JP4621757B2 - Wireless communication system, wireless transmission device, wireless reception device, and wireless communication method - Google Patents

Description

  The present invention relates to a wireless communication system, a wireless transmission device, a wireless reception device, and a wireless communication method that improve the utilization efficiency of wireless communication resources.

  Generally, in a wireless communication system, a wireless transmission device (for example, a wireless base station) allocates a communication channel to a wireless reception device (for example, a wireless terminal), and a wireless signal is transmitted to the wireless reception device using the allocated communication channel. Send. A communication channel is generally configured by a frequency or a time slot, or a combination of these radio communication resources. Usually, a wireless transmission device assigns the same communication channel so as not to overlap between wireless reception devices, thereby preventing interference.

In recent years, wireless communication systems that use the same frequency between adjacent cells and adaptive array control have been used as a method for increasing the number of wireless reception devices that can be communicated by wireless transmission devices by increasing the utilization efficiency of limited wireless communication resources. Spatial multiplexing technology using CDMA has been put into practical use. In the spatial multiplexing technology, the wireless transmission device directs transmission directivity in the direction of the wireless reception device, and can simultaneously transmit wireless signals to a plurality of wireless reception devices using the same communication channel (see Patent Document 1). .
JP 2006-319959 A (paragraph [0005] etc.)

  However, in a wireless communication system that uses the same frequency between adjacent cells, inter-cell interference becomes a major problem. Further, in the spatial multiplexing technique described above, when the spatial correlation between a plurality of radio receiving apparatuses to which the same communication channel is assigned is high, spatial multiplexing becomes impossible and the influence of interference increases.

  As described above, in the conventional technique, when the utilization efficiency of wireless communication resources is improved, the desired signal-to-interference signal power ratio (hereinafter abbreviated as “SIR” as appropriate) due to interference, that is, communication quality deterioration occurs. was there.

  Accordingly, the present invention has been made to solve the above-described problem, and can improve the SIR even when the utilization efficiency of wireless communication resources is improved, a wireless communication system, a wireless transmission device, and a wireless reception device. It is another object of the present invention to provide a wireless communication method.

  A feature of the present invention is that a wireless reception device, a first wireless transmission device that transmits a desired signal for the wireless reception device, and an interference signal that interferes with the desired signal are transmitted to a wireless reception device different from the wireless reception device. A wireless communication system that receives the desired signal and the interference signal, wherein the first wireless transmission device transmits the desired signal to the wireless reception device. A delay desired signal generation unit that generates a delayed desired signal obtained by delaying a signal, a transmission side information holding unit that holds in advance information indicating a delay time of the delayed desired signal with respect to the desired signal, and an amplitude of the delayed desired signal or A desired signal information notifying unit for notifying the wireless reception device of information indicating a phase as delayed desired signal information, the desired signal, and a signal generated by the delayed desired signal generating unit. A desired signal transmission unit that transmits a delayed desired signal, wherein the wireless reception device includes a reception-side information holding unit that holds in advance the same information as the information held by the transmission-side information holding unit; An information acquisition unit that acquires the delayed desired signal information notified from the wireless transmission device, a signal reception unit that receives the desired signal, the interference signal, and the delayed desired signal, and the reception-side information holding unit that holds the information acquisition unit Based on the information and the delayed desired signal information acquired by the information acquiring unit, the desired signal and the delayed desired signal received by the signal receiving unit are matched on the time axis, and the desired signal and the delayed The gist of the present invention is to provide a signal synthesis unit that synthesizes a desired signal in the same phase.

Features of the present invention includes a wireless receiving device (radio reception unit 210), the first radio transmission device for transmitting a desired signal (signal S) of the radio receiving apparatus for a (radio transmission unit 110), the desired signal A second wireless transmission device (wireless transmission unit 120) that transmits an interference signal (signal I) that interferes to a wireless reception device (wireless reception unit 220) different from the wireless reception device, and the wireless reception device includes: A wireless communication system (wireless communication system 10A or wireless communication system 10B) that receives a desired signal and the interference signal, wherein the second wireless transmission device delays the interference signal to be transmitted to the different wireless reception device A delayed interference signal generator (delayed signal generator 122) that generates a delayed interference signal (delayed signal Idelay), and delayed interference signal information (delayed information) that is information related to the delayed interference signal Interference signal information notifying unit (delay information notifying unit 124) for notifying the radio receiving device of information Iinfo), the interference signal, and the interference signal for transmitting the delayed interference signal generated by the delayed interference signal generating unit A transmission unit (transmission unit 125), wherein the wireless reception device acquires an information acquisition unit (delay information acquisition unit 213) that acquires the delayed interference signal information notified from the second wireless transmission device; and the desired signal A signal receiving unit (receiving unit 212) that receives the interference signal and the delayed interference signal, and the interference signal received by the signal receiving unit based on the delayed interference signal information acquired by the information acquiring unit and A signal synthesizing unit (signal synthesizing unit 214) for matching the delayed interference signals on the time axis and synthesizing the interference signal and the delayed interference signal in opposite phases; The gist of the Rukoto.

  According to such a wireless communication system, the wireless reception device receives the interference signal by synthesizing the interference signal and the delayed interference signal in opposite phases based on the delayed interference signal information notified from the second wireless transmission device. Since power can be reduced, SIR can be improved. Therefore, even when the utilization efficiency of wireless communication resources is improved, the SIR in the wireless reception device can be improved.

Features of the present invention relates to the above characteristic of the present invention, the interference signal information notifying unit includes information indicating the delay time of the delay interference signal with respect to the interference signal (delay time .tau.2), as the delay interferometer signal information The gist is to notify the wireless receiver.

Features of the present invention relates to the above characteristic of the present invention, the second wireless transmission apparatus, transmission-side information holding section (delay information holding held in advance information indicating the delay time of the delay interference signal with respect to the interference signal 123), and the radio reception apparatus further includes a reception side information holding unit (delay information holding unit 219) that holds in advance the same information as the information held by the transmission side information holding unit, and the interference The signal information notification unit notifies the wireless reception device as information indicating the amplitude or phase of the delayed interference signal as the delayed interference signal information, and the signal synthesis unit includes the information held by the reception side information holding unit and And based on the delayed interference signal information acquired by the information acquisition unit, the interference signal received by the signal reception unit and the delayed interference signal are matched on the time axis, and And gist the synthesis of Wataru signal and the delayed interference signal in antiphase.

