WO2022044110A1 - Communication control method and signal processing device - Google Patents

Abstract

This signal processing device allocates the transmission timing of a data-transmission polling signal that is addressed to each communication device in a time domain in which uplink data transmission is carried out. The signal processing device calculates the reception timing of a data signal that is transmitted wirelessly from a communication device in response to the data-transmission polling signal transmitted wirelessly with the allocated transmission timing. The signal processing device assesses, on the basis of the calculated reception timing, whether the data signal is colliding, and changes the communication device that is the destination of the data-transmission polling signal corresponding to the data signal for which it is assessed that collision is occurring to another communication device.

Description

Communication control method and signal processing device

The present invention relates to a communication control method and a signal processing device.

In recent years, the use of millimeter wave bands has been attracting attention in order to meet the increasing demand for wireless communication. The millimeter wave band can use a wider radio band than the microwave band. For example, IEEE802.11ay is being discussed as a next-generation 60 GHz band wireless LAN (Local Area Network) standard (see, for example, Non-Patent Document 1).

Various usage models are being studied in IEEE802.11ay (see, for example, Non-Patent Document 2 and Non-Patent Document 3). A model of "mmWave Distribution Network" has been added to this usage model. FIG. 9 is a diagram showing a usage model of a millimeter-wave distributed network. In the usage model shown in FIG. 9, a relay network that replaces the optical fiber is constructed by a millimeter-wave distributed network. The millimeter-wave distributed network is composed of millimeter-wave distributed nodes (mmWaveDistributionNode). The feature of the millimeter wave distributed network is that the millimeter wave distributed node (corresponding to the base station) installed outdoors and the radio (mmWave Sector; equivalent to the terminal station) installed around the building are connected and they are millimeters. The wave distribution node and the radio are fixedly installed. In FIG. 9, (a) is an access using WTTH (Wireless To The Home), (b) is an access using WTTB (Wireless To The Building), and (c) is Wi-Fi. (Registered trademark) AP (Access Point) / Indicates access using a small cell.

Since the propagation loss in free space increases in proportion to the frequency, the propagation distance of millimeter wave band communication is short. Therefore, in millimeter-wave band communication, there is a problem that communication can be performed only in a limited area. In order to expand the communication area, as shown in FIG. 9, a method of multi-hop via a plurality of millimeter-wave distributed nodes can be considered. However, as the number of hops increases, the transmission efficiency deteriorates. In addition, as the number of hops increases, the number of nodes increases, which leads to an increase in cost.

As a method for solving this problem, a method has been proposed in which the signal processing unit and the antenna unit are separated by using radio on fiber (RoF), and the antenna unit is arranged as an overhanging station to expand the apparent coverage area. (See, for example, Non-Patent Document 4). In this method, by connecting a plurality of antenna units to one signal processing unit and installing a plurality of overhanging stations, it is possible to further expand the coverage area. Further, by separating the signal processing unit and the antenna unit, it is possible to simplify the configuration of the overhanging station and save power. Furthermore, by consolidating a plurality of overhanging stations into one signal processing unit, a cost advantage can be expected.

In a system using RoF, a propagation delay occurs due to a longer propagation distance as compared with a normal wireless system, and transmission efficiency deteriorates. Therefore, there is a demand for a wireless communication method that eliminates the deterioration of transmission efficiency in a long-delay environment.

Next, the prior art regarding the wireless communication method in a long delay environment will be described. In a wireless LAN system to which RoF is applied, a wireless communication method for improving throughput characteristics has been proposed (see, for example, Non-Patent Document 5). FIG. 10 is a diagram showing a collision avoidance mechanism proposed in Non-Patent Document 5. Although the details of this collision avoidance mechanism are omitted, frame collision is avoided by extending the NAV (Network Allocation Vector) period in which the terminal station not involved in reception is prohibited from transmitting according to the propagation delay time.

Further, an example of a MAC (Medium Access Control) protocol in a 60 GHz band wireless communication system to which RoF is applied has been proposed (see, for example, Non-Patent Document 6). FIG. 11 is a diagram showing a frame configuration proposed in Non-Patent Document 6. The details of the MAC protocol are omitted, but in this protocol, the Central Office (CO; equivalent to the signal processing unit) assigns the optical wavelength to the Remote Antenna Unit (RAU; equivalent to the antenna unit) and to the Client (corresponding to the terminal station). Allocate wireless resources to centralized control. This efficiently controls both optical and wireless.

As described above, in the wireless communication method in the wireless LAN system to which the conventional RoF is applied, it is possible to avoid the collision of frames (signals) due to the long delay. However, as shown in FIG. 10, since transmission is prohibited for other terminal stations during communication between the base station and the terminal station, it is not possible to effectively utilize the free time of the radio band due to the long delay.

Further, the MAC protocol in the 60 GHz band wireless communication system to which RoF, which is another conventional technique, is applied, applies simple polling control based on the round robin method, particularly in the control of wireless resources. For example, assume that the base station and the three radio stations # 1 to the terminal station # 3 communicate with each other. FIG. 12 shows the traffic amount and the propagation distance of each of the terminal stations # 1 to the terminal station # 3. FIG. 13 is a diagram showing an outline of operations of a base station and radio stations # 1 to terminal station # 3 when radio resource control by the prior art is performed. DL indicates a downlink and UL indicates an uplink. The downlink is from the base station to the terminal station, and the uplink is from the terminal station to the base station. Also. The poll signal addressed to the terminal station # i (i = 1, 2, 3) is Poll _i , the UL data signal from the terminal station # i is Data _i , and the kth (k = 1, 2, ...) Slot is Slot #. It is described as k. Further, in the following, the polling signal is also referred to as a Poll signal.

As shown in the protocol of FIG. 11, the base station transmits a Poll signal to the terminal station to which each slot is assigned. The terminal station that received the Poll signal transmits the UL data signal. However, as shown in FIG. 13, signal collision may occur due to simultaneous reception of uplink data signals from terminal stations having different transmission distances at the base station. In the case of the example of FIG. 13, the base station receives the UL data signal D1 transmitted by the terminal station # 1 corresponding to the Poll signal P1 of the slot # 1, and then corresponds to the Poll signal P9 of the slot # 9. Until the UL data signal D9 transmitted by the terminal station # 3 is received, none of the terminal stations can communicate due to the collision, and the radio band is wasted. In particular, the longer the propagation delay, the more free time in the radio band will occur. As described above, the conventional radio resource control may not be able to prevent the occurrence of free time in the radio band due to the long delay.

In view of the above circumstances, an object of the present invention is to provide a communication control method and a signal processing device capable of improving the transmission efficiency of wireless communication.

One aspect of the present invention is an allocation step in which a signal processing device allocates a transmission timing of a data transmission poll signal addressed to each communication device in a time region in which uplink data transmission is performed, and the signal processing device determines the transmission timing. In the reception timing calculation step of calculating the reception timing of the data signal transmitted by radio from the communication device corresponding to the data transmission poll signal transmitted by radio, and the reception timing calculated by the signal processing device. A determination step for determining the presence or absence of collision of the data signal based on the above, and the communication device of the destination of the data transmission poll signal corresponding to the data signal determined to collide in the determination step. Is a communication control method having a destination change step of changing to another communication device.

