Transmission control method and apparatus using delays in multiple antenna systems

The present invention relates to a transmission control method.

In recent years, mainly in a multi-carrier transmission system, a method has been proposed in which a plurality of blocks are divided along a frequency axis and a time axis, and signals transmitted from a wireless transmitter to each user are scheduled based on these blocks. Here, the area defined by the frequency axis and the time axis secured when the user communicates is called an allocation slot, and the basic block when determining the allocation slot is called a chunk.

Among these, when transmitting broadcast signals, multicast signals, and control signals, a method is proposed to reduce errors even when the received power is low by allocating a wide block in the frequency axis direction to obtain the frequency diversity effect. Has been done. In addition, when transmitting a unicast signal, which is one-to-one communication between a wireless transmitter and a wireless receiver, a narrow block is assigned in the frequency axis direction to obtain a multi-user diversity effect, thereby wirelessly. A method for improving the received power at the receiver has been proposed.

16A and 16B are diagrams showing the relationship between the time (horizontal axis) and the frequency (vertical axis) of the signal transmitted from the wireless transmitter to the wireless receiver. In FIG. 16A, the horizontal axis represents time and the vertical axis represents frequency. Set the transmission times t1 to t3 on the time axis. However, the time widths of the transmission times t1 to t3 are the same. Set the transmission frequencies f1 to f5 on the frequency axis. However, the frequency widths of the transmission frequencies f1 to f5 are the same for Fc. In this way, 15 chunks K1 to K15 are set as shown in FIG. 16A according to the transmission times t1 to t3 and the transmission frequencies f1 to f5.

Further, as shown in FIG. 16B, five chunks K1 to K5 are combined and divided into six equal parts in the time axis direction, and the communication slots s1 to s6 having a time width of t1 / 6 and a frequency width of 5f1. To set. Communication slots s1 and s4 are assigned to the first user, communication slots s2 and s5 are assigned to the second user, and communication slots s3 and s6 are assigned to the third user. As a result, the first to third users can obtain the frequency diversity effect.

Next, the chunk K10 is assigned to the fourth user as the communication slot s11. Chunks K7, K8, and K9 are integrated to form communication slots s8 to s10 with a time width of t2 and a frequency width of 3f1, which are assigned to the fifth user. Further, chunk K6 is assigned to the sixth user as communication slot s7. As a result, all the 4th to 6th users can obtain the multi-user diversity effect, and the 5th user can obtain the frequency diversity effect.

In addition, chunk K11 is assigned to another seventh user as communication slot s12. This allows this user to obtain a multi-user diversity effect. Further, chunks K13 and K15 are assigned to another eighth user as communication slots s19 and s26. This allows this user to obtain a multi-user diversity effect. Further, the two chunks K12 and K14 are divided into six equal parts in the time axis direction to form communication slots s13 to s18 and s20 to s25 as shown in the figure. Communication slots s13, s16, s20, s23 are assigned to the 9th user, communication slots s14, s17, s21, s24 are assigned to the 10th user, and communication slots s15, s18, s22, s25 are assigned to the 11th user. As a result, all the 9th to 11th users can obtain the frequency diversity effect.

<p><nplcit num="1"><text>3GPP Contribution, R1-050249, "Downlink Multiple AccessScheme for Evolved UTRA", [Searched August 17, 2005], Internet (URL: ftp://ftp.3gpp.org/TSG_RAN/WG1_RL1/TSGR1_40bis/Docs/R1- 050249.zip)</text></nplcit><nplcit num="2"><text>3GPP Contribution, R1-050590, "Physical Channels and Multiplexing in Evolved UTRA Downlink", [Searched August 17, 2005], Internet (URL: ftp://ftp.3gpp.org/TSG_RAN/WG1_RL1/R1_Ad_Hocs/LTE_AH_JUNE- 05 / Docs / R1-050590.zip)</text></nplcit></p>

<p> In the above-mentioned conventional method, in order to obtain the frequency diversity effect, it is necessary to increase the diffusion rate or decrease the coding rate at the time of error correction coding according to the frequency fluctuation of the transfer function of the propagation path. There is.</p><p> 17A and 17B and 18A and 18B are diagrams showing delay profiles and transfer functions of signals arriving at a radio receiver through multiple propagation paths with different delay times.</p><p> 17A and 18A show a delay profile showing how a transmitted signal reaches a radio receiver through multiple propagation paths with different delay times in terms of time (horizontal axis) and power (vertical axis). .. Further, FIGS. 17B and 18B show the transfer function obtained by frequency-converting the delay profile and showing the frequency (horizontal axis) and the power (vertical axis).</p><p> Further, FIG. 17A shows the case where the 6-wave delay waves w11 to w16 are present, and FIG. 18A shows the case where the 3-wave delay waves w21 to w23 are present. The maximum delay times t1 and t2 are different between the two.</p><p> As shown in FIGS. 17A and 17B, when the maximum delay time t1 is large, that is, when the frequency fluctuation of the transfer function is relatively fast (power fluctuation in the frequency direction is fast), the diffusion rate is small, or the error correction code. A sufficient frequency diversity effect can be expected even when the coding rate at the time of conversion is high. However, as shown in FIGS. 18A and 18B, when the maximum delay time t2 is small, that is, when the frequency fluctuation of the transfer function is relatively gentle, the diffusion rate is small or the coding rate at the time of error correction coding is small. When it is high, a sufficient frequency diversity effect cannot be expected, and it is necessary to increase the diffusion rate or decrease the coding rate at the time of error correction coding.</p><p> Note that D1 and D2 in FIGS. 17B and 18B indicate signals, that is, data. That is, in FIG. 17B, four subcarriers a11 to a14 are assigned to the data D1 with the spread ratio of the spread spectrum technology being 4 for each of the data D1 and D2. Similarly, four subcarriers a15 to a18 are assigned to the data D2. In this case, since the frequency fluctuation of the transfer function is fast, the received power of the subcarrier a13 is significantly reduced for the data D1 and the received power of the subcarrier a16 is significantly reduced for the data D2. Is. Therefore, there is no problem in receiving any of the data D1 and D2.</p><p> In FIG. 18B, the diffusion ratio is set to 8, and eight subcarriers a21 to a28 are assigned to the data D1. In this case, since the frequency fluctuation of the transfer function is slow, the receiving part of the subcarrier a24 is significantly reduced, and the received power of the subcarriers a23 and a25 is also slightly reduced, but the data diffusion ratio is made larger than in the case of FIG. 17B. Therefore, there is no problem in receiving data D1. The numerical value of the diffusion ratio is for convenience of explanation and is not limited to this.</p><p> The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain a sufficient frequency diversity effect without controlling the diffusion rate and the code rate of the error correction code on the wireless transmitter side. It is an object of the present invention to provide a wireless transmitter and a wireless transmission method capable of the above.</p>

