Transmission method, transmission device, and communication system

Abstract

To provide an AP (Access Point) capable of transmitting via radio by using a frequency bandwidth of millimeter wave.SOLUTION: In an AP4420-1 which is a master AP in a plurality of APs, an instruction section 4402 of the AP4420-1 acquires communication quality with the AP as the partner of communication. When the acquired communication quality is lower than a threshold level, plural APs including the plural transmitters themselves are caused to perform cooperative operation to transmit data. When the acquired communication quality exceeds the threshold level, the plural APs including themselves are caused to stop cooperative operation.SELECTED DRAWING: Figure 45

Description

[Technical Field]

[0001] The present invention relates to a technology for wireless communication. [Background technology]

[0002] In wireless communication, various frequency bands are used. For example, IEEE802.11g standard for wireless LANs uses a frequency band of 2.4 to 2.5 GHz with a maximum transmission speed of 54 Mbps. For mobile phones, LTE standard uses a frequency band of 2 GHz with a maximum transmission speed of 112.5 Mbps. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-258736 [Patent Document 2] Special Publication No. 2010-535450 [Patent Document 3] Special Publication No. 2014-534678 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to achieve even larger capacity transmissions, there is a demand for the introduction of wireless communication using frequencies above 6 GHz, for example, the frequency band known as millimeter waves. In order to meet the above demands, an object of the present invention is to provide a transmission method, a transmission device, and a communication system that can be used in a plurality of transmission devices that transmit wirelessly using, for example, a millimeter wave frequency band. [Means for solving the problem]

[0005] In order to achieve the above object, one aspect of the present invention is a transmission method used in a plurality of transmitting devices that transmit wirelessly to a receiving device using, for example, a millimeter wave frequency band, characterized in that the method acquires communication quality with the receiving device, and when the acquired communication quality becomes below a threshold, causes the plurality of transmitting devices to cooperate and transmit data, and when the acquired communication quality becomes equal to or greater than the threshold, stops the cooperative operation. [Effects of the Invention]

[0006] According to this embodiment, a plurality of transmitting devices can perform wireless transmission using the millimeter wave frequency band. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a configuration of a wireless communication system 100 according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing the configuration of AP120. [Figure 3] FIG. 2 is a block diagram showing the configuration of a master station 110. [Figure 4] An example of data to be transmitted when all four APs 121, 122, 123, and 124 are set for multicast transmission is shown below. [Figure 5] The following shows an example of data transmitted when AP 121 and AP 122 are set for multicast and AP 123 and AP 124 are set for unicast. In this case, the same data is transmitted from AP 123 and AP 124. [Figure 6] The following shows an example of data transmitted when AP 121 and AP 122 are set for multicast and AP 123 and AP 124 are set for unicast. In this case, different data is transmitted from AP 123 and AP 124. [Figure 7]The following shows an example of data received when AP 121 and AP 122 are set for multicast and AP 123 and AP 124 are set for unicast. The same data is received by AP 123 and AP 124. [Figure 8] An example of data received when AP 121 and AP 122 are set for multicast and AP 123 and AP 124 are set for unicast is shown below. In this case, different data is received at AP 123 and AP 124. [Figure 9] (A) shows an example of a mapping method on the IQ plane of the in-phase component I and quadrature component Q that make up a signal in QPSK modulation. (B) shows an example of a mapping method after phase change. [Figure 10] 10 shows the phase change performed by the phase change unit 1002. [Figure 11] 12 is a sequence diagram (part 1) showing packet transmission operations in the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100. Continued in FIG. [Figure 12] 10 is a sequence diagram (part 2) showing packet transmission operations in the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100. FIG. [Figure 13] 10 is a sequence diagram showing packet reception operations in the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100. FIG. [Figure 14] FIG. 14 is a block diagram showing a configuration of a wireless communication system 1400 as a modified example (1). [Figure 15] FIG. 15 is a block diagram showing the configurations of a master station 1598, AP 1599-1, AP 1599-2, AP 1599-3, and AP 1599-4 in a wireless communication system 1500 as a modified example (2). [Figure 16] FIG. 16 is a block diagram showing the configurations of a master station 1698, AP 1699-1, AP 1699-2, AP 1699-3, and AP 1699-4 in a wireless communication system 1600 as a modified example (3). [Figure 17]10 is a flowchart showing the operation of the master station 110 in the wireless communication system 100 when the master station 110 newly controls an AP. [Figure 18] FIG. 18 is a block diagram showing a configuration of a wireless communication system 1800 according to a second embodiment. [Figure 19] FIG. 18 is a block diagram showing the configuration of AP1820-1, which is a master AP. [Figure 20] FIG. 2 is a block diagram showing the configuration of an AP 2000 that is not a master AP. [Figure 21] An example of data to be transmitted when all of AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4 are configured for multicast transmission is shown below. [Figure 22] The following shows an example of data transmitted when AP 1820-1 and AP 1820-2 are set for multicast and AP 1820-3 and AP 1820-4 are set for unicast. In this case, the same data is transmitted from AP 1820-3 and AP 1820-4. [Figure 23] The following shows an example of data transmitted when AP 1820-1 and AP 1820-2 are set for multicast and AP 1820-3 and AP 1820-4 are set for unicast. In this case, different data is transmitted from AP 1820-3 and AP 1820-4. [Figure 24] 18 is a flowchart showing the operation of the wireless communication system 1800 when the master AP AP 1820-1 newly controls an AP. [Figure 25] FIG. 25 is a block diagram showing a configuration of a wireless communication system 2500 according to a third embodiment. [Figure 26] A block diagram showing the configuration of AP2520. [Figure 27] FIG. 25 is a block diagram showing the configuration of a master station 2510. [Figure 28] An example of data to be transmitted when all of AP2520-1, AP2520-2, AP2520-3, and AP2520-4 are configured for multicast transmission is shown below. [Figure 29] Another example of data to be transmitted when all of the APs 2520-1, 2520-2, 2520-3, and 2520-4 are configured for multicast transmission is shown. [Figure 30] The following shows an example of data transmitted when AP 2520-1 and AP 2520-2 are configured for multicast and AP 2520-3 and AP 2520-4 are configured for unicast. In this case, the same data is transmitted from AP 2520-3 and AP 2520-4. [Figure 31] Another example of data transmitted when AP 2520-1 and AP 2520-2 are configured for multicast and AP 2520-3 and AP 2520-4 are configured for unicast is shown below. In this case, the same data is transmitted from AP 2520-3 and AP 2520-4. [Figure 32] The following shows an example of data transmitted when AP 2520-1 and AP 2520-2 are configured for multicast and AP 2520-3 and AP 2520-4 are configured for unicast. In this case, different data is transmitted from AP 2520-3 and AP 2520-4. [Figure 33] Another example of data transmitted when AP 2520-1 and AP 2520-2 are configured for multicast and AP 2520-3 and AP 2520-4 are configured for unicast is shown below. In this case, different data is transmitted from AP 2520-3 and AP 2520-4. [Figure 34] FIG. 11 is a block diagram showing a configuration of a wireless communication system 3400 according to a fourth embodiment. [Figure 35] FIG. 10 is a block diagram showing the configuration of AP3420-1, which is a master AP. [Figure 36] FIG. 10 is a block diagram showing the configuration of an AP 3600 that is not a master AP. [Figure 37] FIG. 34 is a block diagram showing the configuration of a master station 3410. [Figure 38]An example of data to be transmitted when all of AP3420-1, AP3420-2, AP3420-3, and AP3420-4 are configured for multicast transmission is shown below. [Figure 39] Another example of data to be transmitted when all of AP3420-1, AP3420-2, AP3420-3, and AP3420-4 are configured for multicast transmission is shown. [Figure 40] The following shows an example of data transmitted when AP 3420-1 and AP 3420-2 are configured for multicast and AP 3420-3 and AP 3420-4 are configured for unicast. In this case, the same data is transmitted from AP 3420-3 and AP 3420-4. [Figure 41] Another example of data transmitted when AP 3420-1 and AP 3420-2 are configured for multicast and AP 3420-3 and AP 3420-4 are configured for unicast is shown below. In this case, the same data is transmitted from AP 3420-3 and AP 3420-4. [Figure 42] The following shows an example of data transmitted when AP 3420-1 and AP 3420-2 are configured for multicast and AP 3420-3 and AP 3420-4 are configured for unicast. In this case, different data is transmitted from AP 3420-3 and AP 3420-4. [Figure 43] Another example of data transmitted when AP 3420-1 and AP 3420-2 are configured for multicast and AP 3420-3 and AP 3420-4 are configured for unicast is shown below. In this case, different data is transmitted from AP 3420-3 and AP 3420-4. [Figure 44] FIG. 11 is a block diagram showing a configuration of a wireless communication system 4400 according to a fifth embodiment. [Figure 45] FIG. 10 is a block diagram showing the configuration of AP4420-1, which is a master AP. [Figure 46] FIG. 10 is a block diagram showing the configuration of a non-master AP4600. [Figure 47] An example of data transmitted when all of AP4420-1, AP4420-2, AP4420-3, and AP4420-4 are set for unicast transmission on a fine day is shown below. [Figure 48] An example of data transmitted when all APs 4420-1, 4420-2, 4420-3, and 4420-4 are configured for unicast transmission during rainfall is shown below. [Figure 49] 10 is a flowchart showing the operation of AP 4420-1, which is the master AP. DETAILED DESCRIPTION OF THE INVENTION

[0008] 1. Findings that form the basis of the present invention For example, one way to achieve large-capacity transmission in Gbps units is to introduce a wireless communication method using frequency bands such as millimeter waves. Radio waves in the millimeter wave frequency band have the characteristics of being highly directional and attenuating quickly. This makes it difficult to expand the cell range that the radio waves can reach.

[0009] The inventors of the present invention believe that it is difficult to realize a wireless communication system with a wide cell range using radio waves in the millimeter wave frequency band. Therefore, the inventors of the present invention propose a new transmission method that solves the above problem and enables wireless communication using radio waves in the millimeter wave frequency band. The inventors of the present invention also believe that there is a demand for multicast or unicast communication using radio waves in the millimeter wave frequency band. In particular, it is necessary to consider a method for accommodating a large number of terminals in multicast. Furthermore, there is a demand for simultaneous implementation of unicast while implementing multicast.

[0010] In a network, sending data to a specific destination by specifying a single address is called unicast, while sending data to multiple destinations by specifying a single address is called multicast. 2. First Embodiment A wireless communication system 100 as one embodiment of the present invention will be described.

[0011] 2.1 Wireless Communication System 100 As shown in FIG. 1, the wireless communication system 100 includes a master station 110, APs (Access Points) 121, 122, 123, and 124, and terminals 131, 132, . . . , and 138. The master station 110 is connected to a communication device (not shown) directly or indirectly via a communication line. Here, the communication device may be, for example, a broadcasting device that broadcasts data, or a distribution system or server that transmits data. The communication device transmits a control signal and data. The control signal includes a setting for a unicast transmission method or a setting for a multicast transmission method, and a setting for a phase change method (this will be explained later). Furthermore, the communication device may be composed of multiple communication devices. In this case, a first communication device may transmit a control signal, and a second communication device may transmit data. The master station 110 is connected to AP 121, AP 122, AP 123, and AP 124, for example, by wire (or may be connected wirelessly). The master station 110 receives control signals and data from the communication devices. The master station 110 transmits control signals and data to the APs 121, 122, 123, and 124. The APs 121, 122, 123, and 124 transmit the data received from the master station 110 wirelessly.

[0012] Terminal 131, terminal 132, ..., terminal 138 are each a mobile phone, smartphone, tablet, or personal computer (PC) equipped with wireless communication functionality using a frequency band of 6 GHz or higher, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band. For example, when terminal 131 is located close to AP 121, terminal 131 receives data wirelessly from AP 121. Similarly to terminal 131, terminals 132, 133, ..., and 138 each receive data wirelessly from nearby APs.

[0013] Furthermore, the terminal 131 transmits data wirelessly. When the terminal 131 is located close to the AP 121, the AP 121 receives data wirelessly from the terminal 131. The AP 121 transmits the received data to the master station 110. Similar to terminal 131, terminals 132, 133, ..., 138 also transmit data wirelessly. APs located close to each terminal receive data wirelessly from the terminal. The APs transmit the data received from the terminals to master station 110.

[0014] The master station 110 receives data from each terminal via each AP, and outputs the received data to the communication device. 2.2 AP120 The APs 121, 122, 123, and 124 have, for example, the same configuration (the same function). Here, the APs 121, 122, 123, and 124 will be described as being represented by the AP 120.

[0015] As shown in FIG. 2, the AP 120 is made up of an encoder 202, an interleaver 204, a mapping unit 206, a phase change unit 208, a radio unit 210, an antenna 212, an antenna 215, and a receiving device 217. The AP 120 receives a control signal 214 from the master station 110. The control signal 214 includes settings for the unicast transmission method or the multicast transmission method, and settings for the phase change method.

[0016] The AP 120 performs settings related to the unicast transmission method based on the control signal 214 received from the master station 110. The AP 120 also performs settings related to the phase change method based on the control signal 214. When multicast transmission is set, the AP 120 is set to use the same frequency (frequency band) as other APs. When the AP 120 sets unicast transmission, it operates the receiving device 217. When the AP 120 sets multicast transmission, it may stop the operation of the receiving device 217.

[0017] AP120 transmits and receives wirelessly using the same channel (or the same frequency (frequency band)) for unicast transmission and multicast transmission. Here, AP120 may divide one wireless carrier into several time slots and use each time slot as a communication channel. AP120 may also use several different frequencies in the 60 GHz frequency band and use each frequency as a communication channel.

[0018] (1) Encoder 202 The encoder 202 receives data 201 from the master station 110. The encoder 202 also receives a control signal 213 from a controller included in the AP 120. The control signal 213 includes information such as a coding scheme designation, an error correction scheme designation, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 201 using the scheme designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0019] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 120. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0020] (3) Mapping unit 206 The mapping unit 206 receives interleaved data 205 from the interleaver 204. The mapping unit 206 also receives a control signal 213 from a controller included in the AP 120. The control signal 213 includes a modulation scheme designation. In accordance with the modulation scheme designation included in the control signal 213, the mapping unit 206 performs modulation such as QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), or 64QAM (64 Quadrature Amplitude Modulation) on the interleaved data 205, and generates a modulated signal 207 (the modulation scheme is not limited to these). The mapping unit 206 outputs the modulated signal 207.

[0021] The mapping unit 206 may perform mapping that includes a phase change process. (4) Phase change unit 208 Phase changer 208 receives modulated signal 207 from mapping unit 206. Phase changer 208 also receives control signal 214. Control signal 214 includes a setting for the phase change method. Phase changer 208 performs a phase change on modulated signal 207 in accordance with the setting for the phase change method included in control signal 214, and generates phase-changed signal 209. Phase changer 208 outputs phase-changed signal 209.

[0022] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives phase-shifted signal 209 from phase shifter 208. Radio unit 210 also receives control signal 213 from a controller included in AP 120. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on phase-shifted signal 209 to generate transmission signal 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0023] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. The receiving device 217 receives a signal 216 from the antenna 215 using a frequency band above 6 GHz, such as a frequency band called a millimeter wave, for example, a frequency band of 60 GHz, and performs processing such as amplification and frequency conversion on the signal to generate data 218. The receiving device 217 outputs the data 218 to the master station 110.

[0024] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. 2.3 Master station 110 As shown in FIG. 3, the master station 110 is made up of a transmission data distribution unit 302, a reception data distribution unit 305, and an instruction unit 308.

[0025] (1) Instruction section 308 The instruction unit 308 is connected to the communication device and the AP 121, the AP 122, the AP 123, and the AP . The instruction unit 308 receives, for example, a control signal from a communication device. The control signal includes settings related to unicast transmission or multicast transmission, and settings for a phase change method. The communication device includes, for example, a PC (Personal Computer) (or computer, etc.), and a user of the PC inputs the control signal via the PC.

[0026] Furthermore, the control signal may be set individually for each AP, or the same control signal may be set for all APs. All APs may be set to multicast transmission, or all APs may be set to unicast transmission. Some APs may be set to multicast transmission, and other APs may be set to unicast transmission. In this way, APs may have a mixture of multicast transmission settings and unicast settings.

[0027] For multiple APs configured for multicast, the modulated signal before phase change is the same signal, in other words, the same data is transmitted. Then, the method of phase change is instructed to each AP. For multiple APs configured for unicast, the modulated signals before the phase change may be the same or different signals, i.e., the same data may be transmitted or different data may be transmitted.

[0028] The instruction unit 308 outputs the received control signal to the transmission data distribution unit 302, the reception data distribution unit 305, and the APs 121, 122, 123, and 124. (2) Transmission data distribution unit 302 The transmission data distribution unit 302 is connected to the communication device, the instruction unit 308, and the AP 121, AP 122, AP 123, and AP .

[0029] The transmission data distribution unit 302 receives a control signal from the instruction unit 308. The transmission data distribution unit 302 outputs the received control signal to the AP 121, the AP 122, the AP 123, and the AP . Furthermore, the transmission data distribution unit 302 receives data from the communication device. The transmission data distribution unit 302 distributes the received data to AP 121, AP 122, AP 123, and AP 124. The transmission data distribution unit 302 outputs the distributed data to AP 121, AP 122, AP 123, and AP 124, respectively.

[0030] (3) Received data distribution unit 305 The received data distribution unit 305 is connected to the communication device, the instruction unit 308, and the AP 121, AP 122, AP 123, and AP . Furthermore, the received data distribution unit 305 receives data from each of the APs 121, 122, 123, and 124. The received data distribution unit 305 outputs the received data to the communication device.

[0031] 2.4 Examples of data sent and received An example of data transmitted and received by the master station 110, AP 121, AP 122, AP 123, and AP 124 will be described below. (1) When all APs are set to multicast transmission and data is transmitted An example of data to be transmitted when all of the APs 121, 122, 123, and 124 are set for multicast transmission and data is transmitted will be described with reference to FIG.

[0032] 4, the transmission data distribution unit 302 receives packets 401, 402, 403, 404, etc. in this order. Here, the packets 401, 402, 403, 404, etc. are all packets for multicast. The packets 401, 402, 403, 404, etc. are generated from one piece of multicast data. If all APs are set for multicast, when transmission data distribution unit 302 receives packet 401, it outputs the same packet 401 to APs 121, 122, 123, and 124. APs 121, 122, 123, and 124 wirelessly output packets 406, 411, 416, and 421, respectively. Here, packets 406, 411, 416, and 421 are generated based on the same packet 401 and correspond to each other.

[0033] Next, upon receiving packet 402, transmission data distribution unit 302 outputs the same packet 402 to AP 121, AP 122, AP 123, and AP 124. AP 121, AP 122, AP 123, and AP 124 wirelessly output packets 407, 412, 417, and 422, respectively, by multicast. Here, packets 407, 412, 417, and 422 are generated based on the same packet 402 and correspond to each other.

[0034] Next, upon receiving packet 403, transmission data distribution unit 302 outputs the same packet 403 to AP 121, AP 122, AP 123, and AP 124. AP 121, AP 122, AP 123, and AP 124 wirelessly output packets 408, 413, 418, and 423 by multicast, respectively. Here, packets 408, 413, 418, and 423 are generated based on the same packet 403 and correspond to each other.

[0035] Next, upon receiving packet 404, transmission data distribution unit 302 outputs the same packet 404 to AP 121, AP 122, AP 123, and AP 124. AP 121, AP 122, AP 123, and AP 124 wirelessly output packets 409, 414, 419, and 424, respectively, by multicast. Here, packets 409, 414, 419, and 424 are generated based on the same packet 404 and correspond to each other.

[0036] At this time, it is characteristic that AP121, AP122, AP123, and AP124 each perform a phase change on the modulated signal (however, any of AP121, AP122, AP123, and AP124 may not perform a phase change). (The method for changing the phase will be explained in detail later.) By doing this, it is possible to widen the cell range within which the multicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals.

[0037] (2) When two APs are configured for multicast transmission and data is sent An example of data to be transmitted when two APs, AP 121 and AP 122, are set as APs for multicast data transmission, and the other two, AP 123 and AP 124, are set as APs for unicast data transmission, will be described with reference to Fig. 5. In this case, it is assumed that AP 121 and AP 122 transmit the same data (the modulated signals after mapping before phase change are the same). It is also assumed that AP 123 and AP 124 transmit the same data (the modulated signals after mapping before phase change are the same).

[0038] 5, the transmission data distribution unit 302 receives packets 501, 502, 503, 504, 505, 506, etc. in this order. Here, packets 501, 503, 504, and 506, etc. are multicast packets. Packets 502 and 505 are unicast packets. Here, packets 501, 503, 504 and 506 are generated from one piece of data for multicast, and packets 502 and 505 are generated from one piece of data for unicast.

[0039] When the transmission data distribution unit 302 receives the packet 501, it outputs the same packet 501 to the APs 121 and 122. The APs 121 and 122 wirelessly output packets 511 and 521 as multicast transmission, respectively. Here, the packets 511 and 521 are generated based on the same packet 501 and correspond to each other.

[0040] Next, upon receiving packet 502, transmission data distribution unit 302 outputs the same packet 502 to AP 123 and AP 124. AP 123 and AP 124 wirelessly output packets 531 and 541, respectively, as unicast transmission. Here, packets 531 and 541 are generated based on the same packet 502 and correspond to each other.

[0041] Next, upon receiving packet 503, transmission data distribution unit 302 outputs the same packet 503 to AP 121 and AP 122. AP 121 and AP 122 wirelessly output packets 512 and 522, respectively, as multicast transmission. Here, packets 512 and 513 are generated based on the same packet 503 and correspond to each other.

[0042] Next, upon receiving packet 504, transmission data distribution unit 302 outputs the same packet 504 to AP 121 and AP 122. AP 121 and AP 122 wirelessly output packets 513 and 523, respectively, as multicast transmission. Here, packets 513 and 523 are generated based on the same packet 504 and correspond to each other.

