JP6430905B2 - Wireless communication method and wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication method for performing communication with another extended wireless station (receiving when transmitting, receiving when receiving) when an extended wireless station capable of simultaneous transmission and reception is transmitting or receiving, and The present invention relates to a wireless communication system.

  In a wireless communication system such as a wireless LAN using access control by CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance), the wireless station (base station or terminal station) can check the usage status of the wireless channel by carrier sense before starting communication. Check and send when the radio channel is idle and stop sending when it is busy. Since a technique for avoiding frame collision is used in this way, only one frame is transmitted on the same channel.

  In order to improve frequency utilization efficiency, co-channel full-duplex wireless communication (CCFD: Co-Channel Full Duplex) in which bidirectional communication is performed on the same channel has been studied (for example, Non-Patent Document 1). By using CCFD, it is possible to realize twice the throughput as compared with a duplex method such as frequency division duplex (FDD) or time division duplex (TDD).

  Here, as shown in FIG. 8 (1), communication between the extended wireless stations capable of simultaneous transmission / reception and communication from the extended base station 11 to the extended terminal station 12 and communication from the extended terminal station 12 to the extended base station 11 are performed. Are possible on the same channel simultaneously.

J. I. Choi, M. Jain, K. Srinivasan, P. Levis, and S. Katti, "Achieving single channel, full duplex wireless," Proc. 16th ACM MOBICOM, pp.1-12, Sep. 2010. IEICE "Knowledge Forest" (http://www.ieice-hbkb.org/), Group 4-2-Chapter 8-8-3

  Although simultaneous transmission / reception is possible between the extended base station 11 and the extended terminal station 12, as shown in FIG. 8 (2), during the transmission from the extended base station 11 to the extended terminal station 12, the extended base station 11 It is assumed that reception from other extension terminal stations 13 is performed simultaneously. However, in the conventional access control by CSMA / CA, NAV (Network Allocation Vector) is set during communication between the extended base station 11 and the extended terminal station 12, so that the other extended terminal stations 13 send transmission request messages (RTSS: Request to Simultaneous Send) cannot be transmitted, and the extended base station 11 that is transmitting cannot receive data from another extended terminal station 13.

  Further, as shown in FIG. 8 (3), it is assumed that the extended base station 11 simultaneously transmits to another extended terminal station 13 while the extended base station 11 is receiving from the extended terminal station 12. However, in the conventional access control by CSMA / CA, since the NAV is set during communication between the extended base station 11 and the extended terminal station 12, the extended base station 11 sends a transmission request message (RTSS) to the extended terminal station 13. However, the extended terminal station 13 cannot transmit a transmission permission message (CTSS: Clear to Simultaneous Send) corresponding thereto, and the extended base station 11 that is receiving data can transmit data to other extended terminal stations 13. Can not.

  8 (2) and 8 (3), the extended terminal station 12 communicating with the extended base station 11 may be an existing terminal station that does not have a simultaneous transmission / reception function.

  In FIG. 8 (2), when transmitting from the extended base station 11 to the extended base station 11 while transmitting from the extended base station 11 to the extended terminal station 12 (existing terminal station), Transmission directivity control in the direction from the extended terminal station 13 to the extended base station 11 is necessary so that the transmission signal of the extended terminal station 13 does not interfere with the extended terminal station 12.

  Further, in FIG. 8 (3), when the extended base station 11 is receiving from the extended terminal station 12 (existing terminal station), when transmitting from the extended base station 11 to the extended terminal station 13, Reception directivity control in the direction from the extended terminal station 13 to the extended base station 11 is necessary so that the transmission signal of the extended terminal station 12 does not interfere with the extended terminal station 13.

  In order to effectively utilize the simultaneous transmission / reception function in the extended radio station, the present invention communicates with other extended radio stations when the extended radio station is transmitting or receiving (received and received during transmission). It is an object of the present invention to provide a wireless communication method and a wireless communication system that enable transmission sometimes.