Further, in one aspect of the present invention, the signal processing device includes an allocation step for assigning a transmission timing of a data transmission poll signal addressed to each communication device in a time region in which the signal processing device performs uplink data transmission, and the signal processing device. The reception timing calculation step for calculating the reception timing of the data signal transmitted wirelessly from the communication device corresponding to the data transmission poll signal transmitted wirelessly at the transmission timing, and the signal processing device calculated. A determination step for determining the presence or absence of a collision of the data signal based on the reception timing, and a transmission timing of the data transmission poll signal corresponding to the data signal determined to be collided by the signal processing device in the determination step. It is a communication control method having a timing change step to be changed.

Further, one aspect of the present invention includes an allocation unit that allocates a transmission timing of a data transmission poll signal addressed to each communication device in a time region in which uplink data transmission is performed, and a data transmission unit that is wirelessly transmitted at the transmission timing. A reception timing calculation unit that calculates the reception timing of a data signal wirelessly transmitted from the communication device in response to the polling signal, and a determination unit that determines the presence or absence of a collision of the data signal based on the calculated reception timing. A signal processing device including a destination changing unit for changing the communication device of the destination of the data transmission poll signal corresponding to the data signal determined to collide with the determination unit to another communication device.

Further, one aspect of the present invention includes an allocation unit that allocates a transmission timing of a poll signal for data transmission addressed to each communication device in a time region in which uplink data transmission is performed, and a data transmission unit that is wirelessly transmitted at the transmission timing. A reception timing calculation unit that calculates the reception timing of a data signal wirelessly transmitted from the communication device in response to the polling signal, and a determination unit that determines the presence or absence of a collision of the data signal based on the calculated reception timing. A signal processing device including a timing changing unit for changing the transmission timing of the data transmission poll signal corresponding to the data signal determined to collide with the determination unit.

According to the present invention, it is possible to improve the transmission efficiency of wireless communication.

It is a figure which shows the structure of the wireless communication system by 1st Embodiment of this invention. It is a flow diagram which shows the processing of the wireless communication system in the band request phase by the same embodiment. It is a flow diagram which shows the processing of the wireless communication system in the UL data transmission phase by the same embodiment. It is a figure which shows the operation outline in the UL data transmission phase of the wireless communication system by the same embodiment. It is a figure which shows the structure of the wireless communication system by 2nd Embodiment. It is a flow diagram which shows the processing of the wireless communication system in the UL data transmission phase by the same embodiment. It is a figure which shows the operation outline in the UL data transmission phase of the wireless communication system by the same embodiment. It is a figure which shows the hardware composition of the signal transmission / reception part and the terminal station by 1st and 2nd Embodiment. It is a figure which shows the sage model of a millimeter wave distributed network. It is a figure which shows the collision avoidance mechanism of a wireless LAN system. It is a figure which shows the frame structure of the MAC protocol. It is a figure which shows the traffic amount and propagation distance of a terminal station. It is a figure which shows the operation outline of the wireless communication system by a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment relates to a communication control method and a signal processing device that efficiently utilize the band of a wireless communication system in a long delay environment.

The wireless communication system of this embodiment has a base station and a terminal station. The base station wirelessly communicates with one or more terminal stations. The wireless communication system of the present embodiment enhances the utilization efficiency of the UL (uplink) wireless band and improves the transmission efficiency by incorporating the control considering the propagation delay time difference into the centralized control type medium access control based on polling. do. The wireless communication system of the present embodiment performs the following procedures 1 to 3.

[Procedure 1] The wireless communication system divides UL communication into a band request phase and a UL data transmission phase. The band request phase is a time domain in which each terminal station makes a band request to the base station. The UL data transmission phase is a time domain in which UL data transmission from a terminal station to a base station is carried out.

[Procedure 2] The wireless communication system implements the following procedures 2-1 to 2-3 as the operation of the band request phase.

[Procedure 2-1] The base station periodically broadcasts a polling signal for band request. In the following, the polling signal for band request will be referred to as a poll signal for band request.
[Procedure 2-2] The terminal station randomly selects a Poll signal for band request to perform a response.
[Procedure 2-3] The terminal station transmits a response signal to the selected Poll signal for band request. The terminal station sets the response signal with information about traffic in its own station in addition to the amount of data transmitted by UL communication. Information about traffic is, for example, traffic volume, packet generation interval, service type, priority, and the like. It should be noted that only the active terminal station may transmit the response. Active means that there is data to be transmitted by UL data transmission.

[Procedure 3] The wireless communication system implements the following procedures 3-1 to 3-4 as the operation of the UL data transmission phase.

[Procedure 3-1] The base station determines a terminal station to which a polling signal for UL data signal transmission is assigned based on a predetermined criterion. Hereinafter, the polling signal for UL data signal transmission will be referred to as a Poll signal for data transmission. For example, information on traffic, propagation distance, and the like can be used as the determination criteria, but the determination criteria are not limited thereto. Information about traffic includes traffic volume, packet generation interval, service type, priority, and the like.

[Procedure 3-2] The base station determines the transmission timing of the data transmission Poll signal addressed to the terminal station whose allocation has been determined based on the traffic information. For example, the packet generation interval is used as the traffic information, but other information may be used.

[Procedure 3-3] The base station arranges UL data signals from each terminal station based on the determined transmission timing of the data transmission Poll signal. Arranging the UL data signal means allocating a time interval for receiving the UL data signal at the base station. The arrangement of the UL data signal is represented by the reception start timing and the reception end timing of the UL data signal in the base station.

[Procedure 3-4] When the arranged UL data signal collides with another UL data signal, the base station changes the terminal station to which the Poll signal for data transmission is assigned based on a predetermined criterion.

The wireless communication system may perform the following procedure 3-4'instead of the procedure 3-4.
[Procedure 3-4'] When the arranged UL data signal collides with another UL data signal, the base station sets a guard time so that the collision can be avoided. Setting the guard time means changing the arrangement of the UL data signal to a later time than the current arrangement.

The detailed embodiment will be described below.

[First Embodiment]
In the present embodiment, when the arranged UL data signal collides with another UL data signal, the base station changes the terminal station to which the Poll signal for data transmission is assigned based on a predetermined criterion (procedure 3-4). ).

FIG. 1 is a diagram showing a configuration of a wireless communication system 10 according to the present embodiment. In FIG. 1, only the functional blocks related to the present embodiment are extracted and shown. The wireless communication system 10 has a base station 1 and a terminal station 5. In the figure, one base station 1 and one terminal station 5 are shown, but the number of base stations 1 and the number of terminal stations 5 communicating with the base station 1 are arbitrary.