[0043] Next, upon receiving packet 505, transmission data distribution unit 302 outputs the same packet 505 to AP 123 and AP 124. AP 123 and AP 124 wirelessly output packets 532 and 542, respectively, as unicast transmission. Here, packets 532 and 542 are generated based on the same packet 505 and correspond to each other.

[0044] Next, upon receiving packet 506, transmission data distribution unit 302 outputs the same packet 506 to AP 121 and AP 122. AP 121 and AP 122 wirelessly output packets 514 and 524 as multicast transmission, respectively. Here, packets 514 and 524 are generated based on the same packet 506 and correspond to each other.

[0045] In the above, when modulated signals are transmitted by unicast transmission, packets transmitted by AP 123 and AP 124 are based on the same data. In this case, the transmission parameters are the same in AP 123 and AP 124. AP 123 and AP 124 may perform different phase changes. (However, either AP 123 or AP 124 may not perform a phase change.) By doing this, it is possible to widen the cell range within which the unicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals. A characteristic feature of the present invention is that AP 121 and AP 122 each perform a phase change on the modulated signal (however, either AP 121 or AP 122 may not perform a phase change). (The method for changing the phase will be explained in detail later.) By doing this, it is possible to widen the cell range within which the multicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals.

[0046] (3) When two APs are configured for multicast transmission and data is transmitted An example of data to be transmitted when two APs, AP 121 and AP 122, are set for multicast transmission and transmit data, and the other two APs, AP 123 and AP 124, are set for unicast transmission and transmit data, will be described with reference to Fig. 6. In the case of Fig. 6, unlike Fig. 5, different data is transmitted in AP 123 and AP 124.

[0047] 6, the transmission data distribution unit 302 receives packets 601, 602, 603, 604, 605, 606, 607, 608, 609, 610, ... in this order. Here, packets 601, 603, 604, and 606 are multicast packets. Packets 602, 607, and 609 are unicast packets transmitted by AP 123. Packets 605, 608, and 610 are unicast packets transmitted by AP 124.

[0048] Here, packets 601, 603, 604, and 606 are generated from one piece of data for multicasting, packets 602, 607, and 609 are generated from one piece of data for unicasting, and packets 605, 608, and 610 are generated from another piece of data for unicasting. When the transmission data distribution unit 302 receives the packet 601, it outputs the same packet 601 to the APs 121 and 122. The APs 121 and 122 wirelessly output packets 621 and 625 as multicast transmission, respectively. Here, the packets 621 and 625 are generated based on the same packet 601 and correspond to each other.

[0049] Next, upon receiving the packet 602, the transmission data distribution unit 302 outputs the packet 602 to the AP 123. The AP 123 outputs the packet 631 by wireless as a unicast transmission. Next, upon receiving packet 603, transmission data distribution unit 302 outputs the same packet 603 to AP 121 and AP 122. AP 121 and AP 122 wirelessly output packets 622 and 626 as multicast transmission, respectively. Here, packets 622 and 626 are generated based on the same packet 603 and correspond to each other.

[0050] Next, upon receiving packet 604, transmission data distribution unit 302 outputs the same packet 604 to AP 121 and AP 122. AP 121 and AP 122 output packets 623 and 627, respectively, via wireless multicast transmission. Here, packets 623 and 627 are generated based on the same packet 604 and correspond to each other. are identical.

[0051] Next, upon receiving packet 605, transmission data distribution unit 302 outputs packet 605 to AP 124. AP 124 outputs packet 641 by wireless as a unicast transmission. Next, upon receiving packet 606, transmission data distribution unit 302 outputs the same packet 606 to AP 121 and AP 122. AP 121 and AP 122 wirelessly output packets 624 and 628 by multicast, respectively. Here, packets 624 and 628 are generated based on the same packet 606 and correspond to each other.

[0052] Next, upon receiving packet 607, transmission data distribution unit 302 outputs packet 607 to AP 123. AP 123 outputs packet 632 by wireless as a unicast transmission. Next, upon receiving the packet 608, the transmission data distribution unit 302 outputs the packet 608 to the AP 124. The AP 124 outputs the packet 642 by wireless as a unicast transmission.

[0053] Next, upon receiving packet 609, transmission data distribution unit 302 outputs packet 609 to AP 123. AP 123 outputs packet 633 by wireless as a unicast transmission. Next, upon receiving the packet 610, the transmission data distribution unit 302 outputs the packet 610 to the AP 124. The AP 124 outputs the packet 643 by wireless unicast transmission.

[0054] A characteristic feature of the present invention is that AP 121 and AP 122 each perform a phase change on the modulated signal (however, either AP 121 or AP 122 may not perform a phase change). (The method for changing the phase will be explained in detail later.) By doing this, it is possible to widen the cell range within which the multicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals.

[0055] In addition, AP123 and AP124 are flexible systems that can perform unicast communication. For example, by switching between the transmission state of Figure 4, the transmission state of Figure 5, and the transmission state of Figure 6 depending on time (for example, switching depending on the presence status of the terminal), there is an advantage that a flexible system can be realized.

[0056] (4) When two APs are configured for multicast transmission and data is received An example of data received when two APs, AP 121 and AP 122, are set for multicast transmission and the other two, AP 123 and AP 124, are set for unicast transmission will be described with reference to Fig. 7. In this case, data is not received at AP 121 and AP 122 (because they are APs for multicast transmission). Also, suppose that signals containing the same data are received at AP 123 and AP 124.

[0057] It is assumed that the receiving device 217 of AP 123 receives and obtains packets 711, 712, 713, etc. in this order. It is also assumed that the receiving device 217 of AP 124 receives and obtains packets 721, 722, 723, etc. in this order. It is also assumed that one packet is not received between packets 712 and 713 received by the receiving device 217 of AP 123. It is also assumed that one packet is not received between packets 721 and 722 received by the receiving device 217 of AP 124.

[0058] When the receiving device 217 of the AP 123 receives the packet 711, the received data sorting unit 305 receives the packet 701. The packet 711 and the packet 702 correspond to each other. Next, when the receiving device 217 of the AP 124 receives the packet 721, the received data sorting unit 305 receives the packet 702. The packets 721 and 702 correspond to each other.

[0059] Next, when the receiving device 217 of the AP 123 receives the packet 712, the received data sorting unit 305 receives the packet 703. The packet 712 and the packet 703 correspond to each other. Next, when the receiving device 217 of the AP 124 receives the packet 722, the received data sorting unit 305 receives the packet 704. The packet 722 and the packet 704 correspond to each other.

[0060] Next, when the receiving device 217 of the AP 123 receives the packet 713, the received data sorting unit 305 receives the packet 705. The packet 713 and the packet 705 correspond to each other. Next, when the receiving device 217 of the AP 124 receives the packet 723, the received data sorting unit 305 receives the packet 706. The packet 723 and the packet 706 correspond to each other.

[0061] The AP 123 and the AP 124 may perform, for example, maximum ratio combining, and then perform demodulation and decoding to obtain packets. (5) When two APs are configured for multicast transmission and data is received An example of data received when two APs, AP 121 and AP 122, are set for multicast transmission and the other two, AP 123 and AP 124, are set for unicast transmission will be described with reference to Fig. 8. In this case, no data is received at AP 121 and AP 122. Also, different data is received at AP 123 and AP 124.

[0062] The receiver 217 of the AP 123 receives packets 811, 812, 813, 814, etc. in this order by unicast. The receiver 217 of the AP 124 receives packets 816, 817, 818, 819, etc. in this order by unicast. Here, packets 811, 812, 813, 814, etc. are generated from data for one unicast, and packets 816, 817, 818, 819, etc. are generated from data for another unicast.

[0063] When the receiving device 217 of the AP 123 receives the packet 811, the received data sorting unit 305 receives the packet 801. The packet 811 and the packet 801 correspond to each other. When the receiving device 217 of the AP 124 receives the packet 816, the received data sorting unit 305 receives the packet 802. The packet 816 and the packet 802 correspond to each other.

[0064] When the receiving device 217 of the AP 123 receives the packet 812, the received data sorting unit 305 receives the packet 803. The packet 812 and the packet 803 correspond to each other. When the receiving device 217 of the AP 123 receives the packet 813, the received data sorting unit 305 receives the packet 804. The packet 813 and the packet 804 correspond to each other.

[0065] When the receiving device 217 of the AP 124 receives the packet 817, the received data sorting unit 305 receives the packet 805. The packet 817 and the packet 805 correspond to each other. 2.5 Mapping methods and phase changes FIG. 9A shows an example of a mapping method on the IQ plane of an in-phase component I and a quadrature component Q that constitute a signal in QPSK modulation.

[0066] For example, as shown in FIG. 9(A), when the input data is "00", mapping unit 206 outputs an in-phase component I=r of the baseband signal and a quadrature component Q=r of the baseband signal. Similarly, when the input data is "01", mapping unit 206 outputs an in-phase component I=-r of the baseband signal and a quadrature component Q=r of the baseband signal. When the input data is "10", mapping unit 206 outputs an in-phase component I=r of the baseband signal and a quadrature component Q=-r of the baseband signal. Similarly, when the input data is "11", mapping unit 206 outputs an in-phase component I=-r of the baseband signal and a quadrature component Q=-r of the baseband signal. In this way, signal points 901, 902, 903, and 904 shown in FIG. 9(A) are obtained.

[0067] An example of a mapping method after phase change is shown in FIG. 9(B). By rotating signal points 901, 902, 903, and 904 in Figure 9(A) by θ(u) around the origin (u is the symbol number), signal points 911, 912, 913, and 914 in Figure 9(B) can be obtained. Note that the phase change value is expressed as θ(u) because it is a function of the symbol number u.

[0068] 2.6 Phase change section The AP 120 of the wireless communication system 100 may include a phase changer 1002 shown in FIG. 10 instead of the phase changer 208 shown in FIG. The phase changer 1002 receives the modulated baseband signal s(t) (1001). The phase change unit 1002 z(t)=y(t)×s(t) (t is time) Calculate.

[0069] The phase changer 1002 outputs the phase-changed signal z(t) (1005). Here, y(t) may be expressed as follows:

[0070]

number

[0071] In this case, the phase changer 1002 outputs the phase-changed signal z(f). Furthermore, the wireless communication system 100 may store a plurality of phase change patterns, with one phase change pattern being assigned to each AP. For example, the wireless communication system 100 holds four phase change patterns for periods N1, N2, N3, and N4. The phase change pattern for period N1 (where the phase change value is represented as y1(i), where y1(i) is a function of symbol number i) is assigned to AP 121. The phase change pattern for period N2 (where the phase change value is represented as y2(i), where y2(i) is a function of symbol number i) is assigned to AP 122. The phase change pattern for period N3 (where the phase change value is represented as y3(i), where y3(i) is a function of symbol number i) is assigned to AP 123. The phase change pattern for period N4 (where the phase change value is represented as y4(i), where y4(i) is a function of symbol number i) is assigned to AP 124.

[0072] The phase changer 1002 of the AP 121 calculates the phase-changed signal z(i) as follows. z(i)=y1(k) × s(i) Here, k=i mod N1, where N1 is an integer equal to or greater than 2. Also, i is, for example, an integer equal to or greater than 0. i mod N1 represents the remainder when i is divided by N1. (mod:modulo) The phase changer 1002 of the AP 122 calculates the phase-changed signal z(i) as follows.

[0073] z(i)=y2(k) × s(i) Here, k=i mod N2, where N2 is an integer equal to or greater than 2. Also, i is, for example, an integer equal to or greater than 0. i mod N2 represents the remainder when i is divided by N2. (mod:modulo) The phase changer 1002 of the AP 123 calculates the phase-changed signal z(i) as follows.

[0074] z(i)=y3(k) × s(i) Here, k=i mod N3, where N3 is an integer equal to or greater than 2. Also, i is, for example, an integer equal to or greater than 0. i mod N3 represents the remainder when i is divided by N3. (mod:modulo) The phase change unit 1002 of the AP 124 calculates the phase-changed signal z(i) as follows.

[0075] z(i)=y4(k) × s(i) Here, k=i mod N4, where N4 is an integer equal to or greater than 2. Also, i is, for example, an integer equal to or greater than 0. i mod N4 represents the remainder when i is divided by N4. (mod:modulo) It is preferable that the phase change patterns are as different as possible. When a first AP and a second AP are close to each other, it may be preferable that the phase change pattern assigned to the first AP and the phase change pattern assigned to the second AP be different.

[0076] The pattern of phase changes assigned to the first AP and the pattern of phase changes assigned to the second AP may be the same. Also, any one of AP 121, AP 122, AP 123, and AP 124 may not perform a phase change. 2.7 Operation in Wireless Communication System 100 Here, the operation of the wireless communication system 100 will be described.

[0077] (1) Packet transmission behavior The packet transmission operations in the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100 will be described with reference to the sequence diagrams shown in FIGS. The communication device generates a packet (step S1101) and transmits the generated packet to the master station 110 (step S1102). The communication device returns to step S1101 and repeats the generation and transmission of the packet.

[0078] The transmission data distribution unit 302 receives a packet from a communication device (step S1102). It determines whether the received packet is for multicast or unicast (step S1103). If the packet is for unicast ("for unicast" in step S1103), the transmission data distribution unit 302 transfers control to step S1216. If the packet is for multicast ("for multicast" in step S1103), the transmission data distribution unit 302 determines whether or not the AP 121 is set for multicast (step S1104). If the AP 121 is set for multicast ("for multicast" in step S1104), the transmission data distribution unit 302 outputs the received packet to the AP 121 (step S1105). The AP 121 receives the packet (step S1105). The AP 121 performs processing such as encoding, interleaving, mapping, and phase change (step S1106). Next, the AP 121 outputs the signal wirelessly (step S1107).

[0079] If AP 121 is not configured for multicast ("No" in step S1104), the transmission data distribution unit 302 determines whether AP 122 is configured for multicast (step S1108). If AP 122 is configured for multicast ("for multicast" in step S1108), the transmission data distribution unit 302 outputs the received packet to AP 122 (step S1109). AP 122 receives the packet (step S1109). AP 122 performs processing such as encoding, interleaving, mapping, and phase change (step S1110). Next, AP 122 outputs a signal wirelessly (step S1111).

[0080] If AP 122 is not set for multicast ("No" in step S1108), the transmission data distribution unit 302 determines whether AP 123 is set for multicast (step S1112). If AP 123 is set for multicast ("for multicast" in step S1112), the transmission data distribution unit 302 outputs the received packet to AP 123 (step S1113). AP 123 receives the packet (step S1113). AP 123 performs processing such as encoding, interleaving, mapping, and phase change, and outputs the signal wirelessly.

[0081] If AP 123 is not configured for multicast ("No" in step S1112), the transmission data distribution unit 302 determines whether AP 124 is configured for multicast (step S1114). If AP 124 is configured for multicast ("for multicast" in step S1114), the transmission data distribution unit 302 outputs the received packet to AP 124 (step S1115). AP 124 receives the packet (step S1115). AP 124 performs processing such as encoding, interleaving, mapping, and phase change, and outputs the signal wirelessly.

[0082] If the AP 124 is not set for multicasting ("No" in step S1114), the transmission data distribution unit 302 returns the control to step S1102. If the received packet is for unicast ("for unicast" in step S1103), the transmission data distribution unit 302 determines whether the AP 121 is set for unicast (step S1216). If the AP 121 is set for unicast ("for unicast" in step S1216), the transmission data distribution unit 302 outputs the received packet to the AP 121 (step S1217). The AP 121 receives the packet (step S1217). The AP 121 performs processing such as encoding, interleaving, mapping, and phase change (step S1218). Next, the AP 121 outputs a signal wirelessly (step S1219).

[0083] If the AP 121 is not configured for unicast ("No" in step S1216), the transmission data distribution unit 302 determines whether the AP 122 is configured for unicast (step S1220). If the AP 122 is configured for unicast ("Unicast" in step S1220), the transmission data distribution unit 302 outputs the received packet to the AP 122 (step S1221). The AP 122 receives the packet (step S1221). The AP 122 performs processing such as encoding, interleaving, mapping, and phase change (step S1222). Next, the AP 122 outputs a signal wirelessly (step S1223).

[0084] If AP 122 is not configured for unicast ("No" in step S1220), transmission data distribution unit 302 determines whether AP 123 is configured for unicast (step S1224). If AP 123 is configured for unicast ("Unicast" in step S1224), transmission data distribution unit 302 outputs the received packet to AP 123 (step S1225). AP 123 receives the packet (step S1225). AP 123 performs processing such as encoding, interleaving, mapping, and phase change, and outputs the signal wirelessly.

[0085] If AP 123 is not configured for unicast ("No" in step S1224), transmission data distribution unit 302 determines whether AP 124 is configured for unicast (step S1226). If AP 124 is configured for unicast ("Unicast" in step S1226), transmission data distribution unit 302 outputs the received packet to AP 124 (step S1227). AP 124 receives the packet (step S1227). AP 124 performs processing such as encoding, interleaving, mapping, and phase change, and outputs the signal wirelessly.

[0086] If the AP 124 is not set for unicast ("No" in step S1226), the transmission data distribution unit 302 returns the control to step S1102. (2) Packet reception behavior The packet reception operations of the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100 will be described with reference to the sequence diagram shown in FIG.

[0087] The receiving device 217 of the AP 121 receives a signal wirelessly (step S1351). Next, the receiving device 217 outputs a packet to the master station 110 (step S1352). The receiving device 217 returns control to step S1351 (step S1353) and repeats wireless reception and packet output. The received data distribution unit 305 receives the packet from the receiving device 217 of the AP 121 (step S1352). The received data distribution unit 305 outputs the received packet to the communication device (step S1354).

[0088] The receiving device 217 of the AP 122 receives the signal wirelessly (step S1356). Next, the receiving device 217 outputs the packet to the master station 110 (step S1357). The receiving device 217 returns control to step S1356 (step S1358) and repeats wireless reception and packet output. The received data distribution unit 305 receives the packet from the receiving device 217 of the AP 122 (step S1357). The received data distribution unit 305 outputs the received packet to the communication device (step S1359).

[0089] The receiving device 217 of the AP 123 receives a signal wirelessly (step S1361). Next, the receiving device 217 outputs a packet to the master station 110 (step S1362). The receiving device 217 returns control to step S1361 (step S1363) and repeats wireless reception and packet output. The received data distribution unit 305 receives the packet from the receiving device 217 of the AP 123 (step S1362). The received data distribution unit 305 outputs the received packet to the communication device (step S1364).

[0090] The receiving device 217 of the AP 124 receives the signal wirelessly (step S1366). Next, the receiving device 217 outputs the packet to the master station 110 (step S1367). The receiving device 217 returns control to step S1366 (step S1368) and repeats wireless reception and packet output. The received data distribution unit 305 receives the packet from the receiving device 217 of the AP 124 (step S1367). The received data distribution unit 305 outputs the received packet to the communication device (step S1369).

[0091] 2.8 Variation (1) A wireless communication system 1400 as a variation of the wireless communication system 100 will be described. In the wireless communication system 100, the master station 110 is connected to the APs 121, 122, 123, and 124 by wire (or wirelessly). In other words, the master station 110 is connected to the APs 121, 122, 123, and 124 in parallel by wire (or wirelessly). However, the present invention is not limited to this configuration.

[0092] The wireless communication system 1400 has a similar configuration to the wireless communication system 100. Here, the differences from the wireless communication system 100 will be mainly described. As shown in FIG. 14, the wireless communication system 1400 includes a master station 1410, an AP 1421, an AP 1422, an AP 1423, an AP 1424, and a terminal 1431, a terminal 1432, . . . , a terminal 1438.

[0093] In the wireless communication system 1400, the master station 1410 is connected by wire (or wirelessly) to the AP 1421. The AP 1421 is connected by wire (or wirelessly) to the AP 1422, the AP 1422 is connected by wire (or wirelessly) to the AP 1423, and the AP 1423 is connected by wire (or wirelessly) to the AP 1424. In other words, the master station 1410, the AP 1421, the AP 1422, the AP 1423, and the AP 1424 are connected in series by wire (or wirelessly).

[0094] (Packet transmission from the master station 1410 to the terminal) The master station 1410 transmits to the AP 1421 a packet addressed to the AP 1421, a packet addressed to the AP 1422, a packet addressed to the AP 1423, and a packet addressed to the AP 1424. The AP 1421 receives packets addressed to the AP 1421, packets addressed to the AP 1422, packets addressed to the AP 1423, and packets addressed to the AP 1424 from the master station 1410.

[0095] When a packet addressed to the AP 1421 is received, the AP 1421 performs processing such as encoding on the packet and outputs it wirelessly. When the AP 1421 receives the packets addressed to the AP 1422 , the packets addressed to the AP 1423 , and the packets addressed to the AP 1424 , the AP 1421 transmits the packets addressed to the AP 1422 , the packets addressed to the AP 1423 , and the packets addressed to the AP 1424 to the AP 1422 .

[0096] AP 1422 receives packets destined for AP 1422, packets destined for AP 1423, and packets destined for AP 1424 from AP 1421. When a packet destined for the AP 1422 is received, the AP 1422 performs processing such as encoding on the packet and outputs it wirelessly. When the AP 1422 receives the packets addressed to the AP 1423 and the packets addressed to the AP 1424, the AP 1422 transmits the received packets addressed to the AP 1423 and the AP 1424 to the AP 1423.

[0097] AP 1423 receives packets destined for AP 1423 and packets destined for AP 1424 from AP 1422 . When a packet addressed to the AP 1423 is received, the AP 1423 performs processing such as encoding on the packet and outputs it wirelessly. When the AP 1423 receives a packet destined for the AP 1424 , it transmits the received packet destined for the AP 1424 to the AP 1423 .