<p>(1) The present invention has been made to solve the above-mentioned problems, and the transmission control method of the present invention is a transmission control method in a transmission system in which slots are allocated for each chunk divided in the frequency direction and the time direction. Therefore, when transmitting output signals to a plurality of transmitting antennas, a delay is generated in each of the output signals of the plurality of transmitting antennas, and when the frequency bandwidth of the chunk is set to Fc, the between the plurality of transmitting antennas. When the delay is controlled so that the maximum delay time is either a predetermined first value smaller than 1 / Fc or a predetermined second value larger than 1 / Fc, and the transmission signal is transmitted by frequency diversity. It is characterized in that the delay is controlled to the second value.</p><p>(2) Further, the transmission control method of the present invention is the above-mentioned transmission control method, which is a transmission control method in a transmission system that allocates slots for each chunk divided in the frequency direction and the time direction, and is a plurality of transmission control methods. When transmitting the output signal to the transmitting antenna, a delay is generated in each of the output signals of the plurality of transmitting antennas, and when the frequency bandwidth of the chunk is Fc, the maximum delay time between the plurality of transmitting antennas is 1. When the delay is controlled so as to be either a predetermined first value smaller than / Fc or a predetermined second value larger than 1 / Fc, and the moving speed of the destination device is faster than the predetermined speed. It is characterized in that the delay is controlled to a second value.</p>

<p> According to the present invention, by appropriately setting the delay time T, the frequency diversity effect can be obtained without being affected by the state of the propagation path.</p>

<figref num="1">FIG. 1 is a schematic diagram showing that a signal transmitted by a radio transmitter according to the first embodiment of the present invention reaches a radio receiver through a plurality of propagation paths.</figref><figref num="2A">FIG. 2A is a diagram showing a delay profile of a signal arriving at a radio receiver through a plurality of propagation paths having different delay times.</figref><figref num="2B">FIG. 2B is a diagram showing a transfer function obtained by frequency-converting the delay profile shown in FIG. 2A.</figref><figref num="3A">FIG. 3A is a diagram showing another delay profile of a signal arriving at a radio receiver through a plurality of propagation paths having different delay times.</figref><figref num="3B">FIG. 3B is a diagram showing a transfer function in a radio receiver obtained by frequency-converting the delay profile shown in FIG. 3A.</figref><figref num="3C">FIG. 3C is a diagram showing a transfer function in another radio receiver at a different position, obtained by frequency-converting the delay profile shown in FIG. 3A.</figref><figref num="4A">FIG. 4A is a diagram showing the maximum delay time (n-1) T in the delay profile.</figref><figref num="4B">FIG. 4B is a diagram showing the relationship between the maximum delay time (n-1) T shown in FIG. 4A and the frequency fluctuation.</figref><figref num="5A">FIG. 5A is a diagram showing another maximum delay time (n-1) T in the delay profile.</figref><figref num="5B">FIG. 5B is a diagram showing the relationship between the maximum delay time (n-1) T shown in FIG. 5A and the frequency fluctuation.</figref><figref num="6A">FIG. 6A is a diagram showing a case where the same signal is transmitted from a plurality of antennas of a wireless transmitter without giving a delay time in a wireless transmission / reception system.</figref><figref num="6B">FIG. 6B is a diagram showing an example of a received signal in the system shown in FIG. 6A.</figref><figref num="6C">FIG. 6C is a diagram showing another example of the received signal in the system shown in FIG. 6A.</figref><figref num="7A">FIG. 7A is a diagram showing a case where the same signal is transmitted from a plurality of transmitting antennas of a wireless transmitter with different delay times in a wireless transmission / reception system.</figref><figref num="7B">FIG. 7B is a diagram showing an example of a received signal in the system shown in FIG. 7A.</figref><figref num="7C">FIG. 7C is a diagram showing another example of the received signal in the system shown in FIG. 7A.</figref><figref num="8">FIG. 8 is a block diagram showing a configuration of a physical layer portion of the wireless transmitter according to the second embodiment of the present invention.</figref><figref num="9A">FIG. 9A is a diagram showing an example of a signal in which a circulation delay is added to the transmission signal of the third embodiment of the present invention.</figref><figref num="9B">FIG. 9B is a diagram showing another example of a signal in which a circulation delay is added to the transmission signal of the third embodiment of the present invention.</figref><figref num="10">FIG. 10 is a block diagram showing a configuration of a physical layer portion of a wireless transmitter according to a third embodiment of the present invention.</figref><figref num="11">FIG. 11 is a diagram for explaining the operation of the circulation delay addition unit 119-1 according to the third embodiment of the present invention.</figref><figref num="12">FIG. 12 is a block diagram showing a configuration of a physical layer portion of a wireless transmitter according to a fourth embodiment of the present invention.</figref><figref num="13">FIG. 13 is a block diagram showing the configuration of the physical layer portion of the wireless transmitter according to the fifth embodiment of the present invention.</figref><figref num="14">FIG. 14 is a table showing the relationship between the maximum delay time (n-1) T between transmitting antennas and the chunk frequency bandwidth Fc in each physical channel.</figref><figref num="15">FIG. 15 is a table showing another relationship between the maximum delay time (n-1) T between transmitting antennas and the chunk frequency bandwidth Fc in each physical channel.</figref><figref num="16A">FIG. 16A is a diagram showing the relationship between the time (horizontal axis) and the frequency (vertical axis) of the signal transmitted from the wireless transmitter to the wireless receiver.</figref><figref num="16B">FIG. 16B is a diagram showing communication slots assigned to the time-frequency space shown in FIG. 16A.</figref><figref num="17A">FIG. 17A is a diagram showing a delay profile of a signal arriving at a radio receiver through a plurality of propagation paths having different delay times.</figref><figref num="17B">FIG. 17B is a diagram showing a transfer function obtained by frequency-converting the delay profile shown in FIG. 17A.</figref><figref num="18A">FIG. 18A is a diagram showing a delay profile of a signal arriving at a radio receiver through a plurality of propagation paths having different delay times.</figref><figref num="18B">FIG. 18B is a diagram showing a transfer function obtained by frequency-converting the delay profile shown in FIG. 18A.</figref>

[First Embodiment] FIG. 1 is a schematic diagram showing that a signal transmitted by the radio transmitter 1 reaches the radio receiver 7 through a plurality of propagation paths. The radio transmitter 1 has a plurality of transmitting antennas 2 to 4, gives different delay times 0, T, and 2T to the respective transmitting antennas 2 to 4, and transmits from the respective transmitting antennas 2 to 4. The wireless receiver 7 receives the signal transmitted from the wireless transmitter 1. Note that FIG. 1 describes a case where the wireless transmitter 1 includes three transmitting antennas 2 to 4 as an example.

The plurality of transmitting antennas described here are wireless transmissions that are base station equipment such as mobile phones. assuming a transmission antenna mounted on a signal device, in the same sector, different sectors within the same base station apparatus, Three types of transmitting antennas between different base station devices can be envisioned. Here, as an example, the case where they are installed in the same sector will be described, but other configurations may be used. That is, n transmitting antennas may belong to a plurality of different sectors, or n transmitting antennas may belong to a plurality of different base station devices. Further, the delayers 5 and 6 in the figure are assumed to give a delay time T, and as described above, the transmitting antenna 3 is given a delay time T and the transmitting antenna 4 is given a delay time 2T.

