JP2010141660A - Wireless communication device, wireless base station, wireless terminal station, and wireless communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve network throughput characteristics. <P>SOLUTION: A wireless communication device 101 transmits a terminal identification information request signal 11 to wireless communication devices 102-108 in order to request transmission of a terminal identification information signal having a terminal identification field consisting of a plurality of sub-fields. At least one of the wireless communication devices 102-108 selects any one of the plurality of sub-fields on the basis of the reception intensity of the terminal identification information request signal 11 and generates one of terminal identification information signals 12-14 by setting a signal into a predetermined sub-channel in the selected sub-field so as to transmit it to the wireless communication device 101. The wireless communication device 101 detects the sub-channel, into which the signal is set, about each terminal identification information signal 12-14 and determines each wireless communication device 102, 103, and 106 as a transmission source by using sub-channel information showing the sub-channel predetermined in each wireless communication device 102-108. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radio communication device, a radio base station, a radio terminal station, and a radio communication method.

  In recent wireless communication systems, in order to efficiently use wireless resources, a plurality of wireless communication apparatuses perform communication while sharing wireless resources. For example, a frequency division multiple access (FDMA) system is used. Is used.

  In general, in a radio communication system, a base station assigns time slots and subcarriers for frequency division multiple access to terminal stations. For example, the base station acquires the signal strength with the terminal station, specifies a group corresponding to the acquired strength among a plurality of groups, and selects a time slot defined in advance for the specified group. A method of selecting a subcarrier to be allocated to a terminal station from a plurality of subcarriers included in the selected time slot and executing communication with the terminal station using the selected time slot and subcarrier has been proposed (for example, a patent). Reference 1).

  In the conventional method as described above, the base station requests the terminal station on the network to transmit a pilot signal or the like to acquire the signal strength, and both the time slot and the subcarrier are based on the acquired signal strength. The allocation information was broadcasted. Therefore, when all of the plurality of subcarriers included in the selected time slot have already been assigned to another terminal station, the base station instructs the terminal station to reduce the transmission power, and the reduced reception strength Accordingly, it is necessary to select a time slot and a subcarrier again.

As described above, the conventional method has a problem that the overhead until the time slot and the subcarrier are allocated to the terminal station is large, and the throughput characteristic of the network is deteriorated.
JP 2008-60743 A

  An object of the present invention is to provide a radio communication device, a radio base station, a radio terminal station, and a radio communication method that improve the throughput characteristics of a network.

  A wireless communication apparatus according to an aspect of the present invention is a wireless communication apparatus in which a plurality of wireless communication apparatuses communicate by sharing a plurality of subchannels, and includes a synchronization pilot symbol and a plurality of subfields from another wireless communication apparatus. A receiving unit that receives a request signal that requests transmission of an identification signal having a terminal identification field, a measuring unit that measures the reception strength of the request signal, and any of the plurality of subfields based on the reception strength A selection unit that selects any one of them, a generation unit that sets a signal in a predetermined subchannel in a subfield selected by the selection unit in the terminal identification field and generates the identification signal, A transmission unit that transmits the identification signal generated by the generation unit to a transmission source of the request signal after a predetermined time from receiving the request signal; It is those with a.

  A wireless communication device according to an aspect of the present invention is a wireless communication device that communicates with a plurality of first wireless communication devices using a plurality of subchannels, and each of the plurality of first wireless communication devices is mutually connected. Differently, a subchannel allocating unit that allocates one of the plurality of subchannels, a storage unit that stores a subchannel allocation result by the subchannel allocating unit, and the first wireless communication device A transmission unit that performs notification of the allocated subchannel and transmission of an inquiry signal for inquiring an uplink transmission request, and the first wireless communication apparatus transmits a synchronization pilot symbol and a plurality of signals according to the inquiry signal A terminal identification field composed of a plurality of subfields, and the subchannel allocated to any one of the plurality of subfields. A receiving unit that receives an uplink transmission request signal that is transmitted after setting a signal in the signal, and detects which of the plurality of subchannels is set for the uplink transmission request signal received by the receiving unit; And a determination unit that determines the first wireless communication device that is the transmission source using the allocation result.

  A wireless communication apparatus according to an aspect of the present invention is a wireless communication apparatus that communicates with a second wireless communication apparatus by sharing a plurality of subchannels with a plurality of first wireless communication apparatuses, and is assigned by the second wireless communication apparatus A storage unit that stores the received subchannel, a reception unit that receives an inquiry signal inquiring an uplink transmission request from the second wireless communication device, a measurement unit that measures reception intensity of the inquiry signal, and the reception A selection unit that selects any one of a plurality of subfields based on strength; a terminal identification field including a pilot symbol for synchronization and the plurality of subfields; and A generator configured to generate an uplink transmission request signal by setting a signal in an assigned subchannel; and the inquiry for the uplink transmission request signal After the received predetermined time item, in which and a transmission unit for transmitting to the second wireless communication device.

  A wireless communication device according to an aspect of the present invention is a wireless communication device that communicates with a plurality of wireless communication devices by sharing a plurality of subchannels, and uses the hash function from pre-assigned address information to convert the address information into the address information. A subchannel selection unit that generates a corresponding subchannel and selects the subchannel; a reception unit that receives an inquiry signal that inquires a transmission request; a measurement unit that measures reception intensity of the inquiry signal; and the reception A subfield selection unit that selects any one of a plurality of subfields based on strength; a terminal identification field that includes a synchronization pilot symbol and the plurality of subfields; A generator configured to generate a transmission request signal by setting a signal in the selected subchannel; Signal, after a predetermined time from the reception of the interrogation signal, in which and a transmission unit that transmits to the transmission source of the interrogation signal.

  According to the present invention, it is possible to improve network throughput characteristics.

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

  (First Embodiment) FIG. 1 shows a schematic configuration of a radio communication system according to a first embodiment of the present invention. The wireless communication apparatuses 101 to 108 perform wireless communication by sharing a frequency channel composed of a plurality of subchannels. The number of wireless communication devices is not limited to this.

  Each of the wireless communication apparatuses 101 to 108 can transmit a terminal identification information request signal. Each of the wireless communication apparatuses 101 to 108 can transmit a terminal identification information signal with the reception of the terminal identification information request signal. The terminal identification information signal is transmitted through a subchannel assigned in advance (different from each other) to each wireless communication device. The terminal identification information request signal is a signal that requests transmission of the terminal identification information signal. The terminal identification information signal will be described later.

  In FIG. 1, as a response to the terminal identification information request signal 11 transmitted from the wireless communication device 101, the wireless communication device 102, the wireless communication device 103, and the wireless communication device 106 each use a previously assigned subchannel. In this example, identification information signals 12, 13, and 14 are simultaneously transmitted to the wireless communication apparatus 101 by frequency division multiplexing.

  FIG. 2 shows a block configuration of the wireless communication apparatus 101. The wireless communication devices 102 to 108 have the same configuration as the wireless communication device 101. The wireless communication apparatus 101 includes an antenna 121, a wireless unit 122, a reception unit 123, a frame analysis unit 124, a signal strength measurement unit 125, a terminal determination unit 126, a subfield selection unit 127, a control unit 128, a frame generation unit 129, and a transmission unit. 130, a timer 131, and a memory 132.

  The frame generation unit 129 generates a transmission frame (terminal identification information signal, terminal identification information request signal) based on an instruction from the control unit 128. An example of the format of the terminal identification information signal is shown in FIG. The terminal identification information signal includes a synchronization pilot signal (symbol) 51 and a terminal identification field 52. The terminal identification field 52 includes four terminal identification subfields TS1 to TS4. Each terminal identification subfield includes eight subchannels SC1 to SC8.

  Each wireless communication device in the wireless communication system is preassigned a subchannel to be used in each subfield. For example, subchannel SC2 is assigned to radio communication apparatus 102 through four subfields TS1 to TS4. The memory 132 of each wireless communication device stores information on subchannels assigned to the own wireless communication device. In addition, the memory 132 of the wireless communication apparatus that transmits the terminal identification information request signal and receives the terminal identification information signal stores information on subchannels assigned in advance to other wireless communication apparatuses.

  When generating the terminal identification information signal, the frame generation unit 129 sets a signal to a pre-assigned subchannel in the subfield indicated by the control unit 128.

  The transmission unit 130 transmits the transmission frame generated by the frame generation unit 129 via the radio unit 122 and the antenna 121.

  The receiving unit 123 receives a signal via the antenna 121 and the wireless unit 122.

  The frame analysis unit 124 performs frame analysis of the received signal, determines whether the received signal is a terminal identification information request signal, and outputs the determination result to the subfield selection unit 127. The frame analysis unit 124 may further output the determination result to the control unit 128.

  The signal strength measurement unit 125 measures the reception strength of the received signal (received terminal identification information request signal) and outputs the measurement result to the subfield selection unit 127.

  When the received signal is a terminal identification information request signal, subfield selecting section 127 selects a subfield to be used when transmitting a terminal identification information signal that is a response to the terminal identification information request signal, based on the received intensity. The subfield selection unit 127 selects a subfield with reference to a table indicating the relationship between the reception strength and the subfield stored in the memory 132.

  An example of the table is shown in FIG. As shown in FIG. 4, when the signal strength is −20 dBm or more, the subfield TS1 is selected. When the signal strength is less than −20 dBm, the subfield TS2 is selected, and the signal strength is less than −40 dBm. It is stipulated that subfield TS3 is selected when it is −60 dBm or more, and subfield TS4 is selected when the signal strength is less than −60 dBm.

  The subfield selection unit 127 notifies the control unit 128 of the selected subfield.

  When the control unit 128 receives the notification from the subfield selection unit 127, the control unit 128 extracts information on the subchannel assigned in advance to the own wireless communication apparatus from the memory 132. Then, the control unit 128 instructs the frame generation unit 129 to generate a terminal identification information signal together with information on subfields and subchannels to be used.

  When the reception signal input to the reception unit 123 is a terminal identification information signal, the terminal determination unit 126 acquires the subchannel information of the terminal identification information signal, and transmits the terminal identification information signal transmission source wireless communication device. Judgment (identification) is performed. The memory 132 stores information on the subchannels allocated to each wireless communication device, and the terminal determination unit 126 refers to this information to determine which subchannel of the terminal identification information signal is set. Based on the above, the transmission source can be determined.

  The reception unit 123 receives terminal identification information signals from a plurality of terminals, and the terminal determination unit 126 can determine the transmission source of each terminal identification information signal.

  The timer 131 is a time measuring unit that is controlled to be started and stopped by the control unit 128.

  As described above, the radio communication apparatus according to the present embodiment transmits a terminal identification information signal by setting a signal in a pre-assigned subchannel of a subfield based on the reception strength of the terminal identification information request signal. Also, when receiving the terminal identification information signal, the wireless communication apparatus determines the transmission source of the terminal identification information signal depending on which subchannel the signal is set to.