[0098] AP 1424 receives a packet destined for AP 1424 from AP 1423 . When a packet destined for the AP 1424 is received, the AP 1424 performs processing such as encoding on the packet and outputs it wirelessly. (Packet transmission from the terminal to the master station 1410) Terminal 1431, terminal 1432, . . . , terminal 1438 transmit packets wirelessly.

[0099] The AP 1424 receives a packet transmitted by one of the terminals. Upon receiving the packet, the AP 1424 transmits the received packet to the AP 1423. The AP 1423 receives a packet transmitted by any terminal. The AP 1423 also receives a packet (a packet that the AP 1424 has wirelessly received from a terminal) from the AP 1424. Upon receiving the packet from the terminal and the packet from the AP 1424, the AP 1423 transmits the packet from the terminal and the packet from the AP 1424 to the AP 1422.

[0100] AP 1422 receives a packet transmitted by any terminal. AP 1422 also receives packets from AP 1423 (packets received by AP 1424 wirelessly from a terminal and packets received by AP 1423 wirelessly from a terminal). Upon receiving packets from the terminal and packets from AP 1423, AP 1423 transmits the packets from the terminal and packets from AP 1423 to AP 1421.

[0101] The AP 1421 receives a packet transmitted by any of the terminals. The AP 1421 also receives packets from the AP 1422 (packets received by the AP 1424 wirelessly from the terminals, packets received by the AP 1423 wirelessly from the terminals, and packets received by the AP 1422 wirelessly from the terminals). Upon receiving the packets from the terminals and the AP 1422, the AP 1421 transmits the packets from the terminals and the packets from the AP 1422 to the master station 1410.

[0102] 2.9 Variation (2) A wireless communication system 1500 as a variation of the wireless communication system 100 will be described. The wireless communication system 1500 has a configuration similar to that of the wireless communication system 100. As shown in Fig. 15 , the wireless communication system 1500 has a master station 1598, AP1599-1, AP1599-2, AP1599-3, and AP1599-4 instead of the master station 110, AP121, AP122, AP123, and AP124 of the wireless communication system 100. The following description will focus on the differences from the wireless communication system 100.

[0103] The master station 1598, AP 1599-1, AP 1599-2, AP 1599-3, and AP 1599-4 correspond to the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100, respectively. The parent station 1598 is composed of an instruction unit 1504, a transmission data distribution unit 1502, a transmission signal processing unit 1507-1 for AP#1, a transmission signal processing unit 1507-2 for AP#2, a transmission signal processing unit 1507-3 for AP#3, a transmission signal processing unit 1507-4 for AP#4, and a reception data distribution unit 305 (not shown).

[0104] Furthermore, AP 1599-1 includes an AP #1 transmission processing unit 1509-1 and an antenna 1511-1. AP 1599-2 includes an AP #2 transmission processing unit 1509-2 and an antenna 1511-2. AP 1599-3 includes an AP #3 transmission processing unit 1509-3 and an antenna 1511-3. AP 1599-4 includes an AP #4 transmission processing unit 1509-4 and an antenna 1511-4.

[0105] AP 1599-1, AP 1599-2, AP 1599-3, and AP 1599-4 do not perform at least the processes of error correction coding, interleaving, mapping, and phase modification, respectively. The transmission signal processing unit 1507-1 for AP#1, the transmission signal processing unit 1507-2 for AP#2, the transmission signal processing unit 1507-3 for AP#3, and the transmission signal processing unit 1507-4 for AP#4 perform error correction coding, interleaving, mapping, and phase change processing for AP1599-1, AP1599-2, AP1599-3, and AP1599-4, respectively.

[0106] In particular, the transmission signal processing unit 1507-1 for AP#1, the transmission signal processing unit 1507-2 for AP#2, the transmission signal processing unit 1507-3 for AP#3, and the transmission signal processing unit 1507-4 for AP#4 each perform phase change processing. The AP#1 transmission processing unit 1509-1, AP#2 transmission processing unit 1509-2, AP#3 transmission processing unit 1509-3, and AP#4 transmission processing unit 1509-4 each perform processing such as frequency conversion and power amplification.

[0107] The processing contents of the instruction section 1504 and the processing contents of the transmission data distribution section 1502 are similar to the processing contents of the instruction section 308 and the processing contents of the transmission data distribution section 302 of the wireless communication system 100, respectively. An example of the processing by the transmission data distribution unit 1502 is as described with reference to FIGS.

[0108] 2.10 Variation (3) A wireless communication system 1600 as a variation of the wireless communication system 100 will be described. The wireless communication system 1600 has a configuration similar to that of the wireless communication system 100. As shown in Fig. 16 , the wireless communication system 1600 has a master station 1698, AP1699-1, AP1699-2, AP1699-3, and AP1699-4 instead of the master station 110, AP121, AP122, AP123, and AP124 of the wireless communication system 100. The following description will focus on the differences from the wireless communication system 100.

[0109] The main difference from the wireless communication system 100 is that the reception processing (demodulation, decoding) function is shared among the master station 1698 and AP 1699-1, AP 1699-2, AP 1699-3, and AP 1699-467. The master station 1698, AP 1699-1, AP 1699-2, AP 1699-3, and AP 1699-4 correspond to the master station 110, AP 121, AP 122, AP 123, and AP 124 of the wireless communication system 100, respectively.

[0110] The parent station 1698 is composed of an instruction unit 1610, a received data distribution unit 1607, a received signal processing unit 1605-1 for AP#1, a received signal processing unit 1605-2 for AP#2, a received signal processing unit 1605-3 for AP#3, a received signal processing unit 1605-4 for AP#4, and a transmission data distribution unit 302 (not shown). Furthermore, AP 1699-1 includes an AP #1 reception processing unit 1603-1 and an antenna 1601-1. AP 1699-2 includes an AP #2 reception processing unit 1603-2 and an antenna 1601-2. AP 1699-3 includes an AP #3 reception processing unit 1603-3 and an antenna 1601-3. AP 1699-4 includes an AP #4 reception processing unit 1603-4 and an antenna 1601-4.

[0111] The AP#1 reception processing unit 1603-1, AP#2 reception processing unit 1603-2, AP#3 reception processing unit 1603-3, and AP#4 reception processing unit 1603-4 each perform processing such as frequency conversion. The processing performed by the instruction unit 1610 and the processing performed by the received data distribution unit 1607 are similar to the processing performed by the instruction unit 308 and the processing performed by the received data distribution unit 305 of the wireless communication system 100, respectively.

[0112] An example of the processing by the received data sorting unit 1607 is as described with reference to FIGS. 1.11 Operation when the master station controls the AP The operation of the wireless communication system 100 when the master station 110 newly controls an AP will be described with reference to the flowchart shown in FIG.

[0113] Here, it is assumed that four APs 121, AP 122, AP 123, and AP 124 are under the control of the master station 110, and that a new AP is subsequently added. At this point, it is assumed that the phase change pattern (and ID) has already been set for the four APs 121, AP 122, AP 123, and AP 124. An AP that is about to newly come under the control of the master station 110 notifies the master station 110 of its desire to come under its control. The master station 110 receives the request from the new AP (step S1701).

[0114] The master station 110 determines whether to place the new AP under its control (step S1702). If it determines that the new AP should be placed under its control ("Yes" in step S1702), the master station 110 assigns an ID to the new AP. At this time, the ID and the phase change pattern are associated with each other. The new AP sets a phase change pattern based on the assigned ID (step S1703). This completes the operation for placing the new AP under its control.

[0115] If it is determined that the new AP will not be placed under its control (step S1702: No), the master station 110 notifies the new AP that it will not be placed under its control (step S1704), thereby completing the operation for placing a new AP under its control. In step S1703, the following may be performed. The master station 110 transmits information indicating the phase change pattern to be set by the new AP to the new AP. The new AP receives the information indicating the phase change pattern and sets the phase change pattern for the AP based on the received information indicating the phase change pattern. At this time, the master station 110 may assign an ID to the new AP, or may not assign an ID. Here, assigning an ID has the advantage that when the master station 110 designates the newly controlled AP as a unicast AP or a multicast AP, it can easily designate the AP as an ID and whether it is for unicast or multicast by transmitting information indicating "the ID and whether it is for unicast or multicast" to the AP.

[0116] In the above description, a case has been described in which four APs, AP 121, AP 122, AP 123, and AP 124, are under the control of the master station 110, and a new AP is then added. However, the present invention is not limited to such a case. In the initial state, there may be no AP under the control of the master station 110. In this case, as described above, the APs may be placed under the control of the master station 110 one by one.

[0117] In the determination in step S1702 above, the master station 110 may determine whether to place a new AP under its control due to a limit on the number of APs under its control. The master station 110 stores the maximum number of APs under its control. When a request is made by an AP to newly place under its control, it adds "1" to the number of APs currently under its control and compares the obtained value with the maximum value. If the obtained value does not exceed the maximum value or is equal to the maximum value, it is permitted to come under its control. If the obtained value exceeds the maximum value, it is not permitted to come under its control.

[0118] In the determination in step S1702 above, the master station 110 may determine whether to place the new AP under its control depending on the position where the new AP is located and the phase change pattern. At this time, for example, if the location of the new AP is far from the location of the AP that is already under its control, the master station 110 allows the new AP to become under its control.

[0119] Also, for example, when the location of a new AP is close to the location of an AP that is already under its control, if there is a phase change pattern to be assigned to the new AP, the master station 110 will allow the new AP to become under its control. Also, for example, when the location of a new AP is close to the location of an AP that is already under its control, if there is no phase change pattern to be assigned to the new AP, the master station 110 will not allow the new AP to come under its control.

[0120] 2.11 Summary According to this aspect, large-capacity transmission of Gbps can be realized. Also, when multicast is realized, the number of terminals that can be accommodated can be increased. Furthermore, unicast communication can be realized simultaneously with multicast, making the system more flexible. 3. Second Embodiment A wireless communication system 1800 according to another embodiment 2 of the present invention will be described.

[0121] 3.1 Wireless Communication System 1800 As shown in FIG. 18, wireless communication system 1800 is configured with master station 1810, AP 1820-1, AP 1820-2, AP 1820-3, AP 1820-4, and terminals 1830-1, 1830-2, . . . , and 1830-8. The master station 1810 is connected to a communication device (not shown) directly or indirectly via a communication line. Here, examples of the communication device include a broadcasting device that broadcasts data, a distribution system or server that transmits data, etc. The communication device transmits a control signal and data. The control signal includes settings related to unicast transmission or multicast transmission, and settings related to a phase change method. Furthermore, the communication device may be composed of multiple communication devices. In this case, a first communication device may transmit a control signal, and a second communication device may transmit data. The master station 1810 is connected to AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4 by wire (or wireless). Furthermore, AP 1820-1 is connected to AP 1820-2, AP 1820-3, and AP 1820-4 by wire (or wireless).

[0122] The master station 1810 receives control signals and data from the communication devices. The master station 1810 transmits a control signal to the AP 1820-1. The master station 1810 also transmits data to the APs 1820-1, 1820-2, 1820-3, and 1820-4. The APs 1820-1, 1820-2, 1820-3, and 1820-4 also transmit the data received from the master station 1810 wirelessly.

[0123] Terminal 1830-1, terminal 1830-2, ..., terminal 1830-8 are each a mobile phone, smartphone, tablet, or personal computer (PC) equipped with a wireless communication function using a frequency band above 6 GHz, for example, a frequency band called millimeter waves, for example, the 60 GHz frequency band. For example, when terminal 1830-1 is located close to AP 1820-1, terminal 1830-1 receives data wirelessly from AP 1820-1. Terminals 1830-2, ..., terminal 1830-8 also each receive data wirelessly from nearby APs, similar to terminal 1830-1.

[0124] Furthermore, the terminal 1830-1 transmits data wirelessly. When the terminal 1830-1 is located close to the AP 1820-1, the AP 1820-1 receives data wirelessly from the terminal 1830-1. The AP 1820-1 transmits the received data to the master station 1810. Similar to terminal 1830-1, terminals 1830-2, 1830-3, ..., and 1830-8 also transmit data wirelessly. APs located close to each terminal receive data wirelessly from the terminal. The APs transmit the data received from the terminals to master station 1810.

[0125] The master station 1810 receives the data transmitted by each terminal via the AP, and outputs the received data to the communication device. The control signal transmitted from the master station 1810 to the AP 1820-1 includes settings for unicast transmission or multicast transmission in each AP, and settings for the phase change method in each AP. The master station 1810 does not configure settings for unicast transmission or multicast transmission in the APs 1820-2, 1820-3, and 1820-4. Furthermore, the master station 1810 does not configure settings for phase change method in the APs 1820-2, 1820-3, and 1820-4.

[0126] The AP 1820-1 performs settings related to unicast transmission or multicast transmission for the AP 1820-2, AP 1820-3, and AP 1820-4. The AP 1820-1 also performs settings related to the phase change method for the AP 1820-2, AP 1820-3, and AP 1820-4. AP 1820-1 is called the master AP, and AP 1820-2, AP 1820-3, and AP 1820-4 are called non-master APs.

[0127] 3.2 AP1820-1 as the Master AP As shown in FIG. 19, the master AP AP 1820-1 is composed of an encoder 202, an interleaver 204, a mapping unit 206, a phase change unit 208, a radio unit 210, an antenna 212, an antenna 215, a receiving device 217, and an instruction unit 1902. The AP 1820-1 receives a control signal 1901 from the master station 1810. The control signal 1901 includes settings related to unicast transmission or multicast transmission, and settings related to the phase change method.

[0128] The AP 1820-1 performs settings related to unicast transmission or multicast transmission based on the control signal 1901 received from the master station 1810. The AP 1820-1 also performs settings related to the phase change method based on the control signal 1901. When settings related to multicast transmission are performed, the AP 1820-1 is set to use the same frequency (frequency band) as other APs.

[0129] When making settings related to unicast transmission, the AP 1820-1 operates the receiving device 217. When making settings related to multicast transmission, the AP 1820-1 may stop the operation of the receiving device 217. The AP 1820-1 transmits and receives wirelessly using the same channel for both unicast and multicast. The AP 1820-1 may divide a single wireless carrier into several time slots and use each time slot as a communication channel. The AP 1820-1 may also use multiple different frequencies in the 60 GHz frequency band and use each frequency as a communication channel.

[0130] (1) Encoder 202 The encoder 202 receives data 201 from the master station 1810. The encoder 202 also receives a control signal 213 from a controller included in the AP 1820-1. The control signal 213 includes information such as a designation of an encoding method, a designation of an error correction method, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 201 using the method designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0131] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 1820-1. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0132] (3) Mapping unit 206 Mapping unit 206 receives interleaved data 205 from interleaver 204. Mapping unit 206 also receives control signal 213 from a controller included in AP 1820-1. Control signal 213 includes a modulation scheme designation. Mapping unit 206 performs modulation on interleaved data 205 using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like in accordance with the modulation scheme designation included in control signal 213, to generate modulated signal 207. Mapping unit 206 outputs modulated signal 207. Note that the modulation scheme may be another modulation scheme.

[0133] The mapping unit 206 may perform mapping that includes a phase change process. (4) Phase change unit 208 The phase change unit 208 receives the modulated signal 207 from the mapping unit 206. The phase change unit 208 also receives a control signal 1903_0. The control signal 1903_0 includes a setting for the phase change method. The phase change unit 208 performs a phase change on the modulated signal 207 in accordance with the setting for the phase change method included in the control signal 1903_0, and generates a phase-changed signal 209. The phase change unit 208 outputs the phase-changed signal 209.

[0134] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives phase-changed signal 209 from phase change unit 208. Radio unit 210 also receives control signal 213 from a controller included in AP 1820-1. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on phase-changed signal 209 to generate transmission signal 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0135] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. The receiving device 217 receives a signal 216 from the antenna 215 using a frequency band above 6 GHz, for example, a frequency band called a millimeter wave, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the signal to generate data 218. The receiving device 217 outputs the data 218 to the master station 1810.

[0136] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. (7) Instruction section 1902 The instruction unit 1902 is connected to the master station 1810 . The instruction unit 1902 receives a control signal 1901 from the master station 1810. The control signal 1901 includes settings related to unicast transmission or multicast transmission, and settings for the phase change method.

[0137] Also, the control signal 1901 may be used to individually set each AP, or the same control signal 1901 may be used to set all APs. The instruction unit 1902 performs settings related to multicast transmission or settings related to unicast transmission for all APs including the AP 1820-1 using a control signal 1903_0, a control signal 1903_1, . . . , a control signal 1903_N.

[0138] Here, the instruction unit 1902 may set all APs for multicast transmission, or may set all APs for unicast transmission. Alternatively, some APs may be set for multicast transmission, and other APs may be set for unicast transmission. For multiple APs configured for multicast transmission, the modulated signal before phase change is the same signal, in other words, the same data is transmitted.

[0139] Furthermore, the instruction unit 1902 instructs each AP on the phase change method using control signals 1903_1, . . . , 1903_N. For multiple APs configured for unicast transmission, the modulated signals before the phase change may be the same or different signals, i.e., the same data may be transmitted or different data may be transmitted.

[0140] In this way, the instruction unit 1902 generates a control signal 1903_0, a control signal 1903_1, ..., a control signal 1903_N for each AP from the received control signal 1901. Each control signal includes settings related to multicast transmission or settings related to unicast transmission and settings for a phase change method. The instruction unit 1902 outputs the control signal 1903_0, the control signal 1903_1, ..., a control signal 1903_N to itself, AP 1820-2, AP 1820-3, and AP 1820-4.

[0141] When the instruction unit 1902 designates unicast transmission for the AP 1820-1, it operates the receiving device 217. Furthermore, when the instruction unit 1902 designates multicast transmission for the AP 1820-1, it may stop the operation of the receiving device 217. 3.3 Non-Master AP2000 AP 1820-2, AP 1820-3, and AP 1820-4 are non-master APs. Here, AP 1820-2, AP 1820-3, and AP 1820-4 will be described as AP 2000, representing them.

[0142] As shown in FIG. 20, the non-master AP 2000 comprises an encoder 202, an interleaver 204, a mapping unit 206, a phase change unit 208, a radio unit 210, an antenna 212, an antenna 215, and a receiving device 217. The AP 2000 receives a control signal 2001_0 from the AP 1820-1, which is the master AP. The control signal 2001_0 includes settings related to unicast transmission or multicast transmission, and settings for a phase change method. The AP 2000 also receives data 2002 from the AP 1820-1, which is the master AP. When AP cooperation is performed, the AP 2000 may receive data 2003 from another AP that is not the master. When the AP 2000 operates independently as a unicast transmitter, the AP 2000 may receive data 201 from the parent station 1810.

[0143] The AP 2000 performs settings related to unicast transmission or multicast transmission based on the control signal 2001_0. The AP 2000 also performs settings related to the phase change method based on the control signal 2001_0. When set to multicast transmission, the AP 2000 is set to use the same frequency (frequency band) as other APs. When the AP 2000 is set to unicast transmission, it operates the receiving device 217. When the AP 2000 is set to multicast transmission, it may stop the operation of the receiving device 217.

[0144] The AP2000 transmits and receives wirelessly using the same channel (or the same frequency) for both unicast and multicast transmissions. The AP2000 may divide a single wireless carrier into several time slots and use each time slot as a communication channel. The AP2000 may also use multiple different frequencies in the 60 GHz frequency band and use each frequency as a communication channel.

[0145] (1) Encoder 202 The encoder 202 receives data 2002, data 2003, or data 201. The encoder 202 also receives a control signal 213 from a controller included in the AP 2000. The control signal 213 includes information such as a designation of an encoding method, a designation of an error correction method, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 2002, data 2003, or data 201 using the method designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0146] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 2000. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0147] (3) Mapping unit 206 The mapping unit 206 receives interleaved data 205 from the interleaver 204. The mapping unit 206 also receives a control signal 213 from a controller included in the AP 2000. The control signal 213 includes a modulation scheme designation. In accordance with the modulation scheme designation included in the control signal 213, the mapping unit 206 performs modulation using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like on the interleaved data 205 to generate a modulated signal 207. The mapping unit 206 outputs the modulated signal 207. Note that the modulation scheme may be another modulation scheme.

[0148] The mapping unit 206 may perform mapping that includes a phase change process. (4) Phase change unit 208 The phase change unit 208 receives the modulated signal 207 from the mapping unit 206. The phase change unit 208 also receives a control signal 2001_0. The control signal 2001_0 includes a setting for a phase change method. The phase change unit 208 performs a phase change on the modulated signal 207 in accordance with the setting for the phase change method included in the control signal 2001_0, and generates a phase-changed signal 209. The phase change unit 208 outputs the phase-changed signal 209.

[0149] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives phase-changed signal 209 from phase change unit 208. Radio unit 210 also receives control signal 213 from a controller included in AP 2000. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on phase-changed data 209 to generate transmission data 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0150] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. The receiving device 217 receives data 216 from the antenna 215 using a frequency band above 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the data to generate data 218. The receiving device 217 outputs the data 218 to the master station 1810.

[0151] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. 3.4 Example of data sent An example of data transmitted by the master station 1810, AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4 will be described below.

[0152] (1) When all APs are configured for multicast transmission An example of data to be transmitted when all of AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4 are set for multicast transmission will be described with reference to FIG. 21, the master station 1810 receives packets 2101, 2102, 2103, 2104, etc. in this order. Here, packets 2101, 2102, 2103, 2104, etc. are all multicast packets. Also, packets 2101, 2102, 2103, 2104, etc. are generated from one piece of multicast data. The master station 1810 transmits packets 2101, 2102, 2103, 2104, etc. to AP 1820-1 in this order.

[0153] AP 1820-1 receives packets 2101, 2102, 2103, 2104, etc. in this order. Next, AP 1820-1 transmits packets 2101, 2102, 2103, 2104, etc. to AP 1820-2, AP 1820-3, and AP 1820-4 in this order. AP 1820-1 receives packets 2101, 2102, 2103, 2104, etc. in this order. Upon receiving packets 2101, 2102, 2103, 2104, etc. in this order, AP 1820-1 wirelessly outputs packets 2106, 2107, 2108, 2109, etc. in this order as multicast transmission. Here, packets 2101, 2102, 2103, 2104, etc. correspond to packets 2106, 2107, 2108, and 2109, respectively.