2A and 2B are diagrams showing the delay profile and transfer function of signals reaching the radio receiver through multiple (three) propagation paths with different delay times. FIG. 2A shows a delay profile showing how a transmitted signal reaches a radio receiver through a plurality of propagation paths having different delay times in terms of time (horizontal axis) and power (vertical axis). As shown in FIG. 2A, the instantaneous delay profile will have a maximum delay wave of 2T + dmax, and the maximum delay wave will be much larger than when the same signal is transmitted from each transmitting antenna. Note that dmax indicates the difference in arrival time between the fastest-arriving propagation path and the slowest propagation path when radio waves arrive from the transmitting antenna to the receiving antenna.

FIG. 2B shows the transfer function obtained by frequency-converting the delay profile of FIG. 2A and showing the frequency (horizontal axis) and power (vertical axis). As described above, the increase in the maximum delay time 2T + dmax in the delay profile means that the frequency fluctuation of the transfer function becomes faster. Therefore, as shown in FIG. 2B (similar to FIG. 17B), the data D1 and D2 are each diffused at a diffusion ratio of 4 and subcarriers are assigned. It is desirable that the radio transmitter 1 side controls the diffusion rate or the code rate of the error correction code according to the frequency fluctuation of this transmission function, but in the above method, the delay time is controlled on the radio transmitter 1 side. Since 2T is known, the diffusion rate or the code rate of the error correction code can be determined regardless of the frequency fluctuation of the propagation path. On the other hand, if a multi-user diversity effect is desired, it is desirable that the maximum delay time 2T + dmax in the instantaneous delay profile is not very large. The multi-user diversity effect will be described with reference to FIGS. 3A to 3B.

3A to 3C are diagrams showing delay profiles and transfer functions of signals arriving at a radio receiver through a plurality of propagation paths having different delay times. FIG. 3A shows a delay profile showing how the transmitted signal reaches the radio receiver through multiple (three) propagation paths with different delay times in terms of time (horizontal axis) and power (vertical axis). There is. FIG. 3B shows the transfer function at the wireless receiver used by user u1. In addition, FIG. 3C shows the transfer function in the wireless receiver used by the user u2. Since the position of the wireless receiver is different between the user u1 and the user u2, the instantaneous transfer function is different.

That is, assuming that the region on the left side of FIGS. 3B and 3C is the frequency channel b1 and the region on the right side is the frequency channel b2, the frequency channel b2 is of better quality for the user u1 and the frequency channel b1 is of better quality for the user u2. Become. Therefore, the data D1 to D4 are transmitted to the user u1 on the frequency channel b2. Data D1 to D4 are spread spectrum. Data D1 to D4 are transmitted to the user u2 on the frequency channel b1. In this case as well, the data D1 to D4 are spread spectrum.

As described above, by utilizing the quality difference for each frequency channel at a certain moment, it is possible to obtain a multi-diversity effect for improving the transmission efficiency by having different users communicate with each frequency channel. However, if the maximum delay time 2T + dmax is too large, the frequency fluctuation of the transfer function becomes fast, and the quality difference between the frequency channel b1 and the frequency channel b2 described above becomes small. Therefore, in order to obtain a sufficient multi-user diversity effect, it is important to reduce the maximum delay time of 2T + dmax as shown in FIG. 3A.

4A and 4B, and 5A and 5B are diagrams showing the relationship between the maximum delay time (n-1) T and the frequency fluctuation. As shown in FIG. 4A, when the arrival time difference between the two incoming waves w31 and w32 is (n-1) T, the transfer function of this propagation path is as shown in FIG. 4B. That is, the frequency interval of the drop in the amplitude of the electric power (vertical axis) is F = 1 / (n-1) T. Further, as shown in FIG. 5A, even when a plurality of delayed waves w41 to w43 exist, the arrival time difference between the first arrival wave w41 and the latest arrival delay wave w43 is (n-1) T. In some cases, as also shown in FIG. 5B, the frequency interval of the dip in the amplitude of the power (vertical axis) is F = 1 / (n-1) T.

By the way, when it is desired to obtain the frequency diversity effect and when it is desired to obtain the multi-user diversity effect, as described above, the frequency fluctuation of the appropriate transfer function is different. Therefore, when the frequency diversity effect is to be obtained, When the maximum delay time (n-1) T between the transmitting antennas is the frequency bandwidth Fc of the chunk, which is the basic region defined by the frequency axis and the time axis secured when the user communicates, (n). -1) By setting T&gt; 1 / Fc, it is possible to obtain an environment in which the frequency diversity effect can be easily obtained.

On the other hand, when the multi-user diversity effect is desired, the maximum delay time (n-1) T between the transmitting antennas is set to the chunk frequency bandwidth Fc, and then (n-1) T &lt;1 / Fc. By setting, it is possible to obtain an environment in which a multi-user diversity effect can be easily obtained. In the following description, when (n-1) T &lt;1 / Fc, the case of (n-1) T = 0 is also included. Further, in the following explanation, the delay time added to each transmitting antenna is expressed as (n-1) times T, and T is considered to be constant, but T may change for each transmitting antenna. .. If you want to obtain the multi-user diversity effect, you may reduce the maximum delay time by reducing the number of transmitting antennas used for signal transmission instead of setting (n-1) T &lt;1 / Fc. As described above, depending on whether the transmission signal is transmitted by frequency diversity or multi-user diversity, it depends on whether ((n-1) T&gt; 1 / Fc or (n-1) T &lt;Fc. ), The frequency diversity effect and the multi-user diversity effect can be obtained without being affected by the state of the propagation path.

However, as shown in the communication slot s1 shown in FIG. 16B, the first user who performs communication by combining a plurality of consecutive chunks in the frequency direction and the ninth user who is assigned the communication slots s13, s16, s20, and s23. Thus, for users assigned discrete chunks, the bandwidth BW of the communication slot instantly assigned to a user (BW = 5Fc for the first user, BW = 3Fc for the ninth user) has a frequency diversity effect. It is also possible to obtain the frequency diversity effect by setting the maximum delay time (n-1) T&gt; 1 / BW. For example, when the frequency diversity is notified by the notification signal, the delay time T is set so that the maximum delay time (n-1) T between the transmitting antennas is (n-1) T&gt; 1 / BW, and the notification is made. When multi-user diversity is notified by a signal, the delay time T should be set so that the maximum delay time (n-1) T between the transmitting antennas is (n-1) T &lt;1 / Fc. Also, although not shown, when some subcarriers included in each chunk are assigned to a user over a plurality of chunks, the bandwidth BW of the communication slot assigned to that user is instantaneous. Indicates the distance between the subcarriers most distant in the frequency direction among the subcarriers assigned to. Whether to transmit by frequency diversity or multi-user diversity depends on the type of signal to be transmitted (pilot signal, control signal, broadcast / multicast signal, etc.) and the moving speed of the wireless receiver (moving speed is fast). In some cases, it can be switched by frequency diversity, and in slow cases, it can be switched by multi-user diversity).

6A to 6C are explanatory views when the same signal is transmitted from the plurality of antennas of the wireless transmitter 8 without giving a delay time. Considering the case where a wireless transmitter 8 having a plurality (three) omnidirectional transmitting antennas arranged in parallel and having a plurality of omnidirectional transmitting antennas is installed as shown in FIG. 6A, as shown in the elliptical shape shown in FIG. 6A. Since the lobes e11 and e12 are generated, there is a direction in which the received signal is received at a high reception level in the entire frequency band as in the wireless receiver 9 (see FIG. 6B), and the received signal is received as in the wireless receiver 10. In some cases, the signal is received at a low reception level in all bands (see Fig. 6C).