  The terminal identification information signal is a signal transmitted in a subchannel assigned in advance to a terminal (wireless communication apparatus) that is a transmission source, and the wireless communication apparatus that has received the terminal identification information signal has a signal set in which subchannel. The transmission source terminal can be discriminated by detecting whether or not.

  The wireless communication apparatus 101 in FIG. 1 transmits a terminal identification information request signal, receives terminal identification information signals transmitted from other wireless communication apparatuses (wireless communication apparatuses 102, 103, and 106), and determines the source terminal. An example of processing up to this will be described with reference to the flowchart shown in FIG.

  (Step S <b> 101) The frame generation unit 129 generates a terminal identification information request signal based on an instruction from the control unit 128. Then, the transmission unit 130 transmits a terminal identification information request signal via the wireless unit 122 and the antenna 121. For example, when the transmission source of the frame received immediately before is unknown, the control unit 128 instructs the terminal identification information request signal to be transmitted.

  (Step S102) After the terminal identification information request signal is transmitted, the control unit 128 sets a predetermined reception timeout timer for the terminal identification information signal in the timer 131 and starts the timer 131.

  (Step S103) It is determined whether a terminal identification information signal from another wireless communication apparatus has been received. If not received, the process proceeds to step S104. If received, the process proceeds to step S105.

  (Step S104) It is determined whether or not the timer 131 has timed out. If not timed out, the process returns to step S103, and if timed out, the process ends.

  (Step S <b> 105) The terminal determination unit 126 acquires the subchannel information of the terminal identification information signal from the reception unit 123.

  (Step S106) The terminal determination unit 126 determines the wireless communication apparatus that has transmitted the terminal identification information signal based on the subchannel information.

  Next, a process from when the wireless communication device (wireless communication devices 102, 103, 106) receives the terminal identification information request signal (transmitted from the wireless communication device 101) until it transmits the terminal identification information signal is illustrated. This will be described with reference to the flowchart shown in FIG.

  (Step S151) The frame analysis unit 124 analyzes the frame of the reception signal input to the reception unit 123 via the antenna 121 and the radio unit 122, determines that it is a terminal identification information request signal, and displays the determination result as a subfield. The data is output to the selection unit 127.

  (Step S152) The signal strength measuring unit 125 measures the received signal strength.

  (Step S153) The subfield selection unit 127 selects a subfield for transmitting terminal identification information based on the reception strength of the terminal identification information request signal measured by the signal strength measurement unit 125. For example, the subfield selection unit refers to the table shown in FIG. 4 stored in the memory 132, and selects the subfield TS3 when the reception strength of the terminal identification information request signal is −50 dBm.

  (Step S154) The control unit 128 controls the frame generation unit 129 to generate a terminal information request signal in which a signal is set to a subchannel assigned in advance to the own wireless communication device in the subfield selected in step S153. To do.

  (Step S155) The control unit 128 determines whether it is the terminal identification information signal transmission timing. If it is the transmission timing, the process proceeds to step S156, and if it is not the transmission timing, it waits until the transmission timing is reached.

  (Step S156) The transmission unit 130 transmits the terminal identification information signal generated by the frame generation unit 129 via the radio unit 122 and the antenna 121. For example, when the subchannel SC2 is assigned in advance to the own radio communication apparatus, the terminal identification information signal is transmitted using the subchannel SC2 of the subfield TS3.

  Note that the transmission timing in step S155 is the same for all wireless communication apparatuses on the same network. Therefore, the wireless communication apparatus that receives the terminal identification information signal can correctly receive the terminal identification information signal even if the terminal identification information signal is transmitted from a plurality of wireless communication apparatuses.

  As described above, the radio communication apparatus according to the present embodiment autonomously selects a transmission subfield corresponding to the reception strength of the terminal identification information request signal, and transmits the terminal identification information signal on a pre-assigned subchannel. No re-assignment of subfields and subchannels occurs. Accordingly, the overhead of subfield and subchannel allocation can be reduced, so that the network throughput characteristics can be improved.

  Further, since the subfield is selected according to the reception strength of the terminal identification information request signal, the terminal identification information signals transmitted from the plurality of terminals in the same subfield have the same strength and may be influenced by each other. Less reception performance can be improved.

  (Second Embodiment) FIG. 7 shows a schematic configuration of a radio communication system according to a second embodiment of the present invention. The radio base station 201 and the radio terminal stations 202 to 208 perform radio communication by sharing a frequency channel composed of a plurality of subchannels. The number of terminals is not limited to this.

  The radio base station 201 transmits an uplink transmission request inquiry signal. Each of the wireless terminal stations 202 to 207 can transmit an uplink transmission request signal with reception of the uplink transmission request inquiry signal. The uplink transmission request signal is transmitted by a subchannel assigned in advance (different from each other) to each wireless terminal station.

  The uplink transmission request inquiry signal is a signal for inquiring an uplink transmission request, and is the same signal as the terminal identification information request signal in the first embodiment. The uplink transmission request signal is the same signal as the terminal identification information signal in the first embodiment, and has a format as shown in FIG.

  The wireless terminal stations 202 to 208 transmit a registration request frame for requesting registration to the network to the wireless base station 201. The radio base station 201 transmits a registration response frame indicating permission / rejection of registration to the radio terminal stations 202 to 208 as a response to the registration request frame.

  In FIG. 7, as a response to the uplink transmission request inquiry signal 21 transmitted from the radio base station 201, the radio terminal stations 202, 203, and 206 use the subchannels assigned in advance to transmit the uplink transmission request signal 22, In this example, 23 and 24 are simultaneously transmitted to the radio base station 201 by frequency division multiplexing.

  FIG. 8 shows a block configuration of the radio base station 201. The radio base station 201 includes an antenna 221, a radio unit 222, a reception unit 223, a frame analysis unit 224, a terminal determination unit 225, a subchannel allocation unit 226, a timer 227, a control unit 228, a frame generation unit 229, a transmission unit 230, and A memory 231 is provided.

  The frame generation unit 229 generates a transmission frame (a registration response frame, an uplink transmission request inquiry signal) based on an instruction from the control unit 228. Further, when transmitting a registration response frame indicating registration permission, the frame generation unit 229 describes information on subchannels to be allocated to the transmission destination wireless terminal station in the registration response frame. Subchannel allocation is performed by the subchannel allocation unit 226, and the allocation result is stored in the memory 231. Here, different subchannels are assigned to the wireless terminal stations.

  The transmission unit 230 transmits the transmission frame generated by the frame generation unit 229 via the wireless unit 222 and the antenna 221. The frame generation unit 229 may be included in the transmission unit 230.

  The receiving unit 223 receives a signal via the antenna 221 and the radio unit 222.

  The frame analysis unit 224 performs frame analysis of the received signal, determines whether the received signal is a registration request frame or whether the received signal is an uplink transmission request signal, and sends the determination result to the control unit 228. Output.

  When the received signal is a registration request frame, the control unit 228 determines whether to permit or reject registration of the wireless terminal station that is the transmission source of the registration request frame, and generates a registration response frame indicating the determination result To the frame generation unit 229. When it is determined that the registration is permitted, the control unit 228 instructs the subchannel allocation unit 226 to allocate the subchannel to the wireless terminal station, and receives the allocation result.

  When the reception signal input to the reception unit 223 is an uplink transmission request signal, the terminal determination unit 225 acquires the subchannel information of the uplink transmission request signal, and transmits the radio terminal station of the transmission source of the uplink transmission request signal. Judgment (identification) is performed. Since the memory 231 stores information on the subchannels allocated to each wireless terminal station (allocation result), the terminal determination unit 225 refers to this information and determines which subchannel of the uplink transmission request signal. The transmission source can be determined based on whether the signal is set.

  The reception unit 223 receives uplink transmission request signals from a plurality of radio terminal stations, and the terminal determination unit 225 can determine the transmission source of each uplink transmission request signal.

  FIG. 9 shows a schematic configuration of the terminal determination unit 225. The terminal determination unit 225 includes a Fourier transform unit 241, a subchannel power measurement unit 242, and a threshold determination unit 243. Terminal determination processing by the terminal determination unit 225 having such a configuration will be described with reference to the flowchart shown in FIG.

  (Step S241) The Fourier transform unit 241 performs a Fourier transform process on the input signal, and converts a signal in the time axis direction into a signal in the frequency axis direction.

  (Step S242) The sub-channel power measurement unit 242 performs power measurement on any one of the sub-channels (frequency bands) among the frequency axis direction signals converted by the Fourier transform unit 241.

  (Step S243) The threshold determination unit 243 compares the power of the subchannel measured by the subchannel power measurement unit 242 with a predetermined threshold. If it is equal to or greater than the threshold, the process proceeds to step S244, and if it is less than the threshold, the process proceeds to step S245.

  (Step S244) It is determined that there is an uplink transmission request from the wireless terminal station to which the subchannel is assigned.

  (Step S245) It is determined that there is no transmission request from the wireless terminal station to which the subchannel is assigned.

  (Step S246) It is determined whether or not a subchannel that has not been selected remains. If subchannels remain, the process returns to step S242; otherwise, the process ends.

  Thus, terminal determination section 225 determines an uplink transmission request terminal with / without subchannel power.

  The timer 227 is a time measuring unit whose start and stop are controlled by the control unit 228.

  An example of processing from subchannel allocation to terminal determination by the radio base station 201 will be described with reference to the flowchart shown in FIG.

  (Step S201) The frame analysis unit 224 performs frame analysis of the reception signal input to the reception unit 223 via the antenna 221 and the radio unit 222, and determines whether it is a registration request frame from the radio terminal station. . If it is a registration request frame, the process proceeds to step S202. If it is not a registration request frame, the process proceeds to step S206.

  (Step S202) The control unit 228 determines whether or not to register the wireless terminal station that is the transmission source of the registration request frame in the network. For example, the control unit 228 determines whether or not to register based on the number of wireless terminal stations already registered in the network, the set transmission traffic load, and the like.

  If registration is permitted, the process proceeds to step S203, and if registration is rejected, the process proceeds to step S205.

  (Step S203) The subchannel assignment unit 226 assigns a subchannel to be used when transmitting an uplink transmission request signal to the wireless terminal station. Information on the allocated subchannel (allocation result) is stored in the memory 231.

  (Step S204) The frame generation unit 229 generates a registration response frame in which information indicating registration permission and subchannel allocation information are described. Then, the transmission unit 230 transmits this registration response frame via the wireless unit 222 and the antenna 221.

  (Step S205) The frame generation unit 229 generates a registration response frame indicating registration rejection. Then, the transmission unit 230 transmits this registration response frame via the wireless unit 222 and the antenna 221.