[0154] When AP 1820-2 receives packets 2101, 2102, 2103, 2104, etc. in this order, it wirelessly outputs packets 2111, 2112, 2113, 2114, etc. in this order as multicast transmission. Here, packets 2101, 2102, 2103, 2104, etc. correspond to packets 2111, 2112, 2113, and 2114, respectively.

[0155] When AP 1820-3 receives packets 2101, 2102, 2103, 2104, etc. in this order, it wirelessly outputs packets 2116, 2117, 2118, 2119, etc. in this order as multicast transmission. Here, packets 2101, 2102, 2103, 2104, etc. correspond to packets 2116, 2117, 2118, and 2119, respectively.

[0156] When AP 1820-4 receives packets 2101, 2102, 2103, 2104, etc. in this order, it wirelessly outputs packets 2121, 2122, 2123, 2124, etc. in this order as multicast transmission. Here, packets 2101, 2102, 2103, 2104, etc. correspond to packets 2121, 2122, 2123, and 2124, respectively.

[0157] At this time, it is characteristic that AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4 each perform a phase change on the modulated signal (however, any of AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4 may not perform a phase change). By doing this, it is possible to widen the cell range within which the multicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals.

[0158] (2) When two APs are configured for multicast transmission An example of data to be transmitted when two APs, AP 1820-1 and AP 1820-2, are configured for multicast transmission and transmit data, and the other two, AP 1820-3 and AP 1820-4, are configured for unicast transmission and transmit data, will be described with reference to Fig. 22. In this case, it is assumed that AP 1820-1 and AP 1820-2 transmit the same data (the modulated signals after mapping before phase change are the same). It is also assumed that AP 1820-3 and AP 1820-4 transmit the same data (the modulated signals after mapping before phase change are the same).

[0159] 22, the master station 1810 receives packets 2201, 2202, 2203, 2204, 2205, 2206, etc. in this order. Here, packets 2201, 2203, 2204, and 2206 are multicast packets. Packets 2202 and 2205 are unicast packets. Packets 2201, 2203, 2204, and 2206 are generated from one piece of multicast data. Packets 2202 and 2205 are generated from one piece of unicast data.

[0160] When the master station 1810 receives the packets 2201, 2202, 2203, 2204, 2205, 2206, . . . in this order, it transmits the packets 2201, 2202, 2203, 2204, 2205, 2206, . . . to the AP 1820-1 in this order. Upon receiving packets 2201, 2202, 2203, 2204, 2205, 2206, and so on, AP 1820-1 outputs multicast packets 2201, 2203, 2204, 2206, and so on to its own encoder 202, and transmits multicast packets 2201, 2203, 2204, 2206, and so on to AP 1820-2. AP 1820-1 transmits unicast packets 2202, 2205, and so on to AP 1820-3 and AP 1820-4.

[0161] Upon receiving packets 2201, 2203, 2204, and 2206, AP 1820-1 wirelessly outputs packets 2211, 2212, 2213, and 2214 as multicast transmission. Here, packets 2201, 2203, 2204, and 2206 correspond to packets 2211, 2212, 2213, and 2214, respectively. Upon receiving packets 2201, 2203, 2204, and 2206, AP 1820-2 wirelessly outputs packets 2221, 2222, 2223, and 2224 as multicast transmission. Here, packets 2201, 2203, 2204, and 2206 correspond to packets 2221, 2222, 2223, and 2224, respectively.

[0162] Upon receiving packets 2202 and 2205, AP 1820-3 wirelessly outputs packets 2231 and 2232 as unicast transmissions. Here, packets 2202 and 2205 correspond to packets 2231 and 2232, respectively. Upon receiving packets 2202 and 2205, AP 1820-4 wirelessly outputs packets 2241 and 2242 as unicast transmissions. Here, packets 2202 and 2205 correspond to packets 2241 and 2242, respectively.

[0163] In the above, when modulated signals are transmitted by unicast transmission, packets transmitted by AP 1820-3 and AP 1820-4 are based on the same data. In this case, the transmission parameters are the same in AP 1820-3 and AP 1820-4. AP 1820-3 and AP 1820-4 may perform different phase changes. (However, either AP 1820-3 or AP 1820-4 may not perform a phase change.) By doing this, it is possible to widen the cell range within which the unicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals. A characteristic feature of AP 1820-1 and AP 1820-2 is that they each perform a phase change on the modulated signal (however, either AP 1820-1 or AP 1820-2 may not perform a phase change). (The method for changing the phase will be explained in detail later.) By doing this, it is possible to widen the cell range within which the multicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals.

[0164] (3) When two APs are configured for multicast transmission An example of data to be transmitted when two APs, AP 1820-1 and AP 1820-2, are set for multicast transmission and transmit data, and the other two APs, AP 1820-3 and AP 1820-4, are set for unicast transmission and transmit data, will be described with reference to Fig. 23. In the case of Fig. 23, it is assumed that different data is transmitted from AP 1820-3 and AP 1820-4.

[0165] 23, the master station 1810 receives packets 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, etc. in this order. Here, packets 2301, 2303, 2304, and 2306 are multicast packets. Packets 2302, 2307, and 2309 are unicast packets transmitted by AP 1820-3. Packets 2305, 2308, and 2310 are unicast packets transmitted by AP 1820-4.

[0166] Here, packets 2301, 2303, 2304, and 2306 are generated from one piece of data for multicasting, packets 2302, 2307, and 2309 are generated from one piece of data for unicasting, and packets 2305, 2308, and 2310 are generated from another piece of data for unicasting. Upon receiving packets 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, . . . in this order, the master station 1810 transmits multicast packets 2301, 2303, 2304, and 2306 to AP 1820-1 and AP 1820-2.

[0167] Upon receiving packets 2301, 2303, 2304, and 2306, AP 1820-1 wirelessly outputs, as multicast transmission, packets 2321, 2322, 2323, and 2324. Packets 2301, 2303, 2304, and 2306 correspond to packets 2321, 2322, 2323, and 2324, respectively. Upon receiving packets 2301, 2303, 2304, and 2306, AP 1820-2 wirelessly outputs, as multicast transmission, packets 2325, 2326, 2327, and 2328. Packets 2301, 2303, 2304, and 2306 correspond to packets 2325, 2326, 2327, and 2328, respectively.

[0168] Upon receiving packets 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, . . . in this order, the master station 1810 transmits unicast packets 2302, 2307, and 2329 to the AP 1820-3. Upon receiving packets 2302, 2307, and 2329, AP 1820-3 wirelessly outputs packets 2331, 2332, and 2333 as unicast transmissions. Packets 2302, 2307, and 2329 correspond to packets 2331, 2332, and 2333, respectively.

[0169] When the master station 1810 receives packets 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, . . . in this order, the master station 1810 transmits unicast packets 2305, 2308, and 2310 to the AP 1820-4. Upon receiving packets 2305, 2308, and 2310, AP 1820-4 wirelessly outputs, as unicast transmission, packets 2341, 2342, and 2343. Packets 2305, 2308, and 2310 correspond to packets 2341, 2342, and 2343, respectively.

[0170] A characteristic feature of AP 1820-1 and AP 1820-2 is that they each perform a phase change on the modulated signal (however, either AP 1820-1 or AP 1820-2 may not perform a phase change). By doing this, it is possible to widen the cell range within which the multicast modulated signal can reach, and by changing the phase, it is possible to reduce the number of points where reception becomes difficult due to interference between modulated signals.

[0171] In addition, AP1820-3 and AP1820-4 are flexible systems that can perform unicast communication. For example, by switching between the transmission state of Figure 21, the transmission state of Figure 22, and the transmission state of Figure 23 depending on time (for example, switching depending on the presence status of the terminal), there is an advantage that a flexible system can be realized.

[0172] 3.5 Operation when the master AP takes control of a new AP The operation of the wireless communication system 1800 when the master AP AP 1820-1 newly controls an AP will be described with reference to the flowchart shown in FIG. Here, it is assumed that three APs, AP 1820-2, AP 1820-3, and AP 1820-4, are under the control of AP 1820-1, which is the master AP, and that a new AP is then added. At this point, it is assumed that the phase change pattern (and ID (identification) (as an AP)) has already been set for the four APs, AP 1820-1, AP 1820-2, AP 1820-3, and AP 1820-4.

[0173] An AP that wishes to newly become under the control of the AP 1820-1 notifies the AP 1820-1 of a request to become under its control. The AP 1820-1 receives the request (step S2401). The AP 1820-1 determines whether to place the new AP under its control (step S2402). If it determines that the new AP should be placed under its control ("Yes" in step S2402), the AP 1820-1 assigns an ID to the new AP. At this time, the ID and the phase change pattern are associated with each other. The new AP sets a phase change pattern based on the assigned ID (step S2403). This completes the operation for placing a new AP under its control.

[0174] If it is determined that the new AP will not be placed under its control (step S2402: No), the AP 1820-1 notifies the new AP that it will not be placed under its control (step S2404), thereby completing the operation for placing a new AP under its control. In step S2403, the following may be performed. The master AP AP 1820-1 transmits information indicating the phase change pattern to be set by the new AP to the new AP. The new AP receives the information indicating the phase change pattern and sets the phase change pattern for the new AP based on the received information indicating the phase change pattern. At this time, the master AP AP 1820-1 may assign an ID to the new AP, or may not assign an ID. Here, assigning an ID has the advantage that when the master AP AP 1820-1 specifies the newly controlled AP as an AP for unicast transmission or an AP for multicast transmission, it can easily specify the ID and whether the AP is for unicast transmission or multicast transmission by transmitting information indicating "the ID and whether it is for unicast transmission or multicast transmission" to the AP.

[0175] In the above description, it is assumed that three APs, AP 1820-2, AP 1820-3, and AP 1820-4, are under the control of AP 1820-1, which is the master AP, and a new AP is then added. However, the present invention is not limited to this case. In the initial state, there may be no APs under the control of the master AP AP 1820-1. In this case, as described above, the APs may be placed under the control of the master AP AP 1820-1 one by one.

[0176] In the determination in step S2402 above, the master AP AP 1820-1 may determine whether to place the new AP under its control due to a limit on the number of APs under its control. The AP 1820-1 stores the maximum number of APs under its control. When a request is made by a new AP to become under its control, it adds "1" to the number of APs currently under its control and compares the obtained value with the maximum value. If the obtained value does not exceed the maximum value or is equal to the maximum value, it is permitted to become under its control. If the obtained value exceeds the maximum value, it is not permitted to become under its control.

[0177] In the determination in step S2402 above, the AP 1820-1 may determine whether to place the new AP under its control depending on the position where the new AP exists and the phase change pattern. At this time, for example, if the location of the new AP is far from the location of itself and the APs already under its control, the AP 1820-1 allows the new AP to become under its control.

[0178] Also, for example, when the location of a new AP is close to the location of itself or an AP already under its control, if there is a phase change pattern to be assigned to the new AP, AP1820-1 will allow the new AP to become under its control. Also, for example, when the location of a new AP is close to the location of itself or an AP already under its control, if there is no phase change pattern to be assigned to the new AP, AP1820-1 will not allow the new AP to come under its control.

[0179] 3.6 Summary According to this aspect, large-capacity transmission of Gbps can be realized. Also, when multicast is realized, the number of terminals that can be accommodated can be increased. Furthermore, unicast communication can be realized simultaneously with multicast, making the system more flexible. 4. Third Embodiment A wireless communication system 2500 according to another embodiment 3 of the present invention will be described.

[0180] 4.1 Wireless Communication System 2500 As shown in FIG. 25, wireless communication system 2500 includes master station 2510, AP 2520-1, AP 2520-2, AP 2520-3, AP 2520-4, and terminal 2530-1, terminal 2530-2, . . . , terminal 2530-8. The master station 2510 is connected to a communication device (not shown) directly or indirectly via a communication line. Here, the communication device is a broadcasting device that broadcasts data, a distribution system or server that transmits data, or the like. The communication device transmits a control signal and data. The control signal includes a setting for a unicast transmission method or a setting for a multicast transmission method, and a setting for a weighting method. Furthermore, the communication device may be composed of multiple communication devices. In this case, a first communication device may transmit a control signal, and a second communication device may transmit data. Furthermore, the master station 2510 is connected to AP2520-1, AP2520-2, AP2520-3, and AP2520-4 by wire (or may be connected wirelessly). The master station 2510 receives control signals and data from the communication devices. The master station 2510 transmits control signals and data to the APs 2520-1, 2520-2, 2520-3, and 2520-4. The APs 2520-1, 2520-2, 2520-3, and 2520-4 transmit the data received from the master station 2510 wirelessly.

[0181] Terminal 2530-1, terminal 2530-2, ..., terminal 2530-8 are each a mobile phone, smartphone, tablet, or personal computer (PC) equipped with wireless communication functionality using a frequency band above 6 GHz, for example, a frequency band called millimeter waves, such as the 60 GHz frequency band. For example, when terminal 2530-1 is located close to AP 2520-1, terminal 2530-1 receives data wirelessly from AP 2520-1. Terminals 2530-2, ..., terminal 2530-8 also each receive data wirelessly from nearby APs, similar to terminal 2530-1.

[0182] Furthermore, the terminal 2530-1 transmits data wirelessly. When the terminal 2530-1 is located close to the AP 2520-1, the AP 2520-1 receives data wirelessly from the terminal 2530-1. The AP 2520-1 transmits the received data to the master station 2510. Terminal 2530-2, terminal 2530-3, ..., terminal 2530-8 also transmit data wirelessly, similar to terminal 2530-1. APs located close to each terminal receive data wirelessly from the terminal. The APs transmit the data received from the terminals to master station 2510.

[0183] The master station 2510 receives data from each terminal via each AP, and outputs the received data to the communication device. The control signal transmitted from the master station 2510 to the AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4 includes settings for unicast transmission or multicast transmission in each AP, and settings for the weighting method in each AP.

[0184] 4.2 AP2520 The AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4 have, for example, the same configuration (same function). Here, the AP 2520 will be described as a representative of the AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4.

[0185] As shown in FIG. 26, the AP 2520 is made up of an encoder 202, an interleaver 204, a mapping unit 206, a weighting unit 2601, a radio unit 210, an antenna 212, an antenna 215, and a receiving device 217. The AP 2520 receives a control signal 214 from the master station 2510. The control signal 214 includes settings for the unicast transmission method or the multicast transmission method, and settings for the weighting method.

[0186] The AP 2520 performs settings related to the unicast transmission method or settings related to multicast transmission based on the control signal 214 received from the master station 2510. The AP 2520 also performs settings related to the weighting method based on the control signal 214. When multicast transmission is set, the AP 2520 is set to use the same frequency (frequency band) as other APs.

[0187] When unicast transmission is set, the AP 2520 operates the receiving device 217. When multicast transmission is set, the AP 2520 may stop the operation of the receiving device 217. The AP 2520 transmits and receives wirelessly using the same channel (or the same frequency (frequency band)) for both unicast and multicast transmissions. Here, the AP 2520 may divide one wireless carrier into several time slots and use each time slot as a communication channel. Alternatively, the AP 2520 may use several different frequencies in the 60 GHz frequency band and use each frequency as a communication channel.

[0188] (1) Encoder 202 The encoder 202 receives data 201 from the master station 2510. The encoder 202 also receives a control signal 213 from a controller included in the AP 2520. The control signal 213 includes information such as a coding scheme designation, an error correction scheme designation, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 201 using the scheme designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0189] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 2520. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0190] (3) Mapping unit 206 The mapping unit 206 receives interleaved data 205 from the interleaver 204. The mapping unit 206 also receives a control signal 213 from a controller included in the AP 2520. The control signal 213 includes a modulation scheme designation. In accordance with the modulation scheme designation included in the control signal 213, the mapping unit 206 performs modulation using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like on the interleaved data 205 to generate a modulated signal 207. The mapping unit 206 outputs the modulated signal 207. Note that other modulation schemes may also be used.

[0191] The mapping unit 206 may perform mapping including weighting processing. (4) Weighting unit 2601 Weighting section 2601 receives modulated signal 207 from mapping section 206. Weighting section 2601 also receives control signal 214. Control signal 214 includes a setting for the weighting method. Weighting section 2601 weights modulated signal 207 in accordance with the setting for the weighting method included in control signal 214, and generates weighted signal 2602. Weighting section 2601 outputs weighted signal 2602.

[0192] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives weighted data 2602 from weighting unit 2601. Radio unit 210 also receives control signal 213 from a controller included in AP 2520. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on weighted signal 2602 to generate transmission signal 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0193] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. Receiving device 217 receives signal 216 from antenna 215 using a frequency band above 6 GHz, for example, a frequency band called millimeter wave, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the signal to generate data 218. Receiving device 217 outputs data 218 to master station 2510.

[0194] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. 4.3 Master station 2510 As shown in FIG. 27, the master station 2510 is made up of a transmission data distribution unit 302, a reception data distribution unit 305, and an instruction unit 308.

[0195] (1) Instruction section 308 The instruction unit 308 is connected to the communication device and the AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4. The instruction unit 308 receives the control signal 307. The control signal 307 includes settings related to unicast transmission or multicast transmission, and settings for a weighting method. The communication device includes, for example, a PC, and a user of the PC inputs the control signal through the PC.

[0196] Furthermore, the control signal 307 may be set individually for each AP, or the same control signal 307 may be set for all APs. All APs may be set to multicast transmission, or all APs may be set to unicast transmission. Some APs may be set to multicast transmission, and other APs may be set to unicast transmission. In this way, APs may have a mixture of multicast transmission settings and unicast settings.

[0197] For multiple APs configured for multicast, the modulated signals before weighting are the same signal, in other words, the same data is transmitted. Furthermore, the instruction unit 308 instructs each AP on the weighting method. For multiple APs configured for unicast, the pre-weighted modulated signals may be the same or different signals, i.e., the same data may be transmitted or different data may be transmitted.

[0198] The instruction unit 308 outputs the received control signal 307 to the transmission data distribution unit 302, the reception data distribution unit 305, and the APs 2520-1, 2520-2, 2520-3, and 2520-4. (2) Transmission data distribution unit 302 The transmission data distribution unit 302 is connected to the communication device, the instruction unit 308, and the AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4.

[0199] Transmission data distribution section 302 receives control signal 310 from instruction section 308. Transmission data distribution section 302 outputs received control signal 310 to AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4. Furthermore, transmission data distribution unit 302 receives data 301 from a communication device. Transmission data distribution unit 302 distributes the received data to AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4. Transmission data distribution unit 302 outputs the distributed data to AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4, respectively.

[0200] (3) Received data distribution unit 305 The received data distribution unit 305 is connected to the communication device, the instruction unit 308, and the AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4. Furthermore, the received data distribution unit 305 receives data 304-1, 304-2, 304-3, and 304-4 from the AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4, respectively. The received data distribution unit 305 outputs the received data 304-1, 304-2, 304-3, and 304-4 to the communication device.

[0201] 4.4 Example of data sent An example of data transmitted by the master station 2510, AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4 will be described below. (1) When all APs are set to multicast transmission and data is transmitted An example of data to be transmitted when all of the APs 2520-1, 2520-2, 2520-3, and 2520-4 are set for multicast transmission and data is transmitted will be described with reference to FIGS. 28 and 29. FIG.

[0202] 28, the transmission data distribution unit 302 receives packets 2811, 2812, 2813, 2814, etc. in this order. Here, packets 2811, 2812, 2813, 2814, etc. are all packets for multicast. Also, packets 2811, 2812, 2813, 2814, etc. are generated from one piece of multicast data.

[0203] Transmission data distribution unit 302 outputs packets 2811, 2812, 2813, 2814, . . . to AP 2520-1, AP 2520-2, AP 2520-3, and AP 2520-4, respectively, in this order. (a) Processing of each AP 1 25 and 28, AP2520-1 prepares weights A1(0), A1(1), A1(2), A1(3), etc. Similarly, AP2520-2 prepares weights A2(0), A2(1), A2(2), A2(3), etc., AP2520-3 prepares weights A3(0), A3(1), A3(2), A3(3), etc., and AP2520-4 prepares weights A4(0), A4(1), A4(2), A4(3), etc.

[0204] (b) Processing of each AP 2 Next, the processing of each AP will be described with reference to FIG. (AP2520-1 processing) As shown in FIG. 29, the mapping unit 206 of AP 2520-1 generates the mapped baseband signal complex numbers (which may be real numbers) 2911 "c(0)", 2912 "c(1)", 2913 "c(2)", 2914 "c(3)", ... It is assumed that c(0) is the mapped baseband signal associated with packet 2811, c(1) is the mapped baseband signal associated with packet 2812, c(2) is the mapped baseband signal associated with packet 2813, c(3) is the mapped baseband signal associated with packet 2814, and so on.

[0205] When the mapped baseband signal complex number 2911 “c(0)” is generated, the weighting unit 2601 of the AP 2520-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(0)×A1(0)(2931), c(0)×A1(1)(2932), c(0)×A1(2)(2933), and Calculate c(0)×A1(3)(2934).

[0206] AP2520-1 wirelessly outputs c(0)×A1(0)(2931), c(0)×A1(1)(2932), c(0)×A1(2)(2933), and c(0)×A1(3)(2934). When the mapped baseband signal complex number 2912 “c(1)” is generated, the weighting unit 2601 of the AP 2520-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(1)×A1(0)(2935), c(1)×A1(1)(2936), c(1)×A1(2)(2937), and Calculate c(1)×A1(3)(2938).