According to a first aspect of the present invention, there is provided a wireless communication method for transmitting and receiving data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission / reception. while sending data a for the second extension radio station, when transmitting data B to the first extended wireless station and the destination, after releasing the NAV, the first extended wireless station Transmitting a transmission request message; transmitting a transmission permission message to the second extended wireless station when the first extended wireless station receives the transmission request message; and second extended wireless station but, when receiving the transmission permission message, and transmitting the data B to the first extended radio station, the first extended wireless stations, even during transmitting data a, receives the data B A step of performing.

A second invention is a wireless communication method for transmitting and receiving data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception, wherein the first extended wireless station is connected to another wireless station. the data a in the received, a step first extended radio station to transmit when transmitting the data B to the second extended wireless station and the destination, the transmission request message to the second extended radio station When the second extended radio station receives the transmission request message, after canceling the NAV , transmitting a transmission permission message to the first extended radio station ; and upon receiving the transmission permission message, even during receiving the data a, and transmitting the data B to the second extended radio station, the second extended wireless station, receives the data B step And have.

  In the wireless communication method of the first invention, the second extended wireless station has a transmission directivity control function, and forms transmission directivity with respect to the first extended wireless station when transmitting data B. Send.

  In the wireless communication method of the second invention, the second extended wireless station has a reception directivity control function, and forms reception directivity with respect to the first extended wireless station when receiving the data B. Receive.

  In the wireless communication method of the first or second invention, the first extended wireless station and the second extended wireless station are capable of transmitting and receiving at least one of a transmission request message and a transmission permission message by the own station simultaneously. It is provided with an area describing that it is a station, and notifies other stations.

A third invention is a wireless communication system that transmits and receives data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception, wherein the first extended wireless station is another wireless station. When the second extended wireless station receives the transmission request message transmitted after releasing the NAV in order to transmit data B destined for the first extended wireless station while transmitting data A to , A means for transmitting a transmission permission message to the second extended radio station, and a means for receiving data B transmitted by the second extended radio station during transmission of data A. station, when transmitting the data B to the first extended radio station destined, also the first extension radio stations even during transmission, after releasing the NAV, the first extended wireless station Means for transmitting a transmission request message and transmission transmitted by the first extended radio station Means for transmitting data B to the first extended radio station when the permission message is received.

A fourth invention is a wireless communication system that transmits and receives data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception, wherein the second extended wireless station is a first extended wireless station. When the wireless station receives data A from another wireless station and receives a transmission request message transmitted by the first extended wireless station to transmit data B destined for the second extended wireless station, Means for transmitting a transmission permission message to the first extended radio station after canceling the NAV; and means for receiving data B transmitted while the first extended radio station is receiving data A. When the first extended radio station transmits data B destined for the second extended radio station, the first extended radio station transmits a transmission request message to the second extended radio station even if data A is being received. Means and the second extended radio station that has transmitted NAV canceled Means for transmitting data B to the second extended radio station when the communication permission message is received.

  The present invention provides a wireless communication system performing access control by CSMA / CA in an environment where there are many extended wireless stations capable of simultaneous transmission and reception, in a situation where the first extended wireless station can transmit or receive even during communication. Communication with the two extended radio stations becomes possible, and the system throughput can be improved.

It is a figure which shows the control sequence in Example 1 of this invention. It is a figure which shows the structural example of the extended base station 11 and the extended terminal station 13 in Example 1 of this invention. It is a flowchart which shows the process sequence of the extended base station 11 and the extended terminal station 13 in Example 1 of this invention. It is a figure which shows the control sequence in Example 2 of this invention. It is a figure which shows the structural example of the extended base station 11 and the extended terminal station 13 in Example 2 of this invention. It is a flowchart which shows the process sequence of the extended base station 11 and the extended terminal station 13 in Example 2 of this invention. It is a figure which shows the frame format of RTSS and CRSS. It is a figure explaining the simultaneous transmission / reception of an extended radio station, and the subject.

  In Example 1 described below, when an extended base station (11 in FIG. 8 (2)) is transmitting under the access control by CSMA / CA, other extended terminal stations (FIG. 8 (2) A control procedure for enabling reception from 13) will be described. In the second embodiment, when the extended base station (11 in FIG. 8 (3)) is receiving under the access control by CSMA / CA, the extension terminal station (13 in FIG. 8 (3)) is receiving. A control procedure for enabling transmission will be described.