As the background of the wireless communication system 10, the following situations are assumed. The base station 1 is separated into a signal processing unit 2 having a signal processing function and an antenna unit 3 (overhanging station) having a wireless communication function by using RoF. The base station 1 includes one or more antenna units 3. The signal processing unit 2 and the antenna unit 3 are connected by an optical fiber 4. The antenna unit 3 and the terminal station 5 are connected by a millimeter wave wireless communication system 6. The signal processing unit 2 is fixedly installed in a station building or the like. The antenna unit 3 is fixedly installed on a utility pole or the like located around the place where the terminal station 5 is installed. The terminal station 5 is fixedly installed in a building such as a house or a building.

The signal processing unit 2 of the base station 1 includes a communication unit 21, an allocation unit 22, a transmission / reception unit 23, a propagation distance calculation unit 24, a destination determination unit 25, a reception time calculation unit 26, and a determination unit 27. Be prepared.

The communication unit 21 transmits and receives a signal to and from the antenna unit 3 via the optical fiber 4. The allocation unit 22 allocates the transmission timing to the band request Poll signal so that the band request Poll signal is periodically transmitted in the band request phase. For example, the transmission timing is represented by a slot.

The transmission / reception unit 23 has a transmission unit 231 and a reception unit 232. The transmission unit 231 encodes or modulates the data to generate a DL communication signal addressed to the terminal station 5, and outputs the signal to the communication unit 21. The receiving unit 232 performs reception processing such as demodulation and decoding on the UL communication signal transmitted by the terminal station 5.

The propagation distance calculation unit 24 calculates the propagation delay time of communication between the base station 1 and the terminal station 5. Any prior art can be used to calculate the propagation delay time. As an example, the propagation distance calculation unit 24 calculates the propagation delay time based on the difference between the UL signal reception timing in the antenna unit 3 or the communication unit 21 and the transmission timing set in the UL signal by the terminal station 5. Further, the propagation distance calculation unit 24 calculates the propagation distance between the base station 1 and the terminal station 5 based on the calculated propagation delay time.

In the UL data transmission phase, the destination determination unit 25 determines the terminal station 5 to which the Poll signal for data transmission is assigned based on a predetermined determination criterion. As the determination criteria, for example, the traffic amount of the terminal station 5, the communication priority of the terminal station 5, the propagation distance of the terminal station 5, and the like are used. Further, as will be described later, when the determination unit 27 determines that there is a collision of UL data signals, the destination determination unit 25 changes the terminal station 5 to which the Poll signal for data transmission is assigned.

The reception time calculation unit 26 includes the propagation delay time of the terminal station 5 calculated by the propagation distance calculation unit 24, the processing time from the reception of the Poll signal for band request to the transmission of the UL data signal by the terminal station 5. The UL data signal reception time at the base station 1 is calculated based on the signal processing time obtained from the signal length of the UL data signal. The UL data signal reception time is a time interval from the reception start timing of the UL data signal transmitted from the terminal station 5 to the reception end timing of the UL data signal. The reception start timing and reception end timing are represented by, for example, slots.

The determination unit 27 determines whether or not there is a UL data signal collision based on the UL data signal reception time calculated by the reception time calculation unit 26 for each terminal station 5.

The antenna unit 3 of the base station 1 includes a communication unit 31. The communication unit 31 transmits and receives signals to and from the signal processing unit 2 via the optical fiber 4, and transmits and receives signals to and from the terminal station 5 via the millimeter-wave wireless communication system 6. The communication unit 31 may directly communicate with the terminal station 5 by millimeter wave wireless communication.

The terminal station 5 includes a communication unit 51, a reception timing determination unit 52, a response signal allocation unit 53, a transmission / reception unit 54, and a UL data signal allocation unit 55. The communication unit 51 transmits and receives signals to and from the antenna unit 3 via the millimeter-wave wireless communication system 6. The communication unit 51 may directly communicate with the antenna unit 3 by millimeter wave wireless communication.

The reception timing determination unit 52 randomly determines the timing at which the band request Poll signal periodically transmitted from the base station 1 is received by the own station in the band request phase. In the band request phase, the response signal allocation unit 53 allocates the transmission timing of the response signal to the band request Poll signal after receiving the band request Poll signal.

The transmission / reception unit 54 has a transmission unit 541 and a reception unit 542. The transmission unit 541 outputs a UL communication signal generated by encoding or modulation to the communication unit 51. The receiving unit 542 performs reception processing such as demodulation and decoding on the DL communication signal received from the base station 1.

The UL data signal allocation unit 55 allocates the transmission timing of the UL data signal after the receiving unit 542 receives the data transmission Poll signal addressed to its own station in the UL data transmission phase.

FIG. 2 is a flow chart showing the processing of the wireless communication system 10 in the band request phase. The process shown in FIG. 2 is executed by the base station 1 and the terminal station 5 of N units (N is an integer of 1 or more) that wirelessly communicates with the same antenna unit 3 of the base station 1.

First, the wireless communication system 10 sets the initial value of the variable i to 1, and processes the loop 1 for each value of the variable i in which the value of the variable i is incremented by 1 until the value of the variable i reaches the number of terminals N. (Step S105). The variable i represents the i-th unit among the N terminal stations 5. Loop 1 includes the processing of steps S110 to S115. Of the N terminal stations 5, the i-th terminal station 5 (i is an integer of 1 or more and N or less) is referred to as terminal station #i.

The reception timing determination unit 52 of the terminal station #i determines whether or not the Ac signal from the base station 1 has not been received (step S110). This Ack signal is a signal transmitted by the base station 1 with respect to the response signal transmitted from the terminal station 5. When the reception timing determination unit 52 determines that the Ac signal has not been received (step S110: YES), the reception timing determination unit 52 randomly selects the number of the Poll signal for band request to be received (step S115). The number of the Poll signal for band request corresponds to the slot number. As a method of selecting the number of the Poll signal for band request to be received, the idea of binary backoff or the like may be adopted. The response signal allocation unit 53 determines a slot for transmitting a response signal to the band request Poll signal based on the selected band request Poll signal number. When the reception timing determination unit 52 determines that the Ac signal has been received (step S110: NO), the reception timing determination unit 52 does not perform the process of step S115.

When the processing of the loop 1 is completed for each of the terminal station # 1 to the terminal station # N, the wireless communication system 10 sets the initial value of the variable j to 1 and sets the value of the variable j to the number of slots M included in the band request area. Until the value is reached, the loop 2 process is performed for the variable j of each value obtained by incrementing the value of the variable j by 1. (Step S120). The variable j represents the slot number in the bandwidth request area. The j-th slot is described as slot # j. Loop 2 includes the process of step S125 and the process of loop 3.

The transmission unit 231 of the base station 1 generates a Poll # j which is a band requesting Poll signal of the slot number j, and outputs the Poll # j to the antenna unit 3 via the communication unit 21. The communication unit 31 of the antenna unit 3 broadcasts Poll # j to the terminal station 5 in slot # j (step S125).

The wireless communication system 10 sets the initial value of the variable k to 1, and processes the loop 3 for each value of the variable k in which the value of the variable k is incremented by 1 until the value of the variable k reaches the number N of the terminal stations 5. (Step S130). The variable k represents the kth of the N terminal stations 5. The processing of the loop 3 includes the processing of steps S135 to S150.