[0207] AP2520-1 wirelessly outputs c(1)×A1(0)(2935), c(1)×A1(1)(2936), c(1)×A1(2)(2937), and c(1)×A1(3)(2938). AP 2520-1 operates in the same manner as above when it generates mapped baseband signal complex numbers 2913 "c(2)", 2914 "c(3)", . . .

[0208] (AP2520-2 processing) The mapping unit 206 of AP 2520-2 generates the mapped baseband signal complex numbers 2911 “c(0)”, 2912 “c(1)”, 2913 “c(2)”, 2914 “c(3)”, ... as shown in FIG. 29. It is assumed that c(0) is the mapped baseband signal associated with packet 2811, c(1) is the mapped baseband signal associated with packet 2812, c(2) is the mapped baseband signal associated with packet 2813, c(3) is the mapped baseband signal associated with packet 2814, and so on.

[0209] When the mapped baseband signal complex number 2911 “c(0)” is generated, the weighting unit 2601 of the AP 2520-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(0)×A2(0)(2941), c(0)×A2(1)(2942), c(0)×A2(2)(2943), and Calculate c(0)×A2(3)(2944).

[0210] AP2520-2 wirelessly outputs c(0)×A2(0)(2941), c(0)×A2(1)(2942), c(0)×A2(2)(2943), and c(0)×A2(3)(2944). When the mapped baseband signal complex number 2912 “c(1)” is generated, the weighting unit 2601 of the AP 2520-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(1)×A2(0)(2945), c(1)×A2(1)(2946), c(1)×A2(2)(2947), and Calculate c(1)×A2(3)(2948).

[0211] AP2520-2 wirelessly outputs c(1)×A2(0)(2945), c(1)×A2(1)(2946), c(1)×A2(2)(2947), and c(1)×A2(3)(2948). AP 2520-2 operates in the same manner as above when it generates mapped baseband signal complex numbers 2913 "c(2)", 2914 "c(3)", . . .

[0212] (Processing of AP2520-3 and AP2520-4) AP2520-3 and AP2520-4 operate in the same manner as above. Note that weighting section 2601 of AP 2520-3 performs weighting using complex number A3(0), complex number A3(1), complex number A3(2), and complex number A3(3). Furthermore, weighting section 2601 of AP 2520-4 performs weighting using complex number A4(0), complex number A4(1), complex number A4(2), and complex number A4(3). As described above, each packet is characterized in that it is weighted differently and transmitted multiple times, and each packet is also characterized in that it is transmitted multiple times from multiple APs.

[0213] By transmitting using multiple APs, the cell area can be expanded, and by transmitting each packet multiple times with different weighting, the packet is transmitted multiple times with different directivities, which has the effect of maintaining more uniform reception quality within the cell area. The weighting coefficients A1(i), A2(i), A3(i), and A4(i) may have the following properties, for example. Assume that the modulated signal of packet A is transmitted N times (N is an integer greater than or equal to 2). In this case, the weighting coefficient used to transmit the modulated signal of packet A for the uth time is A1(u). The weighting coefficient used to transmit the modulated signal of packet A for the vth time is A1(v). Note that u and v are integers between 1 and N, inclusive, and u ≠ v holds. In this case, u and v are integers between 1 and N, inclusive, and u ≠ v, and for all u and all v that satisfy this, A1(u) ≠ A1(v) holds. Similarly, suppose the modulated signal of packet A is transmitted N times (N is an integer greater than or equal to 2). In this case, the weighting coefficient used to transmit the modulated signal of packet A for the uth time is Ak(u). The weighting coefficient used to transmit the modulated signal of packet A for the vth time is Ak(v). Note that u and v are integers between 1 and N, inclusive, and u ≠ v holds. In this case, u and v are integers between 1 and N, inclusive, and u ≠ v, and for all u and all v that satisfy this, Ak(u) ≠ Ak(v) holds. (k is an integer greater than or equal to 1.) Furthermore, the weighting coefficient Ak(i) may have a period. If the period is M (M is an integer equal to or greater than 2), then the following holds:

[0214] Ak(i)=Ak(i mod M) i mod M is the remainder when i is divided by M. (2) When AP2520-1 and AP2520-2 are set to multicast transmission, and AP2520-3 and AP2520-4 are set to unicast transmission, and data is transmitted. 30 and 31, examples of data to be transmitted when AP2520-1 and AP2520-2 are set for multicast transmission, and AP2520-3 and AP2520-4 are set for unicast transmission and data is transmitted will be described. In this case, it is assumed that AP2520-1 and AP2520-2 transmit the same data (the modulated signals after mapping before phase change are the same). It is also assumed that AP2520-3 and AP2520-4 transmit the same data (the modulated signals after mapping are the same).

[0215] As shown in Fig. 30, the transmission data distribution unit 302 receives packets 3011, 3012, 3013, 3014, etc. in this order. Here, packets 3011, 3013, 3014, 3016, etc. are packets for multicast. Packets 3011, 3013, 3014, 3016, etc. are generated from one piece of multicast data. Furthermore, packets 3012, 3015, etc. are packets for unicast. Packets 3012, 3015, etc. are generated from one piece of unicast data.

[0216] Transmission data distribution unit 302 outputs multicast packets 3011, 3013, 3014, 3016, etc. in this order to AP 2520-1 and AP 2520-2, respectively. Transmission data distribution unit 302 also outputs unicast packets 3012, 3015, etc. in this order to AP 2520-3 and AP 2520-4, respectively.

[0217] (a) Processing of each AP 1 As shown in Figures 25 and 30, AP 2520-1 prepares weights A1(0), A1(1), A1(2), A1(3), etc. Similarly, AP 2520-2 prepares weights A2(0), A2(1), A2(2), A2(3), etc.

[0218] (b) Processing of each AP 2 Next, another example of the processing of each AP will be described with reference to FIG. (AP2520-1 processing) The mapping unit 206 of AP 2520-1 is assumed to generate the mapped baseband signal complex numbers 3111 "c(0)", 3112 "c(1)", 3113 "c(2)", 3114 "c(3)", ... as shown in Figure 31. It is assumed that c(0) is the mapped baseband signal related to packet 3011, c(1) is the mapped baseband signal related to packet 3013, c(2) is the mapped baseband signal related to packet 3014, c(3) is the mapped baseband signal related to packet 3016, and so on.

[0219] When the mapped baseband signal complex number 3111 “c(0)” is generated, the weighting unit 2601 of the AP 2520-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(0)×A1(0)(3131), c(0)×A1(1)(3132), c(0)×A1(2)(3133), and Calculate c(0) × A1(3)(3134).

[0220] AP2520-1 wirelessly outputs c(0)×A1(0)(3131), c(0)×A1(1)(3132), c(0)×A1(2)(3133), and c(0)×A1(3)(3134). When the mapped baseband signal complex number 3112 “c(1)” is generated, the weighting unit 2601 of the AP 2520-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(1)×A1(0)(3135), c(1)×A1(1)(3136), c(1)×A1(2)(3137), and Calculate c(1) × A1(3)(3138).

[0221] AP2520-1 wirelessly outputs c(1)×A1(0)(3135), c(1)×A1(1)(3136), c(1)×A1(2)(3137), and c(1)×A1(3)(3138). Even when post-mapping baseband signal complex numbers 3113 "c(2)", 3114 "c(3)", . . . are generated, AP 2520-1 operates in the same manner as above.

[0222] (AP2520-2 processing) The mapping unit 206 of AP 2520-2 is assumed to generate mapped baseband signal complex numbers 3111 “c(0)”, 3112 “c(1)”, 3113 “c(2)”, 3114 “c(3)”, ... as shown in FIG. 31. It is assumed that c(0) is the mapped baseband signal related to packet 3011, c(1) is the mapped baseband signal related to packet 3013, c(2) is the mapped baseband signal related to packet 3014, c(3) is the mapped baseband signal related to packet 3016, and so on.

[0223] When the mapped baseband signal complex number 3111 “c(0)” is generated, the weighting unit 2601 of the AP 2520-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(0)×A2(0)(3141), c(0)×A2(1)(3142), c(0)×A2(2)(3143), and Calculate c(0)×A2(3)(3144).

[0224] AP2520-2 wirelessly outputs c(0)×A2(0)(3141), c(0)×A2(1)(3142), c(0)×A2(2)(3143), and c(0)×A2(3)(3144). When the mapped baseband signal complex number 3112 “c(1)” is generated, the weighting unit 2601 of the AP 2520-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(1)×A2(0)(3145), c(1)×A2(1)(3146), c(1)×A2(2)(3147), and Calculate c(1) × A2(3)(3148).

[0225] AP2520-2 wirelessly outputs c(1)×A2(0)(3145), c(1)×A2(1)(3146), c(1)×A2(2)(3147), and c(1)×A2(3)(3148). Even when the mapped baseband signal complex numbers 3113 "c(2)", 3114 "c(3)", . . . are generated, the AP 2520-2 operates in the same manner as above.

[0226] (AP2520-3 processing) The mapping section 206 of the AP 2520-3 generates the mapped baseband signal complex numbers "d(0)", "d(1)", "d(2)", . . . It is assumed that d(0) is the baseband signal after mapping related to packet 3051, d(1) is the baseband signal after mapping related to packet 3052, d(2) is the baseband signal after mapping related to packet 3053, and so on.

[0227] When the mapped baseband signal complex number "d(0)" is generated, the AP 2520-3 wirelessly outputs the mapped baseband signal complex number "d(0)" (3151) as shown in FIG. After generating the mapped baseband signal complex number "d(1)", the AP 2520-3 wirelessly outputs the mapped baseband signal complex number "d(1)" (3152) as shown in FIG.

[0228] Similarly, AP2520-3 generates mapped baseband signal complex numbers "d(2)", "d(3)", "d(4)", ..., "d(7)", ... as shown in Figure 31, and outputs the generated "d(2)", "d(3)", "d(4)", ..., "d(7)", ... via wireless. (AP2520-4 processing) The mapping unit 206 of the AP 2520-4 generates the mapped baseband signal complex numbers "d(0)", "d(1)", "d(2)", . . . It is assumed that d(0) is the baseband signal after mapping related to packet 3061, d(1) is the baseband signal after mapping related to packet 3062, d(2) is the baseband signal after mapping related to packet 3063, and so on.

[0229] When the mapped baseband signal complex number "d(0)" is generated, the AP 2520-4 wirelessly outputs the mapped baseband signal complex number "d(0)" (3161) as shown in FIG. When the mapped baseband signal complex number "d(1)" is generated, the AP 2520-4 wirelessly outputs the mapped baseband signal complex number "d(1)" (3162), as shown in FIG.

[0230] Similarly, AP2520-4 generates mapped baseband signal complex numbers "d(2)", "d(3)", "d(4)", ..., "d(7)", ... as shown in Figure 31, and outputs the generated "d(2)", "d(3)", "d(4)", ..., "d(7)", ... via wireless. As described above, each multicast packet is characterized by being weighted differently and transmitted multiple times, and each multicast packet is also characterized by being transmitted multiple times from multiple APs.

[0231] By transmitting using multiple APs, the cell area can be made larger, and by transmitting each multicast packet multiple times with different weighting, the packet is transmitted multiple times with different directivities, which has the effect of maintaining more uniform reception quality within the cell area. Furthermore, in AP2520-3 and AP2520-4, phase changes and weighting may be performed with respect to time and frequency. This provides the effect of improving the reception quality of unicast packets.

[0232] (3) When AP2520-1 and AP2520-2 are configured for multicast and AP2520-3 and AP2520-4 are configured for unicast, An example of data transmitted when AP2520-1 and AP2520-2 are configured for multicast transmission and AP2520-3 and AP2520-4 are configured for unicast transmission will be described with reference to Figures 32 and 33. In this case, different data is transmitted in AP2520-3 and AP2520-4.

[0233] As shown in FIG. 32, the transmission data distribution unit 302 receives packets 3211, 3212, 3213, 3214, etc. in this order. Here, packets 3211, 3213, 3214, 3216, etc. are packets for multicast. Packets 3211, 3213, 3214, 3216, etc. are generated from one piece of data for multicast. Furthermore, packets 3212, etc. are packets for a first unicast. Packets 3212, etc. are generated from first data for unicast. Furthermore, packets 3215, etc. are packets for a second unicast. Packets 3215, etc. are generated from second data for unicast.

[0234] Transmission data distribution unit 302 outputs multicast packets 3211, 3213, 3214, 3216, etc. in this order to AP 2520-1 and AP 2520-2, respectively. Transmission data distribution unit 302 also outputs unicast packets 3212, etc. in this order to AP 2520-3. Transmission data distribution unit 302 also outputs unicast packets 3215, etc. in this order to AP 2520-4.

[0235] (a) Processing of each AP 1 As shown in Figures 25 and 32, AP 2520-1 prepares weights A1(0), A1(1), A1(2), A1(3), etc. Similarly, AP 2520-2 prepares weights A2(0), A2(1), A2(2), A2(3), etc.

[0236] (b) Processing of each AP 2 Next, another example of the processing of each AP will be described with reference to FIG. (AP2520-1 processing) The mapping unit 206 of AP 2520-1 is assumed to generate mapped baseband signal complex numbers 3311 "c(0)", 3312 "c(1)", 3313 "c(2)", 3314 "c(3)", ... as shown in Figure 33. It is assumed that c(0) is the mapped baseband signal related to packet 3211. Then, c(1) is the mapped baseband signal related to packet 3213, c(2) is the mapped baseband signal related to packet 3214, c(3) is the mapped baseband signal related to packet 3216, and so on.

[0237] When the mapped baseband signal complex number 3311 “c(0)” is generated, the weighting unit 2601 of the AP 2520-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(0)×A1(0)(3331), c(0)×A1(1)(3332), c(0)×A1(2)(3333), and Calculate c(0) × A1(3)(3334).

[0238] AP2520-1 wirelessly outputs c(0)×A1(0)(3331), c(0)×A1(1)(3332), c(0)×A1(2)(3333), and c(0)×A1(3)(3334). When the mapped baseband signal complex number 3312 “c(1)” is generated, the weighting unit 2601 of the AP 2520-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(1)×A1(0)(3335), c(1)×A1(1)(3336), c(1)×A1(2)(3337), and Calculate c(1) × A1(3)(3338).

[0239] AP2520-1 wirelessly outputs c(1)×A1(0)(3335), c(1)×A1(1)(3336), c(1)×A1(2)(3337), and c(1)×A1(3)(3338). AP 2520-1 operates in the same manner as above when it generates mapped baseband signal complex numbers 3313 "c(2)", 3314 "c(3)", . . .

[0240] (AP2520-2 processing) The mapping unit 206 of AP 2520-2 is assumed to generate mapped baseband signal complex numbers 3311 "c(0)", 3312 "c(1)", 3313 "c(2)", 3314 "c(3)", ... as shown in Figure 33. It is assumed that c(0) is the mapped baseband signal related to packet 3211. Then, c(1) is the mapped baseband signal related to packet 3213, c(2) is the mapped baseband signal related to packet 3214, c(3) is the mapped baseband signal related to packet 3216, and so on.

[0241] When the mapped baseband signal complex number 3311 “c(0)” is generated, the weighting unit 2601 of the AP 2520-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(0)×A2(0)(3341), c(0)×A2(1)(3342), c(0)×A2(2)(3343), and Calculate c(0)×A2(3)(3344).

[0242] AP2520-2 wirelessly outputs c(0)×A2(0)(3341), c(0)×A2(1)(3342), c(0)×A2(2)(3343), and c(0)×A2(3)(3344). When the mapped baseband signal complex number 3312 “c(1)” is generated, the weighting unit 2601 of the AP 2520-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(1)×A2(0)(3345), c(1)×A2(1)(3346), c(1)×A2(2)(3347), and Calculate c(1)×A2(3)(3348).

[0243] AP2520-2 wirelessly outputs c(1)×A2(0)(3345), c(1)×A2(1)(3346), c(1)×A2(2)(3347), and c(1)×A2(3)(3348). AP 2520-2 operates in the same manner as above when it generates mapped baseband signal complex numbers 3313 "c(2)", 3314 "c(3)", . . .

[0244] (AP2520-3 processing) The mapping section 206 of the AP 2520-3 generates the mapped baseband signal complex numbers "d(0)", "d(1)", "d(2)", . . . It is assumed that d(0) is the baseband signal after mapping related to packet 3251, d(1) is the baseband signal after mapping related to packet 3252, d(2) is the baseband signal after mapping related to packet 3253, and so on.

[0245] When the mapped baseband signal complex number "d(0)" is generated, the AP 2520-3 wirelessly outputs the mapped baseband signal complex number "d(0)" (3351) as shown in FIG. After generating the mapped baseband signal complex number "d(1)", the AP 2520-3 wirelessly outputs the mapped baseband signal complex number "d(1)" (3352), as shown in FIG.

[0246] Similarly, AP2520-3 generates mapped baseband signal complex numbers "d(2)", "d(3)", "d(4)", ..., "d(7)", ... as shown in Figure 33, and outputs the generated "d(2)", "d(3)", "d(4)", ..., "d(7)", ... via wireless. (AP2520-4 processing) The mapping unit 206 of the AP 2520-4 generates the mapped baseband signal complex numbers "e(0)", "e(1)", "e(2)", . . . It is assumed that e(0) is the baseband signal after mapping related to packet 3261. Then, e(1) is the baseband signal after mapping related to packet 3262, e(2) is the baseband signal after mapping related to packet 3263, and so on.

[0247] When the mapped baseband signal complex number "e(0)" is generated, the AP 2520-4 wirelessly outputs the mapped baseband signal complex number "e(0)" (3361) as shown in FIG. When the mapped baseband signal complex number "e(1)" is generated, the AP 2520-4 wirelessly outputs the mapped baseband signal complex number "e(1)" (3362) as shown in FIG.

[0248] Similarly, AP2520-4 generates mapped baseband signal complex numbers "e(2)", "e(3)", "e(4)", ..., "e(7)", ... as shown in Figure 33, and outputs the generated "e(2)", "e(3)", "e(4)", ..., "e(7)", ... via wireless. As described above, each multicast packet is characterized by being weighted differently and transmitted multiple times, and each multicast packet is also characterized by being transmitted multiple times from multiple APs.

[0249] By transmitting using multiple APs, the cell area can be made larger, and by transmitting each multicast packet multiple times with different weighting, the packet is transmitted multiple times with different directivities, which has the effect of maintaining more uniform reception quality within the cell area. In addition, AP2520-3 and AP2520-4 have the flexibility to transmit unicast packets. For example, by switching between the transmission state of Figure 28, the transmission state of Figure 30, and the transmission state of Figure 32 depending on time (for example, switching depending on the presence status of the terminal), there is also the advantage that a flexible system can be realized. 4.5 Summary According to this aspect, large-capacity transmission of Gbps can be realized. Also, when multicast is realized, the number of terminals that can be accommodated can be increased. Furthermore, unicast communication can be realized simultaneously with multicast, making the system more flexible.

[0250] 5. Fourth Embodiment A wireless communication system 3400 according to another fourth embodiment of the present invention will be described. 5.1 Wireless Communication System 3400 As shown in FIG. 34, the wireless communication system 3400 is made up of a master station 3410, AP 3420-1, AP 3420-2, AP 3420-3, AP 3420-4, and terminal 3430-1, terminal 3430-2, . . . , terminal 3430-8.

[0251] The master station 3410 is connected to a communication device (not shown) directly or indirectly via a communication line. Here, examples of the communication device include a broadcasting device that broadcasts data, a distribution system or server that transmits data, etc. The communication device transmits a control signal and data. The control signal includes a setting for a unicast transmission method or a setting for a multicast transmission method, and a setting for a weighting method. Furthermore, the communication device may be composed of multiple communication devices. In this case, a first communication device may transmit a control signal, and a second communication device may transmit data. The master station 3410 is connected to AP3420-1, AP3420-2, AP3420-3, and AP3420-4 by wire (or may be connected wirelessly). Furthermore, AP3420-1 is connected to AP3420-2, AP3420-3, and AP3420-4 by wire (or may be connected wirelessly).

[0252] The master station 3410 receives control signals and data from the communication devices. The master station 3410 transmits a control signal to the AP 3420-1. The master station 3410 also transmits data to the AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4. The AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4 also transmit the data received from the master station 3410 wirelessly.

[0253] Terminal 3430-1, terminal 3430-2, ..., terminal 3430-8 are each a mobile phone, smartphone, tablet, or personal computer (PC) equipped with a wireless communication function using a frequency band above 6 GHz, for example, a frequency band called millimeter waves, for example, a 60 GHz frequency band. For example, when terminal 3430-1 is located close to AP 3420-1, terminal 3430-1 receives data wirelessly from AP 3420-1. Terminals 3430-2, ..., terminal 3430-8 also each receive data wirelessly from nearby APs, similar to terminal 3430-1.

[0254] Furthermore, the terminal 3430-1 transmits data wirelessly. When the terminal 3430-1 is located close to the AP 3420-1, the AP 3420-1 receives data wirelessly from the terminal 3430-1. The AP 3420-1 transmits the received data to the master station 3410. Similar to terminal 3430-1, terminal 3430-2, terminal 3430-3, ..., terminal 3430-8 also transmit data wirelessly. APs located close to each terminal receive data wirelessly from the terminal. The APs transmit the data received from the terminals to master station 3410.

[0255] The master station 3410 receives data from each terminal via each AP, and outputs the received data to the communication device. The control signal transmitted from the master station 3410 to the AP 3420-1 includes settings for unicast or multicast transmission in each AP and settings for the weighting method in each AP. The master station 3410 does not configure settings for unicast or multicast transmission in the APs 3420-2, 3420-3, and 3420-4. Furthermore, the master station 3410 does not configure settings for weighting methods in the APs 3420-2, 3420-3, and 3420-4.

[0256] The AP 3420-1 performs settings related to unicast transmission or multicast transmission for the AP 3420-2, the AP 3420-2, and the AP 3420-3. The AP 3420-1 also performs settings related to weighting methods for the AP 3420-2, the AP 3420-2, and the AP 3420-3. AP 3420-1 is called the master AP, and AP 3420-2, AP 3420-3, and AP 3420-4 are called non-master APs.