(Example 1)
FIG. 1 shows a control sequence in Embodiment 1 of the present invention.
FIG. 2 shows a configuration example of the extended base station 11 and the extended terminal station 13 in Embodiment 1 of the present invention. FIG. 3 shows a processing procedure of the extended base station 11 and the extended terminal station 13 in the first embodiment of the present invention.

  1 to 3, the extended base station 11 is transmitting data A to the extended terminal station (or an existing terminal station is acceptable) 12 (S11). The data A is transmitted via the modulation unit 111, the directivity control unit 112, the radio unit (RF) 113, and the antenna 114 as necessary. At this time, the NAV corresponding to the transmission period of data A is set in the extended terminal station 13 by the RTS transmitted by the extended base station 11 and the CTS transmitted by the extended terminal station 12 (S21). The same applies even if the extended terminal station 12 is an existing terminal station that does not have a simultaneous transmission / reception function. Up to this point, the access control is based on normal CSMA / CA. If NAV is not set, normal access control is performed.

  Here, in the extended terminal station 13, the data B to be transmitted to the extended base station 11 is input to the modulation unit 131 and the simultaneous transmission control unit 137 (S22). The simultaneous transmission control unit 137 determines whether or not the destination of the data B is an extended base station (S23). The determination of whether or not it is an extended base station can be made by monitoring the RTSS or CTSS that the extended terminal station 13 has transmitted and received so far. If the destination of the data B is not an extended base station, it is not a target for simultaneous transmission / reception, so that access control by normal CSMA / CA is performed. If the destination of the data B is the extended base station 11, the simultaneous transmission control unit 137 of the extended terminal station 13 cancels the NAV (S24) and transmits RTSS to the extended base station 11 (S25).

  When receiving the RTSS transmitted from the extended terminal station 13 (S12), the simultaneous transmission control unit 117 of the extended base station 11 determines whether data can be received (S13). For example, if the extended base station 11 is already receiving data from another extended terminal station, data reception is disabled. On the other hand, if the extended base station 11 is transmitting data A, but data reception is possible using the simultaneous transmission / reception function, the CTSS is transmitted to the extended terminal station 13 that is the RTSS transmission source (S14).

  When receiving the CTSS transmitted by the extended base station 11 (S26), the simultaneous transmission control unit 137 of the extended terminal station 13 performs transmission directivity control on the directivity control unit 132 toward the extended base station 11, Data B is transmitted to the extended base station 11 via the RF 133 and the antenna 134 (S27).

In the extended base station 11, the data B is received by the demodulator 116 via the antenna 114, the RF 113, and the directivity controller 115 as necessary (S15).
As described above, the extended base station 11 can receive the data B transmitted from the extended terminal station 13 while transmitting the data A to the extended terminal station 12. Note that when the extended terminal station 13 transmits data B, transmission directivity control is performed toward the extended base station 11, so that interference with the extended terminal station 12 that is already receiving data A can be avoided. it can.

  The directivity control may also be performed for RTSS and CTSS transmitted and received between the extended base station 11 and the extended terminal station 13, but the error correction processing of the extended terminal station 12 that is receiving the data A If it is possible, it is not always necessary.

(Example 2)
FIG. 4 shows a control sequence in the second embodiment of the present invention.
FIG. 5 shows a configuration example of the extended base station 11 and the extended terminal station 13 in the second embodiment of the present invention. FIG. 6 shows a processing procedure of the extended base station 11 and the extended terminal station 13 in the second embodiment of the present invention.

  4 to 6, it is assumed that the extended base station 11 is receiving data A transmitted from the extended terminal station (or an existing terminal station is acceptable) 12 (S31). Data A is received and processed by the demodulation unit 111 via the antenna 114, the RF 113, and the directivity control unit 112 as necessary. At this time, an NAV corresponding to the transmission period of data A is set in the extended terminal station 13 by the RTS transmitted by the extended terminal station 12 or the CTS transmitted by the extended base station 11 (S41). The same applies even if the extended terminal station 12 is an existing terminal station that does not have a simultaneous transmission / reception function. Up to this point, the access control is based on normal CSMA / CA. If NAV is not set, normal access control is performed.