The receiving unit 542 of the terminal station #k receives the Poll # j broadcast in step S125. The reception timing determination unit 52 determines whether or not the received Poll # j is a signal to be received by the own station based on the band request Poll signal number selected in step S115 (step S135). When the reception timing determination unit 52 determines that Poll # j is not a signal to be received by its own station (step S135: NO), the terminal station 5 does not perform the process of step S140, and the base station 1 steps. The processing of S145 to S150 is not performed.

When the reception timing determination unit 52 of the terminal station #k determines that the received Poll # j is a signal to be received by the own station (step S135: YES), the transmission unit 541 of the terminal station #k outputs a response signal. Generate and output to the communication unit 51. The transmission unit 541 sets the Acc information, the amount of data to be transmitted by UL communication, and the information related to traffic in the response signal. Information about traffic includes information such as traffic amount, traffic interval, service type, and priority. The communication unit 51 wirelessly transmits the response signal in the slot assigned by the response signal allocation unit 53 (step S140).

The receiving unit 232 of the base station 1 determines whether or not the response signal from the terminal station #k has been normally received (step S145). When the receiving unit 232 determines that the response signal has been normally received (step S145: YES), the transmitting unit 231 generates an Ac signal addressed to the terminal station #k and connects the antenna unit 3 to the antenna unit 3 via the communication unit 21. Send. The antenna unit 3 wirelessly transmits an Ac signal addressed to the terminal station #k (step S150).

When a plurality of terminal stations 5 including the terminal station #k transmit a response signal to Poll # j, the base station 1 cannot normally receive the response signal due to a collision. When the receiving unit 232 determines that the response signal has not been normally received (step S145: NO), the base station 1 does not perform the process of step S150.

When the value of the variable k reaches the number of terminals N and the wireless communication system 10 finishes the processing of the loop 3, the wireless communication system 10 performs the processing of the loop 2 by the value obtained by adding 1 to the current value of the variable j. .. Then, when the value of the variable j reaches the number of slots M and the wireless communication system 10 finishes the processing of the loop 2, the receiving unit 232 of the base station 1 determines whether or not the Ac signal is transmitted to all the terminal stations 5. Determination (step S155). When the receiving unit 232 determines that there is a terminal station 5 that has not yet transmitted the Ac signal (step S155: NO), the wireless communication system 10 repeats the process from step S105. When it is determined that the receiving unit 232 has transmitted the Ack signal to all the terminal stations 5 (step S155: YES), the wireless communication system 10 completes the processing of the band request phase.

Note that the terminal station 5 to be processed in FIG. 2 may be limited to the active terminal station 5 that stores UL data to be transmitted. Further, the propagation distance calculation unit 24 of the base station 1 calculates the propagation delay time and the propagation distance of each terminal station 5 based on the response signal received from the terminal station 5 or the signal of other UL communication.

FIG. 3 is a flow chart showing the processing of the wireless communication system 10 in the UL data transmission phase. The process shown in FIG. 3 is executed by the base station 1, the same antenna unit 3 of the base station 1, and N terminal stations (N is an integer of 1 or more) that perform UL data transmission. N in the process of FIG. 3 is the number of terminal stations 5 in which the base station 1 normally receives the response signal in the process of FIG.

First, the destination determination unit 25 of the base station 1 sorts the N terminal stations 5 based on a predetermined determination criterion (step S305). For example, the destination determination unit 25 sorts the terminal station 5 in descending order of the traffic amount. The traffic amount information is obtained from the information set in the response signal received from the terminal station 5. Alternatively, the destination determination unit 25 may sort the terminal stations 5 in the order of longest or shortest propagation distance calculated by the propagation distance calculation unit 24. The terminal station 5 whose sort result rank is i-th (i is an integer of 1 or more and N or less) is referred to as terminal station #i.

Subsequently, the destination determination unit 25 temporarily allocates the data transmission Poll signal to be transmitted to each terminal station 5 to the slot based on the traffic information (for example, the packet generation interval) received from each terminal station 5 (step S310). ). The data transmission Poll signal is a Poll signal for permitting the destination terminal station 5 to transmit the UL data signal. For example, the destination determination unit 25 temporarily allocates the data transmission Poll signal to be transmitted to each terminal station 5 to the slot by the same round robin as in the prior art. The traffic information is read from the response signal received from the terminal station 5.

The destination determination unit 25 sets the initial value 1 for the values of the variable i and the variable j (step S315), and sets the initial value 1 for the value of the variable k (step S320). The variable j represents the order in the sort result of the terminal station 5, and the variable k is the slot number in the UL data transmission area. The data transmission Poll signal to which the slot number k is assigned is referred to as Poll # k.

The destination determination unit 25 assigns the value of the variable i to the variable j (step S325). The reception time calculation unit 26 calculates the UL data signal reception time based on the transmission timing of the Poll # k temporarily assigned to the terminal station #i (step S330). The calculated UL data signal reception time is a time interval allocated for receiving the UL data signal transmitted from the terminal station #i that has received Poll # k at the base station 1. The UL data signal reception time may be represented by a slot. The reception time calculation unit 26 determines the UL data signal reception time as the propagation delay time of the terminal station #i and the processing time from the reception of the Poll signal for band request by the terminal station #i to the transmission of the UL data signal. , Calculated based on the signal processing time obtained from the signal length of the UL data signal.

The determination unit 27 determines whether or not a collision occurs between the UL data signal transmitted from the terminal station #i corresponding to Poll # k and another UL data signal (step S335). That is, the determination unit 27 allocates the UL data signal reception time to the UL data signal transmitted from the terminal station #i corresponding to Poll # k to the UL data transmitted from the terminal station 5 different from the terminal station #i. It is determined whether or not the signal overlaps with the UL data signal reception time of the signal. The determination unit 27 determines that a collision does not occur if they do not overlap, and determines that a collision occurs if they do overlap.

When the determination unit 27 determines that a collision does not occur (step S335: NO), the destination determination unit 25 performs the process of step S340. That is, the destination determination unit 25 determines the allocation destination of Poll # k to the terminal station #i, and determines that the UL data signal from the terminal station #i is allocated to the UL data signal reception time calculated in step S330 (). Step S340). The destination determination unit 25 adds 1 to the value of the variable i and increments it (step S345). The destination determination unit 25 determines whether or not the value of the variable i exceeds the number of terminal stations N (step S350). When the destination determination unit 25 determines that the value of the variable i exceeds the number of terminal stations N (step S350: YES), the destination determination unit 25 sets the value of the variable i to 1 (step S355).

When the destination determination unit 25 determines in step S350 that the value of the variable i does not exceed the number of terminal stations N (step S350: NO), or after the process of step S355, the destination determination unit 25 performs the process of step S360. That is, the destination determination unit 25 adds 1 to the value of the variable k and increments it (step S360). The destination determination unit 25 determines whether or not the value of the variable k exceeds the number of slots K in the UL data transmission area (step S365). When the destination determination unit 25 determines that the value of the variable k does not exceed the number of slots K (step S365: NO), the destination determination unit 25 repeats the processing from step S325. Then, when the destination determination unit 25 determines that the value of the variable k exceeds the number of slots K (step S365: YES), the destination determination unit 25 ends the process.