[0257] 5.2 AP3420-1 as Master AP As shown in FIG. 35, the master AP AP3420-1 is composed of an encoder 202, an interleaver 204, a mapping unit 206, a weighting unit 3511, a radio unit 210, an antenna 212, an antenna 215, a receiving device 217 and an instruction unit 3502. The AP 3420-1 receives a control signal 3501 from the master station 3410. The control signal 3501 includes settings related to unicast transmission or multicast transmission, and settings for the weighting method.

[0258] The AP 3420-1 performs settings related to unicast transmission or multicast transmission based on the control signal 3501 received from the master station 3410. The AP 3420-1 also performs settings related to the weighting method based on the control signal 3501. When multicast transmission is configured, the AP 3420-1 is configured to use the same frequency (frequency band) as other APs.

[0259] When setting up unicast transmission, the AP 3420-1 operates the receiving device 217. When setting up multicast transmission, the AP 3420-1 may stop the operation of the receiving device 217. The AP 3420-1 transmits and receives wirelessly using the same channel for both unicast and multicast transmissions. The AP 3420-1 may divide a single wireless carrier into several time slots and use each time slot as a communication channel. The AP 3420-1 may also use multiple different frequencies in the 60 GHz frequency band and use each frequency as a communication channel.

[0260] (1) Encoder 202 The encoder 202 receives data 201 from the master station 3410. The encoder 202 also receives a control signal 213 from a controller included in the AP 3420-1. The control signal 213 includes information such as a designation of an encoding method, a designation of an error correction method, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 201 using the method designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0261] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 3420-1. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0262] (3) Mapping unit 206 Mapping unit 206 receives interleaved data 205 from interleaver 204. Mapping unit 206 also receives control signal 213 from a controller included in AP 3420-1. Control signal 213 includes a modulation scheme designation. Mapping unit 206 performs modulation on interleaved data 205 using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like in accordance with the modulation scheme designation included in control signal 213, to generate modulated signal 207. Mapping unit 206 outputs modulated signal 207. Note that the modulation scheme may be another modulation scheme.

[0263] The mapping unit 206 may perform mapping including weighting processing. (4) Weighting unit 3511 Weighting section 3511 receives modulated signal 207 from mapping section 206. Weighting section 3511 also receives control signal 3503_0. Control signal 3503_0 includes a weighting method setting. Weighting section 3511 weights modulated signal 207 in accordance with the weighting method setting included in control signal 3503_0, and generates weighted signal 3512. Weighting section 3511 outputs weighted signal 3512.

[0264] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives weighted signal 3512 from weighting unit 3511. Radio unit 210 also receives control signal 213 from a controller included in AP 3420-1. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on weighted signal 3512 to generate transmission signal 211. Radio unit 210 outputs generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0265] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. The receiving device 217 receives a signal 216 from the antenna 215 using a frequency band above 6 GHz, for example, a frequency band called a millimeter wave, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the signal to generate data 218. The receiving device 217 outputs the data 218 to the master station 3410.

[0266] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. (7) Instruction section 3502 The instruction unit 3502 is connected to the master station 3410 . The instruction unit 3502 receives a control signal 3501 from the master station 3410. The control signal 3501 includes settings related to unicast transmission or multicast transmission, and settings for the weighting method.

[0267] Furthermore, the control signal 3501 may be set individually for each AP, or the same control signal 3501 may be set for all APs. The instruction unit 3502 sets up multicast or unicast for all APs including the AP 3420-1 using a control signal 3503_0, a control signal 3503_1, . . . , a control signal 3503_N.

[0268] Here, instruction unit 3502 may set all APs to multicast transmission, or may set all APs to unicast transmission. Some APs may be set to multicast transmission, and other APs may be set to unicast transmission. In this way, APs may be set to both multicast transmission and unicast transmission.

[0269] For multiple APs configured for multicast, the modulated signals before weighting are the same signal, in other words, the same data is transmitted. Furthermore, the instruction unit 3502 instructs each AP on the weighting method by using a control signal 3503_0, a control signal 3503_1, . . . , a control signal 3503_N. For multiple APs configured for unicast transmission, the modulated signals before weighting may be the same or different signals, i.e., the same data may be transmitted or different data may be transmitted.

[0270] In this way, instruction unit 3502 generates control signals 3503_0, 3503_1, ..., 3503_N for each AP from received control signal 3501. Each control signal includes settings related to multicast transmission or settings related to unicast transmission and settings for the weighting method. Instruction unit 3502 outputs control signals 3503_0, 3503_1, ..., 3503_N to itself, AP 3420-2, AP 3420-3, and AP 3420-4.

[0271] When instructing unit 3502 specifies unicast transmission for AP 3420-1, it operates receiving device 217. Furthermore, when instructing unit 3502 specifies multicast transmission for AP 3420-1, it may stop the operation of receiving device 217. 5.3 Non-Master AP3600 AP 3420-2, AP 3420-3, and AP 3420-4 are non-master APs. Here, AP 3600 will be described as a representative of AP 3420-2, AP 3420-3, and AP 3420-4.

[0272] As shown in FIG. 36, the non-master AP 3600 is composed of an encoder 202, an interleaver 204, a mapping unit 206, a weighting unit 3611, a radio unit 210, an antenna 212, an antenna 215, and a receiving device 217. The AP 3600 receives a control signal 3601_0 from the master AP 3420-1. The control signal 3601_0 includes settings related to unicast transmission or multicast transmission, and settings for the weighting method. The AP 3600 also receives data 3602 from the master AP 3420-1. When AP cooperation is performed, the AP 3600 may receive data 3603 from another AP that is not the master. When operating independently by unicast transmission, the AP 3600 may receive data 201 from the parent station 3410.

[0273] The AP 3600 performs settings related to unicast transmission or multicast transmission based on the control signal 3601_0. The AP 3600 also performs settings related to the weighting method based on the control signal 3601_0. Note that when multicast transmission is set, the AP 3600 is set to use the same frequency (frequency band) as other APs. When performing unicast transmission and setting, the AP 3600 operates the receiving device 217. When performing multicast transmission and setting, the AP 3600 may stop the operation of the receiving device 217.

[0274] The AP3600 transmits and receives wirelessly using the same channel (or the same frequency (frequency band)) for both unicast and multicast transmissions. Here, the AP3600 may divide one wireless carrier into several time slots and use each time slot as a communication channel. The AP3600 may also use several different frequencies in the 60 GHz frequency band and use each frequency as a communication channel.

[0275] (1) Encoder 202 The encoder 202 receives the data 3602, the data 3603, or the data 201. The encoder 202 also receives a control signal 213 from a controller included in the AP 3600. The control signal 213 includes information such as a designation of an encoding method, a designation of an error correction method, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 3602, the data 3603, or the data 201 using the method designated by the control signal 213. The encoder 202 outputs the encoded data 203.

[0276] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 3600. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0277] (3) Mapping unit 206 The mapping unit 206 receives interleaved data 205 from the interleaver 204. The mapping unit 206 also receives a control signal 213 from a controller included in the AP 3600. The control signal 213 includes a modulation scheme designation. In accordance with the modulation scheme designation included in the control signal 213, the mapping unit 206 performs modulation using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like on the interleaved data 205 to generate a modulated signal 207. The mapping unit 206 outputs the modulated signal 207. Note that other modulation schemes may also be used.

[0278] The mapping unit 206 may perform mapping including weighting processing. (4) Weighting unit 3611 Weighting section 3611 receives modulated signal 207 from mapping section 206. Weighting section 3611 also receives control signal 3601_0. Control signal 3601_0 includes a weighting method setting. Weighting section 3611 weights modulated signal 207 in accordance with the weighting method setting included in control signal 3601_0, and generates weighted signal 3612. Weighting section 3611 outputs weighted signal 3612.

[0279] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives weighted signal 3612 from weighting unit 3611. Radio unit 210 also receives control signal 213 from a controller included in AP 3600. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on weighted signal 3612 to generate transmission signal 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0280] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. The receiving device 217 receives a signal 216 from the antenna 215 using a frequency band above 6 GHz, for example, a frequency band called a millimeter wave, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the signal to generate data 218. The receiving device 217 outputs the data 218 to the master station 3410.

[0281] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. 5.4 Master station 3410 As shown in FIG. 37, the master station 3410 is made up of a transmission data distribution unit 302, a reception data distribution unit 305, and an instruction unit 308.

[0282] (1) Instruction section 308 The instruction unit 308 is connected to the communication device and AP3420-1, AP3420-2, AP3420-3, and AP3420-4. The instruction unit 308 receives the control signal 307. The control signal 307 includes settings related to unicast transmission or multicast transmission, and settings for a weighting method. The communication device includes, for example, a PC, and a user of the PC inputs the control signal through the PC.

[0283] Furthermore, the control signal 307 may be set individually for each AP, or the same control signal 307 may be set for all APs. All APs may be set to multicast transmission, or all APs may be set to unicast transmission. Some APs may be set to multicast transmission, and other APs may be set to unicast transmission. In this way, APs may have a mixture of multicast transmission settings and unicast settings.

[0284] For multiple APs configured for multicast, the modulated signals before weighting are the same signal, in other words, the same data is transmitted. It also instructs each AP on the weighting method. For multiple APs configured for unicast, the pre-weighted modulated signals may be the same or different signals, i.e., the same data may be transmitted or different data may be transmitted.

[0285] The instruction unit 308 outputs the received control signal to the transmission data distribution unit 302, the reception data distribution unit 305, and the APs 3420-1, 3420-2, 3420-3, and 3420-4. (2) Transmission data distribution unit 302 The transmission data distribution unit 302 is connected to the communication device, the instruction unit 308, and the AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4.

[0286] The transmission data distribution unit 302 receives a control signal from the instruction unit 308. The transmission data distribution unit 302 outputs the received control signal to the AP 3420-1, the AP 3420-2, the AP 3420-3, and the AP 3420-4. Furthermore, the transmission data distribution unit 302 receives data from the communication device. The transmission data distribution unit 302 distributes the received data to AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4. The transmission data distribution unit 302 outputs the distributed data to AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4, respectively.

[0287] (3) Received data distribution unit 305 The received data distribution unit 305 is connected to the communication device, the instruction unit 308, and the AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4. Furthermore, the received data distribution unit 305 receives data from each of the APs 3420-1, 3420-2, 3420-3, and 3420-4. The received data distribution unit 305 outputs the received data to the communication device.

[0288] 5.5 Example of data sent An example of data transmitted by the master station 3410, AP 3420-1, AP 3420-2, AP 3420-3, and AP 3420-4 will be described below. (1) When all APs are set to multicast transmission and data is transmitted An example of data to be transmitted when all of the APs 3420-1, 3420-2, 3420-3, and 3420-4 are set for multicast transmission and data is transmitted will be described with reference to FIGS. 38 and 39. FIG.

[0289] 38, the master station 3410 receives packets 3811, 3812, 3813, 3814, etc. in this order. Here, packets 3811, 3812, 3813, 3814, etc. are all multicast packets. Also, packets 3811, 3812, 3813, 3814, etc. are generated from one piece of multicast data. The master station 3410 transmits packets 3811, 3812, 3813, 3814, etc. to AP 3420-1 in this order.

[0290] The AP 3420-1 receives packets 3811, 3812, 3813, 3814, etc. in this order. Next, the AP 3420-1 transmits packets 3811, 3812, 3813, 3814, etc. to the AP 3420-2, AP 3420-3, and AP 3420-4 in this order. (a) Processing of each AP 1 As shown in Figures 34 and 38, AP 3420-1 prepares weights A1(0), A1(1), A1(2), A1(3), etc. Similarly, AP 3420-2 prepares weights A2(0), A2(1), A2(2), A2(3), etc., AP 3420-3 prepares weights A3(0), A3(1), A3(2), A3(3), etc., and AP 3420-4 prepares weights A4(0), A4(1), A4(2), A4(3), etc.

[0291] (b) Processing of each AP 2 Next, another example of the processing of each AP will be described with reference to FIG. (AP3420-1 processing) The mapping unit 206 of AP3420-1 is assumed to generate mapped baseband signal complex numbers 3911 "c(0)", 3912 "c(1)", 3913 "c(2)", 3914 "c(3)", ... as shown in Figure 39. It is assumed that c(0) is the mapped baseband signal related to packet 3811. Then, c(1) is the mapped baseband signal related to packet 3812, c(2) is the mapped baseband signal related to packet 3813, c(3) is the mapped baseband signal related to packet 3814, and so on.

[0292] When the mapped baseband signal complex number 3911 “c(0)” is generated, the weighting unit 3511 of the AP 3420-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(0)×A1(0)(3931), c(0)×A1(1)(3932), c(0)×A1(2)(3933), and Calculate c(0)×A1(3)(3934).

[0293] AP3420-1 wirelessly outputs c(0)×A1(0)(3931), c(0)×A1(1)(3932), c(0)×A1(2)(3933), and c(0)×A1(3)(3934). When the mapped baseband signal complex number 3912 “c(1)” is generated, the weighting unit 3511 of the AP 3420-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the weighting factor c(1). c(1)×A1(0)(3935), c(1)×A1(1)(3936), c(1)×A1(2)(3937), and Calculate c(1) × A1(3)(3938).

[0294] AP3420-1 wirelessly outputs c(1)×A1(0)(3935), c(1)×A1(1)(3936), c(1)×A1(2)(3937), and c(1)×A1(3)(3938). AP 3420-1 operates in the same manner as above when it generates mapped baseband signal complex numbers 3913 "c(2)", 3914 "c(3)", . . .

[0295] (AP3420-2 processing) The mapping unit 206 of AP3420-2 is assumed to generate mapped baseband signal complex numbers 3911 "c(0)", 3912 "c(1)", 3913 "c(2)", 3914 "c(3)", ... as shown in Figure 39. It is assumed that c(0) is the mapped baseband signal related to packet 3811. Then, c(1) is the mapped baseband signal related to packet 3812, c(2) is the mapped baseband signal related to packet 3813, c(3) is the mapped baseband signal related to packet 3814, and so on.

[0296] When the mapped baseband signal complex number 3911 “c(0)” is generated, the weighting unit 3611 of the AP 3420-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(0)×A2(0)(3941), c(0)×A2(1)(3942), c(0)×A2(2)(3943), and Calculate c(0)×A2(3)(3944).

[0297] AP3420-2 wirelessly outputs c(0)×A2(0)(3941), c(0)×A2(1)(3942), c(0)×A2(2)(3943), and c(0)×A2(3)(3944). When the mapped baseband signal complex number 3912 “c(1)” is generated, the weighting unit 3611 of the AP 3420-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(1)×A2(0)(3945), c(1)×A2(1)(3946), c(1)×A2(2)(3947), and Calculate c(1)×A2(3)(3948).

[0298] AP3420-2 wirelessly outputs c(1)×A2(0)(3945), c(1)×A2(1)(3946), c(1)×A2(2)(3947), and c(1)×A2(3)(3948). AP3420-2 operates in the same manner as above when it generates mapped baseband signal complex numbers 3913 "c(2)", 3914 "c(3)", . . .

[0299] (Processing of AP3420-3 and AP3420-4) AP3420-3 and AP3420-4 operate in the same manner as above. Note that weighting section 2601 of AP3420-3 performs weighting using complex number A3(0), complex number A3(1), complex number A3(2), and complex number A3(3). Furthermore, weighting section 2601 of AP3420-4 performs weighting using complex number A4(0), complex number A4(1), complex number A4(2), and complex number A4(3).

[0300] As described above, each packet is characterized in that it is weighted differently and transmitted multiple times, and each packet is also characterized in that it is transmitted multiple times from multiple APs. By transmitting using multiple APs, the cell area can be expanded, and by transmitting each packet multiple times with different weighting, the packet is transmitted multiple times with different directivities, which has the effect of maintaining more uniform reception quality within the cell area.

[0301] The weighting coefficients A1(i), A2(i), A3(i), and A4(i) may have the following properties, for example. Assume that the modulated signal of packet A is transmitted N times (N is an integer greater than or equal to 2). In this case, the weighting coefficient used to transmit the modulated signal of packet A for the uth time is A1(u). The weighting coefficient used to transmit the modulated signal of packet A for the vth time is A1(v). Note that u and v are integers between 1 and N, inclusive, and u ≠ v holds. In this case, u and v are integers between 1 and N, inclusive, and u ≠ v, and for all u and all v that satisfy this, A1(u) ≠ A1(v) holds. Similarly, suppose the modulated signal of packet A is transmitted N times (N is an integer greater than or equal to 2). In this case, the weighting coefficient used to transmit the modulated signal of packet A for the uth time is Ak(u). The weighting coefficient used to transmit the modulated signal of packet A for the vth time is Ak(v). Note that u and v are integers between 1 and N, inclusive, and u ≠ v holds. In this case, u and v are integers between 1 and N, inclusive, and u ≠ v, and for all u and all v that satisfy this, Ak(u) ≠ Ak(v) holds. (k is an integer greater than or equal to 1.) Furthermore, the weighting coefficient Ak(i) may have a period. If the period is M (M is an integer equal to or greater than 2), then the following holds:

[0302] Ak(i)=Ak(i mod M) i mod M is the remainder when i is divided by M. (2) When AP3420-1 and AP3420-2 are set to multicast transmission, and AP3420-3 and AP3420-4 are set to unicast transmission, and data is transmitted 40 and 41, examples of data to be transmitted when AP3420-1 and AP3420-2 are set for multicast transmission and AP3420-3 and AP3420-4 are set for unicast transmission will be described. In this case, the same data is transmitted from AP3420-3 and AP3420-4 (the modulated signals after mapping are the same).

[0303] As shown in Figure 40, the master station 3410 receives packets 4011, 4012, 4013, 4014, ... in this order. Here, packets 4011, 4013, 4014, 4016, ... are packets for multicast. Packets 4011, 4013, 4014, 4016, ... are generated from one piece of data for multicast. Also, packets 4012, 4015, ... are packets for unicast. Packets 4012, 4015, ... are generated from one piece of data for unicast.

[0304] The master station 3410 outputs multicast packets 4011, 4013, 4014, 4016, etc. in this order to the AP 3420-1. The master station 3410 also outputs unicast packets 4012, 4015, etc. in this order to the AP 3420-3 and AP 3420-4, respectively. AP 3420-1 receives multicast packets 4011, 4013, 4014, 4016, etc. in this order. AP 3420-1 transmits multicast packets 4011, 4013, 4014, 4016, etc. to AP 3420-2 in this order.

[0305] (a) Processing of each AP 1 As shown in Figures 34 and 40, AP 3420-1 prepares weights A1(0), A1(1), A1(2), A1(3), etc. Similarly, AP 3420-2 prepares weights A2(0), A2(1), A2(2), A2(3), etc.

[0306] (b) Processing of each AP 2 Next, another example of the processing of each AP will be described with reference to FIG. (AP3420-1 processing) The mapping unit 206 of AP3420-1 is assumed to generate mapped baseband signal complex numbers 4111 "c(0)", 4112 "c(1)", 4113 "c(2)", 4114 "c(3)", ... as shown in Figure 41. It is assumed that c(0) is the mapped baseband signal related to packet 4011, c(1) is the mapped baseband signal related to packet 4013, c(2) is the mapped baseband signal related to packet 4014, c(3) is the mapped baseband signal related to packet 4016, and so on.

[0307] When the mapped baseband signal complex number 4111 “c(0)” is generated, the weighting unit 3511 of the AP 3420-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(0)×A1(0)(4131), c(0)×A1(1)(4132), c(0)×A1(2)(4133), and Calculate c(0) × A1(3)(4134).

[0308] AP3420-1 wirelessly outputs c(0)×A1(0)(4131), c(0)×A1(1)(4132), c(0)×A1(2)(4133), and c(0)×A1(3)(4134). When the mapped baseband signal complex number 4112 “c(1)” is generated, the weighting unit 3511 of the AP 3420-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(1)×A1(0)(4135), c(1)×A1(1)(4136), c(1)×A1(2)(4137), and Calculate c(1) × A1(3)(4138).

[0309] AP3420-1 wirelessly outputs c(1)×A1(0)(4135), c(1)×A1(1)(4136), c(1)×A1(2)(4137), and c(1)×A1(3)(4138). AP3420-1 operates in the same manner as above when it generates mapped baseband signal complex numbers 4113 "c(2)", 4114 "c(3)", . . .

[0310] (AP3420-2 processing) The mapping unit 206 of AP3420-2 is assumed to generate mapped baseband signal complex numbers 4111 "c(0)", 4112 "c(1)", 4113 "c(2)", 4114 "c(3)", ... as shown in Figure 41. It is assumed that c(0) is the mapped baseband signal related to packet 4011, c(1) is the mapped baseband signal related to packet 4013, c(2) is the mapped baseband signal related to packet 4014, c(3) is the mapped baseband signal related to packet 4016, and so on.

[0311] When the mapped baseband signal complex number 4111 “c(0)” is generated, the weighting unit 3611 of the AP 3420-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(0)×A2(0)(4141), c(0)×A2(1)(4142), c(0)×A2(2)(4143), and Calculate c(0)×A2(3)(4144).

[0312] AP3420-2 wirelessly outputs c(0)×A2(0)(4141), c(0)×A2(1)(4142), c(0)×A2(2)(4143), and c(0)×A2(3)(4144). When the mapped baseband signal complex number 4112 “c(1)” is generated, the weighting unit 3611 of the AP 3420-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(1)×A2(0)(4145), c(1)×A2(1)(4146), c(1)×A2(2)(4147), and Calculate c(1)×A2(3)(4148).

[0313] AP3420-2 wirelessly outputs c(1)×A2(0)(4145), c(1)×A2(1)(4146), c(1)×A2(2)(4147), and c(1)×A2(3)(4148). AP3420-2 operates in the same manner as above when it generates mapped baseband signal complex numbers 4113 "c(2)", 4114 "c(3)", . . .

