JPWO2011013410A1 - Multi-hop wireless communication system, control device, relay station, and control method - Google Patents

Abstract

The transmission relay station is a relay station that transmits a measurement signal for measuring signal quality between relay stations. The reception relay station is a relay station that receives the measurement signal from the transmission relay station and measures the signal quality. The control device transmits a transmission instruction message including information for designating a transmission antenna, which is an antenna to be used by the transmission relay station to transmit the measurement signal, to the transmission relay station or to the transmission relay station and the reception relay station. Then, a reception instruction message including information for designating a reception antenna that is an antenna that the reception relay station should use for receiving the measurement signal is transmitted to the reception relay station.

Description

  The present invention relates to multi-hop wireless communication in which a relay station is arranged between a base station and a mobile terminal station.

  In recent years, OFDMA (Orthogonal Frequency Division Multiple Access) and high-speed broadband wireless communication systems utilizing adaptive modulation have been studied. One of them is WiMAX (Worldwide Interoperability for Microwave Access).

  WiMAX is defined in the IEEE 802.16-2004 standard (Non-Patent Document 1) and the IEEE 802.16e standard (Non-Patent Document 2). Hereinafter, the IEEE 802.16-2004 standard and the IEEE 802.16e standard will be collectively referred to as the IEEE 802.16e standard.

  One type of wireless communication system is a multi-hop wireless communication system. Multi-hop communication is also referred to as relay communication. In the IEEE 802.16j TG, the IEEE 802.16j standard that enables multi-hop wireless communication by extending the IEEE 802.16e standard has been developed. Note that the targets of the IEEE 802.16j standard are base stations and relay stations, and no changes are made to mobile terminal stations. A mobile terminal station compliant with the IEEE 802.16e standard can communicate with a base station and a relay station compliant with the IEEE 802.16j standard.

  In the multi-hop wireless communication system, one or more relay stations are arranged between a base station and a mobile terminal station in the wireless communication system for the purpose of coverage expansion, throughput improvement, and dead zone countermeasures. In a multi-hop wireless communication system, a packet from a base station to a mobile terminal station is once transmitted from the base station to the relay station, and then transmitted from the relay station to the mobile terminal station. Similarly, a packet from the mobile terminal station to the base station is once transmitted from the mobile terminal station to the relay station, and then transmitted from the relay station to the base station.

  Therefore, in a multi-hop wireless communication system, it is possible to communicate with a mobile terminal station in an area where direct wireless communication cannot be performed with a base station. By using multi-hop, coverage is expanded and insensitive areas are reduced.

  Furthermore, since the distance between the stations is shortened when the relay station enters the communication path, the quality of the received radio wave is improved. As a result, the throughput is improved by selecting a highly efficient modulation method in adaptive modulation.

  In a multi-hop wireless communication system, in order to determine the operation method of the relay station and the allocation of radio resources used by the relay station, interference related to the relay station such as interference between relay stations or between the base station and the relay station is determined. It is required to measure. In the IEEE 802.16j standard, a method of using channel sounding defined in the IEEE 802.16e standard is defined as one of methods for measuring interference related to a relay station.

  Interference measurement between relay stations using channel sounding is controlled by the base station. Sounding signals are used for interference measurement by channel sounding.

  First, the base station performs interference measurement scheduling. Specifically, a relay station that transmits a sounding signal (transmission relay station), a relay station that receives the sounding signal and measures its signal quality (receiving relay station), and a radio resource that is used to transmit the sounding signal decide. Note that there may be a plurality of transmission relay stations and reception relay stations in one interference measurement.

  Next, the base station transmits a transmission instruction message, a report request message, and a sounding resource allocation message.

  The transmission instruction message is an UL Sounding Command IE (Information Element) in the IEEE 802.16e standard, and includes the number of symbols, the identifier of the transmission relay station, the transmission scheme, the multiplexing scheme, and the like.

  The report request message is a REP-REQ message in the IEEE 802.16e standard, and includes an identifier of a frame to be subjected to reception of a sounding signal and measurement of signal quality, a measurement method, and the like.

  The sounding resource allocation message is a PAPR Reduction / Safety Zone / Sounding Zone Allocation IE in the IEEE 802.16e standard, and includes the position of a radio resource for transmitting a sounding signal in a radio frame.

  The transmission instruction message and the sounding resource allocation message are broadcast in the control signal area in the radio frame, and the report request message is transmitted to the receiving relay station in unicast or multicast in the data signal area.

  In accordance with the transmission instruction message, the transmission relay station transmits a sounding signal using the radio resource indicated by the sounding resource assignment message. At the same time, the receiving relay station refers to the transmission instruction message and the sounding resource allocation message, and receives the sounding signal and measures the signal quality according to the report request message.

  Thereafter, the reception relay station notifies the measurement result to the base station by a report response message. The report response message is a REP-RSP message in the IEEE 802.16e standard. The measurement result is notified in the form of RSSI (Receive Signal Strength Indicator) or CINR (Carrier-to-Interference-and-Noise Ratio).

  The base station estimates the amount of interference between the transmission relay station and the reception relay station with reference to RSSI and CINR included in the REP-RSP message from the reception relay station.