Features of the present invention, the radio receiving device (radio reception unit 210) a desired signal (signal S) and the radio receiving device for receiving the interfering interference signal (signal I) to the desired signal for the interference A delayed interference signal for generating a delayed interference signal (delayed signal Idelay) obtained by delaying the interference signal to be transmitted to a wireless receiver different from the wireless receiver, which is a wireless transmitter (radio transmitter 120) that transmits a signal A generation unit (delay signal generation unit 122), an interference signal information notification unit (delay information notification unit 124) for notifying the radio reception device of delayed interference signal information (delay information Iinfo) that is information related to the delayed interference signal, The gist is provided with an interference signal transmission unit (transmission unit 125) that transmits the interference signal and the delayed interference signal generated by the delayed interference signal generation unit.

Features of the present invention, the desired signal receiving (signal S) from the first radio transmission device (wireless transmission section 110), the desired signal to interference interference signal (signal I) the second radio transmission device (wireless transmission Unit 120) is a radio reception device (radio reception unit 210) that receives the desired signal, the interference signal, and a delayed interference signal (delayed signal Idelay) obtained by delaying the interference signal in the second radio transmission device. ) And an information acquisition unit (delay information) for acquiring delayed interference signal information (delay information Iinfo) that is notified from the second wireless transmission device and that is information related to the delayed interference signal Based on the information acquisition unit 213) and the delayed interference signal information acquired by the information acquisition unit, the interference signal and the delayed interference signal received by the signal reception unit are matched on the time axis. Together is, the gist, further comprising a signal combining unit for combining the interference signals and the delay interference signal in opposite phase (signal synthesizing section 214).

Features of the present invention, a radio receiver, the first and the radio transmitting apparatus for transmitting a desired signal of the radio receiving apparatus for, interfere with the interference signal to the desired signal to the different radio receiving apparatus for radio reception apparatus A wireless communication method applied to a wireless communication system for receiving the desired signal and the interference signal, wherein the wireless reception device transmits to the different wireless reception device. The second radio transmitting apparatus generates a delayed interference signal obtained by delaying an interference signal (step S302), and the second radio transmitting apparatus transmits delayed interference signal information, which is information related to the delayed interference signal, to the radio receiving apparatus. A step (S303) of notifying to the second radio transmission device, the interference signal, and the delayed interference signal generated in the generating step. Transmitting (step S304), the step of acquiring the delayed interference signal information notified from the second wireless transmission device (step S401), the desired signal, the interference signal, and the delay A step of receiving an interference signal by the wireless reception device (step S402), and a step of receiving the interference signal received in the reception step by the wireless reception device based on the delayed interference signal information acquired in the acquisition step; The present invention includes a step (Step S403) of matching the delayed interference signals on the time axis and synthesizing the interference signals and the delayed interference signals in opposite phases.

  According to the present invention, it is possible to provide a wireless communication system, a wireless transmission device, a wireless reception device, and a wireless communication method that can improve SIR even when the utilization efficiency of wireless communication resources is improved.

  Next, the first to fifth embodiments of the present invention will be described with reference to the drawings. In the description of the drawings in the following first to fifth embodiments, the same or similar parts are denoted by the same or similar reference numerals.

[First Embodiment]
In the first embodiment, (1) schematic configuration of radio communication system, (2) detailed configuration of radio communication system, (3) signal synthesis processing example, (4) operation of radio communication system, (5) action and effect Will be described.

(1) Schematic Configuration of Radio Communication System FIG. 1 is an overall schematic configuration diagram of a radio communication system 10A according to the first embodiment.

  As illustrated in FIG. 1, the radio communication system 10 </ b> A includes a radio base station 11, a radio base station 12, a radio terminal 21, and a radio terminal 22. Hereinafter, communication in the downlink direction (direction from the radio base station to the radio terminal) will be described.

  The radio base station 11 (first radio base station) forms a cell C1 (first communication area) which is a communication area capable of communicating with an arbitrary radio terminal. The wireless terminal 21 is located in the cell C <b> 1 and performs wireless communication with the wireless base station 11 using the communication channel assigned from the wireless base station 11. Many radio terminals other than the radio terminal 21 may be located in the cell C1.

  The radio base station 12 (second radio base station) forms a cell C2 (second communication area) which is a communication area capable of communicating with an arbitrary radio terminal. The radio terminal 22 is located in the cell C <b> 2 and performs radio communication with the radio base station 12 using the communication channel assigned by the radio base station 12. Many radio terminals other than the radio terminal 22 may be located in the cell C2.

  The radio base station 11 and the radio base station 12 are connected to a backbone network 100 configured as a wired network, for example. In addition, the cell C1 formed by the radio base station 11 and the cell C2 formed by the radio base station 12 are so-called adjacent cells that partially overlap each other. In the example of FIG. 1, the wireless terminal 21 and the wireless terminal 22 are located in an overlapping portion between the cell C1 and the cell C2.

  The communication channel assigned to the wireless terminal 21 by the wireless base station 11 and the communication channel assigned to the wireless terminal 22 by the wireless base station 12 are the same communication channel, that is, the same frequency f0 and the same time slot. Since the wireless terminal 21 and the wireless terminal 22 are located in the overlapping portion between the cell C1 and the cell C2, the influence of interference is large.

  Specifically, the signal S transmitted from the radio base station 11 to the radio terminal 21 is received not only by the radio terminal 21 but also by the radio terminal 22. The signal I transmitted from the wireless base station 12 to the wireless terminal 22 is received not only by the wireless terminal 22 but also by the wireless terminal 21.

  Hereinafter, the radio terminal 21 will be mainly described, and the signal S received by the radio terminal 21 from the radio base station 11 is appropriately referred to as a “desired signal”. Further, the signal I received by the wireless terminal 21 from the wireless base station 12 is appropriately referred to as an “interference signal”.

(2) Detailed Configuration of Radio Communication System Next, the detailed configuration of the radio communication system 10A will be described in the order of (2.1) configuration of radio base station and (2.2) configuration of radio terminal.

(2.1) Configuration of Radio Base Station FIG. 2A is a functional block diagram showing the configuration of the radio base station 11.

  As illustrated in FIG. 2A, the radio base station 11 includes a radio transmission unit 110 and a transmission signal generation unit 111. The transmission signal generation unit 111 generates a signal S for the wireless terminal 21. The wireless transmission unit 110 configures a first wireless transmission device that transmits the signal S generated by the transmission signal generation unit 111.

  The wireless transmission unit 110 includes a delay signal generation unit 112, a delay information holding unit 113, a delay information notification unit 114, a transmission unit 115, and an antenna 116.

  The delay signal generation unit 112 generates a delay signal Sdelay obtained by delaying the signal S according to the delay information Sinfo held by the delay information holding unit 113. The delayed signal generator 112 constitutes a delayed desired signal generator that generates a delayed desired signal (delayed signal Sdelay) obtained by delaying the desired signal (signal S).