On the other hand, when the determination unit 27 determines that a collision between the UL data signal transmitted from the terminal station #i corresponding to the Variable # k and another UL data signal occurs (step S335: YES), the destination determination unit In 25, 1 is added to the value of the variable j and incremented (step S370). The destination determination unit 25 determines whether or not there is a terminal station 5 that has not yet been selected as a determination target for assigning a UL data signal to the slot # k (step S375). When the destination determination unit 25 determines that there is a terminal station 5 that has not been selected as the determination target (step S375: YES), the destination determination unit 25 determines whether or not the value of the variable j exceeds the number of terminal stations N (step S380). ). When the destination determination unit 25 determines that the value of the variable j exceeds the number of terminal stations N (step S380: YES), the destination determination unit 25 sets the value of the variable j to 1 (step S385).

When the destination determination unit 25 determines that the value of the variable j does not exceed the number of terminal stations N (step S380: NO), or after the processing of step S385, the temporary allocation destination of Poll # k is set to the terminal station #. Update to j (step S390). The reception time calculation unit 26 calculates the UL data signal reception time allocated for receiving the UL data signal transmitted from the terminal station # j that received the Poll # k at the base station 1 by the same processing as in step S330. (Step S395). Similar to step S335, the determination unit 27 determines whether or not a collision occurs between the UL data signal transmitted from the terminal station # j corresponding to Poll # k and another UL data signal (step). S400).

When the determination unit 27 determines that a collision occurs (step S400: YES), the base station 1 repeats the process from step S370. On the other hand, when the determination unit 27 determines that no collision occurs (step S400: NO), the destination determination unit 25 determines the allocation destination of Poll # k to the terminal station # j, and the UL data calculated in step S395. It is determined that the UL data signal from the terminal station #j is assigned to the signal reception time (step S405). After step S405, or when the destination determination unit 25 determines that all the terminal stations 5 are the determination targets (step S375: NO), the base station 1 performs the process from step S360.

FIG. 4 is a diagram showing an outline of operation in the UL data transmission phase of the wireless communication system 10 based on the result of the process of FIG. FIG. 4 shows an example in which the terminal station 5 has three terminals # 1 to terminal station # 3. It is assumed that the traffic amount and the propagation distance of the terminal stations # 1 to the terminal station # 3 are the same as those in FIG. That is, the propagation distance of the terminal station # 1 <the propagation distance of the terminal station # 2 <the propagation distance of the terminal station # 3. Poll _i is a Poll signal for data transmission addressed to the terminal station # i, and Data _i is a UL data signal transmitted by the terminal station # i. In the example of FIG. 4, the description of the Ack signal to be returned when the base station 1 receives the UL data signal is omitted.

First, the destination determination unit 25 of the base station 1 allocates a Poll signal for data transmission to the terminal station # 1, the terminal station # 2, and the terminal station # 3 arranged in descending order of the traffic amount by round robin. The reception time calculation unit 26 calculates the arrival time of the UL data signal transmitted by each of the terminal stations # 1 to the terminal station # 3 corresponding to each data transmission Poll signal. Here, it is assumed that the Poll signal for data transmission is assigned as in FIG. 13, and the arrival time of the UL data signal transmitted from each of the terminal stations # 1 to # 3, that is, the UL data signal reception time is calculated. .. As shown in FIG. 13, a collision of UL data signals occurs, and as a result, the UL data signal D1 transmitted by the terminal station # 1 corresponding to the data transmission Poll signal P1 transmitted by the base station 1 in slot # 1. And, only the UL data signal D9 transmitted by the terminal station # 3 corresponding to the data transmission Poll signal P9 transmitted by the base station 1 in the slot # 9 has succeeded in transmission. That is, a total of two UL data signals can be transmitted in the entire terminal station # 1 to terminal station # 3.

The UL data signal D2 transmitted by the terminal station # 2 corresponding to the data transmission Poll signal P2 transmitted by the base station 1 in the slot # 2, and the data transmission Poll signal P4 transmitted by the base station 1 in the slot # 4. Correspondingly, the UL data signal D4 transmitted by the terminal station # 1 collides. Further, the UL data signal D3 transmitted by the terminal station # 3 corresponding to the data transmission Poll signal P3 transmitted by the base station 1 in the slot # 3, and the data transmission Poll signal transmitted by the base station 1 in the slot # 5. The UL data signal D5 transmitted by the terminal station # 2 corresponding to P5 and the UL data signal D7 transmitted by the terminal station # 1 corresponding to the data transmission Poll signal P7 transmitted by the base station 1 in the slot # 7. collide. Further, the UL data signal D6 transmitted by the terminal station # 3 corresponding to the data transmission Poll signal P6 transmitted by the base station 1 in the slot # 6, and the data transmission Poll signal transmitted by the base station 1 in the slot # 8. The UL data signal D8 transmitted by the terminal station # 2 corresponding to P8 and the UL data signal D10 transmitted by the terminal station # 1 corresponding to the data transmission Poll signal P10 transmitted by the base station 1 in the slot # 10 collide.

Therefore, the base station 1 considers the terminal station 5 to which the Poll signal for data transmission to be transmitted in the slot # 4 is assigned according to the procedure shown in FIG. The data transmission Poll signal in slot # 4 is a signal originally tentatively assigned to terminal station # 1. Although not shown in the figure, a collision occurs even if the data transmission Poll signal P4 in slot # 4 is assigned to any of terminal station # 1, terminal station # 2, and terminal station # 3. Therefore, the destination determination unit 25 of the base station 1 forgoes the allocation of the data transmission Poll signal in the slot # 4.

Subsequently, the base station 1 considers the terminal station 5 to which the Poll signal for data transmission to be transmitted in the slot # 5 is assigned. The data transmission Poll signal in slot # 5 is a signal originally tentatively assigned to terminal station # 2. When the data transmission Poll signal in slot # 5 is assigned to terminal station # 1 or terminal station # 2, a collision occurs. Therefore, the destination determination unit 25 of the base station 1 allocates the data transmission Poll signal P5'in the slot # 5 to the terminal station # 3. Terminal station # 3 receives the data transmission Poll signal P5'and transmits the UL data signal D5'.

Next, the base station 1 considers the terminal station 5 to which the Poll signal for data transmission to be transmitted in slot # 6 is assigned. The data transmission Poll signal in slot # 6 is a signal originally tentatively assigned to terminal station # 3. The destination determination unit 25 of the base station 1 allocates the data transmission Poll signal P6'of the slot # 6 to the terminal station # 1. Terminal station # 1 receives the data transmission Poll signal P6'and transmits the UL data signal D6'.

Next, the base station 1 considers the terminal station 5 to which the second polling signal to be transmitted in slot # 7 is assigned. The data transmission Poll signal in slot # 7 is a signal originally tentatively assigned to terminal station # 1. A collision occurs even if the transmission polling signal of slot # 7 is assigned to any of terminal station # 1, terminal station # 2, and terminal station # 3. Therefore, the destination determination unit 25 of the base station 1 forgoes the allocation of the polling signal for transmission in slot # 7.