7A to 7C are explanatory views when the same signal is transmitted from a plurality of transmitting antennas of the wireless transmitter 8 with different delay times. Considering the case where a wireless transmitter 8 equipped with a plurality (three) omnidirectional transmitting antennas arranged in parallel is installed as shown in FIG. 7A, the lobes e21 to e26 are considered in a narrow band. In the received signal, a high frequency band and a low frequency band are generated in the received signal, but the average received signal level can be made almost constant regardless of the direction, so that the signal reception level at the wireless receiver 9 (Fig. Almost the same quality can be obtained in both the signal reception level at the wireless receiver 10 (see 7B) and the signal reception level at the wireless receiver 10 (see FIG. 7C). Therefore, the method of transmitting signals with different delay times for each transmitting antenna of the wireless transmitter 8 can compensate for the drawbacks when the same signal is transmitted from the plurality of transmitting antennas described with reference to FIGS. 6A to 6C.

[Second Embodiment] In the second embodiment of the present invention, the configuration of the wireless transmitter will be described. The wireless transmitter of the present embodiment has a plurality of transmitting antennas as in the wireless transmitter 1 (FIG. 1) according to the first embodiment. The wireless transmitter described here is a wireless transmitter that transmits a signal with a different delay time for each transmitting antenna, and the delay time is added in the time domain. Further, the signal with a different delay time for each transmitting antenna described in the present embodiment is a signal that is actually delayed by T with respect to the transmitting signal from the first transmitting antenna and is transmitted from the second transmitting antenna. Similarly, it is assumed that the transmission signal of the nth transmitting antenna transmits a signal delayed by (n-1) T.

FIG. 8 is a block diagram showing a configuration of a physical layer portion of the wireless transmitter according to the present embodiment. Here, the physical layer unit is a configuration of a wireless transmitter, in particular, receives a transmission signal, performs signal processing in a form capable of wireless transmission, and passes the signal to a radio frequency conversion unit that performs frequency conversion to a radio frequency. It is a part. As shown in FIG. 8, the physical layer unit includes user-specific signal processing units 11a and 11b and antenna-specific signal processing units 12-1, 12-2, and 12-3. The per-user signal processing unit 11a (the same applies to the per-user signal processing unit 11b) performs signal processing on the signal transmitted to the wireless receiver used by each user. Further, the signal processing unit 12-1 for each antenna (the same applies to the signal processing units 12-2 and 12-3 for each antenna) performs signal processing for each transmitting antenna.

The signal processing unit 11a for each user includes an error correction coding unit 13, a modulation unit 14, a subcarrier allocation unit 15, an IFFT (Inverse Fast Fourier Transform) unit 16, a parallel series transform unit 17, and a GI (Guard Interval). : Guard interval) It has an additional part 18, a delayed additional part 19-1, 19-2, and 19-3. The error correction coding unit 13 performs error correction coding of the transmission signal. The modulation unit 14 performs modulation processing such as QPSK (Quadrature Phase Shift Keying) and 16QAM (Quadrature Amplitude Modulation) on the output of the error correction coding unit 13.

The subcarrier allocation unit 15 allocates the output of the modulation unit 14 to an appropriate subcarrier based on the subcarrier allocation information notified from the upper layer. The IFFT unit 16 performs frequency-time conversion on the output of the subcarrier allocation unit 15. The parallel-series conversion unit 17 converts the output of the IFFT unit 16 in parallel-series. The GI addition unit 18 adds a guard interval to the output of the parallel series conversion unit 17. The delay addition unit 19-1 adds a different delay to the output of the GI addition unit 18 for each transmitting antenna.

The outputs from the delay addition units 19-1 to 19-3 are output to the signal processing units 12-1, 12-2, and 12-3 for each antenna, respectively. Further, the delay addition units 19-1 to 19-3 give different delays (for example, 0, S, 2S). Here, let S = T / sample time. The sample time described here indicates the minimum time interval of the digital signal processed by the GI addition unit 18, the delay addition units 19-1 to 19-3, and the synthesis unit 20. Therefore, adding the delay of the S sample in the delay addition units 19-1 to 19-3 corresponds to giving a delay of time T in consideration of the output end of the D / A conversion unit 22. Further, since the signal processing unit 11a for each user is used in a certain chunk, that is, is used in either the frequency diversity region or the multi-user diversity region, the frequency diversity region or the frequency diversity region is higher than the upper layer that controls the physical layer. Receives a notification signal (frequency div / multi-user div notification signal) notifying that it is used in the multi-user diversity area. The per-user signal processing unit 11a has a function of changing the delay time T by selecting whether to use the frequency diversity region or the multi-user diversity region based on this notification signal. The user-specific signal processing unit 11b has the same configuration as the user-specific signal processing unit 11a, and only the target user is different.

The signal processing unit 12-1 for each antenna has a synthesis unit 20, a filter unit 21, and a D / A (Digital / Analog) conversion unit 22. The compositing unit 20 synthesizes by adding the signals output from the user-per-user signal processing units 11a and 11b to the per-antenna signal processing unit 12-1. The filter unit 21 extracts only signals in a desired band from the outputs of the synthesis unit 20. The D / A conversion unit 22 converts the output of the filter unit 21 into digital / analog. The antenna-per-antenna signal processing units 12-2 and 12-3 also have the same configuration as the antenna-per-antenna signal processing unit 12-1. The output of each antenna signal processing unit 12-1 passes through a radio frequency conversion unit (not shown) that performs frequency conversion to a radio frequency, is output to a plurality of (three) transmitting antennas, and is transmitted as a radio signal. ..

[Third Embodiment] In the third embodiment of the present invention, another configuration of the wireless transmitter will be described. The wireless transmitter of the present embodiment is a wireless transmitter that transmits a signal with a different delay time for each transmitting antenna, and the delay time is added in the time domain. Further, the wireless transmitter of the present embodiment assumes a signal to which a guard interval is added for each symbol (effective symbol section) of the transmission signal. The signal with a different delay time for each transmitting antenna focuses on the part (effective symbol section) of the transmitted signal from the first transmitting antenna from which the guard interval is removed, and only this effective symbol section is used. It is assumed that a signal delayed by T is transmitted from the second transmitting antenna, and similarly, only this valid symbol interval transmits a signal delayed by (n-1) T at the nth transmitting antenna. ..

Therefore, at the time of transmission from each transmitting antenna, a guard interval corresponding to each effective symbol section is added, and unlike the case of the second embodiment, there is no time lag in the symbol timing at the transmitting antenna end. .. The method of adding the delay time by this method is hereinafter referred to as the addition of the circular delay. By performing the process of adding the circulation delay, there is an advantage that the resistance to the delayed wave can be maintained as compared with adding the delay time as described in the second embodiment for each transmitting antenna.