  The delay information Sinfo includes a delay time τ1 (see FIG. 4A) of the delay signal Sdelay with respect to the signal S. The delay information Sinfo may include amplitude or phase information of the delay signal Sdelay in addition to the delay time τ1. The delay information holding unit 113 holds the delay information Sinfo in advance. In the first embodiment, the delay signal generation unit 112 applies the same delay information Sinfo to all wireless terminals located in the cell C1.

  The delay information notification unit 114 notifies the wireless terminal 21 of the delay information Sinfo held by the delay information holding unit 113. In the first embodiment, the delay information notification unit 114 constitutes a desired signal information notification unit that notifies delay desired signal information (delay information Sinfo).

  Specifically, the delay information notification unit 114 notifies the wireless terminal 21 of the delay information Sinfo via the transmission unit 115 at the time of negotiation executed when communication with the wireless terminal 21 is started. Alternatively, the delay information notification unit 114 notifies the wireless terminal 21 of the delay information Sinfo by periodically broadcasting (broadcasting) the delay information Sinfo into the cell C1 via the transmission unit 115.

  An antenna 116 is connected to the transmission unit 115. The transmission unit 115 transmits the signal S and the delayed signal Sdelay to the wireless terminal 21 using the communication channel (frequency f0) described above. Transmitter 115 constitutes a desired signal transmitter that transmits a desired signal (signal S) and a delayed desired signal (delayed signal Sdelay).

  When transmitting the delay information Sinfo by notification, the transmission unit 115 transmits the delay information Sinfo using a notification channel that is a communication channel different from the communication channel used for transmitting the signal S and the delay signal Sdelay, for example.

  Next, the configuration of the radio base station 12 will be described. FIG. 2B is a functional block diagram showing the configuration of the radio base station 12. Note that the radio base station 12 is configured in the same manner as the radio base station 11, and therefore, differences from the radio base station 11 will be mainly described.

  The radio base station 12 includes a radio transmission unit 120 and a transmission signal generation unit 121. The transmission signal generator 121 generates a signal I for the wireless terminal 22. The wireless transmission unit 120 configures a second wireless transmission device that transmits the signal I generated by the transmission signal generation unit 121.

  The wireless transmission unit 120 includes a delay signal generation unit 122, a delay information holding unit 123, a delay information notification unit 124, a transmission unit 125, and an antenna 126.

  The delay signal generation unit 122 generates a delay signal Idelay that is a signal obtained by delaying the signal I in accordance with the delay information Iinfo held by the delay information holding unit 123. The delay information Iinfo includes a delay time τ2 (see FIG. 4A) of the delay signal Idelay with respect to the signal I. The delay time τ2 is different in time length from the delay time τ1. Note that the delay information Iinfo may include information on the amplitude or phase of the delay signal Idelay in addition to the delay time τ2.

  The delay information holding unit 123 holds delay information Iinfo in advance. In the first embodiment, the delay signal generation unit 122 applies the same delay information Iinfo to all wireless terminals located in the cell C2.

  The delay information notification unit 124 notifies the wireless terminal 22 of the delay information Iinfo held by the delay information holding unit 123. Specifically, the delay information notification unit 124 notifies the wireless terminal 22 of the delay information Iinfo via the transmission unit 125 at the time of negotiation executed at the start of communication with the wireless terminal 22. Alternatively, the delay information notification unit 124 notifies the wireless terminal 22 of the delay information Iinfo by periodically broadcasting (broadcasting) the delay information Iinfo into the cell C2 via the transmission unit 125.

  An antenna 126 is connected to the transmission unit 125. The transmission unit 125 transmits the signal I and the delayed signal Idelay to the wireless terminal 22 using the communication channel (frequency f0) described above. In addition, when transmitting the delay information Iinfo by notification, the transmission unit 125 transmits the delay information Sinfo using a notification channel different from the communication channel used for transmitting the signal I and the delay signal Idelay, for example.

(2.2) Configuration of Radio Terminal FIG. 3A is a functional block diagram showing the configuration of the radio terminal 21.

  As illustrated in FIG. 3A, the radio terminal 21 includes a radio reception unit 210 that receives the signal S from the radio base station 11 and receives the signal I from the radio base station 12. The wireless reception unit 210 constitutes a wireless reception device that receives a desired signal (signal S) and an interference signal (signal I).

  The wireless reception unit 210 includes an antenna 211, a reception unit 212, a delay information acquisition unit 213, and a signal synthesis unit 214.

  The antenna 211 is connected to the receiving unit 212. The delay information acquisition unit 213 acquires the delay information Sinfo notified from the radio transmission unit 110 of the radio base station 11 via the reception unit 212. The delay information acquisition unit 213 constitutes an information acquisition unit that acquires delay desired signal information (delay information Sinfo).

  The receiving unit 212 constitutes a signal receiving unit that receives the signal S, the signal I, the delayed signal Sdelay, and the delayed signal Idelay. Based on the delay information Sinfo acquired by the delay information acquisition unit 213, the signal synthesis unit 214 matches the signal S and the delay signal Sdelay received by the reception unit 212 on the time axis, and the signal S and the delay signal Sdelay are the same. Synthesize with phase. Details of such synthesis processing will be described later.

  Next, the configuration of the wireless terminal 22 will be described. FIG. 3B is a functional block diagram showing the configuration of the wireless terminal 22. Since the wireless terminal 22 is configured in the same manner as the wireless terminal 21, differences from the wireless terminal 21 will be mainly described.

  As illustrated in FIG. 3B, the radio terminal 22 includes a radio reception unit 220 that receives the signal S from the radio base station 11 and receives the signal I from the radio base station 12.

  The wireless reception unit 220 includes an antenna 221, a reception unit 222, a delay information acquisition unit 223, and a signal synthesis unit 224.

  The antenna 221 is connected to the receiving unit 222. The delay information acquisition unit 223 acquires the delay information Iinfo notified from the radio transmission unit 120 of the radio base station 12 via the reception unit 222.

  The receiving unit 222 receives the signal S, the signal I, the delayed signal Sdelay, and the delayed signal Idelay. Based on the delay information Iinfo acquired by the delay information acquisition unit 223, the signal synthesis unit 224 matches the signal I and the delay signal Idelay received by the reception unit 222 on the time axis, and the signal I and the delay signal Idelay are the same. Synthesize with phase.

(3) Signal Synthesis Process Example Next, an example of the signal synthesis process executed by the signal synthesis unit 214 of the wireless terminal 21 will be described with reference to FIG.