[0314] (AP3420-3 processing) The mapping unit 206 of the AP 3420-3 generates the mapped baseband signal complex numbers "d(0)", "d(1)", "d(2)", "d(3)", . . . It is assumed that d(0) is the baseband signal after mapping related to packet 4051, d(1) is the baseband signal after mapping related to packet 4052, d(2) is the baseband signal after mapping related to packet 4053, and so on.

[0315] After generating the mapped baseband signal complex number "d(0)", the AP3420-3 outputs the generated d(0) (4151) wirelessly. After generating the mapped baseband signal complex number "d(1)", AP3420-3 outputs the generated d(1) (4152) wirelessly. Similarly, when the mapped baseband signal complex numbers "d(2)", "d(3)", ... are generated, AP3420-3 outputs the generated "d(2)", "d(3)", ... wirelessly.

[0316] (AP3420-4 processing) The mapping unit 206 of the AP 3420-4 is assumed to generate the mapped baseband signal complex numbers "d(0)", "d(1)", "d(2)", "d(3)", . . . It is assumed that d(0) is the baseband signal after mapping related to packet 4061, d(1) is the baseband signal after mapping related to packet 4062, d(2) is the baseband signal after mapping related to packet 4063, and so on.

[0317] After generating the mapped baseband signal complex number "d(0)", AP3420-4 outputs the generated d(0) (4161) wirelessly. After generating the mapped baseband signal complex number "d(1)", AP3420-4 outputs the generated d(1) (4162) wirelessly. Similarly, when the mapped baseband signal complex numbers "d(2)", "d(3)", ... are generated, AP3420-4 outputs the generated "d(2)", "d(3)", ... wirelessly.

[0318] As described above, each multicast packet is characterized by being weighted differently and transmitted multiple times, and each multicast packet is also characterized by being transmitted multiple times from multiple APs. By transmitting using multiple APs, the cell area can be made larger, and by transmitting each multicast packet multiple times with different weighting, the packet is transmitted multiple times with different directivities, which has the effect of maintaining more uniform reception quality within the cell area.

[0319] Furthermore, in AP2520-3 and AP2520-4, phase changes and weighting may be performed with respect to time and frequency. This provides the effect of improving the reception quality of unicast packets. (3) When AP3420-1 and AP3420-2 are set for multicast transmission and AP3420-3 and AP3420-4 are set for unicast transmission An example of data transmitted when AP 3420-1 and AP 3420-2 are configured for multicast transmission and AP 3420-3 and AP 3420-4 are configured for unicast transmission will be described with reference to Figures 42 and 43. In this case, different data is transmitted in AP 3420-3 and AP 3420-4.

[0320] As shown in FIG. 42, the master station 3410 receives packets 4211, 4212, 4213, 4214, 4215, 4216, etc. in this order. Here, packets 4211, 4213, 4214, 4216, etc. are packets for multicast. Packets 4211, 4213, 4214, 4216, etc. are generated from one piece of data for multicast. Packets 4212, etc. are packets for a first unicast. Packets 4212, etc. are generated from first data for unicast. Packets 4215, etc. are packets for a second unicast. Packets 4215, etc. are generated from second data for unicast.

[0321] The master station 3410 outputs multicast packets 4211, 4213, 4214, 4216, etc. in this order to AP 3420-1. The master station 3410 also outputs unicast packets 4212, etc. in this order to AP 3420-3. The master station 3410 also outputs unicast packets 4215, etc. in this order to AP 3420-4.

[0322] The AP 3420-1 receives the multicast packets 4211, 4213, 4214, 4216, etc. in this order. Next, the AP 3420-1 transmits the multicast packets 4211, 4213, 4214, 4216, etc. in this order to the AP 3420-2. (a) Processing of each AP 1 As shown in Figures 34 and 42, AP 3420-1 prepares weights A1(0), A1(1), A1(2), A1(3), etc. Similarly, AP 3420-2 prepares weights A2(0), A2(1), A2(2), A2(3), etc.

[0323] (b) Processing of each AP 2 Next, another example of the processing of each AP will be described with reference to FIG. (AP3420-1 processing) The mapping unit 206 of AP3420-1 is assumed to generate mapped baseband signal complex numbers 4311 "c(0)", 4312 "c(1)", 4313 "c(2)", 4314 "c(3)", ... as shown in Figure 43. It is assumed that c(0) is the mapped baseband signal related to packet 4211. Then, c(1) is the mapped baseband signal related to packet 4213, c(2) is the mapped baseband signal related to packet 4214, c(3) is the mapped baseband signal related to packet 4216, and so on.

[0324] When the mapped baseband signal complex number 4311 “c(0)” is generated, the weighting unit 3511 of the AP 3420-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(0)×A1(0)(4331), c(0)×A1(1)(4332), c(0)×A1(2)(4333), and Calculate c(0)×A1(3)(4334).

[0325] AP3420-1 wirelessly outputs c(0)×A1(0)(4331), c(0)×A1(1)(4332), c(0)×A1(2)(4333), and c(0)×A1(3)(4334). When the mapped baseband signal complex number 4312 “c(1)” is generated, the weighting unit 3511 of the AP 3420-1 uses the complex number A1(0), the complex number A1(1), the complex number A1(2), and the complex number A1(3) to calculate the following: c(1)×A1(0)(4335), c(1)×A1(1)(4336), c(1)×A1(2)(4337), and Calculate c(1) × A1(3)(4338).

[0326] AP3420-1 wirelessly outputs c(1)×A1(0)(4335), c(1)×A1(1)(4336), c(1)×A1(2)(4337), and c(1)×A1(3)(4338). AP3420-1 operates in the same manner as above when it generates mapped baseband signal complex numbers 4313 "c(2)", 4314 "c(3)", . . .

[0327] (AP3420-2 processing) The mapping unit 206 of AP3420-2 is assumed to generate mapped baseband signal complex numbers 4311 "c(0)", 4312 "c(1)", 4313 "c(2)", 4314 "c(3)", ... as shown in Figure 43. It is assumed that c(0) is the mapped baseband signal related to packet 4211. Then, c(1) is the mapped baseband signal related to packet 4213, c(2) is the mapped baseband signal related to packet 4214, c(3) is the mapped baseband signal related to packet 4216, and so on.

[0328] When the mapped baseband signal complex number 4311 “c(0)” is generated, the weighting unit 3611 of the AP 3420-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(0)×A2(0)(4341), c(0)×A2(1)(4342), c(0)×A2(2)(4343), and Calculate c(0)×A2(3)(4344).

[0329] AP3420-2 wirelessly outputs c(0)×A2(0)(4341), c(0)×A2(1)(4342), c(0)×A2(2)(4343), and c(0)×A2(3)(4344). When the mapped baseband signal complex number 4312 “c(1)” is generated, the weighting unit 3611 of the AP 3420-2 uses the complex number A2(0), the complex number A2(1), the complex number A2(2), and the complex number A2(3) to calculate the following: c(1)×A2(0)(4345), c(1)×A2(1)(4346), c(1)×A2(2)(4347), and Calculate c(1)×A2(3)(4348).

[0330] AP3420-2 wirelessly outputs c(1)×A2(0)(4345), c(1)×A2(1)(4346), c(1)×A2(2)(4347), and c(1)×A2(3)(4348). AP3420-2 operates in the same manner as above when it generates mapped baseband signal complex numbers 4313 "c(2)", 4314 "c(3)", . . .

[0331] (AP3420-3 processing) The mapping unit 206 of the AP 3420-3 generates the mapped baseband signal complex numbers "d(0)", "d(1)", "d(2)", "d(3)", . . . It is assumed that d(0) is the baseband signal after mapping related to packet 4251, d(1) is the baseband signal after mapping related to packet 4252, d(2) is the baseband signal after mapping related to packet 4253, and so on.

[0332] After generating the mapped baseband signal complex number "d(0)", AP3420-3 outputs the generated d(0) (4351) wirelessly. After generating the mapped baseband signal complex number "d(1)", AP3420-3 outputs the generated d(1) (4352) wirelessly. Similarly, when the mapped baseband signal complex numbers "d(2)", "d(3)", ... are generated, AP3420-3 outputs the generated "d(2)", "d(3)", ... wirelessly.

[0333] (AP3420-4 processing) The mapping unit 206 of the AP 3420-4 is assumed to generate the mapped baseband signal complex numbers "e(0)", "e(1)", "e(2)", "e(3)", . . . It is assumed that e(0) is the baseband signal after mapping related to packet 4261. Then, e(1) is the baseband signal after mapping related to packet 4262, e(2) is the baseband signal after mapping related to packet 4263, and so on.

[0334] After generating the mapped baseband signal complex number "e(0)", AP3420-4 outputs the generated e(0) (4361) wirelessly. After generating the mapped baseband signal complex number "e(1)", AP3420-4 outputs the generated e(1) (4362) wirelessly. Similarly, when the mapped baseband signal complex numbers "d(2)", "d(3)", ... are generated, AP3420-3 outputs the generated "d(2)", "d(3)", ... wirelessly. As described above, each multicast packet is characterized by being weighted differently and transmitted multiple times, and each multicast packet is also characterized by being transmitted multiple times from multiple APs.

[0335] By transmitting using multiple APs, the cell area can be made larger, and by transmitting each multicast packet multiple times with different weighting, the packet is transmitted multiple times with different directivities, which has the effect of maintaining more uniform reception quality within the cell area. In addition, AP3420-3 and AP3420-4 have the flexibility to transmit unicast packets. For example, by switching between the transmission state of Figure 38, the transmission state of Figure 40, and the transmission state of Figure 42 depending on the time (for example, switching depending on the presence status of the terminal), there is also the advantage that a flexible system can be realized. 5.6 Summary According to this aspect, large-capacity transmission of Gbps can be realized. Also, when multicast is realized, the number of terminals that can be accommodated can be increased. Furthermore, unicast communication can be realized simultaneously with multicast, making the system more flexible.

[0336] 6. Fifth Embodiment A wireless communication system 4400 according to another embodiment 5 of the present invention will be described. 6.1 Wireless Communication System 4400 As shown in FIG. 44, the wireless communication system 4400 is composed of a master station 4410-1, an AP 4420-1, an AP 4420-2, an AP 4420-3, an AP 4420-4, a master station 4410-2, an AP 4420-11, an AP 4420-12, an AP 4420-13, and an AP 4420-14.

[0337] AP4420-1, AP4420-2, AP4420-3, and AP4420-4 are installed, for example, on the roof of building 4451, and master station 4410-1 is installed, for example, inside building 4451. AP4420-11, AP4420-12, AP4420-13, and AP4420-14 are installed, for example, on the roof of building 4452, and master station 4410-2 is installed, for example, inside building 4452. Note that the installation method is not limited to this.

[0338] One use case is when there are no obstacles, such as other buildings, between AP4420-1, AP4420-2, AP4420-3, and AP4420-4 and AP4420-11, AP4420-12, AP4420-13, and AP4420-14 (however, the use case is not limited to this). In the wireless communication system 4400, wireless communication is performed between the building 4451 and the building 4452 by AP 4420-1, AP 4420-2, AP 4420-3, and AP 4420-4, and AP 4420-11, AP 4420-12, AP 4420-13, and AP 4420-14.

[0339] The master station 4410-1 is connected directly or indirectly via a communication line to a communication device (not shown) (communication device A) that holds data to be transmitted by the AP. Here, communication device A is, for example, a mobile phone, a smartphone, a tablet, or a personal computer. Furthermore, communication device A may be, for example, a broadcasting device that broadcasts data, or a distribution system or server that transmits data. Here, communication device A transmits control signals for controlling the master station and the AP, and "data to be transmitted by the AP." The control signals may include unicast settings. Furthermore, communication device A may be composed of multiple communication devices. In this case, a first communication device may transmit the control signal, and a second communication device may transmit the data. Furthermore, communication device A may be used inside building 4451. Furthermore, communication device A may be used outside building 4451 and building 4452. The master station 4410-1 is connected to the AP 4420-1, AP 4420-2, AP 4420-3, and AP 4420-4 by wire (or wirelessly), and the data obtained from the communication device A is transmitted to the AP 4420-1, AP 4420-2, AP 4420-3, and AP 4420-4.

[0340] The control signal includes setting parameters for each AP when it performs unicast transmission, and information on parameters of a phase change method when each AP performs a phase change. The AP 4420-1 is called the master AP, and the APs 4420-2, 4420-3, and 4420-4 are called non-master APs. The master station 4410-2 is connected to another communication device (communication device B) directly or indirectly via a communication line. Here, communication device B may be, for example, a mobile phone, a smartphone, a tablet, or a personal computer, but may also be a communication device installed in a building such as a building or outdoors, as described above. Communication device B may be used inside building 4452, but communication device B may also be used outside building 4451 and building 4452. Furthermore, the master station 4410-2 is connected to AP 4420-11, AP 4420-12, AP 4420-13, and AP 4420-14 by wire (or wireless), and AP 4420-1, AP 4420-2, AP 4420-3, and AP 4420-4 transmit data obtained from communication device B.

[0341] The AP 4420-11 is also a master AP. The AP 4420-12, AP 4420-13, and AP 4420-14 are non-master APs. 6.2 AP4420-1 as Master AP As shown in FIG. 45, the master AP AP 4420-1 is composed of an encoder 202, an interleaver 204, a mapping unit 206, a phase change unit 208, a radio unit 210, an antenna 212, an antenna 215, a receiving device 217 and an instruction unit 4402.

[0342] Since the AP 4420-11 is also a master AP, the AP 4420-11 has the same configuration as the AP 4420-1 as the master AP. AP 4420-1 receives control signal 4401 from master station 4410-1. Control signal 4401 includes a setting for each AP as to whether to perform unicast transmission, and a setting for parameters for phase change when a phase change is performed.

[0343] The AP 4420-1 performs settings related to unicast transmission based on the control signal 4401 received from the master station 4410-1. The AP 4420-1 also performs settings related to the parameters of the phase change method based on the control signal 4401. When transmitting unicast data, the AP 4420-1 operates the receiving device 217. (1) Encoder 202 The encoder 202 receives data 201 from the master station 4410-1. The encoder 202 also receives a control signal 213 from a controller included in the AP 4420-1. The control signal 213 includes information such as a designation of an encoding method, a designation of an error correction method, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 201 using the method designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0344] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP 4420-1. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0345] (3) Mapping unit 206 Mapping section 206 receives interleaved data 205 from interleaver 204. Mapping section 206 also receives control signal 213 from a controller included in AP 4420-1. Control signal 213 includes a modulation scheme designation. Mapping section 206 performs modulation on interleaved data 205 using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like in accordance with the modulation scheme designation included in control signal 213, to generate modulated signal 207. Mapping section 206 outputs modulated signal 207. Note that other modulation schemes may also be applied as the modulation scheme.

[0346] The mapping unit 206 may perform mapping that includes a phase change process. (4) Phase change unit 208 Phase changer 208 receives modulated signal 207 from mapping section 206. Phase changer 208 also receives control signal 4403_0. Control signal 4403_0 includes a setting for the phase change method. Phase changer 208 performs a phase change on modulated signal 207 in accordance with the setting for the phase change method included in control signal 4403_0, and generates phase-changed signal 209. Phase changer 208 outputs phase-changed signal 209.

[0347] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives phase-changed signal 209 from phase change unit 208. Radio unit 210 also receives control signal 213 from a controller included in AP 4420-1. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on phase-changed signal 209 to generate transmission signal 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band.

[0348] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. Receiving device 217 receives signal 216 from antenna 215 using a frequency band above 6 GHz, for example, a frequency band called millimeter wave, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the signal to generate data 218. Receiving device 217 outputs data 218 to master station 4410-1.

[0349] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. (7) Instruction section 4402 The instruction unit 4402 is connected to the master station 4410-1. The instruction unit 4402 receives a control signal 4401 from the master station 4410-1. The control signal 4401 includes unicast-related settings and setting information on the phase change method.

[0350] An instruction unit 4402 provides setting information related to unicast transmission to all APs including AP 4420-1 based on a control signal 4401. Furthermore, the instruction unit 4402 instructs each AP on the method of phase change. The instruction unit 4402 generates a control signal 4403_0, a control signal 4403_1, ..., a control signal 4403_N for each AP from the received control signal 4401. Each control signal includes information related to unicast transmission and information related to phase change. The instruction unit 4402 outputs the control signal 4403_0, the control signal 4403_1, ..., a control signal 4403_N to itself, AP 4420-2, AP 4420-3, and AP 4420-4.

[0351] When unicast transmission is to be performed to AP 4420-1, instruction unit 4402 operates receiving device 217. 6.3 Non-Master AP4600 AP 4420-2, AP 4420-3, and AP 4420-4 are non-master APs. AP 4420-12, AP 4420-13, and AP 4420-14 are also non-master APs.

[0352] Hereinafter, the operations of AP 4420-2, AP 4420-3, and AP 4420-4 will be described. In this description, AP 4600 will be used to represent AP 4420-2, AP 4420-3, and AP 4420-4. As shown in FIG. 46, the non-master AP 4600 is composed of an encoder 202, an interleaver 204, a mapping unit 206, a phase change unit 208, a radio unit 210, an antenna 212, an antenna 215, and a receiving device 217.

[0353] The AP 4600 receives a control signal 4601_0 from the AP 4420-1, which is the master AP. The control signal 4601_0 includes information related to unicast transmission and information related to a phase change. The AP 4600 also receives data 4602 (no AP cooperation) from the AP 4420-1, which is the master AP. When AP cooperation is performed, the AP 4600 may receive data 4603 from another AP. The AP 4600 may also receive data 201 from the parent station 4410-1, and may pass this data on to another AP.

[0354] The AP 4600 performs settings related to unicast transmission based on the control signal 4601_0. The AP 4600 also performs settings for the phase change method based on the control signal 4601_0. When setting up unicast, the AP 4600 activates the receiving device 217 . (1) Encoder 202 The encoder 202 receives data 4602, 4603, or 201 from the master station 4410-1. The encoder 202 also receives a control signal 213 from a controller included in the AP 4600. The control signal 213 includes information such as a coding method designation, an error correction method designation, a coding rate, and a block length. The encoder 202 performs error correction coding, such as a convolutional code, an LDPC code, or a turbo code, on the data 4602, 4603, or 201 using the method designated by the control signal 213. The encoder 202 outputs encoded data 203.

[0355] (2) Interleaver 204 The interleaver 204 receives coded data 203 from the encoder 202. The interleaver 204 also receives a control signal 213 from a controller included in the AP4600. The control signal 213 includes a designation of an interleaving method. The interleaver 204 interleaves, that is, rearranges the order of, the coded data 203 using the interleaving method designated by the control signal 213. The interleaver 204 outputs interleaved data 205.

[0356] (3) Mapping unit 206 The mapping unit 206 receives interleaved data 205 from the interleaver 204. The mapping unit 206 also receives a control signal 213 from a controller included in the AP 4600. The control signal 213 includes a modulation scheme designation. In accordance with the modulation scheme designation included in the control signal 213, the mapping unit 206 performs modulation using, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), or the like on the interleaved data 205 to generate a modulated signal 207. The mapping unit 206 outputs the modulated signal 207. Note that other modulation schemes may also be applied as the modulation scheme.

[0357] The mapping unit 206 may perform mapping that includes a phase change process. (4) Phase change unit 208 Phase changer 208 receives modulated signal 207 from mapping section 206. Phase changer 208 also receives control signal 4601_0. Control signal 4601_0 includes a setting for the phase change method. Phase changer 208 performs a phase change on modulated signal 207 in accordance with the setting for the phase change method included in control signal 4601_0, and generates phase-changed signal 209. Phase changer 208 outputs phase-changed signal 209.

[0358] (5) Radio Unit 210 and Antenna 212 Radio unit 210 receives phase-shifted signal 209 from phase shifter 208. Radio unit 210 also receives control signal 213 from a controller included in AP 4600. Control signal 213 includes instructions for frequency conversion, amplification, etc. Radio unit 210 performs processing such as frequency conversion and amplification on phase-shifted signal 209 to generate transmission signal 211. Radio unit 210 outputs the generated transmission signal 211 to antenna 212 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter wave, such as a 60 GHz frequency band.

[0359] The antenna 212 outputs the transmission signal 211 as a radio wave. (6) Antenna 215 and receiving device 217 An antenna 215 receives signals 216 emitted as radio waves by each terminal. Receiving device 217 receives signal 216 from antenna 215 using a frequency band equal to or higher than 6 GHz, for example, a frequency band called millimeter waves, such as a 60 GHz frequency band, and performs processing such as amplification and frequency conversion on the signal to generate data 218. Receiving device 217 outputs data 218 to master station 4410-1 or master station 4410-2.

[0360] The antenna 212 and the antenna 215 may be the same body, but are shown as separate symbols for convenience. 6.4 Example of data sent An example of data transmitted by the master station 4410-1, AP 4420-1, AP 4420-2, AP 4420-3, and AP 4420-4 will be described below.

[0361] Here, we assume that all APs are configured for unicast transmission. (1) When the weather is fine An example of data transmitted when all of the APs 4420-1, 4420-2, 4420-3, and 4420-4 are configured for unicast transmission and the weather is fine will be described with reference to FIG.

[0362] (sender) As shown in Fig. 47, master station 4410-1 receives packets 4701, 4702, 4703, ..., 4706, ... (packets from the communication device) in this order. Here, packets 4701, 4702, 4703, ..., 4706, ... are all unicast packets. Also, packets 4701, 4705, ... are generated from first unicast data, and packets 4702, 4706, ... are generated from second unicast data. Packets 4703, ... are generated from third unicast data, and packets 4704, ... are generated from fourth unicast data.