9A and 9B are diagrams showing an example of a signal in which a circulation delay is added to the transmission signal of the present embodiment. FIG. 9A shows the signal transmitted from the first antenna, and FIG. 9B shows the signal transmitted from the second antenna. Figures 9A and 9B show the case where the effective symbol interval is 4 samples and the guard interval interval is 1 sample. Focusing on the effective symbol interval, the second antenna has a delay of 1 sample compared to the first antenna. Is occurring. On the other hand, both the first antenna and the second antenna have no symbol timing shift when viewed in symbol units, so even if a circulation delay is added, the effect of the guard interval is that it becomes more resistant to interference with adjacent symbols. You can see that it is maintained.

FIG. 10 is a block diagram showing a configuration of a physical layer portion of the wireless transmitter according to the present embodiment. As shown in the figure, the physical layer unit includes user-specific signal processing units 111a and 111b, and antenna-specific signal processing units 112-1, 112-2, and 112-3. The user-specific signal processing unit 111a (the same applies to the user-specific signal processing unit 111b) performs signal processing addressed to the wireless receiver used by each user. The per-antenna signal processing unit 112-1 (the same applies to the per-antenna signal processing units 112-2 and 112-3) performs signal processing for each transmitting antenna. The configuration of the per-user signal processing unit 111a is almost the same as the configuration of the per-user signal processing unit 11a (FIG. 8) described in the second embodiment, but there is no GI addition unit 18 and the delay addition unit 19-1. The difference is that instead of ~ 19-3, circulation delay addition parts 111-1 to 119-3 are provided. The functions of the error correction coding unit 13, the modulation unit 14, the subcarrier allocation unit 15, the IFFT unit 16, and the parallel series conversion unit 17 of the signal processing unit 111a for each user are the same as those of the second embodiment (see FIG. 8). Therefore, the same reference numerals are given and the description thereof will be omitted.

The circulation delay addition unit 119-1 adds a different circulation delay to the output of the parallel series conversion unit 17 for each transmitting antenna. The outputs from the circulation delay addition units 119-1 to 119-3 are output to the signal processing units 112-1, 112-2, and 112-3 for each antenna, respectively. Further, the circulation delay addition units 111-1 to 119-3 give different circulation delays (for example, 0, S, 2S). Here, let S = T / sample time. Further, since the signal processing unit 111a for each user is used in a certain chunk, that is, is used in either the frequency diversity region or the multi-user diversity region, the frequency diversity region or the frequency diversity region is higher than the upper layer that controls the physical layer. Receives a notification signal notifying that it will be used in the multi-user diversity area. The per-user signal processing unit 111a has a function of selecting whether to use the frequency diversity region or the multi-user diversity region based on this notification signal and changing the delay time T. The user-specific signal processing unit 111b has the same configuration as the user-specific signal processing unit 111a, and only the target user is different.

FIG. 11 is a diagram for explaining the circulation delay addition unit 119-1 shown as an example according to the present embodiment. The circulation delay addition unit 119-1 includes a memory 110. Here, if you want to add a circular delay of k samples, input data D11 sequentially from address k + 1 to address n of memory 110, and then input (1, 2, 3, ..., (Nk)). (After), by inputting the continuation of data D11 from address 1 of memory 110, ((n-k + 1), (n-k + 2), (n-k + 3, ..., n) (By inputting), input n sample data D11. Next, data D12 ((n-k + 1), (n-k + 2), with k sample circulation delay added to n sample data D11 by outputting in order from address 1 of memory 110, (n-k + 3), ..., n, 1, 2, ... (nk)) can be output. An example in which a circulation delay of 0 samples is added to the data of 4 samples is the signal shown in FIG. 9A, and an example in which a circulation delay of 1 sample is added is a signal shown in FIG. 9B.

The configuration of the per-antenna signal processing unit 112-1 (FIG. 10) is almost the same as the configuration of the per-antenna signal processing unit 12-1 (FIG. 8) described in the second embodiment, but the GI addition unit 18 It differs in that it is provided. The functions of the synthesis unit 20, the GI addition unit 18, the filter unit 21, and the D / A conversion unit 22 of the signal processing unit 112-1 for each antenna are the same as those in the second embodiment (FIG. 8), and are therefore the same. References are given and their description is omitted. The antenna-per-antenna signal processing units 112-2 and 112-3 also have the same configuration as the per-antenna signal processing unit 112-1. The outputs of the signal processing units 112-1, 112-2, and 112-3 for each antenna pass through the radio frequency conversion unit (not shown) that performs frequency conversion to the radio frequency, respectively, to multiple (three) transmitting antennas. It is output and transmitted as a radio signal.

[Fourth Embodiment] In the fourth embodiment of the present invention, the configuration of yet another wireless transmitter will be described. The wireless transmitter according to the present embodiment is a wireless transmitter that transmits a signal with a different delay time for each transmitting antenna, and the delay time is added in the frequency domain. Further, in the present embodiment, a signal in which a guard interval is added for each symbol (effective symbol section) of the transmission signal is assumed, and the circulation delay is increased as in the radio transmitter (FIG. 10) of the third embodiment. It is assumed that it will be added.

FIG. 12 is a block diagram showing a configuration of a physical layer portion of the wireless transmitter according to the present embodiment. As shown in the figure, the physical layer unit includes user-specific signal processing units 211a and 211b, subcarrier allocation unit 215, and antenna-specific signal processing units 212-1, 212-2, and 212-3. The per-user signal processing unit 211a (the same applies to the per-user signal processing unit 211b) performs signal processing addressed to the wireless receiver used by each user. The subcarrier allocating unit 215 allocates the output from the signal processing unit 211a for each user to each subcarrier. The per-antenna signal processing unit 212-1 (the same applies to the per-antenna signal processing units 212-2 and 212-3) performs signal processing for each antenna.

Each user signal processing unit 211a and 211b has an error correction coding unit 13 and a modulation unit 14. Since the functions of the error correction coding unit 13 and the modulation unit 14 are the same as those of the second embodiment (FIG. 8) described above, the same reference numerals are given and the description thereof will be omitted. The outputs of the signal processing units 211a and 211b for each user are assigned to the appropriate subcarriers in the subcarrier allocation unit 215, which is assigned to the appropriate subcarriers based on the subcarrier allocation information notified from the upper layer, and then the antenna. It is output to each signal processing unit 212-1, 212-2, 212-3.

The signal processing unit 212-1 for each antenna includes a phase rotation unit 219, an IFFT unit 16, a parallel series conversion unit 17, a GI addition unit 18, a filter unit 21, and a D / A conversion unit 22. Since the functions of the IFFT unit 16, the parallel series conversion unit 17, the GI addition unit 18, the filter unit 21, and the D / A conversion unit 22 are the same as those in the second embodiment (FIG. 8) described above, the same reference numerals are used. The explanations thereof will be omitted. The phase rotation unit 219 rotates the output of the subcarrier allocation unit 215 by θm for each subcarrier and outputs the output to the IFFT unit 16. The antenna-per-antenna signal processing units 212-2 and 212-3 also have the same configuration as the per-antenna signal processing unit 212-1.

The outputs of the signal processing units 211-1, 212-2, and 212-3 for each antenna pass through the radio frequency conversion unit (not shown) that performs frequency conversion to radio frequencies, respectively, and are output to a plurality of transmitting antennas to provide radio signals. Will be sent as. In this embodiment, the rotation of the phase θm in the phase rotating unit 219 is set to θm = 2πfm · (n-1) T. Where fm is the frequency interval between the 0th and mth subcarriers and can be expressed as fm = m / Ts, where (n-1) T is the nth antenna with respect to the 1st antenna. The magnitude of the circulation delay time in. Note that Ts indicates the effective symbol time of the OFDM symbol.