  As shown in FIG. 4A, the wireless transmission unit 110 of the wireless base station 11 transmits a delay signal Sdelay obtained by delaying the signal S by a delay time τ1 in addition to the signal S. On the other hand, the radio transmission unit 120 of the radio base station 12 transmits a delay signal Idelay obtained by delaying the signal I by the delay time τ2 in addition to the signal I.

  Since each of the signal S, the delayed signal Sdelay, the signal I, and the delayed signal Idelay is transmitted through the same communication channel, the reception unit 212 of the wireless terminal 21 receives the signal S, the delay, as illustrated in FIG. A reception signal in which the signal Sdelay, the signal I, and the delay signal Idelay are mixed is output to the signal synthesis unit 214.

  The signal synthesis unit 214 specifies the delay time τ1 from the delay information Sinfo acquired by the delay information acquisition unit 213, and detects the signal S and the delay signal Sdelay according to the delay time τ1. Here, since the delay time τ1 and the delay time τ2 are set to different time lengths, the signal synthesis unit 214 can distinguish the signal S and the delay signal Sdelay from the signal I and the delay signal Idelay.

  Then, the signal synthesis unit 214 separates the signal S and the delayed signal Sdelay from the signal I and the delayed signal Idelay, and makes the signal S and the delayed signal Sdelay coincide on the time axis. At this time, since the delay time τ1 and the delay time τ2 are set to different time lengths, the signal I and the delay signal Idelay do not match.

  In the example of FIG. 4A, the delay time τ2 is longer than the delay time τ1. The delay time τ1 and the delay time τ2 are set to a relatively long time in consideration of the propagation delay difference and the phase rotation in the radio propagation path.

  In this way, the signal synthesizer 214 synthesizes the signal S and the delayed signal Sdelay with the same phase, so that the received power of the delayed signal Sdelay is added to the signal S as shown in FIG. On the other hand, the signal I and the delayed signal Idelay are inconsistent on the time axis, and when the signal S and the delayed signal Sdelay are synthesized in the same phase, the signal I and the delayed signal Idelay are not synthesized. That is, compared with the received power of the signal I and the delayed signal Idelay, the received power of the combined signal S is significantly increased, and the SIR is improved.

  Note that the same processing is executed in the signal synthesis unit 224 of the wireless terminal 22, but the signal synthesis unit 224 synthesizes the signal I and the delayed signal Idelay in the same phase.

(4) Operation of Radio Communication System Next, the operation of the radio communication system 10A will be described in the order of (4.1) operation of the radio base station and (4.2) operation of the radio terminal.

(4.1) Operation of Radio Base Station FIG. 5 is a flowchart showing an operation of the radio transmission unit 110 (first radio transmission device) of the radio base station 11 according to the first embodiment.

  In step S <b> 101, the transmission signal generation unit 111 generates a signal S for the wireless terminal 21.

  In step S102, the delay signal generation unit 112 generates a delay signal Sdelay obtained by delaying the signal S in accordance with the delay information Sinfo held by the delay information holding unit 113.

  In step S <b> 103, the delay information notification unit 114 notifies the wireless terminal 21 of the delay information Sinfo held by the delay information holding unit 113. Note that the process of step S103 may be executed before step S102 or before step S101.

  In step S104, the transmission unit 115 transmits the signal S generated by the transmission signal generation unit 111 and the delayed signal Sdelay generated by the delay signal generation unit 112 to the wireless terminal 21 using the communication channel (frequency f0). .

(4.2) Operation of Radio Terminal FIG. 6 is a flowchart showing an operation of the radio reception unit 210 (radio reception device) of the radio terminal 21 according to the first embodiment.

  In step S <b> 201, the delay information acquisition unit 213 acquires the delay information Sinfo notified from the radio base station 11 via the reception unit 212.

  In step S202, the reception unit 212 receives the signal S and the delayed signal Sdelay from the radio base station 11, and receives the signal I and the delayed signal Idelay from the radio base station 12.

  In step S203, the signal synthesis unit 214 matches the signal S and the delay signal Sdelay received by the reception unit 212 on the time axis based on the delay information Sinfo acquired by the delay information acquisition unit 213, as well as the signal S and the delay. The signal Sdelay is synthesized with the same phase.

(5) Operation and Effect As described above, according to the first embodiment, the radio terminal 21 performs in-phase synthesis of the signal S and the delay signal Sdelay based on the delay information Sinfo notified from the radio base station 11. Can improve the SIR. For this reason, the communication channel (frequency f0) of the same frequency can be allocated to the wireless terminal 21 between adjacent cells (cell C1 and cell C2), and the utilization efficiency of wireless communication resources, specifically, the frequency utilization efficiency can be improved. Can be improved.

  According to the first embodiment, the radio terminal 22 can improve the SIR by performing in-phase synthesis of the signal I and the delay signal Idelay based on the delay information Iinfo notified from the radio base station 12. Therefore, a communication channel (frequency f0) having the same frequency can be assigned to the radio terminal 22 between adjacent cells (cell C1 and cell C2), and frequency use efficiency can be improved.

[First Modification of First Embodiment]
In the first embodiment described above, the radio base station 11 notifies the radio terminal 21 of the delay information Sinfo including the delay time τ1 of the delay signal Sdelay based on the signal S. Further, the radio base station 12 notifies the radio terminal 22 of delay information Iinfo including the delay time τ2 of the delay signal Idelay with the signal I as a reference.

  In the first modification of the first embodiment, the radio base station 11 and the radio base station 12 notify the identification information for identifying the delay time τ1 and the delay time τ2 without directly reporting the delay time τ1 and the delay time τ2. To do. Then, the wireless terminal 21 obtains the delay time τ1 from the identification information notified from the wireless base station 11. The wireless terminal 22 obtains the delay time τ 2 from the identification information notified from the wireless base station 12.

  FIG. 7 is a block diagram illustrating configurations of the wireless terminal 21 and the wireless terminal 22 according to the first modification.

  As illustrated in FIG. 7A, the wireless reception unit 210 of the wireless terminal 21 includes a delay information holding unit 219 that holds a table in which the delay time τ1 is associated with identification information. When the reception unit 212 receives the delay information Sinfo including the identification information, the delay information acquisition unit 213 acquires the delay time τ1 corresponding to the identification information from the delay information holding unit 219.

  As illustrated in FIG. 7B, the wireless reception unit 220 of the wireless terminal 22 includes a delay information holding unit 229 that holds a table in which the delay time τ2 is associated with the identification information. When the reception unit 222 receives the delay information Iinfo including the identification information, the delay information acquisition unit 223 acquires the delay time τ2 corresponding to the identification information from the delay information holding unit 229.