Next, the base station 1 considers the terminal station 5 to which the Poll signal for data transmission to be transmitted in slot # 8 is assigned. The data transmission Poll signal in slot # 8 is a signal originally tentatively assigned to terminal station # 2. When the data transmission Poll signal in slot # 8 is assigned to terminal station # 1 or terminal station # 2, a collision occurs. Therefore, the destination determination unit 25 of the base station 1 allocates the data transmission Poll signal P8'in the slot # 8 to the terminal station # 3. Terminal station # 3 receives the data transmission Poll signal P8'and transmits the UL data signal D8'.

Next, the base station 1 considers the terminal station 5 to which the Poll signal for data transmission to be transmitted in slot # 9 is assigned. The data transmission Poll signal in slot # 9 is a signal originally tentatively assigned to terminal station # 3. A collision occurs even if the data transmission Poll signal of slot # 9 is assigned to any of terminal station # 1, terminal station # 2, and terminal station # 3. Therefore, the destination determination unit 25 of the base station 1 forgoes the allocation of the transmission polling signal P9.

From the above, the transmission of the two UL data signals transmitted by the terminal station # 1, the one UL data signal transmitted by the terminal station # 2, and the three UL data signals transmitted by the terminal station # 3 is transmitted. It can be seen that it was successful and a total of 6 UL data signals could be transmitted.

In the above, the base station 1 determines the time for allocating the polling signal based on the slot, but it is not limited to the slot and may allocate the timing of transmitting the polling signal.

Further, in the present embodiment, the UL data signal length may be either a fixed length or a variable length. When the UL data signal length is variable, the terminal station 5 transmits a response signal set with information regarding the UL data signal length to the base station 1 in the band request phase.

According to the present embodiment, the base station 1 calculates the arrival time of the UL data signal transmitted by the terminal station 5, and determines whether or not the UL data signal collides. When the base station 1 determines that a collision occurs, the base station 1 avoids the collision by changing the terminal station 5 to which the Poll signal for UL data signal transmission is assigned. As a result, the wireless communication system 10 can effectively utilize the free band of the wireless band due to the long delay to improve the transmission efficiency.

[Second Embodiment]
In the present embodiment, when the arranged UL data signal collides with another UL data signal, the time for allocating the Poll signal for data transmission is changed. Hereinafter, the differences from the first embodiment will be mainly described.

FIG. 5 is a diagram showing a configuration of a wireless communication system 10a according to the present embodiment. In FIG. 5, only the functional blocks related to the present embodiment are extracted and shown. In the figure, the same parts as those of the wireless communication system 10 according to the first embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. The difference between the wireless communication system 10a and the wireless communication system 10 shown in FIG. 1 is that the wireless communication system 10a has a base station 1a instead of the base station 1.

In the present embodiment, as in the first embodiment, the base station 1a is separated into a signal processing unit 2a having a signal processing function and an antenna unit 3 having a wireless communication function by using RoF. The signal processing unit 2a is fixedly installed in a station building or the like, and the antenna unit 3 is fixedly installed in a utility pole or the like located around the place where the terminal station 5 is installed. The signal processing unit 2a and the antenna unit 3 are connected by an optical fiber 4. The antenna unit 3 and the terminal station 5 are connected by a millimeter wave wireless communication system 6.

The signal processing unit 2a differs from the signal processing unit 2 of the first embodiment shown in FIG. 1 in that it includes a destination determination unit 25a instead of the destination determination unit 25 and further includes an allocation time determination unit 28. Is. Similar to the first embodiment, the destination determination unit 25a determines the terminal station 5 to which the Poll signal for data transmission is assigned based on a predetermined determination criterion in the UL data transmission phase. As the determination criteria, for example, the traffic amount, priority, transmission distance, and the like are used. However, unlike the first embodiment, the destination determination unit 25a does not change the terminal station 5 to which the data transmission Poll signal is assigned even when the determination unit 27 determines that there is a collision. When the determination unit 27 determines that there is a collision, the allocation time determination unit 28 changes the transmission timing of the data transmission Poll signal assigned to the terminal station 5.

The processing in the band request phase of the wireless communication system 10a is the same as the processing of the first embodiment shown in FIG.

FIG. 6 is a flow chart showing the processing of the wireless communication system 10a in the UL data transmission phase. The process shown in FIG. 6 is executed by the base station 1a, the same antenna unit 3 of the base station 1a, and N terminal stations (N is an integer of 1 or more) that perform UL data transmission. N in the process of FIG. 6 is the number of terminal stations 5 in which the base station 1a normally receives the response signal in the process of FIG.

First, the destination determination unit 25a of the base station 1a sorts the N terminal stations 5 based on a predetermined determination criterion in the same manner as in the process of step S305 of the first embodiment shown in FIG. 3 (step S505). .. The terminal station 5 whose sort result rank is i-th (i is an integer of 1 or more and N or less) is referred to as terminal station #i.

Subsequently, the destination determination unit 25a is for data transmission to be transmitted to each terminal station 5 based on the traffic information received from each terminal station 5, as in the process of step S310 of the first embodiment shown in FIG. The Poll signal is provisionally assigned to the slot (step S510). The destination determination unit 25a sets the initial value 1 in the value of the variable i (step S515), and sets the initial value 1 in the value of the variable k (step S520). The variable k is a slot number in the UL data transmission area. The data transmission Poll signal to which the slot number k is assigned is referred to as Poll # k.

The reception time calculation unit 26 calculates the UL data signal reception time based on the transmission timing of the Poll # k provisionally assigned to the terminal station #i, as in the process of step S330 of the first embodiment shown in FIG. (Step S525). The calculated UL data signal reception time is a time interval allocated for receiving the UL data signal transmitted from the terminal station #i that has received Poll # k at the base station 1a. Similar to the process of step S335 of the first embodiment shown in FIG. 3, the determination unit 27 combines the UL data signal transmitted from the terminal station #i corresponding to Poll # k with another UL data signal. It is determined whether or not a collision occurs (step S530).

When the determination unit 27 determines that a collision does not occur (step S530: NO), the destination determination unit 25a performs the process of step S535. That is, the destination determination unit 25a determines the allocation destination of Poll # k to the terminal station #i, and determines that the UL data signal from the terminal station #i is allocated to the UL data signal reception time calculated in step S525 (). Step S535). The destination determination unit 25a adds 1 to each of the value of the variable i and the value of the variable k and increments them (step S540). The destination determination unit 25a determines whether or not the value of the variable i exceeds the number of terminal stations N (step S545). When the destination determination unit 25a determines that the value of the variable i does not exceed the number of terminal stations N (step S545: NO), the destination determination unit 25a repeats the processing from step S525. Then, when it is determined that the value of the variable i exceeds the number of terminal stations N (step S545: YES), the destination determination unit 25a ends the process.