  (Step S206) The control unit 228 determines whether or not to transmit an uplink transmission request inquiry signal. If it is not the transmission timing of the uplink transmission request inquiry signal, the process returns to step S201, and if it is the transmission timing of the uplink transmission request inquiry signal, the process proceeds to step S207.

  (Step S207) The frame generation unit 229 generates an uplink transmission request inquiry signal based on an instruction from the control unit 228. Then, the transmission unit 230 transmits an uplink transmission request inquiry signal via the radio unit 222 and the antenna 221. For example, when the start of the uplink period is determined, the control unit 228 broadcasts an uplink transmission request inquiry signal for the purpose of inquiring whether there is an uplink transmission request to the terminal.

  (Step S208) After the uplink transmission request inquiry signal is transmitted, the control unit 228 sets a predetermined reception timeout timer for the uplink transmission request signal in the timer 227, and starts the timer 227.

  (Step S209) It is determined whether or not an uplink transmission request signal is received from the wireless terminal station. If not received, the process proceeds to step S210. If received, the process proceeds to step S211.

  (Step S210) It is determined whether or not the timer 227 has timed out. If not timed out, the process returns to step S209. If timed out, the process ends.

  (Step S211) The terminal determination unit 225 acquires subchannel information from the uplink transmission request signal received by the reception unit 223.

  (Step S212) The terminal determination unit 225 refers to the subchannel assignment result stored in the memory 231 using the acquired subchannel information, and determines (identifies) the wireless terminal station that has transmitted the uplink transmission request signal. I do. The terminal determination unit 225 notifies the determination result to the control unit 228.

  Next, the configuration of the wireless terminal station 202 will be described using the block configuration diagram shown in FIG. The wireless terminal stations 203 to 208 have the same configuration as the wireless terminal station 202. The wireless terminal station 202 includes an antenna 261, a wireless unit 262, a reception unit 263, a frame analysis unit 264, a signal strength measurement unit 265, a subfield selection unit 266, a memory 267, a timer 268, a control unit 269, a frame generation unit 270, and a transmission. Unit 271 and data storage unit 272.

  The frame generation unit 270 generates a transmission frame (registration request frame, uplink transmission request signal) based on an instruction from the control unit 269. The format of the uplink transmission request signal is the same as that of the terminal identification information signal in the first embodiment shown in FIG. That is, the uplink transmission request signal includes a synchronization pilot signal and a terminal identification field. The terminal identification field is composed of a plurality of terminal identification subfields, and signals can be set in a plurality of subchannels in each terminal identification subfield.

  When generating the uplink transmission request signal, the frame generation unit 270 sets a signal in the subchannel of the subfield instructed by the control unit 269.

  The transmission unit 271 transmits the transmission frame generated by the frame generation unit 270 via the wireless unit 262 and the antenna 261.

  The receiving unit 263 receives a signal via the antenna 261 and the wireless unit 262.

  The frame analysis unit 264 performs frame analysis of the received signal, determines whether the received signal is a registration response frame or an uplink transmission request inquiry signal, and outputs the determination result to the control unit 269. To do.

  When the received signal is a registration response frame indicating registration permission, the frame analysis unit 264 acquires allocation subchannel information described in the registration response frame, and outputs it to the control unit 269.

  The signal strength measurement unit 265 measures the reception strength of the received uplink transmission request inquiry signal and outputs the measurement result to the subfield selection unit 266.

  The subfield selection unit 266 selects a subfield to be used when transmitting the uplink transmission request signal based on the reception strength received from the signal strength measurement unit 265. The subfield selection unit 226 receives a table indicating the relationship between the reception intensity and the subfield stored in the memory 267 from the control unit 269, and selects the subfield with reference to this table. The table is the same as the table in the first embodiment shown in FIG. For example, this table is set as a beacon periodically transmitted by the wireless base station 201 and is notified to the wireless terminal stations 202 to 208.

  The subfield selection unit 266 notifies the control unit 269 of the selected subfield.

  Upon receiving the allocation subchannel information described in the registration response frame from the frame analysis unit 264, the control unit 269 stores it in the memory 267. When the control unit 269 receives a determination result that the received signal is an uplink transmission request inquiry signal from the frame analysis unit 264, the control unit 269 extracts the table (a table showing the relationship between the reception intensity and the subfield) from the memory 267. , Output to the subfield selection unit 266.

  In addition, when receiving the notification of the selected subfield from the subfield selecting unit 266, the control unit 269 takes out the subchannel allocation information from the memory 267. Then, the control unit 269 instructs the frame generation unit 270 to generate an uplink transmission request signal together with information on subfields and subchannels to be used.

  The timer 268 is a time measuring unit whose start and stop are controlled by the control unit 269. The data storage unit 272 can store uplink transmission data.

  An example of processing from transmission of a registration request frame to transmission of an uplink transmission request signal by the radio base station 202 will be described with reference to the flowchart shown in FIG. It is assumed that a table indicating the relationship between the reception intensity and the subfield is already stored in the memory 267.

  (Step S251) The frame generation unit 270 generates a registration request frame based on an instruction from the control unit 269. Then, the transmission unit 271 transmits the registration request frame via the wireless unit 262 and the antenna 261.

(Step S252) After the registration request frame is transmitted, the control unit 269 sets a predetermined timeout time in the timer 268 and starts the timer 268. (Step S253) The frame analysis unit 264 includes the antenna 261 and the radio unit. A frame analysis is performed on the received signal input to the receiving unit 263 via the H.262 to determine whether a registration response frame has been received. If a registration response frame has not been received, the process proceeds to step S254. If a registration response frame has been received, the process proceeds to step S255.

  (Step S254) It is determined whether or not a timeout has occurred. If it is timed out, the process ends. If it is not timed out, the process returns to step S253.

  (Step S255) It is determined whether or not the registration response frame indicates registration permission. If registration permission is indicated, the process proceeds to step S256. If registration rejection is indicated, the process ends.

  (Step S256) The subchannel allocation information described in the registration response frame is stored in the memory 267.

  (Step S257) The frame analysis unit 264 performs frame analysis of the reception signal input to the reception unit 263 via the antenna 261 and the radio unit 262, and determines whether an uplink transmission request inquiry signal has been received. If an uplink transmission request inquiry signal is received, the process proceeds to step S258, and if not received, it waits until it is received.

  (Step S258) The signal strength measurement unit 265 measures the reception strength of the uplink transmission request inquiry signal.

  (Step S259) The control unit 229 makes an inquiry to the data storage unit 272 and determines whether there is uplink transmission data. If there is uplink transmission data, the process proceeds to step S260. If there is no uplink transmission data, the process ends.

  (Step S260) The subfield selection unit 266 selects a subfield for transmitting the uplink transmission request signal based on the reception strength measured in step S258. For example, when the reception strength of the uplink transmission request signal is −50 dBm and the table as shown in FIG. 4 is referred to, the subfield TS3 is selected.

  (Step S261) The control unit 269 acquires the subchannel allocation information stored in the storage unit 267 in step S256. Then, the control unit 269 generates an uplink transmission request signal by mapping the signal to the subchannel determined by the subfield selected in step S260 and the subchannel allocation information stored in the memory 267, to the frame generation unit 270. Instruct to do.

  (Step S262) The control unit 269 determines whether or not it is a predetermined uplink transmission request signal transmission timing. If it is the transmission timing, the process proceeds to step S263, and if it is not the transmission timing, it waits until the transmission timing is reached. The transmission timing is the same for all wireless terminal stations on the same network.

  (Step S263) The transmission unit 271 transmits an uplink transmission request signal via the radio unit 262 and the antenna 261.

  As described above, in this embodiment, the radio terminal station autonomously selects a transmission subfield corresponding to the reception intensity of the uplink transmission request inquiry signal transmitted from the radio base station, and is assigned in advance by the radio base station. By mapping the signal to the subchannel and transmitting the uplink transmission request signal, subfield and subchannel reassignment does not occur, and the overhead of subfield and subchannel assignment can be reduced. Accordingly, the overhead of subfield and subchannel allocation can be reduced, so that the network throughput characteristics can be improved.

  In addition, since the subfield is selected according to the reception strength of the terminal identification information request signal, the terminal identification information signals transmitted from a plurality of terminals in the same subfield are less affected by each other, and reception performance is improved. It is possible to solve the perspective problem in the radio base station.

  (Third Embodiment) FIG. 14 shows a schematic configuration of a radio communication system according to a third embodiment of the present invention. Similar to the second embodiment, the wireless base station 301 and the wireless terminal stations 302 to 308 perform wireless communication by sharing a frequency channel composed of a plurality of subchannels. The number of terminals is not limited to this.

  FIG. 14 is a diagram illustrating a response to the uplink transmission request inquiry signal 31 transmitted from the radio base station 301. The wireless terminal stations 302, 303, and 306 use the subchannels assigned in advance to transmit the uplink transmission request signal 32, In the example, 33 and 34 are simultaneously transmitted to the radio base station 301 by frequency division multiplexing.

  FIG. 15 shows an example of the frame format of the uplink transmission request inquiry signal 31 transmitted from the radio base station 301. The uplink transmission request inquiry signal 31 has a frame type field 31a and a transmission power field 31b. The frame type field 31a describes a predetermined identifier indicating that the frame is an uplink transmission request inquiry signal. The transmission power field 31b describes the transmission power when transmitting the uplink transmission request inquiry signal. For example, when an uplink transmission request inquiry signal is transmitted with a transmission power of 10 dBm, a code representing “10 dBm” is described in the transmission power field 31b.

  Each of the wireless terminal stations 302 to 307 can transmit the uplink transmission request signal in accordance with the reception of the uplink transmission request inquiry signal. The uplink transmission request signal is transmitted by the wireless terminal station 301 through subchannels assigned in advance (different from each other) to each wireless terminal station.

  FIG. 16 shows a block configuration of the radio base station 301. Similar to the radio base station 201 according to the second embodiment, the radio base station 301 includes an antenna 221, a radio unit 222, a reception unit 223, a frame analysis unit 224, a terminal determination unit 225, a subchannel allocation unit 226, a timer. 227, a control unit 228, a frame generation unit 229, a transmission unit 230, and a memory 231. Since the operation of each part is the same as in the second embodiment, description thereof is omitted. However, the difference is that the control unit 228 can set the signal transmission power for the wireless unit 222.

  An example of processing from subchannel allocation to terminal determination by the radio base station 301 will be described with reference to the flowchart shown in FIG. Steps S301 to S306 are the same as steps S201 to S206 in the second embodiment, and a description thereof will be omitted.

  (Step S307) The control unit 228 outputs a transmission power value P when transmitting the uplink transmission request inquiry signal to the frame generation unit 229. The frame generation unit 229 sets the transmission power value P input from the control unit 228 in the transmission power field 31b of the uplink transmission request inquiry signal 31. Further, the frame generation unit 229 sets an identifier indicating that it is an uplink transmission request inquiry signal in the frame type field 31 a of the uplink transmission request inquiry signal 31.