[Second Modification of First Embodiment]
In the first embodiment described above, the radio base station 11 notifies the radio terminal 21 of the delay information Sinfo including the delay time τ1. Further, the radio base station 12 notifies the radio terminal 22 of delay information Iinfo including the delay time τ2.

  However, this delay time is not limited to being included in the delay information Sinfo and the delay information Iinfo, and information indicating the amplitude or phase of the delay signal Sdelay and the delay signal Idelay may be included in the delay information Sinfo and the delay information Iinfo.

  In the second modification of the first embodiment, when the delay time τ1 and the delay time τ2 are set to the same time length, and the amplitude or phase of the delay signal Sdelay and the delay signal Idelay are different, FIG. This will be described with reference to FIG. However, overlapping description of operations similar to those in the first embodiment is omitted.

  In the radio base station 11 shown in FIG. 2A, the delay information holding unit 113 preliminarily uses the amplitude ratio between the signal S and the delay signal Sdelay or the phase rotation amount of the delay signal Sdelay from the signal S as the delay information Sinfo. I remember it. The delay signal generation unit 112 adjusts the amplitude or phase of the delay signal Sdelay according to the amplitude ratio or phase rotation amount held by the delay information holding unit 113 when generating the delay signal Sdelay obtained by delaying the signal S by the delay time τ1. To do. For example, if the phase rotation amount in the delay information Sinfo is set to π / 2, the delay signal generation unit 112 rotates the phase of the delay signal Sdelay by π / 2.

  In the radio base station 12 shown in FIG. 2B, the delay information holding unit 123 sets the amplitude ratio between the signal I and the delay signal Idelay or the phase rotation amount of the delay signal Idelay from the signal I as the delay information Sinfo. As previously stored. The delay signal generator 122 adjusts the amplitude or phase of the delay signal Idelay according to the amplitude ratio or phase rotation amount held by the delay information holding unit 123 when generating the delayed signal Idelay obtained by delaying the signal I by the delay time τ2. To do. Here, the amplitude or phase adjustment amount in the delay signal Idelay is different from the amplitude or phase adjustment amount in the delay signal Sdelay.

  In the second modified example, since the delay time τ1 and the delay time τ2 are set to the same time length, the delay information notification unit 114 of the radio base station 11 does not notify the delay time τ1, and the delay signal Sdelay Only the amplitude or phase information is notified as delay information Sinfo. Also, the delay information notification unit 124 of the radio base station 12 notifies only the amplitude or phase information of the delay signal Idelay as the delay information Iinfo without notifying the delay time τ2.

  In the wireless terminal 21 shown in FIG. 7A, the delay information acquisition unit 213 acquires delay information Sinfo including information indicating the amplitude or phase of the delay signal Sdelay, and acquires the delay time τ1 from the delay information holding unit 219. . The signal synthesis unit 214 performs in-phase synthesis of the signal S and the delay signal Sdelay received by the reception unit 212 based on the information indicating the amplitude or phase of the delay signal Sdelay and the delay time τ1.

  In the wireless terminal 22 shown in FIG. 7B, the delay information acquisition unit 223 acquires delay information Iinfo including information indicating the amplitude or phase of the delay signal Idelay, and acquires the delay time τ2 from the delay information holding unit 229. . The signal synthesis unit 224 performs in-phase synthesis of the signal I and the delay signal Idelay received by the reception unit 222 based on the information indicating the amplitude or phase of the delay signal Idelay and the delay time τ2.

  As described above, according to the second modification, even when the delay time τ1 and the delay time τ2 have the same time length, the SIR can be improved in the radio terminal 21 and the radio terminal 22.

[Second Embodiment]
In the first embodiment described above, the SIR is improved by in-phase combining the signal S and the delayed signal Sdelay in the wireless terminal 21 and in-phase combining the signal I and the delayed signal Idelay in the wireless terminal 22.

  In the second embodiment, a configuration will be described in which SIR is improved by reverse-phase combining the signal I and the delayed signal Idelay in the wireless terminal 21 and reverse-phase combining the signal S and the delayed signal Sdelay in the wireless terminal 22.

  In the following second to fifth embodiments, differences from the first embodiment will be mainly described, and overlapping descriptions will be omitted.

  In the second embodiment, the delay information notification unit 114 of the radio base station 11 illustrated in FIG. 2A notifies the radio terminal 22 of the delay information Sinfo. For example, the delay information notification unit 114 can notify the wireless terminal 22 of the delay information Sinfo by the above-described notification (broadcast). Alternatively, the delay information notification unit 114 may notify the delay information Sinfo to the radio terminal 22 via the backbone network 100 and the radio base station 12.

  On the other hand, the delay information notification unit 124 of the radio base station 12 illustrated in FIG. 2B notifies the radio terminal 21 of the delay information Iinfo. For example, the delay information notification unit 124 can notify the wireless terminal 21 of the delay information Iinfo by the above-described notification (broadcast). Alternatively, the delay information notification unit 124 may notify the wireless terminal 21 of the delay information Iinfo via the backbone network 100 and the wireless base station 11.

  Furthermore, in the second embodiment, the delay information acquisition unit 213 of the wireless terminal 21 illustrated in FIG. 3A acquires the delay information Iinfo notified from the delay information notification unit 124 of the wireless base station 12. Based on the delay information Iinfo acquired by the delay information acquisition unit 213, the signal synthesis unit 214 of the wireless terminal 21 matches the signal I and the delay signal Idelay received by the reception unit 212 on the time axis, By combining the signal Idelay with an opposite phase, the received power of the signal I is reduced. At this time, if the received power (amplitude) of the signal I and the delayed signal Idelay are equal, the signal I (and the delayed signal Idelay) can be completely removed.

  On the other hand, the delay information acquisition unit 223 of the wireless terminal 22 illustrated in FIG. 3B acquires the delay information Sinfo notified from the delay information notification unit 114 of the wireless base station 11. Based on the delay information Sinfo acquired by the delay information acquisition unit 223, the signal synthesis unit 224 of the wireless terminal 22 matches the signal S and the delay signal Sdelay received by the reception unit 212 on the time axis, as well as the signal S and the delay. The received power of the signal S is reduced by synthesizing the signal Sdelay with an opposite phase. At this time, if the received power (amplitude) of the signal S and the delayed signal Sdelay is equal, the signal S (and the delayed signal Sdelay) can be completely removed.

  FIG. 8 is a flowchart showing the operation of the wireless transmission unit 120 (second wireless transmission device) of the wireless base station 12 according to the second embodiment.

  In step S <b> 301, the transmission signal generation unit 121 illustrated in FIG. 2B generates a signal I for the wireless terminal 22.