On the other hand, when the determination unit 27 determines that a collision between the UL data signal transmitted from the terminal station #i corresponding to the Variable # k and another UL data signal occurs (step S530: YES), the allocation time is determined. The unit 28 adds 1 to the value of the variable k and increments it (step S550). The allocation time determination unit 28 updates the data transmission Poll signal provisionally allocated to the terminal station #i to the Poll # k of the slot # k incremented in step S550 (step S555).

The reception time calculation unit 26 calculates the UL data signal reception time, which is a time interval allocated for receiving the UL data signal transmitted from the terminal station #i that has received Poll # k at the base station 1a (step S560). .. The determination unit 27 determines whether or not a collision occurs between the UL data signal transmitted from the terminal station #i corresponding to Poll # k and another UL data signal (step S565). When the determination unit 27 determines that a collision occurs (step S565: YES), the base station 1a repeats the process from step S550.

On the other hand, when the determination unit 27 determines that no collision occurs (step S565: NO), the allocation time determination unit 28 allocates Poll # k to the terminal station #i, and the UL data signal reception time calculated in step S560. It is determined that the UL data signal from the terminal station #i is assigned to (step S570). The base station 1a performs the processing from step S540.

FIG. 7 is a diagram showing an outline of operation in the UL data transmission phase of the wireless communication system 10a based on the result of the process of FIG. In FIG. 7, it is assumed that the terminal stations 5 are the three terminals # 1 to the terminal station # 3, and the traffic amount and the propagation distance of the terminal stations # 1 to the terminal station # 3 are the same as those in FIG. In the example of FIG. 7, the description of the Ack signal to be returned when the base station 1a receives the UL data signal is omitted.

First, the destination determination unit 25a of the base station 1a allocates a Poll signal for data transmission to the terminal station # 1, the terminal station # 2, and the terminal station # 3 arranged in descending order of the traffic amount by round robin. The reception time calculation unit 26 calculates the arrival time of the UL data signal transmitted by each of the terminal stations # 1 to the terminal station # 3 corresponding to each data transmission Poll signal. Here, it is assumed that the Poll signal for data transmission is assigned as in FIG. 13, and the arrival time of the UL data signal from each of the terminal stations # 1 to the terminal station # 3 is calculated. That is, a total of two UL data signals, the UL data signal D1 transmitted by the terminal station # 1 and the UL data signal D9 transmitted by the terminal station # 3, can be transmitted.

Therefore, the base station 1a examines the time for allocating the data transmission Poll signal P4 temporarily allocated to the slot # 4 to the terminal station # 1 according to the procedure shown in FIG. Although not shown in the figure, a collision occurs even if a data transmission Poll signal is assigned to any of the slots from slot # 4 to slot # 8, so that the allocation time determination unit 28 uses the terminal in slot # 9. Allocate a Poll signal P9 ”for data transmission addressed to station # 1.

Subsequently, the base station 1a examines the time for allocating the data transmission Poll signal P5 temporarily allocated to the slot # 5 to the terminal station # 2. The allocation time determination unit 28 allocates the data transmission Poll signal P10 ”to the terminal station # 2 to the slot # 10 where the collision does not occur. In the flow shown in FIG. 6, it was originally allocated to the slot # 5. The slot to which the Poll signal for data transmission is newly assigned is selected from the slots # 10 and later, but the slot may be selected from the slots after slot # 5.

From the above, the transmission of the two UL data signals transmitted by the terminal station # 1, the two UL data signals transmitted by the terminal station # 2, and the one UL data signal transmitted by the terminal station # 3 is transmitted. It can be seen that it was successful and a total of 5 UL data signals could be transmitted.

In the above, the base station 1a determines the time for allocating the Poll signal based on the slot, but the time is not limited to the slot, and the timing for transmitting the Poll signal may be allocated.

Further, in the present embodiment, the UL data signal length may be either a fixed length or a variable length. When the UL data signal length is variable, the terminal station 5 transmits a response signal set with information regarding the UL data signal length to the base station 1a in the band request phase.

According to the present embodiment, the base station 1a calculates the arrival time of the UL data signal transmitted by the terminal station 5 and determines whether or not the UL data signal collides, as in the first embodiment. When the base station 1a determines that a collision occurs, the base station 1a avoids the collision by changing the transmission timing assigned to the Poll signal for UL data signal transmission. Therefore, the wireless communication system 10a can effectively utilize the free band of the wireless band due to the long delay to improve the transmission efficiency.

Although the above-described embodiment describes a wireless communication method applied to a millimeter-wave wireless communication system to which RoF is applied, it may be applied not only to RoF but also to a wireless communication system having a large propagation delay time. As described above, the communication unit 31 of the antenna unit 3 and the communication unit 51 of the terminal station 5 may perform wireless communication by a wireless communication method different from the millimeter wave wireless communication.

Further, in the above-described embodiment, the wireless communication method applied to the fixedly installed base station and the terminal station is described, but the wireless communication provided with a mechanism capable of acquiring the propagation distance between the base station and the terminal station. If it is a system, it may be applied to base stations and terminal stations that are not fixedly installed.

Since the conventional polling control does not consider the transmission delay in the wireless section, the uplink signal may collide or the wireless line may be used inefficiently due to the collision. The wireless communication system of the present embodiment solves this problem within the framework of an existing protocol by transmitting polling signals having two different roles from a base station to a terminal station. Specifically, the band request Poll signal causes the base station to inquire how much uplink data the terminal station has. Based on the response to the inquiry, the base station determines the transmission timing of the data transmission Poll signal to be transmitted to each terminal station so that the reception timings of the UL data signals from each terminal do not overlap, taking into consideration the propagation delay. do. When the terminal station receives the data transmission Poll signal addressed to its own station from the base station, the terminal station transmits the UL data signal to the base station.

A hardware configuration example of the signal processing unit 2, the signal processing unit 2a, and the terminal station 5 will be described. FIG. 8 is a device configuration diagram showing a hardware configuration example of the signal processing unit 2 signal processing unit 2a and the terminal station 5. The signal processing unit 2, the signal processing unit 2a, and the terminal station 5 include a processor 71, a storage unit 72, a communication interface 73, and a user interface 74.

The processor 71 is a central processing unit that performs calculations and controls. The processor 71 is, for example, a CPU (central processing unit). The processor 71 reads a program from the storage unit 72 and executes it. The storage unit 72 further has a work area for the processor 71 to execute various programs and the like. The communication interface 73 is connected so as to be able to communicate with another device. The user interface 74 is an input device such as a button, a keyboard, and a pointing device, and a display device such as a lamp and a display. An artificial operation is input by the user interface 74.

All or part of the functions of the allocation unit 22, the destination determination unit 25, the reception time calculation unit 26, and the determination unit 27 of the signal processing unit 2 are realized by the processor 71 reading a program from the storage unit 72 and executing the program. .. All or part of these functions may be realized by using hardware such as ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), and FPGA (Field Programmable Gate Array). The communication unit 21 and the transmission / reception unit 23 of the signal processing unit 2 are realized by the communication interface 73. Some functions of the communication unit 21 and the transmission / reception unit 23 may be realized by the processor 71 reading a program from the storage unit 72 and executing the program.