  (Step S308) The control unit 228 outputs the transmission power value P of the uplink transmission request inquiry signal to the radio unit 222. The transmission unit 230 transmits an uplink transmission request inquiry signal via the wireless unit 222 and the antenna 221. At this time, the radio unit 222 sets the transmission power value of the uplink transmission request inquiry signal to P.

  Since steps S309 to S313 are the same as steps S208 to S212 in the second embodiment, description thereof is omitted.

  Next, the configuration of the wireless terminal station 302 will be described using the block configuration diagram shown in FIG. The wireless terminal stations 303 to 308 have the same configuration as the wireless terminal station 302. The wireless terminal station 302 is configured to further include a propagation loss calculation unit 351 and a received power estimation unit 352 in the wireless terminal station 202 shown in FIG.

  The frame analysis unit 264 extracts the transmission power value described in the transmission power field of the received uplink transmission request inquiry signal, and outputs it to the propagation loss calculation unit 351. In addition, the signal strength measurement unit 265 measures the reception strength of the uplink transmission request inquiry signal and outputs it to the propagation loss calculation unit 351.

  The propagation loss calculation unit 351 calculates a propagation loss from the transmission power value extracted by the frame analysis unit 264 and the reception intensity measured by the signal strength measurement unit 265. For example, when the transmission power value extracted by the frame analysis unit 264 is 15 dBm and the reception strength measured by the signal strength measurement unit 265 is −40 dBm, the propagation loss is calculated as 15 − (− 40) = 55 dBm.

  The reception power estimation unit 352 estimates the reception power at the radio base station 301 from the transmission power of the radio terminal station 302 and the value of the propagation loss calculated by the propagation loss calculation unit 351. For example, when the transmission power when the wireless terminal station 302 transmits the uplink transmission request signal is 10 dBm and the propagation loss calculated by the propagation loss calculation unit 351 is 55 dB, the reception power at the wireless base station 301 is 10−55. = −45 dBm.

  The subfield selection unit 266 determines the uplink transmission request signal based on, for example, a value obtained by subtracting a predetermined margin due to fading or the like from the estimation value of the reception power at the radio base station 301 estimated by the reception power estimation unit 352. Select the subfield to send. For example, when the predetermined margin is 5 dB and the estimated value of the received power at the radio base station 301 estimated by the received power estimation unit 352 is −45 dBm, the uplink is based on the value −45−5 = −50 dBm. Select a subfield to transmit the transmission request signal.

  When the correspondence relationship between the terminal identification subfield and the signal intensity range is determined as shown in the table of FIG. 4, the subfield selection unit 266 selects the subfield TS3.

  An example of processing from transmission of a registration request frame to transmission of an uplink transmission request signal by the wireless terminal station 302 will be described with reference to the flowchart shown in FIG. Since steps S351 to S359 are the same as steps S251 to S259 in the second embodiment, description thereof is omitted.

  (Step S360) The frame analysis unit 264 extracts a transmission power value from the transmission power field of the received uplink transmission request inquiry signal.

  (Step S361) The propagation loss calculation unit 351 calculates a propagation loss from the transmission power value extracted by the frame analysis unit 264 in step S360 and the reception strength measured by the signal strength measurement unit 265 in step S358.

  (Step S362) The reception power estimation unit 352 estimates the reception power at the radio base station 301 from the transmission power of the radio terminal station 302 and the value of the propagation loss calculated by the propagation loss calculation unit 351.

  (Step S363) The subfield selection unit 266 selects a subfield for transmitting an uplink transmission request signal from the estimated value of the reception power at the radio base station 301 estimated by the reception power estimation unit 352. A subfield may be selected based on a value obtained by subtracting a predetermined margin due to fading or the like from an estimated value of received power at the radio base station 301.

  Steps S364 to S366 are the same as steps S261 to S263 in the second embodiment, and a description thereof will be omitted.

  As described above, in this embodiment, the overhead of subfield and subchannel allocation can be reduced as in the second embodiment, so that the throughput characteristics of the network can be improved.

  Furthermore, in the present embodiment, the radio terminal station can estimate the reception strength of the uplink transmission request signal by the radio base station by describing the transmission power value in the uplink transmission request inquiry signal. Since the radio terminal station selects the subfield corresponding to the estimated reception strength and transmits the uplink transmission request signal, the accuracy of subfield selection increases, and the detection accuracy of the terminal that transmitted the uplink transmission request signal in the radio base station Can be increased.

  (Fourth Embodiment) A radio base station 401 and radio terminal stations 402 to 408 according to a fourth embodiment of the present invention are the same as the radio base station 301 and radio terminal stations according to the third embodiment shown in FIG. Similar to 302 to 308, the radio base station 401 and the radio terminal stations 402 to 408 perform radio communication by sharing a frequency channel composed of a plurality of subchannels.

  FIG. 20 shows a block configuration of the wireless terminal station 402. The wireless terminal station 402 is configured to further include an AGC (Automatic Gain Control) pilot (known signal) insertion unit 451 in addition to the wireless terminal station 302 according to the third embodiment. The wireless terminal stations 403 to 408 have the same configuration as the wireless terminal station 402.

  An example of the format of the uplink transmission request signal transmitted from the wireless terminal station 402 is shown in FIG. The uplink transmission request signal is obtained by adding AGC pilot fields APF1 to APF4 to the subfields TS1 to TS4 in the format shown in FIG. AGC pilot fields APF1 to APF4 are configured by symbols corresponding to subchannels SC1 to SC8, respectively.

  When generating an uplink transmission request signal, AGC pilot insertion section 451 sets a predetermined signal in the pilot field corresponding to the assigned subchannel of the selected subfield.

  An example of processing from transmission of the registration request frame to transmission of the uplink transmission request signal by the wireless terminal station 402 will be described with reference to the flowchart shown in FIG. Steps S451 to S464 are the same as steps S351 to S364 in the third embodiment, and a description thereof will be omitted.

  (Step S465) The AGC pilot insertion unit 451 corresponds to the subfield selected in step S463 and the subchannel allocated to the wireless terminal station 402 (subchannel allocation information stored in the memory 267 in step S456). A predetermined signal is mapped to the pilot field. In other words, the AGC pilot insertion unit 451 maps the signal to the AGC pilot field immediately before the subfield to which the signal is mapped in step S464.

  Steps S466 and S467 are the same as steps S365 and S366 in the third embodiment, and a description thereof will be omitted.

  Next, the configuration of the wireless base station 401 will be described using the block configuration diagram shown in FIG. The radio base station 401 is configured to further include a gain adjustment unit 411, a time synchronization unit 412, an AGC pilot power measurement unit 413, and an AGC control unit 414 in the radio base station 301 shown in FIG.

  The gain adjustment unit 411 adjusts the gain of the signal received via the antenna 221 and the radio unit 222 based on the gain adjustment value output from the AGC control unit 414 and outputs the adjusted signal to the reception unit 223. Time synchronization section 412 performs time synchronization processing using a synchronization pilot signal included in the uplink transmission request signal, and detects the start position of the terminal identification field.

  The AGC pilot power measurement unit 413 measures the power of the AGC pilot included in the subfield of the uplink transmission request signal. The AGC control unit 414 calculates a gain adjustment value based on the measured AGC pilot power and outputs the gain adjustment value to the gain adjustment unit 411. Thereby, the signal of each subfield is adjusted to an appropriate level.

  An example of processing from subchannel assignment to terminal determination by the radio base station 401 will be described with reference to the flowchart shown in FIG. Steps S401 to S411 are the same as steps S301 to S311 in the third embodiment, and a description thereof will be omitted.

  (Step S412) Time synchronization section 412 performs time synchronization processing using a synchronization pilot signal included in the uplink transmission request signal. The time synchronization process is, for example, a process for obtaining a timing information of a received signal by performing a matched filter process of a synchronization pilot signal known between transmitting and receiving terminals. From the uplink transmission request signal as shown in FIG. 21, the start position information of the terminal identification field is acquired.

  (Step S413) The AGC pilot power measurement unit 413 measures the power of the AGC pilot corresponding to any one of the plurality of subfields.

  (Step S414) The AGC control unit 414 calculates a gain adjustment value based on the power of the AGC pilot measured by the AGC pilot power measurement unit 413, and outputs the calculation result to the gain adjustment unit 411. The gain adjustment unit 411 adjusts the gain of the received signal based on the received adjustment value.

  (Step S415) The terminal determination unit 225 acquires subchannel information from the uplink transmission request signal whose gain is adjusted by the gain adjustment unit 411.

  (Step S416) The terminal determination unit 225 refers to the subchannel allocation information stored in the memory 231 using the acquired subchannel information, and determines the wireless terminal station that has transmitted the uplink transmission request signal.

  (Step S417) It is determined whether or not a terminal identification subfield remains in the uplink transmission request signal. If it remains, the process returns to step S413, and if it does not remain, the process ends. The processes in steps S413 to S416 are performed as many times as the number of predetermined terminal identification subfields in the uplink transmission request signal.

  Thus, in this embodiment, as in the second and third embodiments, the overhead of subfield and subchannel allocation can be reduced, so that the network throughput characteristics can be improved.

  Furthermore, in this embodiment, since it is possible to A / D convert the uplink transmission request signal in each subfield at an appropriate level, it is possible to further improve the detection accuracy of the terminal that has transmitted the uplink transmission request signal. .

  (Fifth Embodiment) A radio base station 501 and radio terminal stations 502 to 508 according to a fifth embodiment of the present invention are the same as the radio base station 301 and the radio terminal station according to the third embodiment shown in FIG. Similar to 302 to 308, the radio base station 501 and the radio terminal stations 502 to 508 perform radio communication by sharing a frequency channel composed of a plurality of subchannels. Further, in the present embodiment, when the radio base station 501 determines the radio terminal stations 502 to 508 that transmitted the uplink transmission request signal, the phase information is used in addition to the signal strength.

  FIG. 25 shows a block configuration of the wireless terminal station 502. The wireless terminal station 502 is configured to further include a transmission path estimation pilot (known signal) insertion unit 551 in the wireless terminal station 402 according to the fourth embodiment. The wireless terminal stations 503 to 508 have the same configuration as the wireless terminal station 502. Transmission path estimation pilot insertion section 551 inserts a transmission path estimation pilot signal into the uplink transmission request signal.

  An example of the format of the uplink transmission request signal transmitted from the wireless terminal station 502 is shown in FIG. The uplink transmission request signal is obtained by adding transmission path estimation pilot fields TPF1 to TPF4 to the subfields TS1 to TS4 in the format shown in FIG. Transmission path estimation pilot fields TPF1 to TPF4 are configured by symbols corresponding to subchannels SC1 to SC8, respectively.