  In step S302, the delay signal generation unit 122 generates a delay signal Idelay obtained by delaying the signal I. That is, in the second embodiment, the delay signal generation unit 122 configures a delay interference signal generation unit that generates a delay interference signal (delay signal Idelay) obtained by delaying the interference signal (signal I).

  In step S303, the delay information notification unit 124 notifies the wireless terminal 21 of the delay information Iinfo. In the second embodiment, the delay information notification unit 124 notifies the interference signal information (delay information Iinfo) including the delay time τ2 of the delay interference signal (delay signal Idelay) with respect to the interference signal (signal I). Configure.

  In step S304, the transmission unit 125 transmits the signal I and the delayed signal Idelay. In the second embodiment, the transmission unit 125 configures an interference signal transmission unit that transmits an interference signal (signal I) and a delayed interference signal (delayed signal Idelay).

  FIG. 9 is a flowchart illustrating an operation of the wireless reception unit 210 (wireless reception device) of the wireless terminal 21 according to the second embodiment.

  In step S401, the delay information acquisition unit 213 illustrated in FIG. 3A acquires the delay information Iinfo notified from the delay information notification unit 124 of the radio base station 12 via the reception unit 212.

  In step S <b> 402, the reception unit 212 receives the signal S that is a desired signal and the delay signal Sdelay from the radio base station 11, and receives the signal I and the delay signal Idelay that are interference signals from the radio base station 12. To do.

  In step S403, the signal synthesis unit 214 matches the signal I and the delay signal Idelay received by the reception unit 212 on the time axis based on the delay information Iinfo acquired by the delay information acquisition unit 213, and the signal I and the delay. By combining the signal Idelay with an opposite phase, the received power of the signal I is reduced.

  As described above, according to the second embodiment, since the reception power of the signal I for the wireless terminal 22 can be reduced in the wireless terminal 21, the SIR of the wireless terminal 21 can be improved. Further, according to the second embodiment, since the reception power of the signal S for the wireless terminal 21 can be reduced at the wireless terminal 22, the SIR of the wireless terminal 22 can be improved.

  Also in the second embodiment, as described in the first modification of the first embodiment, the identification information for identifying the delay time τ1 and the delay time τ2 without directly reporting the delay time τ1 and the delay time τ2. It is good also as a structure which notifies. Further, as described in the second modification of the first embodiment, the delay time τ1 and the delay time τ2 are equal, and the delay signal Sdelay and the delay signal Idelay have different amplitudes or phases. It is not necessary to notify the delay time τ2.

[Third Embodiment]
In the third embodiment, a configuration in which the first embodiment and the second embodiment described above are used together will be described. Specifically, the radio terminal 21 performs in-phase synthesis of the signal S and the delayed signal Sdelay, and performs antiphase synthesis of the signal I and the delayed signal Idelay. The radio terminal 22 combines the signal I and the delayed signal Idelay in phase, and combines the signal S and the delayed signal Sdelay in reverse phase.

  FIG. 10 is a flowchart illustrating the operation of the wireless reception unit 210 (wireless reception device) of the wireless terminal 21 according to the third embodiment.

  In step S <b> 501, the delay information acquisition unit 213 illustrated in FIG. 3A acquires the delay information Sinfo and the delay information Iinfo via the reception unit 212.

  In step S <b> 502, the reception unit 212 receives the signal S that is a desired signal and the delayed signal Sdelay from the radio base station 11, and receives the signal I and the delayed signal Idelay that are interference signals from the radio base station 12.

  In step S503, the signal synthesis unit 214 matches the signal I and the delay signal Idelay received by the reception unit 212 on the time axis based on the delay information Iinfo acquired by the delay information acquisition unit 213, and the signal I and the delay. The signal Idelay is synthesized with the opposite phase.

  In step S504, the signal synthesis unit 214 matches the signal S and the delay signal Sdelay received by the reception unit 212 on the time axis based on the delay information Sinfo acquired by the delay information acquisition unit 213, as well as the signal S and the delay. The signal Sdelay is synthesized with the same phase. Note that the process of step S504 may be executed before step S503.

  As described above, according to the third embodiment, the wireless terminal 21 and the wireless terminal 22 can further improve the SIR as compared with each of the first embodiment and the second embodiment.

[Fourth Embodiment]
In the fourth embodiment, the radio terminal 21 selects one of the in-phase synthesis of the signal S and the delayed signal Sdelay, or the reverse phase synthesis of the signal I and the delayed signal Idelay, and executes the selected one. The radio terminal 22 selects either one of the in-phase synthesis of the signal I and the delayed signal Idelay or the reverse phase synthesis of the signal S and the delayed signal Sdelay, and executes the selected one.

  FIG. 11 is a functional block diagram showing the configuration of the wireless terminal 21A according to the fourth embodiment.

  As illustrated in FIG. 11, the wireless reception unit 210A of the wireless terminal 21A is different from the first to third embodiments described above in that it includes an SIR calculation unit 215 and an SIR comparison unit 216.

  The SIR calculation unit 215 calculates the SIR (desired signal to interference signal power ratio) from the received power of the signal S (desired signal) received by the receiving unit 212 and the received power of the signal I (interference signal) received by the receiving unit 212. Is calculated. The SIR comparison unit 216 compares the SIR calculated by the SIR calculation unit 215 with a predetermined threshold value.

  The signal synthesis unit 214 selects an appropriate synthesis process according to the comparison result in the SIR comparison unit 216. Specifically, the signal synthesis unit 214 synthesizes the signal S and the delayed signal Sdelay in the same phase when the SIR is larger than the predetermined threshold, and reverses the signal I and the delayed signal Idelay when the SIR is smaller than the predetermined threshold. Synthesize with phase.

  FIG. 12 is a flowchart showing the operation of the wireless reception unit 210A of the wireless terminal 21A according to the fourth embodiment.

  In step S <b> 601, the delay information acquisition unit 213 illustrated in FIG. 11 acquires the delay information Sinfo and the delay information Iinfo via the reception unit 212.

  In step S <b> 602, the reception unit 212 receives the signal S that is a desired signal and the delayed signal Sdelay from the radio base station 11, and receives the signal I and the delayed signal Idelay that are interference signals from the radio base station 12.

  In step S603, the SIR calculation unit 215 calculates SIR.

  In step S604, the SIR comparison unit 216 compares the SIR calculated by the SIR calculation unit 215 with a predetermined threshold value. If the calculated SIR is greater than the predetermined threshold, the process proceeds to step S605. On the other hand, when the calculated SIR is smaller than the predetermined threshold, the process proceeds to step S606.