In the case of the signal processing unit 2a, the processor 71 reads a program from the storage unit 72 for all or part of the functions of the allocation unit 22, the destination determination unit 25a, the reception time calculation unit 26, the determination unit 27, and the allocation time determination unit 28. It is realized by executing it. In addition, all or a part of these functions may be realized by using hardware such as ASIC, PLD and FPGA. The communication unit 21 and the transmission / reception unit 23 of the signal processing unit 2a are realized by the communication interface 73. Some functions of the communication unit 21 and the transmission / reception unit 23 may be realized by the processor 71 reading a program from the storage unit 72 and executing the program.

In the case of the terminal station 5, all or part of the functions of the reception timing determination unit 52, the response signal allocation unit 53, and the UL data signal allocation unit 55 are realized by the processor 71 reading a program from the storage unit 72 and executing the program. To. In addition, all or a part of these functions may be realized by using hardware such as ASIC, PLD and FPGA. The communication unit 51 and the transmission / reception unit 54 of the terminal station 5a are realized by the communication interface 73. Note that some functions of the communication unit 51 and the transmission / reception unit 54 may be realized by the processor 71 reading a program from the storage unit 72 and executing the program.

According to the embodiment described above, the wireless communication system includes a signal processing device and a communication device. For example, the signal processing device is the base stations 1 and 1a of the embodiment, and the communication device is the terminal station 5 of the embodiment. The signal processing device has an allocation unit, a reception timing calculation unit, a determination unit, and a destination change unit. For example, the allocation unit is the destination determination unit 25, 25a of the embodiment, the reception timing calculation unit is the reception time calculation unit 26 of the embodiment, and the determination unit is the determination unit 27 of the embodiment, and the destination is changed. The unit is the destination determination unit 25 of the embodiment.

The allocation unit allocates the transmission timing of the polling signal for data transmission addressed to each communication device in the time domain in which the uplink data transmission is performed. The reception timing calculation unit calculates the reception timing of the data signal transmitted wirelessly from the communication device in response to the polling signal for data transmission transmitted wirelessly at the transmission timing assigned by the allocation unit. The determination unit determines whether or not there is a collision of data signals based on the calculated reception timing. The destination change unit changes the communication device of the destination of the data transmission polling signal corresponding to the data signal determined by the determination unit to collide with another communication device.

The signal processing device may have a timing changing unit instead of the destination changing unit. For example, the timing changing unit is the allocation time determination unit 28 of the embodiment. The timing changing unit changes the transmission timing of the data transmission polling signal corresponding to the data signal determined by the determination unit to collide.

The signal processing device may have a transmission unit that broadcasts the band request polling signal to the communication device multiple times at different timings in the time domain in which the band request is executed. In this case, the communication device further includes a transmission unit that returns a response to the band request poll signal selected from the band request poll signals transmitted at different timings. Further, the communication device may further have a timing determination unit that randomly selects the timing at which the own device receives the band request polling signal. The allocation unit allocates a transmission timing for transmitting a data transmission polling signal addressed to each communication device based on the information obtained from the response received from the communication device.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and the design and the like within a range not deviating from the gist of the present invention are also included.

1 ... Base station, 1a ... Base station, 2 ... Signal processing unit, 2a ... Signal processing unit, 3 ... Antenna unit, 4 ... Optical fiber, 5 ... Terminal station, 6 ... Millimeter-wave wireless communication system, 10 ... Wireless communication system 10a ... wireless communication system, 21 ... communication unit, 22 ... allocation unit, 23 ... transmission / reception unit, 24 ... propagation distance calculation unit, 25 ... destination determination unit, 25a ... destination determination unit, 26 ... reception time calculation unit, 27 ... Judgment unit, 28 ... Allocation time determination unit, 31 ... Communication unit, 51 ... Communication unit, 53 ... Response signal allocation unit, 54 ... Transmission / reception unit, 55 ... UL data signal allocation unit, 231 ... Transmission unit, 232 ... Reception unit, 541 ... Transmitter, 542 ... Receiver

Claims (6)

1. An allocation step in which the signal processing device allocates the transmission timing of the data transmission poll signal addressed to each communication device in the time domain in which the uplink data transmission is performed, and
   A reception timing calculation step in which the signal processing device calculates a reception timing of a data signal transmitted wirelessly from the communication device in response to a data transmission poll signal transmitted wirelessly at the transmission timing.
   A determination step in which the signal processing device determines the presence or absence of a collision of the data signal based on the calculated reception timing.
   A destination change step in which the signal processing device changes the communication device of the destination of the data transmission polling signal corresponding to the data signal determined to collide in the determination step to another communication device.
   Communication control method having.
2. An allocation step in which the signal processing device allocates the transmission timing of the data transmission poll signal addressed to each communication device in the time domain in which the uplink data transmission is performed, and
   A reception timing calculation step in which the signal processing device calculates a reception timing of a data signal transmitted wirelessly from the communication device in response to a data transmission poll signal transmitted wirelessly at the transmission timing.
   A determination step in which the signal processing device determines the presence or absence of a collision of the data signal based on the calculated reception timing.
   A timing change step in which the signal processing device changes the transmission timing of the data transmission polling signal corresponding to the data signal determined to collide in the determination step, and
   Communication control method having.
3. A transmission step in which the signal processing device broadcasts a band request polling signal to the communication device multiple times at different timings in the time domain in which the band request is executed.
   The communication device further includes a response step of returning a response to a band request poll signal selected from the band request poll signals transmitted at different timings.
   In the allocation step, the transmission timing of the polling signal for data transmission addressed to each communication device is allocated based on the information obtained from the response.
   The communication control method according to claim 1 or 2.
4. The communication device further includes a timing determination step of randomly selecting the timing at which the own device receives the band request polling signal in the response step.
   The communication control method according to claim 3.
5. An allocation unit that allocates the transmission timing of the polling signal for data transmission addressed to each communication device in the time domain in which uplink data transmission is performed, and an allocation unit.
   A reception timing calculation unit that calculates the reception timing of the data signal transmitted wirelessly from the communication device in response to the polling signal for data transmission transmitted wirelessly at the transmission timing.
   A determination unit that determines the presence or absence of a collision of the data signal based on the calculated reception timing,
   A destination changing unit that changes the communication device of the destination of the data transmission polling signal corresponding to the data signal determined to collide with the determination unit to another communication device.
   A signal processing device.
6. An allocation unit that allocates the transmission timing of the polling signal for data transmission addressed to each communication device in the time domain in which uplink data transmission is performed, and an allocation unit.
   A reception timing calculation unit that calculates the reception timing of the data signal transmitted wirelessly from the communication device in response to the polling signal for data transmission transmitted wirelessly at the transmission timing.
   A determination unit that determines the presence or absence of a collision of the data signal based on the calculated reception timing,
   A timing changing unit for changing the transmission timing of the data transmission polling signal corresponding to the data signal determined to collide with the determination unit, and a timing changing unit.
   A signal processing device.

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