  Transmission path estimation pilot insertion section 551 sets a known signal in the pilot field determined by the subfield selected by subfield selection section 266 and the assigned subchannel.

  In addition, when generating the uplink transmission request signal, the frame generation unit 170 of the wireless terminal station 502 generates an initial signal to be mapped according to the subfield selected by the subfield selection unit 266 and the assigned subchannel. Change the phase. FIG. 27 shows an example of a correspondence table between subfields and subchannels and initial phases. This table is stored in the memory 267, and the control unit 269 refers to this table, and selects the initial value corresponding to the subchannel assigned to the own radio terminal station when the subfield selection unit 266 is selected and registered in the network. The phase is detected and notified to the frame generation unit 270. The wireless base station 501 sets this beacon signal and periodically reports this table.

  An example of processing from transmission of a registration request frame to transmission of an uplink transmission request signal by the wireless terminal station 502 will be described with reference to a flowchart shown in FIG. Steps S551 to S563 are the same as steps S451 to S463 in the fourth embodiment, and a description thereof will be omitted.

  (Step S564) With reference to the initial phase table as shown in FIG. 27 stored in the memory 267, it corresponds to the subchannel allocation information stored in the memory 267 in Step S556 and the subfield selected in Step S563. An initial phase is detected. Then, frame generation section 270 maps the detected initial phase signal to the assigned subchannel of the selected subfield, and generates an uplink transmission request signal.

  For example, when subfield selecting section 266 selects subfield TS2 and subchannel SC4 is assigned, a signal having an initial phase of 3π / 4 is mapped based on the initial phase table of FIG.

  (Step S567) The AGC pilot insertion unit 451 maps a predetermined signal to the AGC pilot field corresponding to the subfield and subchannel to which the signal is mapped in step S566.

  (Step S568) Transmission path estimation pilot insertion section 551 maps a predetermined signal to the transmission path estimation pilot field corresponding to the subfield and subchannel to which the signal is mapped in step S566. In other words, the transmission path estimation pilot insertion unit 551 outputs a signal to the transmission path estimation pilot field between the subfield to which the signal is mapped in step S566 and the AGC pilot field to which the signal is mapped in step S567. To map.

  Steps S567 and S568 are the same as steps S466 and S467 in the fourth embodiment, and a description thereof will be omitted.

  Next, the radio base station 501 will be described. The radio base station 501 has the same configuration as the radio base station 401 in the fourth embodiment except for the terminal determination unit 225. A block configuration of the terminal determination unit 225 of the radio base station 501 is shown in FIG. The terminal determination unit 225 of this embodiment includes a Fourier transform unit 541, a transmission path correction unit 542, a transmission path estimation unit 543, a subchannel power measurement unit 544, a subchannel phase determination unit 545, a threshold determination unit 546, and a request terminal determination. Part 547. The operation of each part of the terminal determination unit 225 having such a configuration will be described with reference to a flowchart showing terminal determination processing by the terminal determination unit 225 shown in FIG.

  (Step S521) The Fourier transform unit 541 performs a Fourier transform process on the input uplink transmission request signal, and converts the signal in the time axis direction into the signal in the frequency axis direction.

  (Step S522) The transmission path estimation unit 543 performs complex division on the transmission path estimation pilot signal held inside the signal Fourier-transformed by the Fourier transform unit 541 in step S521, and estimates the transmission path response.

  (Step S523) The transmission path correction unit 542 multiplies the terminal determination subfield signal Fourier-transformed by the Fourier transform unit 541 in Step S521 by the transmission path response estimated by the transmission path estimation unit 543 in Step S522, Perform transmission path correction.

  (Step S524) The subchannel power measurement unit 544 measures the power of any one subchannel in the terminal determination subfield in the frequency direction corrected by the transmission path correction unit 542 in step S523.

  (Step S525) The threshold value determination unit 546 compares the subchannel power measured by the subchannel power measurement unit 544 in step S524 with a predetermined threshold value. If the subchannel power is greater than or equal to the threshold, the process proceeds to step S526, and if it is less than the threshold, the process proceeds to step S529.

  (Step S526) The subchannel phase determination unit 545 detects the phase of the subchannel.

  (Step S527) The subchannel phase determination unit 545 determines whether or not the phase detected in step S526 is within a predetermined quadrant. When it exists, it progresses to step S528, and when it does not exist, it progresses to step S529.

  (Step S528) The request terminal determination unit 547 determines from the determination result of the threshold determination unit 546 and the determination result of the subchannel phase determination unit 545 that there is an uplink transmission request from the radio terminal station to which the subchannel is assigned. .

  (Step S529) The requesting terminal determination unit 547 determines from the determination result of the threshold determination unit 546 and the determination result of the subchannel phase determination unit 545 that there is no uplink transmission request from the wireless terminal station to which the subchannel is assigned. .

  (Step S530) It is determined whether or not the subchannel to be determined remains. If there are any remaining subchannels to be determined, the process returns to step S524, and if not, the process ends.

  In this way, by mapping the terminal identification subchannel signal to a predetermined phase, it is possible to determine the terminal that made the uplink transmission request using the phase information in addition to the signal strength (subchannel power). Therefore, the accuracy of terminal determination is improved.

  (Sixth Embodiment) FIG. 31 shows a block configuration of a radio base station 601 according to a sixth embodiment of the present invention. The radio base station 601 has a configuration in which a permitted terminal selection unit 611 is added to the radio base station 401 according to the fourth embodiment. The permitted terminal selection unit 611 selects a wireless terminal station that permits uplink transmission from the wireless terminal stations that are determined by the terminal determination unit 225 to have transmitted the uplink transmission request signal. For example, the permitted terminal selection unit 611 permits uplink transmission to the radio terminal station detected in any one of the plurality of subfields (determined that the uplink transmission request signal has been transmitted). .

  An example of processing from subchannel assignment by the radio base station 601 to uplink transmission permitted terminal determination will be described with reference to the flowchart shown in FIG. Since steps S601 to S617 are the same as steps S401 to S417 in the fourth embodiment, description thereof is omitted.

  (Step S618) The permitted terminal selection unit 611 selects a permitted terminal for uplink transmission. For example, among the wireless terminal stations detected in step S616, uplink transmission is permitted to the wireless terminal stations detected in the same terminal identification subfield.

  As described above, by granting uplink transmission permission to the wireless terminal stations detected in the same terminal identification subfield, the wireless base station 601 has the same strength for receiving data transmitted from a plurality of wireless terminal stations. Strength. If the reception strengths of a plurality of reception data are the same, the accuracy of data level adjustment can be improved, and the data reception characteristics can be improved.

  (Seventh Embodiment) FIG. 33 shows a block configuration of a radio base station 701 according to a seventh embodiment of the present invention. The radio base station 701 includes a plurality of antennas 221 of the radio base station 601 according to the sixth embodiment, a MIMO (Multi Input Multi Output) demodulator 711, a demodulator 712, an error checker 713, a pilot signal receiver 714, a channel information calculation unit 715, a channel capacity calculation unit 716, and a transmission mode determination unit 717 are added. The memory 231 is not shown.

  An example of processing from such subchannel assignment by the wireless base station 701 to reception of data transmitted by the wireless terminal station permitted to perform uplink transmission will be described with reference to the flowchart shown in FIG. Steps S701 to S717 are the same as steps S601 to S617 in the sixth embodiment, and a description thereof will be omitted.

  (Step S718) The frame generation unit 229 requests the wireless terminal station detected in the same terminal identification subfield to transmit a pilot signal based on an instruction from the control unit 228. A pilot signal request packet describing the order of transmission is generated. Then, the transmission unit 230 transmits a pilot signal request packet via the radio unit 222 and the antenna 221.

  (Step S719) The control unit 228 determines whether a pilot signal is received from each candidate wireless terminal station in the designated order. If received, the process proceeds to step S720. If not received, the process ends.

  (Step S720) The channel information calculation unit 715 receives a pilot signal from the reception unit 223 via the pilot signal reception unit 714, and calculates channel information with each wireless terminal station.

  (Step S721) The channel capacity calculation unit 716 uses the channel information calculated by the channel information calculation unit 715 to obtain a combination of wireless terminal stations that maximizes the channel capacity. And the permission terminal selection part 611 selects the radio | wireless terminal station contained in the calculated | required combination as a permission terminal.

  (Step S722) The transmission mode determination unit 717 determines the transmission mode based on the channel information of the permitted terminal selected by the permitted terminal selection unit 611.

  (Step S723) The permitted terminal information selected by the permitted terminal selection unit 611 and the transmission mode determined by the transmission mode determination unit 717 are input to the frame generation unit 229 via the control unit 228. The frame generation unit 229 generates a permitted terminal notification packet indicating a terminal that permits uplink transmission, an order of transmitting pilot signals, and a transmission mode. Then, the transmission unit 230 transmits the permitted terminal notification packet via the wireless unit 222 and the antenna 221.

  (Step S724) After transmitting the permitted terminal notification packet, the receiving unit 223 receives a pilot signal in order from each permitted terminal after a predetermined time has elapsed. Then, after receiving pilot signals from all permitted terminals, the MIMO demodulator 711 performs a MIMO demodulation process.

  (Step S725) The demodulator 712 performs a decoding process.

  (Step S726) The error check unit 713 performs error check such as CRC check on the data decoded by the demodulation unit 712. The error check result is input to the frame generation unit 229.

  (Step S727) The frame generation unit 229 generates an Ack (acknowledgment response) frame based on the error check result. Then, the transmission unit 230 transmits the Ack frame via the wireless unit 222 and the antenna 221.

  FIG. 35 is a flowchart for explaining the details of the selection of permitted terminals (step S721 in FIG. 34) for uplink spatial multiplexing transmission processing performed by the radio base station 701 shown in FIG.

  (Step S731) One of the combinations of radio terminal stations that are candidates for uplink transmission permission (the radio terminal station that has transmitted the pilot signal) is selected.

  (Step S732) The channel capacity calculation unit 716 calculates the channel capacity for the combination extracted in step S731, using the channel information calculated by the channel information calculation unit 715.

  (Step S733) It is determined whether or not the channel capacity calculated in step S732 is the maximum value. If it is the maximum value, the process proceeds to step S734, and if it is not the maximum value, the process proceeds to step S735.

  (Step S734) The channel capacity calculation unit 715 holds the combination of radio terminal stations and the channel capacity. These may be stored in the memory 231 (not shown).

  (Step S735) It is determined whether all combinations of wireless terminal stations have been selected. If all are selected, the process proceeds to step S736. If there is a combination that is not selected, the process returns to step S731.

  (Step S736) The permitted terminal selection unit 611 selects a combination of wireless terminal stations that maximizes the channel capacity as a terminal that grants transmission permission.