  Here, in the extended base station 11, the data B to be transmitted to the extended terminal station 13 is input to the modulation unit 111 and the simultaneous transmission control unit 117 (S32). The simultaneous transmission control unit 117 determines whether or not the data B can be transmitted (S33). For example, if the extended base station 11 is already transmitting data to another extended terminal station, data transmission is disabled. On the other hand, if the extended base station 11 is receiving data A but data transmission is possible using the simultaneous transmission / reception function, it is determined whether or not the destination of data B is the extended terminal station (S34). If the destination of the data B is not an extended terminal station, it is not a target for simultaneous transmission / reception, so that access control by normal CSMA / CA is performed. If the destination of the data B is the extended terminal station 13, the RTSS is transmitted to the extended terminal station 13 (S35).

  When receiving the RTSS transmitted from the extended base station 11 (S42), the simultaneous transmission control unit 137 of the extended terminal station 13 determines whether data can be received (S43). For example, if the extended terminal station 13 is already receiving data from another extended base station, data reception is disabled. On the other hand, if the extended terminal station 13 can receive data, the simultaneous transmission control unit 137 cancels the NAV (S44), and transmits the CTSS to the extended base station 11 that is the RTSS transmission source (S45).

  When receiving the CTSS transmitted from the extended terminal station 13 (S36), the simultaneous transmission control unit 117 of the extended base station 11 transmits data B to the extended terminal station 13 via the RF 113 and the antenna 114 (S27).

  In the extended terminal station 13, after the CTSS is transmitted to the extended base station 11, the demodulating unit 116 performs the reception directivity control to the extended base station 11 with respect to the directivity control unit 135, while the antenna 114 and the RF 113 are used. Data B is received (S46).

  As described above, the extended base station 11 can transmit the data B to the extended terminal station 13 while receiving the data A from the extended terminal station 12. When the extended terminal station 13 receives the data B, reception directivity control is performed toward the extended base station 11, so that interference from the extended terminal station 12 that is already transmitting the data A is avoided. Can do. Further, even if the reception terminal directivity control is not performed in the extended terminal station 13, if the reception level difference between the desired data B and the interference wave (data A) is a predetermined value or more, the NOMA (Non-Orthogonal Multiple Access) technique is used. The desired data B can be restored.

  Moreover, directivity control may be performed for RTSS and CTSS transmitted / received between the extended base station 11 and the extended terminal station 13 as long as the error correction processing of the extended terminal stations 12 and 13 is applicable. This is not always necessary.

  Further, the transmission directivity control in the first embodiment and the reception directivity control in the second embodiment are realized by a technique such as an adaptive array antenna using a plurality of antennas. Transmission path information and the like are calculated based on RTSS and CTSS received so far, and directivity control is performed using the information (Non-patent Document 2).

FIG. 7 shows RTSS and CRSS frame formats.
In FIG. 7 (1), the RTSS has a “frame control” field for discriminating the frame type, a “duration” field indicating the scheduled transmission period (NAV), a “receiver address” field indicating the destination, and whether simultaneous transmission / reception is possible. A "simultaneous transmission / reception flag" field indicating the sender, a "transmitter address" field indicating the sender, and an "FCS" field for frame error checking.

  In FIG. 7 (2), the CTSS includes a “frame control” field, a “duration” field, a “receiver address” field, a “simultaneous transmission / reception flag” field, and an “FCS” field.

  Further, the extended base station 11 and the extended terminal stations 12 and 13 may use normal RTS and CTS. In this case, the extended base station 11 and the extended terminal stations 12 and 13 are dedicated control messages (enhanced notification messages) for notifying that the own device is compatible with the communication protocol according to the present invention when the local area network is connected and periodically. Send. In the extended notification message, the source MAC address is described, and the extended base station 11 and the extended terminal stations 12 and 13 that have received the MAC address store the MAC address of the device that transmitted the extended notification message.