[0363] The master station 4410-1 transmits packets 4701, 4702, 4703, . . . , 4706, . . . to the AP 4420-1 in this order. The AP 4420-1 receives packets 4701, 4702, 4703, . . . , 4706, . . . in this order. The AP 4420-1 processes packets 4701, 4705, ... generated from the first data for unicast by itself in this order. The AP 4420-1 also transmits packets 4702, 4706, ... generated from the second data for unicast to the AP 4420-2 in this order. The AP 4420-1 also transmits packets 4703, ... generated from the third data for unicast to the AP 4420-3 in this order. The AP 4420-1 also transmits packets 4704, ... generated from the fourth data for unicast to the AP 4420-4 in this order.

[0364] The AP 4420-1 receives packets 4701, 4705, etc. addressed to itself in this order. Upon receiving packets 4701, 4705, etc. in this order, the AP 4420-1 wirelessly outputs packets 4711, 4712, 4713, 4714, etc. in this order by unicast. Here, packets 4701, 4705, etc. correspond to packets 4711, 4712, 4713, and 4714, respectively.

[0365] Upon receiving packets 4702, 4706, etc. in this order, AP 4420-2 wirelessly outputs packets 4721, 4722, 4723, 4724, etc. in this order by unicast. Here, packets 4702, 4706, etc. correspond to packets 4721, 4722, 4723, and 4724, respectively. Upon receiving packets 4703, ... in this order, AP 4420-3 wirelessly outputs packets 4731, 4732, 4733, 4734, ... in this order by unicast. Here, packets 4703, ... correspond to packets 4731, 4732, 4733, and 4734, respectively.

[0366] Upon receiving packets 4704, etc. in this order, AP 4420-4 wirelessly outputs packets 4741, 4742, 4743, 4744, etc. in this order by unicast. Here, packets 4704, etc. correspond to packets 4741, 4742, 4743, and 4744, respectively. (receiving side) For example, it is assumed that APs 4420-1, 4420-2, 4420-3, 4420-4, 4420-11, 4420-12, 4420-13, and 4420-14 in Fig. 44 perform beamforming, for example, and are equipped with antennas with high directivity. In this case, it is assumed that AP 4420-1 and AP 4420-11 communicate with each other, AP 4420-2 and AP 4420-12 communicate with each other, AP 4420-3 and AP 4420-13 communicate with each other, and AP 4420-4 and AP 4420-14 communicate with each other.

[0367] At this time, the receiving device 217 of AP4420-11 will receive the packet transmitted by AP4420-1, the receiving device 217 of AP4420-12 will receive the packet transmitted by AP4420-2, the receiving device 217 of AP4420-13 will receive the packet transmitted by AP4420-3, and the receiving device 217 of AP4420-14 will receive the packet transmitted by AP4420-4.

[0368] When 4420-11, 4420-12, 4420-13, and 4420-14 simultaneously receive the modulated signal transmitted by AP 4420-1, the modulated signal transmitted by AP 4420-2, the modulated signal transmitted by AP 4420-3, and the modulated signal transmitted by AP 4420-4, a separation process is performed on the received signal received by 4420-11, the received signal received by 4420-12, the received signal received by 4420-13, and the received signal received by 4420-14, separating each packet and obtaining each packet. As another example, it is also possible that the master station 4410-1 receives only packet U1-#X (X=1, 2, 3, . . .). In this case, for example, AP 4420-1 may transmit packet U1-#X, while other APs are stopped from operating. By doing so, the number of operating APs is reduced, which has the effect of reducing power consumption in the system. Then, it is assumed that when it is raining, transmission is performed as shown in FIG. 48 (the operation of FIG. 48 will be explained in detail later). The advantages of this case will be explained below.

[0369] In particular, when modulated signals are transmitted using millimeter-wave frequencies, rainfall causes significant attenuation of the signal (radio wave). To maintain the strength of the received electric field at the communication partner despite this attenuation, communication devices must transmit modulated signals at a high average transmission power. However, there are often regulations regarding the average transmission power that each communication device can transmit, and it is not always possible for communication devices to transmit modulated signals at an average transmission power level that can mitigate the effects of rain attenuation.

[0370] To address this issue, as shown in Figure 48, by transmitting modulated signals containing the same data using multiple communication devices, the communication parties can obtain high received field strength, and each communication device can comply with the regulated value for the average transmission power that it can transmit. Furthermore, as mentioned above, by operating in the following manner on clear days, "AP4420-1 sends packet U1-#X, and other APs are stopped operating," it is possible to obtain the effect of reducing power consumption in the system on clear days.

[0371] Therefore, by making the parent station and AP operate differently in fine weather and rainy weather, it is possible to build a system that has the advantage of ensuring communication quality and being able to flexibly change power consumption control as needed. (2) When it rains An example of data transmitted when it is raining when all of the APs 4420-1, 4420-2, 4420-3, and 4420-4 are configured for unicast transmission will be described with reference to FIG.

[0372] (sender) 48, the master station 4410-1 receives packets 4801, 4802, 4803, ..., 4806, ... in this order. Here, packets 4801, 4802, 4803, ..., 4806, ... are all unicast packets. Also, packets 4801, 4802, 4803, ..., 4806, ... are generated from one piece of unicast data.

[0373] The master station 4410-1 transmits packets 4801, 4802, 4803, . . . , 4806, . . . to the AP 4420-1 in this order. The AP 4420-1 receives packets 4801, 4802, 4803, . . . , 4806, . . . in this order, and processes packets 4801, 4802, 4803, . . . , 4806, . . . in this order. The AP 4420-1 also transmits packets 4801, 4802, 4803, . . . , 4806, . . . to the AP 4420-2, AP 4420-3, and AP 4420-4, respectively, in this order.

[0374] The AP 4420-1 receives packets 4801, 4802, 4803, ..., 4806, ... in this order. Upon receiving packets 4801, 4802, 4803, ..., 4806, ... in this order, the AP 4420-1 wirelessly outputs packets 4811, 4812, 4813, 4814, ... in this order by unicast. Here, packets 4801, 4802, 4803, ..., 4806, ... correspond to packets 4811, 4812, 4813, and 4814, respectively.

[0375] AP 4420-2 receives packets 4801, 4802, 4803, ..., 4806, ... in this order. Upon receiving packets 4801, 4802, 4803, ..., 4806, ... in this order, AP 4420-2 wirelessly outputs packets 4821, 4822, 4823, 4824, ... in this order by unicast under the control of AP 4420-1, which is the master AP. Here, packets 4801, 4802, 4803, ..., 4806, ... correspond to packets 4821, 4822, 4823, and 4824, respectively.

[0376] AP 4420-3 receives packets 4801, 4802, 4803, ..., 4806, ... in this order. Upon receiving packets 4801, 4802, 4803, ..., 4806, ... in this order, AP 4420-3 wirelessly outputs packets 4831, 4832, 4833, 4834, ... in this order by unicast under the control of AP 4420-1, which is the master AP. Here, packets 4801, 4802, 4803, ..., 4806, ... correspond to packets 4831, 4832, 4833, and 4834, respectively.

[0377] AP 4420-4 receives packets 4801, 4802, 4803, ..., 4806, ... in this order. Upon receiving packets 4801, 4802, 4803, ..., 4806, ... in this order, AP 4420-4 wirelessly outputs packets 4841, 4842, 4843, 4844, ... in this order by unicast under the control of AP 4420-1, which is the master AP. Here, packets 4801, 4802, 4803, ..., 4806, ... correspond to packets 4841, 4842, 4843, and 4844, respectively.

[0378] As a feature of this case, as described in the other embodiments, AP4420-1, AP4420-2, AP4420-3, and AP4420-4 transmit the same packet at the same time (the modulated signals after mapping at the same time are the same). Therefore, a phase change is performed in AP4420-1, a phase change is also performed in AP4420-2, a phase change is also performed in AP4420-3, and a phase change is also performed in AP4420-4 (however, it is also possible that any of AP4420-1, AP4420-2, AP4420-3, and AP4420-4 does not perform a phase change). In Figure 48, as an example, an example is described in which there are four APs and the four APs transmit packets U1-#X (X = 1, 2, 3, ...), but this is not limited to this. For example, there may be N APs (N is an integer greater than or equal to 2) and M APs (M is an integer less than or equal to N and greater than or equal to 2) that transmit packets U1-#X (X = 1, 2, 3, ...). From the above, the following configuration can be considered.

[0379] There are N APs (N is an integer greater than or equal to 2). Then, on clear days (when radio wave attenuation due to rainfall is small. (When it is raining but radio wave attenuation is small, it is treated as "clear days.")), L APs (L is an integer greater than or equal to 1 and less than or equal to N-1) transmit packets U1-#X (X=1, 2, 3, ...). Then, during rainfall (when radio wave attenuation due to rain is significant), M APs (M is an integer less than or equal to N, and M is an integer greater than or equal to 2, and M is an integer greater than L) may transmit packets U1-#X (X=1, 2, 3, ...).

[0380] By transmitting in this manner, as mentioned above, it is possible to suppress the degradation of reception quality at the other end of the communication due to propagation attenuation during rainfall, and this makes it possible to build a system that has the advantage of ensuring communication quality and being able to flexibly change power consumption control as needed. Note that on a fine day, an AP that is not transmitting packet U1-#X may transmit other packets (or may not transmit other packets), and similarly, when it is raining, an AP that is not transmitting packet U1-#X may transmit other packets (or may not transmit other packets).

[0381] The present invention may also be a communication system including N transmitters that wirelessly transmit data to a receiver using a millimeter wave frequency band, and the receiver. Here, one of the N transmitters may include control means for acquiring communication quality between a transmitting means, a receiving means, and the receiver, and causing L transmitters, including itself, among the N transmitters, that are smaller than N, to transmit data when the acquired communication quality is equal to or greater than a threshold, causing M transmitters, including itself, among the N transmitters, that are smaller than N but larger than L, to cooperate and transmit data when the acquired communication quality is below the threshold, and stopping the cooperative operation when the acquired communication quality is equal to or greater than the threshold. (receiving side) The receiving device 217 of AP 4420-11 simultaneously receives the modulated signal corresponding to packet 4811, the modulated signal corresponding to packet 4821, the modulated signal corresponding to packet 4831, and the modulated signal corresponding to packet 4841. Next, the receiving device 217 of AP 4420-11 simultaneously receives the modulated signal corresponding to packet 4812, the modulated signal corresponding to packet 4822, the modulated signal corresponding to packet 4832, and the modulated signal corresponding to packet 4842. Next, the receiving device 217 of AP 4420-11 simultaneously receives the modulated signal corresponding to packet 4813, the modulated signal corresponding to packet 4823, the modulated signal corresponding to packet 4833, and the modulated signal corresponding to packet 4843. Next, the receiving device 217 of AP 4420-11 simultaneously receives the modulated signal corresponding to packet 4814, the modulated signal corresponding to packet 4824, the modulated signal corresponding to packet 4834, and the modulated signal corresponding to packet 4844. The same applies below.

[0382] Therefore, by demodulating and decoding the combined received signal, packets 4801, 4802, 4803, 4804, 4805, . . . can be obtained. 6.5 Operation of the master AP, AP4420-1 The operation of the master AP AP 4420-1 will be described with reference to the flowchart shown in FIG.

[0383] The instruction unit 4402 of the AP 4420-1, which is the master AP, acquires the communication quality with the AP 4420-11, which is the communication partner (step S4901). Next, the instruction unit 4402 determines whether the acquired communication quality is equal to or greater than a threshold (step S4902). If the acquired communication quality is below the threshold (step S4902: "below threshold"), the instruction unit 4402 causes, for example, the AP 4420-2, AP 4420-3, and AP 4420-4 to cooperate and transmit the same data (step S4903). Next, the process returns to step S4901 and is repeated.

[0384] If the acquired communication quality is equal to or greater than the threshold ("equal to or greater than threshold" in step S4902), the instruction unit 4402 causes, for example, AP 4420-2, AP 4420-3, and AP 4420-4 to stop cooperative operation (stop transmitting the same data) (step S4904). The instruction unit 4402 causes, for example, AP 4420-2, AP 4420-3, and AP 4420-4 to resume independent operation. The independent operation is the operation before the cooperative operation was started (step S4905). Next, the process returns to step S4901 and is repeated.

[0385] 6.6 Transmission of training signals by each AP AP4420-1 transmits, for example, a training signal in both sunny weather and rainy weather. The communication partner then receives the training signal and transmits the reception result to AP4420-1. AP4420-1 obtains the reception result to acquire the communication quality with the receiving AP. AP4420-1 uses the acquired communication quality to determine whether to perform the above-mentioned cooperative operation or to stop the cooperative operation. AP4420-1 then transmits the result of "whether to perform cooperative operation or to stop the cooperative operation" to AP4420-2, 4420-3, and 4420-4. (At this time, AP 4420-1 may transmit the result of "whether to perform cooperative operation or to stop cooperative operation" via the parent station, or may transmit the result of "whether to perform cooperative operation or to stop cooperative operation" directly to APs 4420-2, 4420-3, and 4420-4.) Furthermore, if AP 4420-1 determines to "perform cooperative operation," it transmits information about the phase change value method, modulation method, and encoding method to be used to APs 4420-2, 4420-3, and 4420-4. (At this time, AP 4420-1 may transmit information about the phase change value method, modulation method, and encoding method to APs 4420-2, 4420-3, and 4420-4 via the parent station.) In this embodiment, there may be no mode set to "multicast." (For example, when this embodiment is applied to a communication device installed in a building and a communication device not installed in the building, there may be cases where multicasting is not required.) In the above explanation, an example was given of cooperative operation between a master AP and a non-master AP, but as explained in other embodiments, even if the frame configuration as shown in Figure 47 and the frame configuration as shown in Figure 48 are switched between fine weather and rainy weather through cooperative operation when the parent station has some of the functions of the master AP, as shown in Figure 1, Figure 25, etc., it is possible to implement the same as above. Furthermore, the configuration of a transmission system that switches cooperative operation between fine weather and rainy weather is not limited to these, and in this case, the function itself of "switching cooperative operation between fine weather and rainy weather" as explained above becomes important.

[0386] 6.4 Summary According to this embodiment, large-capacity transmission of Gbps can be realized. Furthermore, wireless communication can be ensured even in rainy weather. Furthermore, when the weather returns from rainy weather to sunny weather, the master AP stops cooperative operation. This prevents unnecessary power consumption due to cooperative operation in sunny weather.

[0387] In the above embodiment, four APs are assumed to operate in cooperation with each other, but this is not limiting, and two or more APs may operate in cooperation with each other. <<Additional Information>> Naturally, the embodiments and other contents described in this specification may be combined and implemented.

[0388] Furthermore, each embodiment and other contents are merely examples, and for example, even if "modulation method, error (erasure) correction coding method (error correction code to be used, code length, coding rate, etc.), control information, etc." is exemplified, even if another "modulation method, error (erasure) correction coding method (error correction code to be used, code length, coding rate, etc.), control information, etc." is applied, it can be implemented with the same configuration.

[0389] Regarding the modulation method, even if a modulation method other than the modulation methods described in this specification is used, it is possible to implement the embodiments and other contents described in this specification. For example, APSK (Amplitude Phase Shift Keying) (e.g., 16APSK, 64APSK, 128APSK, 256APSK, 1024APSK, 4096APSK, etc.), PAM (Pulse Amplitude Modulation) (e.g., 4PAM, 8PAM, 16PAM, 64PAM, 128PAM, 256PAM, 1024PAM, 4096PAM, etc.), PSK (Phase Shift Keying) (e.g., BPSK, QPSK, 8PSK, 16PSK, 64PSK, 128PSK, 256PSK, 1024PSK, 4096PSK, etc.), QAM (Quadrature Amplitude Modulation) (e.g., 4QAM, 8QAM, 16QAM, 64QAM, 128QAM, For each modulation method, uniform mapping or non-uniform mapping may be used.

[0390] Furthermore, the transmission method in the wireless communication system may be a transmission method in which a transmitter uses one antenna and a receiver uses one or more antennas to receive signals (Single-Input Single-Output (SISO) transmission method, Single-Input Multiple-Output (SIMO) transmission method), or a method in which a transmitter transmits multiple streams and a receiver uses one or more antennas to receive modulated signals (Multiple-Input Multiple-Output (MIMO) transmission method, Multiple-Input Single-Output (MISO) transmission method). Space-time block coding or space-time trellis coding may also be used (in this case, when a multicarrier system such as OFDM is used, symbols may be arranged in the time axis direction, the frequency axis direction, or the frequency-time axis direction).

[0391] Furthermore, when the term "complex number" is used in this specification, it means that it is "defined as a complex number," and in some cases the imaginary component is zero, making it a real number. The present invention is not limited to the contents described in the above embodiments, and can be implemented in any form that achieves the objects of the present invention and related or attendant objects, for example, the following.

[0392] (1) According to one aspect of the present disclosure, an AP assigns different weights to multiple packets transmitting the same data and transmits the packets. Furthermore, multiple APs assign different weights to multiple packets transmitting the same data and transmit the packets. This configuration allows multiple packets transmitting the same data to be transmitted with different directivities, thereby maintaining more uniform reception quality within a cell area.

[0393] Here, multiple packets carrying the same data do not have to be transmitted consecutively. Also, multiple antennas may be provided by a single AP instead of multiple APs. Even in this case, it is clear that the same effect as above can be achieved. (2) The operational procedures of the communication device on the communication station side described in each of the above embodiments may be written into a program, the program may be stored in advance in a ROM (Read Only Memory), and a CPU (Central Processing Unit) may read and execute the program stored in the ROM. Alternatively, the program describing the operational procedures of the communication device on the communication station side may be stored in a computer-readable storage medium, the program stored in the storage medium may be stored in a computer's RAM (Random Access Memory), and the computer's CPU may read and execute the program stored in the RAM.

[0394] (3) Each of the configurations of the above-described embodiments may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be implemented individually as single chips, or may be implemented as a single chip that includes all or part of the configuration of each embodiment. Here, we refer to it as an LSI, but depending on the level of integration, it may also be called an IC (Integrated Circuit), system LSI, super LSI, or ultra LSI.

[0395] Furthermore, the method of integration is not limited to LSI, but may be realized by dedicated circuits or general-purpose processors. It is also possible to use FPGAs (Field Programmable Gate Arrays), which can be programmed after LSI manufacturing, or reconfigurable processors, which allow the connections and settings of circuit cells inside LSI to be reconfigured. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0396] In this specification, the transmitting device may be, for example, a communication or broadcasting device such as a broadcast station, a base station, an access point, a terminal, a mobile phone, etc., and the receiving device may be, for example, a communication device such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, a base station, etc. In addition, the transmitting device and receiving device in the present invention may be devices having a communication function, and may be configured to be connectable via some kind of interface to a device for executing an application, such as a television, a radio, a personal computer, or a mobile phone.

[0397] In this embodiment, symbols other than data symbols, such as pilot symbols (preambles, unique words, postambles, reference symbols, etc.), control information symbols, etc. may be arranged in any manner in a frame. Here, they are called pilot symbols and control information symbols, but any naming method may be used; what is important is the function itself.

[0398] The pilot symbol may be, for example, a known symbol modulated by PSK modulation in the transmitter / receiver (or the receiver may be able to know the symbol transmitted by the transmitter by synchronizing with the symbol), and the receiver uses this symbol to perform frequency synchronization, time synchronization, channel estimation (for each modulated signal) (CSI (Channel State Information) estimation), signal detection, etc.

[0399] In addition, the control information symbols are used to transmit information that needs to be transmitted to the other party in order to realize communication other than data (such as applications) (for example, the modulation method, error (erasure) correction coding method, coding rate of the error (erasure) correction coding method used in the communication, setting information in the upper layer, etc.). The transmitting device needs to notify the receiving device of the transmission method (MIMO, SISO, space-time block coding, interleaving), modulation method, error correction coding method, and packet-level error (erasure) correction method, but this point is omitted depending on the embodiment. Note that the frame transmitted by the transmitting device will contain symbols that transmit this information, and the receiving device will change its operation by obtaining this information. The present invention is not limited to the embodiments, and can be implemented with various modifications. For example, in the embodiments, the case where the communication is performed as a communication device is described, but the present invention is not limited to this, and the communication method can also be implemented as software. [Industrial Applicability]

[0400] The transmission method of the present invention enables wireless transmission using the millimeter wave frequency band in a plurality of transmission devices, and is useful as a technology for wireless communication. [Explanation of symbols]

[0401] 110 Master station 121~124 AP 131~138 terminals 202 Encoder 204 Interleaver 206 Mapping Department 208 Phase change unit 210 Radio Department 212 Antenna 215 Antenna 217 Receiving Device 302 Transmission data distribution unit 305 Received data distribution unit 308 Instruction section 100, 1400, 1500, 1600 wireless communication systems 1800, 2500, 3400, 4400 wireless communication systems

Claims

1. 1. A method implemented by a controller controlling a plurality of transmitters, comprising: generating control information indicating a phase change pattern to be used by each of the plurality of transmitters in a phase change process performed by each of the plurality of transmitters when transmitting the same data; transmitting the control information to the plurality of transmitters; The phase change pattern indicated in the control information indicates a period Nx of phase change when a transmitter x transmits data, When a transmitter x among a plurality of transmitters requests to be controlled, a value of Nx is selected that is different from the period already assigned to other nearby transmitters among the plurality of transmitters, and if there is no value different from the period already assigned to other nearby transmitters, the method does not allow the transmitter x to be controlled.

2. A control device for controlling a plurality of transmitters, the control device comprising: a circuit and a transmitting unit; generating control information indicating a phase change pattern to be used by each of the plurality of transmitters in a phase change process performed by each of the plurality of transmitters when transmitting the same data; transmitting the control information to the plurality of transmitters via the transmitting unit; When a transmitter x among a plurality of transmitters requests to be controlled, the control device selects a value for Nx that is different from the period already assigned to other nearby transmitters among the plurality of transmitters, and does not allow the transmitter x to be controlled if there is no value different from the period already assigned to other nearby transmitters.

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