IEEE Standard 802.16-2004, "IEEE Standard for Local and Metropolitan Area Networks-Part16: Air Interface for Fixed Broadband Access Accelerated Access Wireless Access IEEE Std 802.16e-2005, "Amendment to IEEE Standard for Local and Metropolitan Area Networks-Part16: Air Interface for Fixed Broadband Wireless Access Systems-Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands"

  In order to improve the performance of a multi-hop wireless communication system, a relay station includes a wireless link (relay link) for communicating with a base station, and a wireless link (access link) for communicating with a mobile terminal station under its own relay station. It is conceivable to use different antennas. The relay station can perform stable and high-speed communication by using an antenna having strong directivity toward the base station in the relay link. Further, the relay station can avoid unnecessary interference with surrounding cells by using a sector antenna or the like having directivity to the area to be serviced by the relay station in the access link.

  However, at present, when the relay station uses different antennas for the relay link and the access link, a method for efficiently measuring the interference related to the relay station has not been established. For example, in the above-described interference measurement using channel sounding in the IEEE 802.16j standard, an antenna to be used for measurement cannot be specified.

  An object of the present invention is to provide a technique for efficiently measuring signal quality related to a relay station even if antennas are different between a relay link and an access link in a multi-hop wireless communication system.

In order to achieve the above object, a multi-hop wireless communication system of the present invention is a multi-hop wireless communication system in which a relay station relays data between a base station and a mobile terminal station,
A transmission relay station that is a relay station that transmits a measurement signal for measuring signal quality between relay stations;
A reception relay station that is a relay station that receives the measurement signal from the transmission relay station and measures the signal quality;
A transmission instruction message including information for designating a transmission antenna, which is an antenna that the transmission relay station should use for transmitting the measurement signal, to the transmission relay station or to the transmission relay station and the reception relay station And a control device that transmits to the reception relay station a reception instruction message including information for designating a reception antenna that is an antenna that the reception relay station should use for receiving the measurement signal. ing.

The control device of the present invention is a control device that controls measurement of signal quality between relay stations in a multi-hop wireless communication system in which a relay station relays data between a base station and a mobile terminal station,
A transmission instruction message including designation of a transmission antenna that is an antenna to be used by a transmission relay station to transmit a measurement signal for measuring signal quality between relay stations, and the measurement signal Control means for generating a reception instruction message including designation of a reception antenna that is an antenna to be used by the reception relay station to receive the measurement signal;
Communication means for transmitting the transmission instruction message generated by the control means to the transmission relay station, and transmitting the reception instruction message generated by the control means to the reception relay station;
have.

A control method of the present invention is a control method for controlling measurement of signal quality between relay stations in a multi-hop wireless communication system in which a relay station relays data between a base station and a mobile terminal station,
A transmission relay station that transmits a measurement signal for measuring signal quality between relay stations generates a transmission instruction message including a designation of a transmission antenna that is an antenna to be used for transmission of the measurement signal;
A reception relay station that receives the measurement signal generates a reception instruction message including a designation of a reception antenna that is an antenna to be used for receiving the measurement signal;
Transmitting the reception instruction message to the reception relay station;
The transmission instruction message is transmitted to the transmission relay station.

It is a block diagram which shows the structure of the multihop radio | wireless communications system by 1st, 2nd and 3rd embodiment. 2 is a block diagram showing a configuration of a base station 100. FIG. It is a block diagram which shows the structure of relay station 200-1 to n. It is a figure which shows the structure of PAPR Reduction / Safety Zone / Sounding Zone Allocation IE prescribed | regulated by IEEE802.16-2009 specification. It is a figure which shows an example of a structure of UL Sounding Command IE prescribed | regulated by the IEEE802.16-2009 specification. It is a figure which shows an example of a structure of the REP-REQ message prescribed | regulated by IEEE802.16-2009 specification. It is a figure which shows an example of the TLV set used by the REP-REQ message prescribed | regulated by the IEEE802.16-2009 standard and the IEEE802.16j standard. It is a figure which shows an example of a structure of the REP-RSP message prescribed | regulated by IEEE802.16-2009 specification. It is a figure which shows an example of the TLV set used by the REP-RSP message prescribed | regulated by the IEEE802.16-2009 standard and the IEEE802.16j standard. It is a figure which shows the field which the multihop radio | wireless communications system by 1st Embodiment adds to a transmission instruction | indication message. It is a figure which shows the TLV set which the multihop radio | wireless communications system by 1st Embodiment adds to a report request message. It is a flowchart which shows an example of operation | movement when the base station 100 in the multihop radio | wireless communications system by 1st, 2nd and 3rd embodiment starts interference measurement. 5 is a flowchart illustrating an example of an operation when relay stations 200-1 to 200-n in the multi-hop wireless communication system according to the first, second, and third embodiments receive a report request message from the base station 100. The flowchart which shows an example of operation | movement when the relay station 200-1 to n in the multihop radio | wireless communications system by 1st, 2nd and 3rd embodiment receives the sounding resource allocation message and the transmission instruction message from the base station 100. It is. It is a flowchart which shows an example of operation | movement when the base station 100 in the multihop radio | wireless communications system by 1st, 2nd and 3rd embodiment receives the report response message from the relay station 200-1 to n. It is a figure which shows an example of the link which needs an interference measurement, the basic CID of a relay station, and an interference scheduling result. It is a figure which shows an example of the transmission instruction | indication message produced | generated by the base station 100 in the multihop radio | wireless communications system by 1st Embodiment. It is a figure which shows an example of the report request message produced | generated by the base station 100 in the multihop radio | wireless communications system by 1st Embodiment. It is a figure which shows an example of the report response message produced | generated by relay station 200-1 to n in the multihop radio | wireless communications system by 1st Embodiment. It is a figure which shows the field which the multihop radio | wireless communications system by 2nd and 3rd embodiment adds to a transmission instruction | indication message. It is a figure which shows the TLV set which the multihop radio | wireless communications system by 2nd and 3rd embodiment adds to a report request message. It is a figure which shows an example of the link which needs an interference measurement, the basic CID and type of a relay station, and an interference scheduling result. It is a figure which shows an example of the transmission instruction | indication message produced | generated by the base station 100 in the multihop radio | wireless communications system by 2nd and 3rd embodiment. It is a figure which shows an example of the report request message produced | generated by the base station 100 in the multihop radio | wireless communications system by 2nd Embodiment. It is a figure which shows an example of the measurement necessity judgment table | surface used by the multihop radio | wireless communications system by 3rd Embodiment. It is a figure which shows an example of the report request message produced | generated by the base station 100 in the multihop radio | wireless communications system by 3rd Embodiment.

  Embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  As an embodiment of the present invention, a WiMAX system based on the IEEE 802.16j standard that performs multi-hop communication by arranging a relay station between a base station and a mobile terminal station is exemplified.

  First, the outline of the configuration and operation common to each embodiment of the present invention will be described.

  As an embodiment of the present invention, a base station based on the IEEE 802.16-2009 standard and the IEEE 802.16j standard, which is a standard summarizing the IEEE 802.16-2004 standard and the IEEE 802.16e standard, and a mobile terminal based on the IEEE 802.16-2009 standard A WiMAX system in which relay stations based on the IEEE 802.16-2009 standard and the IEEE 802.16j standard are arranged between the stations to perform multi-hop communication is exemplified. A WiMAX system including a base station and a relay station is basically a system based on the IEEE 802.16-2009 standard and the IEEE 802.16j standard, but has a unique function for performing multi-hop communication according to the present embodiment. Prepared for the station.

  In this system, the base station transmits information indicating an antenna to be used by a transmission relay station, which is a relay station scheduled to transmit a sounding signal (measurement signal), to the relay station. It is included in the transmission instruction message.

  Further, in this system, information for determining an antenna to be used by a receiving relay station that is a relay station scheduled to receive and measure a sounding signal transmitted by the transmitting relay station, It is included in the report request message that the base station transmits to the receiving relay station.

  In this system, the transmission relay station and the reception relay station determine an antenna to be used for transmission and reception of the sounding signal based on the above information.

  According to the present embodiment, the transmission instruction message transmitted from the base station includes information for designating a transmission antenna that is an antenna that the transmission relay station should use for transmitting the measurement signal, and the reception instruction message , Because it contains information for specifying the receiving antenna, which is the antenna that the receiving relay station should use for receiving the measurement signal, even if the relay station uses different antennas for the relay link and the access link It is possible to identify and measure the signal quality efficiently.

  When the technique described above is applied to an actual WiMAX system, various embodiments can be adopted. Hereinafter, some embodiments will be described in detail with reference to the drawings.

(First embodiment)
First, the schematic configuration and operation of the embodiment of the present invention will be described.

  FIG. 1 is a block diagram showing a configuration of a multi-hop wireless communication system according to the first embodiment. Referring to FIG. 1, the multi-hop wireless communication system according to the first embodiment includes a base station 100 and relay stations 200-1 to 200-n and is connected to a mobile terminal station 300. The base station 100 and the relay stations 200-1 to 200-n are connected via the wireless communication line 1. The relay stations 200-1 to 200-n and the mobile terminal station 300 are also connected via the wireless communication line 1.

  The base station 100 and the mobile terminal station 300 perform multihop wireless communication via any one of the relay stations 200-1 to 200-n. That is, a packet from the base station 100 to the mobile terminal station 300 is first transmitted from the base station 100 to any one of the relay stations 200-1 to 200-n, and then transmitted from the relay station to the mobile terminal station 300. Similarly, a packet from the mobile terminal station 300 to the base station 100 is first transmitted from the mobile terminal station 300 to any one of the relay stations 200-1 to 200-n, and then transmitted from the relay station to the base station 100.

  A radio link between the relay stations 200-1 to 200-n and the base station 100 is referred to as a relay link. A radio link between the relay stations 200-1 to 200-n and the mobile terminal station 300 is called an access link.

  Each of relay stations 200-1 to 200-n has two antennas. One is an antenna (antenna in the relay link direction) used for radio communication with the base station 100, and the other is an antenna (antenna in the access link direction) used for radio communication with the mobile terminal station 300. When the relay stations 200-1 to 200-n perform communication by MIMO (Multiple Input Multiple Output), the antenna means an antenna set including a plurality of antennas used in MIMO.

