is low or the communication terminal device is stationary, the process of allocating subcarriers can be simplified and speeded up.

Further, according to the second embodiment, the communication terminal device selects the number of subcarriers instructed by the base station device based on the number of subcarriers information in the order of good line quality and notifies the base station device. Since the base station apparatus can allocate the packet data to the subcarriers having good reception quality, the user diversity effect can be obtained, and as a result, the throughput of the entire system can be improved.

In the first embodiment or the second embodiment, the CQI is used as the line quality information, but the information is not limited to this, and any information other than the CQI can be used. Further, the wireless communication device 100 of the first embodiment or the wireless communication device 500 of the second embodiment can be applied to a base station device.

Each functional block used in the description of each of the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip so as to include a part or all of them.

Although it is referred to as LSI here, it may be referred to as IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of making an integrated circuit is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connection and settings of circuit cells inside the LSI may be used.

Furthermore, if an integrated circuit technology that replaces an LSI appears due to advances in semiconductor technology or another technology derived from it, it is naturally possible to integrate functional blocks using that technology. There is a possibility of adaptation of biotechnology.

This specification is based on Japanese Patent Application No. 2003-295972 filed on August 20, 2003. All this content is included here.

The communication terminal device and transmission method according to the present invention have an effect of improving communication efficiency by reducing the amount of control information to be transmitted, and are useful for allocating subcarriers.

101, 201 antenna 102, 202 Reception RF section 103 Line quality information extraction department 104 Assignment control unit 105 Requested subcarrier number determination unit 106 User Information Storage Unit 107 Request subcarrier number information generator 108 Assignment information generator 109 Control information multiplex 110 Subcarrier allocation department 111-1 ~ 111-N Modulator 112 Switching part 113 IFFT section 114 GI insertion part 115, 216 Transmission RF section 203 GI removal part 204 FFT section 205 Line Quality Estimator 206 Line estimation unit 207 Equalization Department 208 Separation 209-1 ~ 209-N Demodulation section 210 P / S section 211 Control information retrieval unit 212 Allocation Information Extraction Department 213 Subcarrier information retrieval department 214 Subcarrier selection section 215 Line Quality Information Formation Department