  In step S605, the signal synthesis unit 214 synthesizes the signal S and the delayed signal Sdelay with the same phase. In step S606, the signal synthesis unit 214 synthesizes the signal I and the delayed signal Idelay with opposite phases.

  As described above, according to the fourth embodiment, the radio terminal 21 executes either one of the in-phase synthesis of the signal S and the delayed signal Sdelay or the anti-phase synthesis of the signal I and the delayed signal Idelay. Compared with the case where it does, the processing load and power consumption of the radio | wireless terminal 21 can be reduced. Further, since the radio terminal 21 selects an appropriate synthesis process for the calculated SIR, the effect of improving the SIR can be kept high even when only one of the in-phase synthesis and the reverse-phase synthesis is executed.

[Fifth Embodiment]
In the first to fourth embodiments described above, the configuration for reducing the influence of interference between adjacent cells has been described. In the fifth embodiment, a configuration for reducing the influence of interference in the same cell will be described.

  FIG. 13 is an overall schematic configuration diagram of a wireless communication system 10B according to the fifth embodiment.

  As illustrated in FIG. 13, the radio communication system 10 </ b> B includes a radio base station 11 </ b> A, a radio terminal 21, and a radio terminal 22. Each of the wireless terminal 21 and the wireless terminal 22 is configured in the same manner as in the first to fourth embodiments.

  The radio base station 11A is a radio base station that performs spatial multiplexing communication using adaptive array control. That is, the radio base station 11A directs the transmission directivity (directional beam) in the direction in which each of the radio terminal 21 and the radio terminal 22 is located, and simultaneously transmits radio signals using the same communication channel (frequency f0). 21 and the wireless terminal 22. In the example of FIG. 13, the spatial correlation between the wireless terminal 21 and the wireless terminal 22 is high, and the wireless terminal 21 and the wireless terminal 22 are affected by interference with each other.

  FIG. 14 is a functional block diagram showing the configuration of the radio base station 11A according to the fifth embodiment. As illustrated in FIG. 14, the radio base station 11 </ b> A is described in the radio transmission unit 110 (first radio transmission device) described in the first to fourth embodiments and in the first to fourth embodiments. And a wireless transmission unit 120 (second wireless transmission device). However, the antenna 116 and the antenna 126 may be a single antenna unit.

  According to the fifth embodiment, in the wireless communication system 10B using the spatial multiplexing technology, even when the distance between the wireless terminal 21 and the wireless terminal 22 to which the same communication channel is assigned in the same cell C1 is short, the wireless terminal 21 and The SIR can be improved in the wireless terminal 22.

[Other Embodiments]
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In each of the above-described embodiments, the same communication channel is assigned to the wireless terminal 21 and the wireless terminal 22, but the problem of interference may also occur in an adjacent channel (adjacent frequency). For this reason, the present invention is also effective when communication channels adjacent to each other are assigned to the wireless terminal 21 and the wireless terminal 22.

  In each of the above-described embodiments, transmission using a plurality of antennas is not described in the above examples. However, when transmission is performed using a plurality of antennas on the base station side, the same delay is applied to all antennas used for transmission. Apply information and send. When performing adaptive transmission or the like with a plurality of antennas, it is preferable to apply the method of the present invention at a later stage of adaptive transmission or the like.

  In addition, when receiving with a plurality of antennas on the terminal side, the same delay information is similarly used for all antennas used for reception. It is preferable to perform adaptive reception with a plurality of antennas and delay wave equalization processing in the propagation path in the subsequent stage of the method of the present invention.

  Further, in each of the above-described embodiments, the communication in the downlink direction has been mainly described. However, the present invention is not limited to the communication in the downlink direction, and the present invention is applied to the communication in the uplink direction (the direction from the wireless terminal to the wireless base station). Also good.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

1 is an overall schematic configuration diagram of a radio communication system according to a first embodiment. It is a functional block diagram which shows the structure of the wireless base station which concerns on 1st Embodiment. It is a functional block diagram which shows the structure of the radio | wireless terminal which concerns on 1st Embodiment. It is a conceptual diagram for demonstrating the signal synthesis process which concerns on 1st Embodiment. 5 is a flowchart showing an operation of the radio base station according to the first embodiment. 3 is a flowchart showing an operation of the wireless terminal according to the first embodiment. It is a functional block diagram which shows the structure of the radio | wireless terminal which concerns on the 1st modification of 1st Embodiment. It is a flowchart which shows operation | movement of the radio base station which concerns on 2nd Embodiment. It is a flowchart which shows operation | movement of the radio | wireless terminal which concerns on 2nd Embodiment. It is a flowchart which shows operation | movement of the radio | wireless terminal which concerns on 3rd Embodiment. It is a functional block diagram which shows the structure of the radio | wireless terminal which concerns on 4th Embodiment. It is a flowchart which shows operation | movement of the radio | wireless terminal which concerns on 4th Embodiment. It is a whole schematic block diagram of the radio | wireless communications system which concerns on 5th Embodiment. It is a functional block diagram which shows the structure of the wireless base station which concerns on 5th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10A, 10B ... Wireless communication system, 11, 11A, 12 ... Wireless base station, 21, 21A, 22 ... Wireless terminal, 100 ... Backbone network, 110 ... Wireless transmission part, 111 ... Transmission signal generation part, 112 ... Delay signal generation 113: Delay information holding unit, 114 ... Delay information notification unit, 115 ... Transmission unit, 116 ... Antenna, 120 ... Radio transmission unit, 121 ... Transmission signal generation unit, 122 ... Delay signal generation unit, 123 ... Delay information holding , 124 ... delay information notification unit, 125 ... transmission unit, 126 ... antenna, 210, 210A ... radio reception unit, 211 ... antenna, 212 ... reception unit, 213 ... delay information acquisition unit, 214 ... signal synthesis unit, 215 ... SIR calculation unit, 216 ... SIR comparison unit, 219 ... delay information holding unit, 220 ... wireless reception unit, 221 ... antenna, 222 ... reception unit, 223 The delay information acquisition unit, 224 ... signal combining unit, 229 ... delay information holding unit

Claims (9)