  FIG. 2 is a block diagram showing a configuration of base station 100. The base station 100 includes an upper layer processing unit 105, a wireless MAC processing unit 101, a wireless IF unit 102, an interference measurement control unit 103, and an antenna unit 104.

  The upper layer processing unit 105 performs protocol processing for upper layer communication using the multihop wireless communication system. An example of the upper layer communication protocol is IP (Internet Protocol).

  The wireless MAC processing unit 101 performs processing of a MAC (Media Access Control) layer of a base station defined by the IEEE 802.16-2009 standard and the IEEE 802.16j standard. The MAC processing performed by the wireless MAC processing unit 101 includes scheduling, conversion from upper layer packets to MAC PDU (Media Access Payload Data Unit) and its reverse conversion, connection management, QoS (Quality of Service) control, route control, Network entry processing, retransmission control, transmission queue management, relay station control, mobile terminal station control, and the like are included.

  When the interference measurement regarding the relay stations 200-1 to n is necessary, the wireless MAC processing unit 101 requests the interference measurement control unit 103 to measure the interference regarding the relay stations 200-1 to 200-n. At that time, a set of relay stations (measurement link) whose interference is to be measured is passed as a parameter. In addition, the parameters include parameters related to the designation of the antenna to be used by the relay station and the sounding (sounding type, measurement method, etc.).

  The wireless IF unit 102 performs processing of the PHY layer of the base station defined by the IEEE 802.16-2009 standard and the IEEE 802.16j standard. The wireless IF unit 102 is connected to the relay stations 200-1 to 200-n via the wireless communication line 1, and performs wireless communication with the relay stations 200-1 to 200-n.

  The interference measurement control unit 103 performs interference measurement scheduling for the relay stations 200-1 to 200-n. Also, the interference measurement control unit 103 generates a MAC message (interference measurement control MAC message) for controlling interference measurement, and transmits the MAC message to the relay stations 200-1 to 200-n via the wireless MAC processing unit 101. To do. The interference measurement control MAC message used by the interference measurement control unit 103 will be described later.

  The antenna unit 104 is an antenna that transmits and receives radio waves for the wireless IF unit 102 to perform wireless communication with the relay stations 200-1 to 200-n.

  FIG. 3 is a block diagram showing a configuration of relay stations 200-1 to 200-n. Each of the relay stations 200-1 to 200-n includes a wireless MAC processing unit 201, a wireless IF unit 202, an interference measurement control unit 203, a relay link antenna unit 204, and an access link antenna unit 205.

  The wireless MAC processing unit 201 performs processing of the MAC layer of the relay station defined by the IEEE 802.16-2009 standard and the IEEE 802.16j standard. The MAC processing performed by the wireless MAC processing unit 201 includes MAC PDU relay, scheduling, QoS control, route control, network entry processing, retransmission control, and the like.

  The wireless MAC processing unit 201 specifies an antenna unit to be used for transmission / reception of radio waves to the wireless IF unit 202. The wireless MAC processing unit 201 wirelessly uses the relay link antenna unit 204 for communication with the base station 100 and the access link antenna unit 205 for transmission / reception of radio waves during the time for communication with the mobile terminal station 300. Specify for the IF unit 202.

  The wireless IF unit 202 performs processing of the PHY layer of the relay station defined by the IEEE 802.16-2009 standard and the IEEE 802.16j standard. The wireless IF unit 202 is connected to the base station 100 and the mobile terminal station 300 via the wireless communication line 1 and performs wireless communication with the base station 100 and the mobile terminal station 300.

  The wireless IF unit 202 provides the wireless MAC processing unit 201 with a function for designating an antenna unit to be used for wireless communication. The wireless IF unit 202 uses an antenna unit (one of the relay link antenna unit 204 and the access link antenna unit 205) designated by the wireless MAC processing unit 201 when transmitting and receiving radio waves.

  The relay link antenna unit 204 is an antenna that transmits and receives radio waves for the relay stations 200-1 to 200-n to perform wireless communication with the base station 100.

  The access link antenna unit 205 is an antenna that transmits and receives radio waves for the relay stations 200-1 to 200-n to perform wireless communication with the mobile terminal station 300.

  The interference measurement control unit 203 receives the interference measurement control MAC message from the base station 100 via the wireless MAC processing unit 201 and analyzes it. Further, the interference measurement control unit 203 instructs the wireless MAC processing unit 201 on the antenna to be used in the interference measurement based on the instruction in the interference measurement control MAC message.

  An interference measurement control MAC message used by the multi-hop wireless communication system according to the first embodiment will be described.

  The multi-hop wireless communication system according to the first embodiment uses a MAC message used for interference measurement by channel sounding in the IEEE 802.16-2009 standard and the IEEE 802.16j standard as an interference measurement control MAC message. That is, a PAPR Reduction / Safety Zone / Sounding Zone Allocation IE is used as a sounding resource allocation message, a UL Sounding Command IE is used as a transmission instruction message, a REP-REQ message is used as a report request message, and a REP-RSP message is used as a report response message. .