The phase rotation unit 219 and the IFFT unit 16 constitute a delay addition unit 220. As a result, the phase rotation added by the phase rotation unit 219 is frequency-time transformed by the IFFT unit 16, so that the output of the IFFT unit 16 can be regarded as a time delay. Further, since the signal processing unit 211a for each user is used in a certain chunk, that is, is used in either the frequency diversity region or the multi-user diversity region, the frequency diversity region or the frequency diversity region is higher than the upper layer that controls the physical layer. Receives a notification signal notifying that it will be used in the multi-user diversity area. The per-user signal processing unit 211a has a function of selecting whether to use the frequency diversity region or the multi-user diversity region based on this notification signal and changing the delay time T.

In the wireless transmitter according to the second to fourth embodiments described above, n lines (n) are set by a delay time T corresponding to a notification signal for notifying whether the transmission signal is transmitted by frequency diversity or multi-user diversity. A delay addition part is provided to delay the transmission signal supplied to the transmitting antenna (an integer of 2 or more) by the maximum delay time (n-1) T or less. As a result, by appropriately setting the delay time T depending on whether the transmission signal is transmitted by frequency diversity or multi-user diversity, the frequency diversity effect and multi-user diversity are not affected by the state of the propagation path. The effect can be obtained.

[Fifth Embodiment] In the fifth embodiment of the present invention, the configuration of yet another wireless transmitter will be described. In the frequency diversity region, the wireless transmitter according to the present embodiment transmits a signal with a different delay time for each transmitting antenna, while in the multi-user diversity region, it is oriented by giving an appropriate weight to each transmitting antenna. It is a wireless transmitter that performs control, and performs this delay time and directional control in the frequency region. Further, in the present embodiment, a signal to which a guard interval is added for each symbol (effective symbol section) of the transmission signal is assumed, and a case where a circulation delay is added is assumed as in the third and fourth embodiments. ing.

FIG. 13 is a block diagram showing a configuration of a physical layer portion of the wireless transmitter according to the present embodiment. As shown in the figure, the physical layer unit includes user-specific signal processing units 211a and 211b, subcarrier allocation unit 215, weight calculation unit 310, and antenna-specific signal processing units 312-1, 312-2, and 312-3. Since the configurations of the signal processing unit 211a for each user and the subcarrier allocation unit 215 are the same as those in the fourth embodiment (FIG. 12), the same reference numerals are given and the description thereof will be omitted.

The per-antenna signal processing unit 312-1 (the same applies to the per-antenna signal processing units 312-2 and 312-3) performs signal processing for each transmitting antenna. The signal processing unit 312-1 for each antenna has a weight multiplication unit 319, an IFFT unit 16, a parallel series conversion unit 17, a GI addition unit 18, a filter unit 21, and a D / A conversion unit 22. Since the functions of the IFFT unit 16, the parallel series conversion unit 17, the GI addition unit 18, the filter unit 21, and the D / A conversion unit 22 are the same as those in the first embodiment, they are described with the same reference numerals. Is omitted.

The weight multiplication unit 319 multiplies the output of the subcarrier allocation unit 215 by weight for each subcarrier and outputs the output to the IFFT unit 16. The per-antenna signal processing units 312-2 and 312-3 also have the same configuration as the per-antenna signal processing unit 312-1. The outputs of the signal processing units 312-1, 312-2, and 312-3 for each antenna pass through the radio frequency conversion unit (not shown) that performs frequency conversion to radio frequencies, respectively, and are output to the transmitting antenna and transmitted as radio signals. Will be done.

Note that certain subcarriers are used in certain chunks. That is, it is used in either the frequency diversity region or the multi-user diversity region. Therefore, the weight multiplication unit 319 is notified by the upper layer that controls the physical layer unit that it is used in the frequency diversity region or the multi-user diversity region, and based on this, a different delay time is added to each antenna in the frequency diversity region. Therefore, the phase rotation θm is added, and the weight wm is multiplied to control the direction in the multi-user diversity region.

The delay addition / directional control unit 320 is configured by the weight multiplication unit 319 and the IFFT unit 16. As a result, when the phase rotation is added by the weight multiplication unit 319, the frequency time is converted in the IFFT unit 16 so that the output of the IFFT unit 16 can be regarded as a time delay. On the other hand, when the weight wm is multiplied by the weight multiplication unit 319, the frequency time is converted in the IFFT unit 16, and the direction control is performed when the output of the IFFT unit 16 is output from the transmitting antenna. ..

Further, when the phase is rotated by θm in the weight multiplication unit 319 described above, θm = 2πfm · (n-1) T is set as in the fourth embodiment. Note that fm is the frequency interval between the 0th subcarrier and the mth subcarrier, and can be expressed as fm = m / Ts, and (n-1) T is for the nth antenna with respect to the first antenna. Indicates the magnitude of the circulation delay time. Note that Ts indicates the effective symbol time of the OFDM symbol. Further, when multiplying the weight wm, the direction control can be performed by setting the weight as shown below. Assuming a linear array of n antennas whose element spacing is half the wavelength of the carrier frequency, the following equation (1) can be used as the weight wm.

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The weight wm represents the weight used by the weight multiplication unit 319 as a vector, and is the weight used by the first antenna to the nth antenna from the beginning of the equation (1), respectively. However, in the weight wm of Eq. (1), n is the number of antennas, n = 3 in this embodiment, θ indicates the direction in which the main beam is directed, and k is the frequency at which the signal is transmitted and θ is measured. Shows the frequency ratio. Here, as the direction θ in which the main beam is directed, the value measured by the wireless receiver or the terminal of the communication partner is notified to the weight calculation unit 310, and is used when deriving the weight wm. However, the weight wm in the above equation (1) is an example, and other methods can be used. The method for deriving the θ and wm is described in "Science Technical Report RCS2004-229" (published by the Institute of Electronics, Information and Communication Engineers, November 2004).

The delay addition / directional control unit 320 described above adds a delay of the maximum delay time (n-1) T or less between the transmitting antennas when the frequency diversity is notified by the notification signal, and when the multi-user diversity is notified. , Multiply the weight wm for directional control. As described in the first embodiment, when the frequency diversity is notified by the notification signal in the delay addition / directional control unit 320, the maximum delay time (n-1) T between the transmitting antennas is (n-). 1) The delay time T may be set so that T&gt; 1 / Fc. Further, as described in the first embodiment, when the frequency diversity is notified by the notification signal in the delay addition / directional control unit 320, the maximum delay time (n-1) T between the transmitting antennas is (n-). 1) The delay time T may be set so that T&gt; 1 / BW.