A wireless receiver, a first wireless transmitter that transmits a desired signal for the wireless receiver, and a second wireless transmitter that transmits an interference signal that interferes with the desired signal to a wireless receiver different from the wireless receiver The wireless reception device is a wireless communication system for receiving the desired signal and the interference signal,
The first wireless transmission device includes:
A delayed desired signal generator for generating a delayed desired signal obtained by delaying the desired signal to be transmitted to the wireless reception device;
A transmission side information holding unit that holds in advance information indicating a delay time of the delayed desired signal with respect to the desired signal ;
A desired signal information notification unit for notifying the wireless reception device of information indicating the amplitude or phase of the delayed desired signal as delayed desired signal information ;
A desired signal transmitter that transmits the desired signal and the delayed desired signal generated by the delayed desired signal generator;
With
The wireless receiver is
A receiving side information holding unit that holds in advance the same information as the information held by the transmitting side information holding unit;
An information acquisition unit for acquiring the delayed desired signal information notified from the first wireless transmission device;
A signal receiver for receiving the desired signal, the interference signal, and the delayed desired signal;
Based on the information held by the reception-side information holding unit and the delayed desired signal information acquired by the information acquiring unit, the desired signal and the delayed desired signal received by the signal receiving unit on the time axis A radio communication system comprising: a signal combining unit configured to match and combine the desired signal and the delayed desired signal in the same phase. A wireless receiver, a first wireless transmitter that transmits a desired signal for the wireless receiver, and a second wireless transmitter that transmits an interference signal that interferes with the desired signal to a wireless receiver different from the wireless receiver The wireless reception device is a wireless communication system for receiving the desired signal and the interference signal,
The second wireless transmission device is
A delayed interference signal generation unit that generates a delayed interference signal obtained by delaying the interference signal transmitted to the different wireless reception device;
An interference signal information notifying unit for notifying the radio reception device of delayed interference signal information which is information related to the delayed interference signal;
An interference signal transmitter that transmits the interference signal and the delayed interference signal generated by the delayed interference signal generator;
The wireless receiver is
An information acquisition unit for acquiring the delayed interference signal information notified from the second wireless transmission device;
A signal receiver for receiving the desired signal, the interference signal and the delayed interference signal;
Based on the delayed interference signal information acquired by the information acquisition unit, the interference signal and the delayed interference signal received by the signal receiving unit are matched on the time axis, and the interference signal and the delayed interference signal are reversed. A radio communication system comprising a signal synthesis unit for synthesis by phase. The wireless communication system according to claim 2 , wherein the interference signal information notification unit notifies the wireless reception device of information indicating a delay time of the delayed interference signal with respect to the interference signal as the delayed interference signal information. The second wireless transmission device further includes a transmission side information holding unit that holds in advance information indicating a delay time of the delayed interference signal with respect to the interference signal,
The wireless reception device further includes a reception side information holding unit that holds in advance the same information as the information held by the transmission side information holding unit,
The interference signal information notification unit notifies the radio reception device of information indicating the amplitude or phase of the delayed interference signal as the delayed interference signal information,
The signal combining unit is configured to receive the interference signal and the delayed interference received by the signal receiving unit based on the information held by the receiving side information holding unit and the delayed interference signal information acquired by the information acquiring unit. The radio communication system according to claim 2 , wherein the signals are matched on the time axis, and the interference signal and the delayed interference signal are combined in opposite phases. A wireless transmission device that transmits the interference signal to the wireless reception device that receives a desired signal for the wireless reception device and an interference signal that interferes with the desired signal,
A delayed interference signal generation unit that generates a delayed interference signal obtained by delaying the interference signal transmitted to a wireless reception device different from the wireless reception device;
An interference signal information notifying unit for notifying the radio reception device of delayed interference signal information which is information related to the delayed interference signal;
A radio transmission apparatus comprising: an interference signal transmission unit that transmits the interference signal and the delayed interference signal generated by the delayed interference signal generation unit. A wireless reception device that receives a desired signal from a first wireless transmission device and receives an interference signal that interferes with the desired signal from a second wireless transmission device,
A signal receiver that receives the desired signal, the interference signal, and a delayed interference signal obtained by delaying the interference signal in the second wireless transmission device;
An information acquisition unit that is notified from the second wireless transmission device and acquires delayed interference signal information that is information related to the delayed interference signal;
Based on the delayed interference signal information acquired by the information acquisition unit, the interference signal and the delayed interference signal received by the signal receiving unit are matched on the time axis, and the interference signal and the delayed interference signal are reversed. A radio receiving apparatus comprising: a signal combining unit configured to combine with a phase. A wireless receiver, a first wireless transmitter that transmits a desired signal for the wireless receiver, and a second wireless transmitter that transmits an interference signal that interferes with the desired signal to a wireless receiver different from the wireless receiver The wireless reception device is a wireless communication method applied to a wireless communication system that receives the desired signal and the interference signal,
The second wireless transmission device generating a delayed interference signal obtained by delaying the interference signal transmitted to the different wireless reception device;
The second wireless transmission device notifying the wireless reception device of delayed interference signal information that is information related to the delayed interference signal;
The second radio transmitting apparatus transmitting the interference signal and the delayed interference signal generated in the generating step;
The wireless reception device acquiring the delayed interference signal information notified from the second wireless transmission device;
Receiving the desired signal, the interference signal and the delayed interference signal by the wireless receiver;
Based on the delayed interference signal information acquired in the acquiring step, the wireless reception device matches the interference signal received in the receiving step and the delayed interference signal on a time axis, and the interference signal and A wireless communication method comprising: synthesizing the delayed interference signal with an opposite phase.   A wireless transmission device that transmits the desired signal to the wireless reception device that receives a desired signal for the wireless reception device and an interference signal that interferes with the desired signal,
  A delayed desired signal generation unit that generates a delayed desired signal obtained by delaying the desired signal to be transmitted to the wireless reception device;
  A transmission side information holding unit that holds in advance information indicating a delay time of the delayed desired signal with respect to the desired signal;
  A desired signal information notifying unit for notifying the wireless reception device of information indicating the amplitude or phase of the delayed desired signal as delayed desired signal information;
  A desired signal transmitter that transmits the desired signal and the delayed desired signal generated by the delayed desired signal generator;
A wireless transmission device comprising: A wireless reception device that receives a desired signal from a first wireless transmission device and receives an interference signal that interferes with the desired signal from a second wireless transmission device,
A signal receiver that receives the desired signal, the interference signal, and a delayed interference signal obtained by delaying the desired signal in the first wireless transmission device;
An information acquisition unit that is notified from the first wireless transmission device and acquires information indicating the amplitude or phase of the delayed desired signal as delayed desired signal information;
A receiving-side information holding unit that holds in advance information that is the same as the information held by the first wireless transmission device and that indicates the delay time of the delayed desired signal with respect to the desired signal;
Based on the information held by the reception-side information holding unit and the delayed desired signal information acquired by the information acquiring unit, the desired signal and the delayed desired signal received by the signal receiving unit on the time axis And a signal synthesis unit for synthesizing the desired signal and the delayed desired signal in the same phase.
A wireless receiver comprising:

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