  FIG. 4 shows the configuration of the PAPR Reduction / Safety Zone / Sounding Zone Allocation IE. The IE includes the start OFDM symbol position of the sounding signal transmission area (sounding zone), the number of OFDM symbols, and parameters for sounding.

  The structure of UL Sounding Command IE is shown in FIG. The IEEE 802.16-2009 standard defines two types of sounding signal transmission methods, Type A and Type B. FIG. 5 shows the case of Type B. The IE includes a subchannel arrangement method to be used in the sounding zone, a basic CID (Connection Identifier) of a station to which the sounding signal is to be transmitted, information on resources allocated to the station, and the like. In the IEEE 802.16-2009 standard, a base station assigns a 2-octet long CID to a connection established between a relay station and a mobile terminal station with the base station, and uses the CID for connection identification. The basic CID is a CID assigned to a connection for transmitting a MAC message, and is also used for identifying a relay station and a mobile terminal station.

  The structure of the REP-REQ message is shown in FIG. All the information included in the message is stored in a TLV (Type-Length-Value) format. A TLV used in the REP-REQ message is shown in FIG. The highest TLV set used in the REP-REQ message is only the Report Request. The value of the TLV set Report Request is also expressed in TLV format. FIG. 7B shows a TLV set used in the report request, which is related to interference measurement related to the relay station.

  The structure of the REP-RSP message is shown in FIG. All information included in the message is stored in TLV format. FIG. 9A shows a TLV set used in the REP-RSP message that is related to interference measurement related to the relay station. The value of the TLV set Channel Type Report in WirelessMAN OFDMA PHY is also expressed in TLV format. FIG. 9B illustrates a TLV set used as a value of the TLV set Channel Type Report in WirelessMAN OFDMA PHY, which is related to interference measurement related to the relay station.

  The multi-hop wireless communication system according to the first embodiment includes information on an antenna to be used for transmission / reception of a sounding signal in the above-described interference measurement control MAC message.

  FIG. 10 shows fields used by the multi-hop wireless communication system according to the first embodiment additionally included in the transmission instruction message (UL Sounding Command IE). The field to be added is arranged outside the loop of item number 18 in the loop of item number 15 in FIG. The j-th bit of the added Antenna assignments field means an antenna to be used by the relay stations 200-1 to 200-n identified by the j-th Shorted basic CID in the loop of item number 18 to transmit the sounding signal. To do. When the bit is 0, it means that an antenna in the relay link direction, that is, an antenna for communicating with the base station 100 should be used. When the bit is 1, it means that an antenna in the access link direction, that is, an antenna for communicating with the mobile terminal station 300 should be used. Hereinafter, the transmission instruction for the transmission relay station identified by the Shorted basic CID field identified by the index i of the loop of item number 15 and the index j of the loop of item number 18 is referred to as a transmission instruction entry.

  FIG. 11 shows a TLV set used by the multi-hop wireless communication system according to the first embodiment additionally included in a report request message (REP-REQ message). The added TLV set Receive antenna assignments is used as a TLV set included in the value of Report Request, which is a TLV set for a REP-REQ message. The TLV set includes information on an antenna to be used for receiving a sounding signal transmitted based on the transmission instruction message.

  Next, the operation of the multihop wireless communication system according to the first embodiment will be described in detail with reference to FIG. 12, FIG. 13, FIG. 14, and FIG.

  First, FIG. 12 illustrates the operation of the base station 100 when the wireless MAC processing unit 101 of the base station 100 requires interference measurement regarding the relay stations 200-1 to 200-n and requests the interference measurement control unit 103 to perform interference measurement. The description will be given with reference.

The interference measurement control unit 103 of the base station 100 performs interference measurement scheduling based on a request from the wireless MAC processing unit 101 (step S111). Specifically, a relay station that transmits a sounding signal (transmission relay station) and a relay station that receives the sounding signal and measures its signal quality so that the measurement link requested from the wireless MAC processing unit 101 can be measured. (Reception relay station) and radio resources to be used for transmitting the sounding signal are determined. Here, it is assumed that the sounding signal is transmitted in the frame having the frame number F _SOUNDING .

  The interference measurement control unit 103 of the base station 100 generates a sounding resource assignment message, a transmission instruction message, and a report request message (step S112). The content of the sounding resource assignment message is set according to the sounding signal transmission radio resource determined in step S111. The content of the transmission instruction message is set according to the antenna designation and sounding parameters received as parameters from the wireless MAC processing unit 101, and the interference measurement schedule (list of transmission relay stations and allocated radio resources) determined in step S111. The The content of the report request message includes the antenna designation and sounding parameters received as parameters from the wireless MAC processing unit 101, and the interference measurement schedule (transmission relay station list, reception relay station list, and assignment) determined in step S111. Radio resources). The report request message is generated for each relay station that should receive the report request message.

An example of the transmission instruction message and the report request message generated in step S112 will be described with reference to FIGS. Here, assuming that n = 5, the measurement link requested by the wireless MAC processing unit 101, the basic CIDs of the relay stations 200-1 to 200-n, and the interference measurement scheduling result in step S111 are as shown in FIG. Suppose there is. In step S111, it is assumed that the interference measurement control unit 103 allocates 3 OFDM symbols in the frame F _SOUNDING for sounding in order to process the request.