The weight multiplication unit 319 constituting the delay addition / directional control unit 320 is notified by the upper layer that controls the physical layer unit that it uses the frequency diversity region or the multi-user diversity region, and based on this, the frequency diversity region is used. In the above, a phase rotation θm is added to give a different delay time for each antenna, and a weight wm is multiplied to perform directional control in the multi-user diversity region. However, as shown in the fourth embodiment, the main beam is used. Before the direction θ to be directed is derived, the phase rotation θm is added in both the frequency diversity region and the multi-user diversity region, and after the direction θ to direct the main beam is derived in the multi-user diversity region, the weight wm is used for directing. In the multi-user diversity region, such as performing control, it is also possible to use a method in which the phase rotation θm and the weight wm are used together. As in the fourth embodiment, the delay time T of θm changes according to the frequency diversity region / multi-user diversity region. As a result, the multi-user diversity effect can be obtained even at the stage where the direction θ for directing the main beam is not derived, while the weight wm is used after the direction θ for directing the main beam is derived. A higher multi-user diversity effect can be expected by performing strict directional control. Further, by using the configuration of the physical layer portion of the wireless transmitter shown in FIG. 13, it is possible to obtain the characteristic improvement by the directional control by slightly increasing the circuit configuration from the fourth embodiment.

The delay addition / directional control unit 320 described above adds a delay of the maximum delay time (n-1) T or less between the transmitting antennas when the frequency diversity is notified by the notification signal, and when the multi-user diversity is notified. , Add a delay less than or equal to the maximum delay time (n-1) T between the transmitting antennas, or multiply by the weight wm for directional control.

The wireless transmitter that performs such processing has the configuration shown in FIG. 13, and the delay addition / directional control unit determines the maximum delay time between the transmitting antennas when the multi-user diversity is notified by the notification signal. (n-1) Add a delay of T or less, or multiply by the weight wm for directional control.

As described in the first embodiment, the delay addition / directional control unit sets the maximum delay time (n-1) T between the transmitting antennas to (n-1) T when the frequency diversity is notified by the notification signal. If the delay time T is set to&gt; 1 / Fc and a delay is added between the transmitting antennas when multi-user diversity is notified, the maximum delay time (n-1) T &lt;1 / Fc. Set the delay time T so as to. As described in the first embodiment, the delay addition / directional control unit sets the maximum delay time (n-1) T between the transmitting antennas to (n-1) when the frequency diversity is notified by the notification signal. ) The delay time T may be set so that T&gt; 1 / BW.

In the above-described second to fifth embodiments, the case where the number of users is 2 and the number of antennas is 3 has been described, but the number of users and the number of antennas are not limited to these values. Further, in the fourth and fifth embodiments described above, a signal multiplied by a specific scramble code determined for each antenna, each sector, and each base station may be transmitted for each transmitting antenna.

[Sixth Embodiment] In this embodiment, a case where the magnitude of the maximum delay time (n-1) T for each physical channel is changed will be described. In the first to fifth embodiments described above, it is assumed that one-to-one communication is performed in one chunk at a certain moment, and if a frequency diversity effect is desired, (n-1) T If you want to set&gt; 1 / Fc and obtain the multi-user diversity effect, the explanation is based on the assumption that (n-1) T &lt;1 / Fc is set.

Normally, in the case of communication, in addition to one-to-one communication, a known signal called a pilot channel is transmitted to a wireless transmitter in order to estimate the propagation path, and various types are performed before data communication is performed. Use the control channel to notify the parameters of. In this embodiment, a method of setting the maximum delay time (n-1) T in these physical channels will be described.

In Evolved UTRA &amp; UTRAN, which is being studied in 3GPP (3rd Generation Partnership Project), the main physical channels are DCPCH (Downlink Common Pilot Channel), individual pilot channel DDPCH (Downlink Dedicated Pilot Channel), and downlink synchronization channel DSCH (Downlink Dedicated Pilot Channel). Downlink Synchronization Channel (Downlink Synchronization Channel), Common Control Channel DCCCH (Downlink Common Control Channel), Downlink Shared Control Channel DSCSCH (Downlink Shared Control Channel), and Multicast / Broadcast Channel (Multicast / Broadcast Channel) have been proposed.

The common pilot channel DCPCH is equivalent to the W-CDMA (Wideband Code Division Multiple Access) pilot channel CPICH, and estimates the downlink propagation path conditions in the AMCS (Adaptive Modulation and Coding Scheme) system, as well as cell search and uplink transmission power. It is used for control propagation path loss measurement. The individual pilot channel DDPCH is a downlink common pilot channel for a mobile station that is transmitted to an individual mobile station or has low reception quality from a transmitting antenna that has a different propagation path (directivity) from the cell shared antenna such as an adaptive array antenna. It can also be used to reinforce DCPCH.

The downlink synchronization channel DSCH corresponds to the W-CDMA synchronization channel SCH, and is equivalent to mobile station cell search, OFDM (Orthogonal Frequency Division Multiplexing) signal radio frame, time slot, transmission timing interval (TTI), and OFDM. Used for symbol timing synchronization. The common control channel DCCCH is the W-CDMA system's first common control physical channel P-CCPCH, second common control physical channel S-CCPCH, and broadcast information (equivalent to broadcast channel BCH) corresponding to the paging indicator channel PICH, and packet calls. Contains common control information such as packet paging indicator PI information (equivalent to paging indicator channel PICH), packet paging information corresponding to packet calls (equivalent to paging channel PCH), and downlink access information (equivalent to downlink access channel FACH). ing.

The downlink shared control signaling channel DSCSCH is the HS-DSCH related shared control channel HS-SCCH, downlink individual control channel DPCCH, and acquisition indicator AICH included in the HSDPA (High Speed Downlink Packet Access) high-speed physical downlink shared channel HS-PDSCH. Information required for demodulation of the high-speed downlink shared channel HS-DSCH (modulation method, diffusion code, etc.) shared by multiple mobile stations, information required for error correction decoding processing and HARQ processing, And it is used for transmission of scheduling information of radio resources (frequency, time).

The downlink shared data channel DSDCH corresponds to the high-speed downlink shared channel HS-DSCH and the downlink individual data channel DPDCH included in the HSDPA high-speed physical downlink shared channel HS-PDSCH, and transmits packet data from the upper layer to the mobile station. Is used for. Multicast / broadcast channels are used for information signal notification. The physical channels of W-CDMA and HSDPA are described in "Keiji Tachikawa," W-CDMA Mobile Communication System ", ISBN4-621-04894-5" and the like.

14 and 15 are tables summarizing the relationship between the maximum delay time (n-1) T between transmitting antennas and the chunk frequency bandwidth Fc for each physical channel. As shown in the figure, it is desirable to set (n-1) T &lt;1 / Fc for the common pilot channel, the common control channel, and the individual control channel regardless of the frequency diversity region and the multi-user diversity region. Further, it is desirable to set (n-1) T&gt; 1 / Fc for the downlink synchronization channel regardless of the frequency diversity region and the multi-user diversity region. It is desirable to set the individual pilot channel to (n-1) T&gt; 1 / Fc in the frequency diversity region and (n-1) T &lt;1 / Fc in the multi-user diversity region. A chunk that includes individual pilot channels when transmitting individual pilot channels from the transmitting antennas by a delay addition unit that delays the transmission signals supplied to n transmitting antennas by the maximum delay time (n-1) T or less. When the frequency diversity is notified by the notification signal notifying whether to transmit by the frequency diversity or the multi-user diversity, the maximum delay time (n-1) T is (n-1) T&gt; 1 / Fc. When the delay time T is set so as to be, and the multi-user diversity is notified by the notification signal, the direction control is performed using the weight output from the weight calculation unit, or the maximum delay time (n-1) T is ( n-1) The delay time T may be set so that T &lt;1 / Fc. Also, the multicast / broadcast channel is used only in the frequency diversity region, and it is desirable to set (n-1) T&gt; 1 / Fc.