  FIG. 36 shows a timing diagram of frame exchange for uplink spatial multiplexing transmission performed by the radio base station 701 and the radio terminal stations 702 to 706.

  The radio base station 701 transmits an uplink period start (uplink transmission request inquiry) packet P1, and the radio terminal stations 702 to 706 receive the uplink period start packets P2 to P6, respectively.

  After a predetermined period T1, the wireless terminal stations 702 to 705 that hold the transmission data transmit transmission request packets P7 to P10 at the same time. The wireless base station 701 receives the transmission request packet P11 transmitted from the wireless terminal stations 702 to 705, and identifies the terminal that transmitted the transmission request packet.

  The wireless base station 701 selects three wireless terminal stations 702 to 704 detected in the same terminal identification subfield from the specified wireless terminal stations 702 to 705. Then, after elapse of a predetermined period T2, a pilot signal transmission request packet P12 describing the identifiers of the selected wireless terminal stations 702 to 704 and the transmission order of the pilot signals is transmitted. Wireless terminal stations 702 to 705 receive pilot signal transmission request packets P13 to P16, respectively. Here, it is assumed that the order of transmitting the pilot signals is the order of the wireless terminal stations 702, 703, and 704.

  The wireless terminal station 702 that transmits the pilot signal first transmits the pilot signal P17 from each antenna in a time-division manner after a predetermined period T3 has elapsed after receiving the pilot signal transmission request packet. Pilot signal P20 is received.

  As soon as the pilot signal transmission period assigned to the wireless terminal station 702 ends, the wireless terminal station 703 that transmits the pilot signal secondly transmits the pilot signal P18 from each antenna in a time division manner. Receives the pilot signal P21.

  Similarly, as soon as the pilot signal transmission period assigned to the wireless terminal station 703 ends, the wireless terminal station 704 that transmits the pilot signal thirdly transmits the pilot signal P19 from each antenna in a time division manner. The base station 701 receives the pilot signal P22.

  Since the wireless terminal station 705 is not selected as the wireless base station 701, the wireless terminal station 705 does not transmit a pilot signal.

  The radio base station 701 calculates channel information from the pilot signals received from each of the radio terminal stations 702 to 704 and the pilot signal held therein in advance, and sets a radio terminal station that grants transmission permission based on the calculated channel information. The transmission mode is determined from the channel information with the wireless terminal station that determines and grants the transmission permission.

  In the example illustrated in FIG. 36, it is assumed that transmission permission is given to the wireless terminal station 702 and the wireless terminal station 704, and the transmission mode is, for example, 72 Mbps mode.

  The wireless base station 701 transmits the terminal identifiers of the wireless terminal station 702 and the wireless terminal station 704 and the transmission order of pilot signals for data demodulation after a predetermined period T4 has elapsed from the end of the transmission period of the last pilot signal P19. And the permitted terminal notification packet P23 in which the determined transmission mode identifier is described. The wireless terminal stations 702 to 704 receive the permitted terminal notification packets P24 to P26, respectively. Here, it is assumed that the order in which pilot signals are transmitted is the order of wireless terminal stations 702 and 704.

  The wireless terminal station 702 that first transmits the pilot signal transmits the pilot signal P27 from each antenna in a time-division manner after a predetermined period T5 has elapsed after receiving the permitted terminal notification packet P24. Pilot signal P29 is received.

  As soon as the pilot signal transmission period assigned to the wireless terminal station 702 ends, the wireless terminal station 704 that transmits the pilot signal secondly transmits the pilot signal P28 from each antenna in a time-sharing manner. Receives the pilot signal P30.

  The wireless terminal stations 702 and 704 transmit data D1 and D2 respectively as soon as the pilot signal transmission period of the wireless terminal station 704 ends. The radio base station 701 receives the data D3 and demodulates the data using the pilot signals P29 and P30 received from the radio terminal stations 702 and 704.

  After demodulating data, the radio base station 701 performs an error check on the data from the respective radio terminal stations 702 and 704, and transmits the error check result in the Ack packet P31 to the radio terminal stations 702 and 704. The wireless terminal stations 702 and 704 receive Ack packets P32 and P33, respectively.

  Thus, the radio base station according to the present embodiment acquires channel information with the radio terminal station that has transmitted the uplink transmission request signal, and permits uplink data transmission based on the acquired channel information. The above wireless terminal station is determined, and the transmission mode is determined from the channel information between the determined terminal and notified. As a result, a radio terminal station with little mutual interference can be selected and the packet error rate characteristics can be improved, so that the throughput of the network can be improved.

  (Eighth Embodiment) FIG. 37 shows a block configuration of a radio base station 801 according to an eighth embodiment of the present invention. The radio base station 801 has a configuration in which the AGC pilot power measurement unit 413 is omitted from the radio base station 401 according to the fourth embodiment.

  An example of processing from subchannel assignment to terminal determination by the radio base station 801 will be described with reference to the flowchart shown in FIG. Steps S801 to S812 are the same as steps S401 to S412 in the fourth embodiment, and a description thereof will be omitted.

  (Step S813) The AGC control unit 414 sets upper limit value information and lower limit value information of a predetermined subfield for one subfield that has not yet been subjected to terminal determination processing among the plurality of terminal identification subfields. Based on this, the gain adjustment value is calculated. Then, gain adjustment section 411 adjusts the gain of the received signal using the calculated adjustment value.

  (Step S814) The terminal determination unit 225 receives the uplink transmission request signal whose gain has been adjusted by the gain adjustment unit 411 from the reception unit 223, and acquires subchannel information.

  (Step S815) The terminal determination unit 225 uses the acquired subchannel information to determine the wireless terminal station that has transmitted the uplink transmission request signal.

  (Step S816) It is determined whether a terminal identification subfield that has not yet been subjected to terminal determination processing remains in the uplink transmission request signal. When it remains, it returns to step S813, and when it does not remain, a process is complete | finished. The terminal determination process in steps S813 to S815 is performed as many times as the number of predetermined terminal identification subfields in the uplink transmission request signal.

  FIG. 39 is a table showing an example of a correspondence between a predetermined signal strength range of the terminal identification subfield and an input signal level of the A / D converter. The AGC control unit 414 of the radio base station 801 performs gain adjustment based on the time synchronization information so that the signal of the first subfield (signal level is 0 dBm to 20 dBm) corresponds to the input signal level of the A / D converter. .

  Next, the AGC control unit 414 performs gain adjustment so that the signal of the second subfield (signal level is −20 dBm to 0 dBm) corresponds to the input signal level of the A / D converter. Subsequently, the AGC control unit 414 performs gain adjustment so that the signal of the third subfield (signal level is −40 dBm to −20 dBm) corresponds to the input signal level of the A / D converter. Similarly, the AGC control unit 414 performs gain adjustment for the signals of the fourth, fifth, and sixth subfields so as to correspond to the input signal level of the A / D converter, respectively.

  In this way, since it is possible to A / D convert the uplink transmission request signal in each terminal identification subfield at an appropriate level, it is possible to improve the detection accuracy of the wireless terminal station that has transmitted the uplink transmission request signal. it can. In addition, since gain adjustment is performed using a predetermined signal strength for each subfield, it is not necessary to measure the power of the AGC pilot signal. Further, the radio terminal station does not need to insert an AGC pilot signal into the uplink transmission request signal.

  (Ninth Embodiment) FIG. 40 shows a block configuration of a wireless terminal station 902 according to a ninth embodiment of the present invention. The wireless terminal station 902 has a configuration in which a subchannel selection unit 951, a subchannel determination unit 952, and a terminal determination unit 953 are added to the wireless terminal station 202 according to the second embodiment. The wireless terminal station 902 can transmit a transmission request signal using a subchannel and specify a transmission source of the transmission request signal in an autonomous network in which no wireless base station exists.

  An example of processing from subchannel selection to transmission of a transmission request signal by such a wireless terminal station 902 will be described with reference to the flowchart shown in FIG.

  (Step S951) The subchannel selection unit 951 selects a subchannel. The subchannel selection unit 951 has a function of a hash function inside, and performs subchannel selection by inputting the MAC address of the own terminal to the hash function and outputting the subchannel.

  The hash function is a function that can generate another value from an arbitrary value, and outputs different values for different input values. Therefore, terminals with different MAC addresses select different subchannels.

  (Step S952) The frame analysis unit 264 performs frame analysis of the reception signal input to the reception unit 263 via the antenna 261 and the radio unit 262, and determines whether it is a transmission request inquiry signal. If it is a transmission request inquiry signal, the process proceeds to step S953. If it is not a transmission request inquiry signal, it waits until a transmission request inquiry signal is received.

  (Step S953) The signal strength measuring unit 265 measures the reception strength of the transmission request inquiry signal.

  (Step S954) Subfield selecting section 266 selects a subfield for transmitting terminal identification information based on the reception intensity measured in step S953. At this time, the subfield selection unit 266 refers to a table as shown in FIG.

  (Step S955) The frame generation unit 270 sets a signal in the subchannel selected in step S951 in the subfield selected in step S954, and generates a transmission request signal.

  (Step S956) The control unit 269 determines whether or not it is a predetermined transmission timing. If it is the transmission timing, the process proceeds to step S957, and if it is not the transmission timing, it waits until the transmission timing is reached.

  (Step S957) The transmission unit 271 transmits a transmission request signal via the wireless unit 262 and the antenna 261.

  Next, an example of processing from transmission request inquiry signal transmission to terminal determination by the wireless terminal station 802 will be described with reference to the flowchart shown in FIG.

  (Step S901) In response to an instruction from the control unit 269, the frame generation unit 270 generates a transmission request inquiry signal. Then, the transmission unit 271 transmits a transmission request inquiry signal via the wireless unit 262 and the antenna 261.

  (Step S902) After the transmission request inquiry signal is transmitted, the control unit 269 sets a predetermined reception timeout time in the timer 268 and starts the timer 268.

  (Step S903) It is determined whether or not a transmission request signal from another wireless terminal station has been received. If received, the process proceeds to step S904. If not received, the process proceeds to step S907.

  (Step S904) The subchannel determination unit 952 determines a subchannel, and outputs the subchannel information in which the signal is detected to the terminal determination unit 953.

  (Step S905) The terminal determination unit 953 acquires correspondence information between subchannels and MAC addresses from the subchannel selection unit 951. The subchannel selection unit 951 calculates the corresponding relationship between the MAC address of the other wireless terminal station and the subchannel acquired by the frame exchange so far, and stores it in the memory 267 via the control unit 269.

  (Step S906) The wireless terminal that has transmitted a transmission request signal from the subchannel information received from the subchannel determination unit 952 and the subchannel and MAC address correspondence information received from the subchannel selection unit 951 by the terminal determination unit 953 Determine the station.