  FIG. 17 shows an example (part) of the transmission instruction message generated in step S112. In this example, since 3 OFDM symbols are allocated for interference measurement, the Num_Sounding_symbols field is set to 3. For each symbol, the number of basic CIDs of relay stations to which sounding signals are to be transmitted within the symbol and the lower 12 bits of the basic CID are stored. Taking the first symbol (when i is 0) as an example, the number of CIDs field is set to 1 because the relay station 200-1 is the only relay station that should transmit with that symbol. In addition, since the basic CID of the relay station 200-1 is 201 and the relay station 200-1 is required to use an antenna in the relay link direction in the symbol, the Shorted basic CID field and the Antenna assignments field are Set to 201 and 0, respectively. Values are similarly set for the second and third symbols. FIG. 17 shows an example in which the sounding type is Type B. In sounding by Type B, only one relay station transmits a sounding signal in one OFDM symbol. However, in sounding by Type A, a plurality of relay stations can transmit a sounding signal in one OFDM symbol. In such a case, the value of the Number of CIDs field is set to 2 or more, and the value of the Antenna assignments field is a bit string including antenna designation information for each relay station assigned to the symbol.

FIG. 18 shows an example of the report request message generated by the base station 100 in step S112 and destined for the relay station 200-4. The value of the TLV set Channel Type request is set to 0b11 which means measurement in the sounding zone. The value of the TLV set Start Frame Number is set to the lower 8 bits of the frame number F _SOUNDING to which the radio resource is allocated. According to FIG. 16 (C), since relay station 200-4 needs to perform measurement three times, the length of the TLV set Receive antenna assignments is 6 octets (3 elements), and the value is assigned to three receiving antennas. Is set. Since relay station 200-4 needs to measure the signal quality by receiving the sounding signal from relay station 200-1 (basic CID 201) using the antenna in the relay link direction in the first symbol, the first receiving antenna The assigned Symbol index field is set to 0, the Shorted basic CID is set to 201, and the Antenna assignment field is set to 0. Values are similarly set for the second and third receiving antenna assignments.

  The interference measurement control unit 103 of the base station 100 transmits each report request message generated in step S112 to each receiving relay station via the wireless MAC processing unit 101 by unicast (step S113).

The interference measurement control unit 103 of the base station 100 transmits the sounding resource assignment message and the transmission instruction message generated in step S112 by broadcast via the wireless MAC processing unit 101 in the frame F _SOUNDING (step S114).

  Next, the operation of relay stations 200-1 to 200-n when receiving the report request message transmitted from base station 100 in step S113 will be described with reference to FIG. Here, it is assumed that the receiving relay station is the relay station 200-x.

The interference measurement control unit 203 of the relay station 200-x receives the report request message transmitted from the base station 100 via the wireless MAC processing unit 201 (step S121). At that time, the interference measurement control unit 203 extracts the value of the Start Frame Number field, which is the lower 8 bits of the frame number to be measured, from the report request message. Further, the interference measurement control unit 203 calculates F _SOUNDING from the current frame number and the value of the field.

The interference measurement control unit 203 of the relay station 200-x receives the sounding resource allocation message and the transmission instruction message transmitted from the base station 100 in the frame _having the frame number F _SOUNDING via the wireless MAC processing unit 201 (step). S122).

  The interference measurement control unit 203 of the relay station 200-x determines an antenna to be used for receiving the sounding signal based on the contents of the report request message received in step S121 and the transmission instruction message received in step S122 ( Step S123). Specifically, the transmission instruction entry for the transmission relay station in the transmission instruction message corresponding to the entry is specified using the values of the Symbol index field and Shortend basic CID field of the report request message as keys. Further, it is determined according to the value of the Antenna assignment field of the report request message which antenna should be used for receiving the sounding signal transmitted by the transmission instruction entry. The interference measurement control unit 203 notifies the wireless MAC processing unit 201 of the determination result.

  The wireless MAC processing unit 201 and the wireless IF unit 202 of the relay station 200-x are configured so that the transmission relay station determines the contents of the report request message received in step S121 and the sounding resource assignment message and transmission instruction message received in step S122. The sounding signal to be transmitted is received and the signal quality is measured (step S124). The operation is performed based on the IEEE 802.16-2009 standard and the IEEE 802.16j standard, except as described below. At that time, the wireless MAC processing unit 201 uses an antenna (one of the relay link antenna unit 204 and the access link antenna unit 205) used when receiving the sounding signal based on the determination result of the interference measurement control unit 203 in step S123. The wireless IF unit 202 is controlled so as to appropriately select.

  The wireless MAC processing unit 201 of the relay station 200-x generates a report response message including the measurement result in step S124 (step S125). The operation is performed based on the IEEE 802.16-2009 standard and the IEEE 802.16j standard, except as described below. At that time, when the sounding signal from one transmission relay station is measured a plurality of times, the wireless MAC processing unit 201 sets a plurality of basic CIDs of the transmission relay station to the value of the TLV set Vector of neighbor stations of the report response message to be generated. include. Further, the TLV set value for notifying the measurement result includes the measurement result for the transmission relay station in the same order as the order of appearance of the transmission instruction entry for the transmission relay station in the transmission instruction message.