The reason for setting in this way is that the common pilot channel is used to notify the signal strength etc. observed by the terminal, so it is not desirable that the delay time changes for each chunk, but for multi-user diversity. In addition, since it is necessary to know the signal strength for each chunk when (n-1) T &lt;1 / Fc in the wireless transmitter, (n-1) T so that the maximum delay time does not change for each chunk. This is because it is desirable to set &lt;1 / Fc. In addition, the individual pilot channel is used to obtain a propagation path estimated value used for demodulation of a data signal or the like. Therefore, in the frequency diversity region, set (n-1) T&gt; 1 / Fc, and in the multi-user diversity region, set (n-1) T &lt;1 / Fc for communication. This is desirable.

In addition, although the downlink synchronization channel is used during frame synchronization, it is not necessary to estimate the propagation path, and it is desirable that it be received correctly even when the received power is low. Therefore, in order to obtain the frequency diversity effect, (n) -1) This is because it is desirable to set T&gt; 1 / Fc. In particular, in the downlink synchronization channel, the same signal may be transmitted from a plurality of sectors and a plurality of antennas included in one base station at the same time and at the same frequency. Therefore, in the downlink synchronization channel, a frequency diversity effect higher than that of other physical channels can be obtained by transmitting from a plurality of sectors and a plurality of antennas included in one base station with different delays added to each antenna. You can expect to get it.

In addition, since it is assumed that the common control channel and the individual control channel use the propagation path estimated value obtained from the common pilot channel, it is desirable that the common control channel and the individual control channel are set to the same maximum delay time as the common pilot channel and transmitted. is there. However, since it is desirable that the common control channel and the individual control channel are correctly received even when the reception power is low, it is desirable that the frequency diversity effect can be obtained, and when the improvement of the reception performance of the control channel is prioritized, it is considered. When the common pilot channel includes a common control channel, an individual control channel, and a multicast / broadcast channel in the same chunk, the frequency diversity in the control channel is set by setting (n-1) T&gt; 1 / Fc. It is desirable to get the effect.

On the other hand, when the same chunk is used as a multi-user diversity, the signal strength when actually performing communication suitable for the multi-user diversity (communication as (n-1) T &lt;1 / Fc) is notified. Since it is necessary, it is desirable to set (n-1) T &lt;1 / Fc for transmission. From this, the relationship between the maximum delay time (n-1) T between the transmitting antennas and the chunk frequency bandwidth Fc in each physical channel may be the same as the relationship shown in FIG. In addition, it is desirable to set (n-1) T&gt; 1 / Fc for communication on the multicast / broadcast channel in order to obtain the frequency diversity effect.

In the above-described embodiment, the case where the maximum delay time is set to (n-1) T &lt;1 / Fc in the multi-user diversity region has been described, but in the wireless transmitter described in the fifth embodiment, the multi-user is used. In the user diversity area, the weight wm notified by the weight calculation unit 310 can be used. In the second to fifth embodiments described above, the case where a signal is transmitted from a wireless transmitter provided with n transmitting antennas by giving a predetermined delay time to each of n transmitting antennas has been described. It is not limited to such a configuration. For example, if the wireless transmitter has n transmitting antennas and the wireless transmitter chooses to use multi-user diversity, then j of the n transmitting antennas (j is an integer and 1 ) A predetermined delay time T'may be given to each transmitting antenna of j &lt;n) to transmit the signal.

With such a configuration, the maximum delay time (j-1) T'of the signal transmitted from the j transmitting antennas is smaller than that when the signal is transmitted using all of the n transmitting antennas. Therefore, the variation of the propagation path can be made smaller, so that a good multi-user diversity effect can be obtained. In particular, when j = 1, the circuit scale of the delay portion can be reduced. Further, in the present embodiment, in order to obtain the frequency diversity effect, it is assumed that the maximum delay time (n-1) T&gt; 1 / Fc is set, but as described in the first embodiment, the physical channel Maximum delay time (n-1) T because the allocated bandwidth BW of the physical channel is the basis for obtaining the frequency diversity effect when is assigned to chunks that span multiple frequency directions for communication. It is also possible to obtain the frequency diversity effect by setting&gt; 1 / BW.

If the wireless transmitter according to the embodiment of the present invention described above is used, when transmitting signals from n transmitting antennas, whether to use frequency diversity or multi-user diversity is selected, and the selection result is selected. Since the delay time of the signals transmitted from the n transmitting antennas is changed based on this, the frequency diversity effect and the multi-user diversity effect can be obtained without being affected by the state of the propagation path.

In the embodiment described above, the error correction coding unit 13, the modulation unit 14, the subcarrier allocation units 15, 215, the IFFT unit 16, and the parallel series conversion unit 17 in FIGS. 8, 10, 12, and 13. GI addition section 18, delay addition section 19-1 to 19-3, circulation delay addition section 119-1 to 119-3, composition section 20, filter section 21, D / A conversion section 22, phase rotation section 219, weight calculation A program for realizing the functions of the unit 310 and the weight multiplication unit 319 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by the computer system and executed. Control may be performed. The computer system referred to here includes hardware such as an OS and peripheral devices.

The computer-readable recording medium refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system. Furthermore, a computer-readable recording medium is one that dynamically holds a program for a short period of time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In that case, it shall include the one that holds the program for a certain period of time, such as the volatile memory inside the computer system that is the server or client. Further, the above-mentioned program may be a program for realizing a part of the above-mentioned functions, and may be a program for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs and the like within a range that does not deviate from the gist of the present invention.

The present invention can be applied to wireless transmitters and wireless transmission methods for transmitting a signal to a wireless receiver using a plurality of transmitting antennas, and the transmitted signal is transmitted by frequency diversity or multi. By appropriately setting the delay time depending on whether the transmission is performed by the user diversity, the frequency diversity effect or the multi-user diversity effect can be obtained without being affected by the state of the propagation path.

1 ... Wireless transmitter 2 ~ 4 ... Transmit antenna 5, 6 ... Delayer 7, 8, 9, 10 ... Wireless receiver 11a, 11b, 111a, 111b, 211a, 211b ... Signal processing unit for each user 12-1, 12-2, 12-3, 112-1 to 112-3, 212-1 to 212-3, 312-1 to 312-3 ... Signal processing unit for each antenna 13. .. Error correction Coding section 14 ... Modulation section 15, 215 ... Subcarrier allocation section 16 ... IFFT section 17 ... Parallel series conversion section 18 ... GI addition section 19-1 ~ 19- 3 ... Delay addition part 119-1 ~ 119-3 ... Circulation delay addition part 20 ... Synthesis part 21 ... Filter part 22 ... D / A conversion part 110 ... Memory 219 .. .Phase rotation part 220 ... Delay addition part 310 ... Weight calculation part 319 ... Weight multiplication part 320 ... Delay addition / direction control part