  In the subsequent processing, for example, as shown in FIG. 36, the wireless terminal station that has transmitted the transmission request signal is requested to transmit a pilot signal. Then, the channel information is acquired from the pilot signal received from the other radio terminal station, the channel capacity is calculated from the acquired channel information, the radio terminal station that gives the transmission permission is selected, and the radio terminal station that gives the transmission permission Notify information.

  (Step S907) It is determined whether or not the timer 268 has timed out. If not timed out, the process returns to step S903, and if timed out, the process ends.

  In this way, by selecting a subchannel autonomously using a hash function that inputs a MAC address and outputs a subchannel, the subchannel can be selected even in an autonomous network where there is no radio base station. It is possible to transmit a transmission request signal using the transmission request signal, and it is possible to specify a transmission source radio terminal station from the transmission request signal.

  Also in this embodiment, since sub-field and sub-channel reassignment does not occur, the overhead of sub-field and sub-channel assignment can be reduced, so that the throughput characteristics of the network can be improved.

  In the second to eighth embodiments, a table representing the relationship between the signal strength range and the terminal identification subfield is set in the beacon periodically transmitted by the radio base station, and the radio terminal station is notified. However, the radio base station may change the relationship between the signal strength range and the terminal identification subfield according to the signal strength of the frame received from the radio terminal station.

  For example, when the radio base station sets a table as shown in FIG. 43 in a beacon and periodically broadcasts it, the maximum value of the received signal strength of the frame received from the radio terminal station is −40 dBm and the minimum value is If it is −60 dBm, a table in which terminal identification subfields are set in increments of 5 dBm from −40 dBm to −60 dBm as shown in FIG. 44 may be newly notified.

  Thereby, since the range of the received signal corresponding to each subfield can be reduced, the detection accuracy can be improved, and the detection accuracy of the wireless terminal station that has transmitted the uplink transmission request signal can be increased. Also, since it is possible to set the range of the received signal corresponding to each subfield to an appropriate range according to the situation after the start of communication, the detection accuracy of the terminal that transmitted the uplink transmission request signal is increased. be able to.

  In the above-described embodiment, one terminal identification subfield is associated with one intensity range. However, a plurality of terminal identification subfields are associated with one intensity range, and each substation is assigned to one wireless terminal station. Different subchannels may be assigned in the field. An example of the internal configuration of such an uplink transmission request signal is shown in FIG.

  For example, the subfield TS1 is composed of the second subfield STS11 and the second subfield STS12, but the radio terminal station to which the subchannel SC1 is assigned in the second subfield STS11 is subchannel SC3 in the second subfield STS12. To be assigned.

  As a result, even when the detection characteristic is deteriorated due to multipath distortion in one second subfield, the radio of the transmission source of the uplink transmission request signal is located at a different subchannel position in the second and subsequent second subfields. The terminal station can be detected. Therefore, the detection characteristics of the terminal can be improved even when there is multipath distortion.

  The order in which the subchannel allocation unit 226 in the radio base station according to the above embodiment allocates the subchannels to the radio terminal station can be arbitrarily set. An example of the subchannel allocation order will be described with reference to FIG. In the example shown in FIG. 46, it is assumed that one OFDM symbol is composed of 16 subchannels.

  As shown in FIG. 46, the subchannel allocating unit 226 assigns the subchannel “1” to the wireless terminal station to which the registration permission is given first, and the subchannel “16” to the wireless terminal station that gives the second registration permission. Assigns subchannel “8” to the third wireless terminal station that has given permission to register, assigns subchannel “12” to the fourth wireless terminal station that has given permission to register, and gives fifth permission to register. The subchannel “4” is assigned to the wireless terminal station, the subchannel “6” is assigned to the wireless terminal station that has been granted the sixth registration permission, and the subchannel “10” is assigned to the wireless terminal station that has been given the seventh registration permission. , Assigns the subchannel “14” to the radio terminal station that has given the registration permission to the eighth, assigns the subchannel “2” to the radio terminal station that has given the registration permission to the ninth, and grants the registration permission to the tenth and later Given radio Subchannel "3" to the end station, "5", "7", "9", "11", "13", "15" arbitrarily assign any of subchannels.

  In this way, by sequentially assigning wireless terminal stations from subchannels whose frequencies are separated from each other, it is possible to reduce interference due to signal side lobes and improve the detection accuracy of the terminals.

  At least a part of the wireless communication device, the wireless base station, and the wireless terminal station described in the above-described embodiments may be configured by hardware or software. When configured with software, a program that realizes at least a part of the functions of the wireless communication device, the wireless base station, and the wireless terminal station is stored in a recording medium such as a flexible disk or a CD-ROM, and is read by a computer and executed. You may let them. The recording medium is not limited to a removable medium such as a magnetic disk or an optical disk, but may be a fixed recording medium such as a hard disk device or a memory.

  Further, a program that realizes at least a part of the functions of the wireless communication device, the wireless base station, and the wireless terminal station may be distributed via a communication line (including wireless communication) such as the Internet. Further, the program may be distributed in a state where the program is encrypted, modulated or compressed, and stored in a recording medium via a wired line such as the Internet or a wireless line.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a schematic configuration diagram of a radio communication system according to a first embodiment of the present invention. It is a block block diagram of the radio | wireless communication apparatus which concerns on the 1st Embodiment. It is a figure which shows an example of a format of a terminal identification information signal. It is a table which shows the relationship between the receiving strength of a terminal identification information request signal, and the subfield to select. 6 is a flowchart for explaining a reception process of a terminal identification information signal by the wireless communication apparatus according to the first embodiment. 7 is a flowchart for explaining a terminal identification information signal transmission process by the wireless communication apparatus according to the first embodiment. It is a schematic block diagram of the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. FIG. 6 is a block configuration diagram of a radio base station according to the second embodiment. It is a block block diagram of the terminal determination part in the wireless base station which concerns on the 2nd Embodiment. It is a flowchart explaining the terminal determination process by the terminal determination part which concerns on the 2nd Embodiment. It is a flowchart explaining the radio | wireless communication method by the radio base station which concerns on the 2nd Embodiment. It is a block block diagram of the radio | wireless terminal station which concerns on the 2nd Embodiment. It is a flowchart explaining the radio | wireless communication method by the radio | wireless terminal station which concerns on the 2nd Embodiment. It is a schematic block diagram of the radio | wireless communications system which concerns on the 3rd Embodiment of this invention. It is a figure which shows an example of the frame format of an uplink transmission request inquiry signal. It is a block block diagram of the wireless base station which concerns on the said 3rd Embodiment. It is a flowchart explaining the radio | wireless communication method by the radio base station which concerns on the 3rd Embodiment. It is a block block diagram of the radio | wireless terminal station which concerns on the 3rd Embodiment. It is a flowchart explaining the radio | wireless communication method by the radio | wireless terminal station which concerns on the 3rd Embodiment. It is a block block diagram of the radio | wireless terminal station which concerns on the 4th Embodiment of this invention. It is a figure which shows an example of a format of an uplink transmission request signal. It is a flowchart explaining the radio | wireless communication method by the radio | wireless terminal station which concerns on the 4th Embodiment. It is a block block diagram of the wireless base station which concerns on the 4th Embodiment. It is a flowchart explaining the radio | wireless communication method by the radio base station which concerns on the 4th Embodiment. It is a block block diagram of the radio | wireless terminal station which concerns on the 5th Embodiment of this invention. It is a figure which shows an example of a format of an uplink transmission request signal. It is a figure which shows an example of the correspondence table of a subchannel and a subfield, and an initial phase. It is a flowchart explaining the radio | wireless communication method by the radio | wireless terminal station which concerns on the 5th Embodiment. It is a block block diagram of the terminal determination part in the wireless base station which concerns on the 5th Embodiment. It is a flowchart explaining the terminal determination process by the terminal determination part which concerns on the said 5th Embodiment. It is a block block diagram of the radio base station which concerns on the 6th Embodiment of this invention. It is a flowchart explaining the radio | wireless communication method by the radio base station which concerns on the 6th Embodiment. It is a block block diagram of the radio base station which concerns on the 7th Embodiment of this invention. It is a flowchart explaining the radio | wireless communication method by the radio base station which concerns on the 7th Embodiment. It is a flowchart explaining the permission terminal selection process by the wireless base station which concerns on the said 7th Embodiment. It is a timing chart of the frame exchange example of the uplink spatial multiplexing transmission in said 7th Embodiment. It is a block block diagram of the radio base station which concerns on the 8th Embodiment of this invention. It is a flowchart explaining the radio | wireless communication method by the radio base station which concerns on the said 8th Embodiment. It is the table which showed an example of the correspondence of the signal strength range of the terminal identification subfield and the input signal level of the A / D converter. It is a block block diagram of the radio | wireless terminal station which concerns on the 9th Embodiment of this invention. It is a flowchart explaining the transmission processing of the transmission request signal by the wireless terminal station according to the ninth embodiment. It is a flowchart explaining the terminal determination process by the radio | wireless terminal station which concerns on the 9th embodiment. It is a table which shows an example of the relationship between the reception strength of an uplink transmission request signal, and the subfield to select. It is a table which shows an example of the relationship between the reception strength of an uplink transmission request signal, and the subfield to select. It is a figure which shows an example of a format of an uplink transmission request signal. It is a sequence diagram which shows an example of the order which assigns a subchannel to a radio | wireless terminal station.