  FIG. 19 shows an example of a report response message addressed to the base station 100 generated by the relay station 200-4 in step S125. The report response message shown in FIG. 19 is generated corresponding to the report request message shown in FIG. In the value of the TLV set Vector of neighbor stations of the report response message, three basic CIDs to be measured are stored corresponding to the value of the TLV set Receive antenna assignments of the report request message. In this example, since the relay station 200-4 measures the sounding signal from the relay station 200-1 twice, the basic CID (201) of the relay station 200-1 is stored twice in the value of the TLV set. Is done. The measurement result in step S124 is stored in the value of the TLV set UL Sounding CINR Report of the report response message. The measurement results for relay station 200-1 are stored in the same order as the order of appearance of the transmission instruction entries for relay station 200-1 in the transmission instruction message.

  The wireless MAC processing unit 201 of the relay station 200-x transmits the report response message generated in step S125 to the base station 100 via the wireless IF unit 202 (step S126).

  Next, the operation of relay stations 200-1 to 200-n when receiving the sounding resource allocation message and the transmission instruction message transmitted from base station 100 in step S114 will be described with reference to FIG. Here, a description will be given assuming that the transmission relay station is the relay station 200-x.

  The interference measurement control unit 203 of the relay station 200-x receives the sounding resource assignment message and the transmission instruction message transmitted from the base station 100 via the wireless MAC processing unit 201 (step S131).

  The interference measurement control unit 203 of the relay station 200-x confirms whether the transmission instruction message received in step S131 includes a transmission instruction for the own station (step S132). Specifically, it is confirmed whether or not the transmission basic message includes a Shorted basic CID field having a value that matches the lower 12 bits of the basic CID of the own station. When the transmission instruction for the own station is not included, the relay station 200-x ends the process.

  When a transmission instruction for the own station is included in step S132, the interference measurement control unit 203 of the relay station 200-x should be used for transmitting a sounding signal based on the content of the transmission instruction message received in step S131. The antenna is determined (step S133). Specifically, when the Shorted basic CID field corresponding to the basic CID of the local station is found in the loop of item number 18 in FIG. 5 showing the configuration of the transmission instruction message, the interference measurement control unit 203 sets the loop variable at that time. Based on the value of j, the jth bit of the Antenna assignments field is referred to. When the bit is 0, the interference measurement control unit 203 determines that the antenna in the relay link direction is used in the transmission instruction. When the bit is 1, the interference measurement control unit 203 determines that the antenna in the access link direction is used in the transmission instruction. The interference measurement control unit 203 notifies the wireless MAC processing unit 201 of the determination result.

  The wireless MAC processing unit 201 and the wireless IF unit 202 of the relay station 200-x transmit a sounding signal based on the contents of the sounding resource assignment message and the transmission instruction message received in step S131 (step S134). The operation is performed based on the IEEE 802.16-2009 standard and the IEEE 802.16j standard, except as described below. At that time, the wireless MAC processing unit 201 uses an antenna (one of the relay link antenna unit 204 and the access link antenna unit 205) used when transmitting each sounding signal based on the determination result of the interference measurement control unit 203 in step S133. The wireless IF unit 202 is controlled so as to select appropriately.

  Next, the operation of the base station 100 when receiving the report response message transmitted from the relay stations 200-1 to 200-n in step S126 will be described with reference to FIG. Here, it is assumed that the receiving relay station is the relay station 200-x.

  The interference measurement control unit 103 of the base station 100 receives the report response message transmitted from the relay station 200-x via the wireless MAC processing unit 101 (step S141).

  The interference measurement control unit 103 of the base station 100 refers to the value of the TLV set Vector of neighbor stations in the report response message, the value of the TLV set UL Sounding CINR Report, and the value of the UL Sounding RSSI Report. An interference measurement result between the transmission relay stations is extracted (step S142). When the same basic CID appears multiple times in the value of the TLV set Vector of neighbor stations, the interference measurement control unit 103 determines in step S113 which antenna of the relay station 200-x the corresponding measurement result is. The determination is made with reference to the order of appearance of transmission instruction entries for the transmission relay station in the transmitted report request message and the scheduling result in step S111.

  As described above, according to the multi-hop wireless communication system in the first embodiment, when a relay station uses different antennas for the relay link and the access link, it is possible to efficiently measure interference related to the relay station. It is.

  It includes the information on the antenna to be used by the transmission relay station in the transmission instruction message and the information on the antenna to be used by the reception relay station in the report request message. This is because it becomes possible to indicate correctly.

  Note that although the relay station has two antennas as the multi-hop wireless communication system according to the first embodiment, the present invention is not limited to this, and the relay station has three or more antennas. It may be. This can be realized by extending the field used for antenna specification in the transmission instruction message and the report request message from 1 bit to a plurality of bits.

  As an example of the multi-hop wireless communication system according to the first embodiment, the two antennas of the relay station are used for communication with the relay link direction and the access link direction, respectively, but the present invention is not limited to this. Absent. For example, the relay station may use one of a plurality of antennas of the relay station for communication with a lower relay station.