  In the transmission control, when the RTS frame is received, it is checked whether or not the transmission source device has the extended function according to the present invention by checking with the MAC address of the extended compatible device that stores the “transmitter address”. to decide.

11 Extended base station 12 Extended terminal station (existing terminal station)
13 Extension terminal station 111 Modulation unit 112 Directivity control unit 113 Radio unit (RF)
114 Antenna 115 Directivity Control Unit 116 Demodulation Unit 117 Simultaneous Transmission Control Unit 131 Modulation Unit 132 Directivity Control Unit 133 Radio Unit (RF)
134 Antenna 135 Directivity Control Unit 136 Demodulation Unit 137 Simultaneous Transmission Control Unit

Claims (7)

In a wireless communication method for transmitting and receiving data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception,
While sending data A first extended radio station to the other radio station, the second extended wireless station, when transmitting data B addressed to the first extended radio station, After releasing the NAV, transmitting a transmission request message to the first extended radio station;
A step wherein the first extended wireless station, to send upon receiving the transmission request message, the transmission permission message to the second extended radio station,
A step wherein the second extended radio station, when receiving the transmission permission message, to transmit data B to the first extended radio station,
It said first extended radio station, even during transmitting the data A, the wireless communication method characterized by comprising the steps of: receiving the data B. In a wireless communication method for transmitting and receiving data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception,
While receiving data A from the first extended wireless stations other radio station, the first extended wireless station, when transmitting data B addressed to the second extended radio station, before Symbol Transmitting a transmission request message to the second extended radio station;
A step wherein the second extended wireless station, to send upon receiving the transmission request message, after releasing the NAV, the transmission permission message to the first extended radio station,
A step wherein the first extended radio station, when receiving the transmission permission message, even during receiving the data A, which transmits the data B to the second extended radio station,
A wireless communication method and the second extended radio station, characterized in that a step of receiving the data B. The wireless communication method according to claim 1,
The second extended radio station has a transmission directivity control function, and transmits the data B by forming transmission directivity to the first extended radio station. Wireless communication method. The wireless communication method according to claim 2,
The second extended radio station has a reception directivity control function, and when receiving the data B, the second extended radio station forms a reception directivity with respect to the first extended radio station and receives the data B. Wireless communication method. The wireless communication method according to claim 1 or 2,
The first extended radio station and the second extended radio station have an area in which at least one of the transmission request message and the transmission permission message is an extended radio station that can transmit and receive at the same time. A wireless communication method comprising: notifying other stations. In a wireless communication system that transmits and receives data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception,
The first extended radio station is
While transmitting data A to another wireless station, the second extended wireless station transmits a data request destined for the first extended wireless station to release the NAV and transmits the transmission request. Means for transmitting a transmission permission message to the second extended radio station when a message is received;
Means for receiving the data B transmitted by the second extended radio station during transmission of the data A;
The second extended radio station is
When transmitting data B addressed to the first extended radio station, even if the first extension radio stations even during transmission, after releasing the NAV, to the first extended radio station Means for transmitting a transmission request message;
A wireless communication system, comprising: means for transmitting data B to the first extended wireless station when the transmission permission message transmitted by the first extended wireless station is received. In a wireless communication system that transmits and receives data between a first extended wireless station and a second extended wireless station capable of simultaneous transmission and reception,
The second extended radio station is
A transmission request transmitted by the first extended wireless station to transmit data B destined for the second extended wireless station while the first extended wireless station is receiving data A from another wireless station. Means for transmitting a transmission permission message to the first extended radio station after canceling NAV when receiving the message;
Means for receiving the data B transmitted by the first extended wireless station during reception of the data A;
The first extended radio station is
Means for transmitting the transmission request message to the second extended radio station even when the data A is being received when transmitting the data B destined for the second extended radio station;
Means for transmitting data B to the second extended radio station when the second extended radio station receives the transmission permission message transmitted after canceling the NAV. Wireless communication system.

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