Explanation of symbols

101 to 108 Radio communication device 121 Antenna 122 Radio unit 123 Reception unit 124 Frame analysis unit 125 Signal strength measurement unit 126 Terminal determination unit 127 Subfield selection unit 128 Control unit 129 Frame generation unit 130 Transmission unit 131 Timer 132 Memory

Claims (23)

A wireless communication device in which a plurality of wireless communication devices communicate by sharing a plurality of subchannels,
A receiving unit that receives a request signal for requesting transmission of an identification signal having a terminal identification field composed of a synchronization pilot symbol and a plurality of subfields from another wireless communication device;
A measurement unit for measuring the reception intensity of the request signal;
A selection unit that selects any one of the plurality of subfields based on the reception strength;
A generation unit configured to generate the identification signal by setting a signal in a predetermined subchannel in the subfield selected by the selection unit in the terminal identification field;
A transmission unit that transmits the identification signal generated by the generation unit to a transmission source of the request signal after a predetermined time from receiving the request signal;
A wireless communication device comprising: A storage unit that stores subchannel information indicating a predetermined subchannel in another wireless communication device;
When the generation unit generates the request signal, the transmission unit transmits the request signal to another wireless communication device, and the reception unit receives the identification signal transmitted from at least one other wireless communication device. A determination unit that detects which of the plurality of subchannels is set for each of the identification signals, and determines a wireless communication device that is a transmission source using the subchannel information;
The wireless communication apparatus according to claim 1, further comprising: A wireless communication device that communicates with a plurality of first wireless communication devices by sharing a plurality of subchannels,
A subchannel assigning unit that assigns any one of the plurality of subchannels to each of the plurality of first wireless communication devices so as to be different from each other;
A storage unit for storing a subchannel allocation result by the subchannel allocation unit;
A transmission unit that performs notification of the assigned subchannel and transmission of an inquiry signal inquiring an uplink transmission request to the first wireless communication device;
The first wireless communication apparatus has a terminal identification field composed of a synchronization pilot symbol and a plurality of subfields according to the inquiry signal, and is assigned to any one of the plurality of subfields A receiving unit for receiving an uplink transmission request signal for setting and transmitting a signal in a subchannel;
A determination unit that detects which one of the plurality of subchannels is set for the uplink transmission request signal received by the reception unit, and determines a first wireless communication device that is a transmission source using the allocation result When,
A wireless communication device comprising: A wireless communication device that communicates with a second wireless communication device by sharing a plurality of subchannels with a plurality of first wireless communication devices,
A storage unit for storing subchannels allocated by the second wireless communication device;
A receiving unit that receives an inquiry signal inquiring an uplink transmission request from the second wireless communication device;
A measurement unit for measuring the reception intensity of the inquiry signal;
A selection unit that selects any one of a plurality of subfields based on the reception strength;
A generation unit having a terminal identification field composed of a pilot symbol for synchronization and the plurality of subfields, and generating an uplink transmission request signal by setting a signal in the assigned subchannel in the selected subfield; ,
A transmission unit for transmitting the uplink transmission request signal to the second wireless communication device after a predetermined time from receiving the inquiry signal;
A wireless communication device comprising: The determination unit
A Fourier transform unit that performs a Fourier transform process on the uplink transmission request signal and transforms the uplink transmission request signal in a frequency axis direction;
A subchannel power measurement unit that measures power in each subchannel of the uplink transmission request signal that has undergone the Fourier transform processing;
The measured power of each subchannel is compared with a predetermined threshold, a subchannel whose power is equal to or greater than the threshold is detected, and the first wireless communication apparatus to which the detected subchannel is assigned is assigned to the uplink transmission request signal A threshold determination unit that determines a transmission source;
The wireless communication apparatus according to claim 3, further comprising:   The wireless communication apparatus according to claim 3, wherein the transmission unit describes transmission power information when transmitting the inquiry signal in the inquiry signal. A frame analysis unit that detects transmission power information when the second wireless communication device transmits the inquiry signal, which is described in the inquiry signal;
A propagation loss calculation unit that calculates a propagation loss of the inquiry signal using the reception strength and the transmission power information;
A reception power estimation unit that subtracts the propagation loss from the transmission power of the transmission unit to estimate reception power of the uplink transmission request signal in the second wireless communication device;
Further comprising
The radio communication apparatus according to claim 4, wherein the selection unit selects any one of the plurality of subfields based on the estimated received power.   Of the first known signal field into which the first known signal provided corresponding to each of the plurality of subfields in the terminal identification field can be inserted, the first corresponding to the selected subfield. The wireless communication apparatus according to claim 7, further comprising a first known signal insertion unit that inserts the first known signal into a known signal field. A gain adjusting unit that adjusts the gain of the uplink transmission request signal received by the receiving unit based on a gain adjustment value;
A time synchronization unit that performs time synchronization processing using the synchronization pilot symbol included in the uplink transmission request signal received by the reception unit, and acquires a start position of the terminal identification field;
A power measuring unit that sequentially measures the power of the first known signal inserted in front of each of the plurality of subfields in the terminal identification field based on the start position;
A gain controller that calculates the gain adjustment value based on the measured power;
Further comprising
The wireless communication apparatus according to claim 6, wherein the determination unit determines the first wireless communication apparatus in a subfield corresponding to the gain adjustment value. A gain adjusting unit that adjusts the gain of the uplink transmission request signal received by the receiving unit based on a gain adjustment value;
A gain control unit for calculating the gain adjustment value based on a corresponding signal strength range in order for each of the plurality of subfields in the terminal identification field;
Further comprising
The wireless communication apparatus according to claim 6, wherein the determination unit determines the first wireless communication apparatus in a subfield corresponding to the gain adjustment value. Of the second known signal field in which the second known signal provided corresponding to each of the plurality of subfields in the terminal identification field can be inserted, the second corresponding to the selected subfield. A second known signal insertion unit for inserting the second known signal into the known signal field of
The radio according to claim 8, wherein the generation unit sets the signal with an initial phase corresponding to the selected subfield and the assigned subchannel to generate the uplink transmission request signal. Communication device. The determination unit
A Fourier transform unit that performs a Fourier transform process on the uplink transmission request signal and transforms the uplink transmission request signal in a frequency axis direction;
Complex division of a second known signal inserted between each of the plurality of subfields and the first known signal in the terminal identification field of the uplink transmission request signal subjected to the Fourier transform process A channel estimation unit for estimating the channel response;
A transmission path correction unit that performs transmission path correction by multiplying the signals set in the plurality of subfields by the estimated transmission path response;
A subchannel power measurement unit that measures power in each subchannel of the uplink transmission request signal that has been corrected for the transmission path;
A threshold determination unit that compares the measured power of each subchannel with a predetermined threshold and determines whether the power is equal to or higher than the threshold;
A subchannel phase determination unit that detects a phase in each subchannel of the uplink transmission request signal subjected to the transmission path correction, and determines whether or not the detected phase exists in a predetermined quadrant;
The uplink transmission request is sent to the first wireless communication apparatus to which a subchannel indicating that the determination result of the threshold determination unit is equal to or greater than the threshold and the determination result of the subchannel phase determination unit is in the predetermined quadrant is assigned A requesting terminal determination unit for determining a signal transmission source;
The wireless communication apparatus according to claim 9, further comprising: A permission terminal selection unit that selects a first wireless communication device that grants permission for uplink transmission from among the first wireless communication devices determined by the determination unit as a transmission source of the uplink transmission request signal;
The wireless communication device according to claim 12, wherein the first wireless communication device selected by the permitted terminal selection unit is a device in which a signal is set in the same subfield. The first wireless communication device that has set the signal in the same subfield is selected from the first wireless communication devices that are determined by the determination unit as the transmission source of the uplink transmission request signal, and the selected wireless communication device A permitted terminal selection unit that grants uplink transmission permission to the first wireless communication device that constitutes the combination having the largest channel capacity among a plurality of combinations configured by all or a part of
The pilot transmitted from each first radio communication device in response to a pilot signal request packet requesting transmission of a pilot signal transmitted from the transmission unit to the first radio communication device selected by the permitted terminal selection unit A channel information calculation unit for calculating channel information between each first wireless communication device using a signal;
Using the channel information, the channel capacity is calculated for each of a plurality of combinations configured by all or part of the first wireless communication device selected by the permitted terminal selection unit, and the channel capacity is maximized. A channel capacity calculator for notifying the permitted terminal selector of the combination;
The wireless communication apparatus according to claim 12, further comprising: The second pilot transmitted from each first wireless communication device in response to the permission notification packet transmitted from the transmitting unit to the first wireless communication device that has been granted permission for uplink transmission by the permitted terminal selection unit. A demodulator that receives a signal and a data signal and demodulates the data signal using the second pilot signal;
An error check unit for performing an error check on the demodulated data signal;
Further comprising
15. The transmission unit according to claim 14, wherein the transmission unit transmits an acknowledgment frame to the first wireless communication device that is a transmission source of the second pilot signal and the data signal based on the result of the error check. Wireless communication device.   Informing the first wireless communication device of a table indicating a relationship between the reception strength of the inquiry signal and a subfield used when generating the uplink transmission request signal, and receiving the uplink received from the first wireless communication device The wireless communication apparatus according to claim 3, wherein the table is changed based on a maximum reception intensity and a minimum reception intensity of a transmission request signal. A table indicating the relationship between the reception strength of the inquiry signal and the subfield used when generating the uplink transmission request signal is notified from the second wireless communication device,
The radio communication apparatus according to claim 4, wherein the selection unit refers to the table and selects a subfield based on the reception intensity measured by the measurement unit.   The radio communication apparatus according to claim 16, wherein the subfield includes a plurality of second subfields.   The subfield includes a plurality of second subfields, and different subchannels are allocated to the plurality of second subfields included in the same subfield by the first wireless communication apparatus. The wireless communication device according to 17.   The subchannel allocating unit allocates one of the plurality of subchannels to each of the plurality of first wireless communication devices, and sequentially assigns the first wireless communication device to which the assignment order is continuous. The radio communication apparatus according to claim 3, wherein the frequency bands of the subchannels to be allocated are not adjacent to each other. A wireless communication device that communicates with a plurality of wireless communication devices by sharing a plurality of subchannels,
Generating a subchannel corresponding to the address information using a hash function from pre-assigned address information, and selecting a subchannel;
A receiving unit for receiving an inquiry signal for inquiring a transmission request;
A measurement unit for measuring the reception intensity of the inquiry signal;
A subfield selection unit that selects any one of a plurality of subfields based on the reception strength;
A generator having a terminal identification field composed of a synchronous pilot symbol and the plurality of subfields, and generating a transmission request signal by setting a signal in the selected subchannel in the selected subfield;
A transmission unit that transmits the transmission request signal to a transmission source of the inquiry signal after a predetermined time from receiving the inquiry signal;
A wireless communication device comprising: When the generation unit generates the inquiry signal, the transmission unit transmits the inquiry signal, and the reception unit receives the transmission request signal transmitted from at least one other wireless communication device, For each of the transmission request signals, a subchannel determination unit that determines which of the plurality of subchannels is set with the signal;
The subchannel selection unit generates a subchannel of the other radio communication device generated using the hash function from the address information of the other radio communication device acquired in advance, and the determination result of the subchannel determination unit. A terminal determination unit that determines a wireless communication device that is a transmission source of the transmission request signal received by the reception unit;
The wireless communication apparatus according to claim 21, further comprising: A wireless communication method in which a plurality of wireless communication devices communicate by sharing a plurality of subchannels,
The first wireless communication device transmits a request signal for requesting transmission of an identification signal having a terminal identification field composed of a synchronization pilot symbol and a plurality of subfields to the plurality of second wireless communication devices,
At least one of the plurality of second wireless communication devices measures the reception strength of the request signal, selects any one of the plurality of subfields based on the reception strength, In the selected subfield, a signal is set in a predetermined subchannel to generate the identification signal, and after a predetermined time after receiving the request signal, transmits to the first wireless communication device,
The first wireless communication apparatus receives the identification signal, detects which of the plurality of subchannels is set for each of the identification signals, and the plurality of second wireless communication apparatuses A second wireless communication device as a transmission source is determined using subchannel information indicating a predetermined subchannel in
Wireless communication method.

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