  As an example of the multi-hop wireless communication system according to the first embodiment, an example has been shown in which a reception relay station that has received the message includes all antenna specifications to be used for receiving a sounding signal in the report request message. It is not limited to. For example, the receiving relay station may determine the default of an antenna to be used for receiving a sounding signal, and the antenna specification may be included in the report request message only for a measurement that does not use the default antenna. This is because the receiving relay station determines that all sounding signals by the transmission instruction message corresponding to the report request message are received, and if the antenna information to be used for reception is included in the report request message, the information is included in the information. This can be realized by selecting a base antenna and, if not included, selecting a default antenna. The default antenna setting may be fixed, or may be dynamically determined by the base station and notified to the relay station. With such a configuration, the size of the report request message can be reduced, and the signaling overhead can be reduced.

(Second Embodiment)
In the first embodiment, a transmission instruction message including information on an antenna to be used by a transmission relay station is generated and used, and a report including antenna information to be used by the reception relay station for each reception relay station Interference measurement between relay stations using different antennas for relay link and access link was realized by generating and using request messages. In the multi-hop wireless communication system according to the first embodiment, any combination of interference measurements can be performed.

  However, in the measurement of interference between relay stations, measurement in an arbitrary combination is not necessary, and measurement with a limited pattern is often sufficient. In particular, the measurement pattern is often limited by the type of relay station. Therefore, it may be sufficient to specify an antenna to be used for interference measurement for each relay station type.

  The multi-hop wireless communication system according to the second embodiment generates and uses a transmission instruction message including the type of transmission relay station together with information on the antenna to be used by the transmission relay station, and further transmits the type and transmission of the transmission relay station. For each antenna used by the relay station, a report request message including information on the antenna to be used for measurement for each type of the receiving relay station is generated and used. Since the multi-hop wireless communication system according to the second embodiment designates an antenna for each type of relay station, the overhead of the interference measurement control MAC message can be reduced as compared with the first embodiment.

  In the multi-hop wireless communication system according to the second embodiment, a distinction between a non-transparent type and a transparent type specified in the IEEE 802.16j standard is used as a relay station type. A non-transparent relay station is a relay station that transmits a preamble and a control signal by itself. The non-transparent relay station behaves as if it is a base station with respect to the mobile terminal station. On the other hand, a transmissive relay station is a relay station that does not transmit a preamble or a control signal. A mobile terminal station supported by a transparent relay station receives a preamble and a control signal directly from the base station. The transparent relay station performs a relay operation only on the data portion of the signal transmitted and received by the mobile terminal station.

  The configuration of the multi-hop wireless communication system according to the second embodiment is the same as that of the first embodiment shown in FIG. The configurations of the base station 100 and the relay stations 200-1 to 200-n of the multi-hop wireless communication system according to the second embodiment are the same as those of the first embodiment shown in FIGS.

  The interference measurement control MAC message used by the multi-hop wireless communication system according to the second embodiment is the same as that according to the first embodiment except for the points described below.

  FIG. 20 shows fields used by the multi-hop wireless communication system according to the second embodiment additionally included in the transmission instruction message (UL Sounding Command IE). The field to be added is arranged outside the loop of item number 18 in the loop of item number 15 in FIG. The configuration and meaning of the Antenna assignments field are the same as those in the first embodiment. The j-th bit of the added Sender RS types field means the type of the relay stations 200-1 to 200-n identified by the j-th Shorted basic CID in the loop of item number 18. When this bit is 0, it means that the corresponding transmission relay station is non-transparent. When the bit is 1, it means that the corresponding transmission relay station is a transmission type. The value of the Sender RS types field is used by the receiving relay station.

  FIG. 21 shows a TLV set that is additionally used in the report request message (REP-REQ message) by the multi-hop wireless communication system according to the second embodiment. The added TLV set Receive antenna assignments is used as a TLV set included in the value of Report Request, which is a TLV set for a REP-REQ message. The TLV set includes information on an antenna to be used for receiving a sounding signal transmitted based on the transmission instruction message. The value of the TLV set is composed of one or more 4-bit data. Each 4-bit data is used for measurement by the non-transparent receiving relay station when the transmitting relay station of the type indicated by the Sender RS type field transmits a sounding signal using the antenna indicated by the Sender RS antenna assignment field. The antenna to be used and the antenna to be used for measurement by the transmission type reception relay station are shown. Antennas that should be used for measurement by the non-transparent and transparent reception relay stations are indicated by the Antenna for non-transparent RS field and the Antenna for transparent RS field, respectively. The reception relay station that has received the report request message grasps the type of transmission relay station and the antenna used for transmission with reference to the transmission instruction message.

  Next, the operation of the multi-hop wireless communication system according to the second embodiment will be described in detail.

  The multi-hop wireless communication system according to the second embodiment when the wireless MAC processing unit 101 of the base station 100 requires interference measurement regarding the relay stations 200-1 to 200-n and requests interference measurement from the interference measurement control unit 103. The operation of the base station 100 is the same as that of the first embodiment except for the points described below.

  In step S112, when generating the transmission instruction message, the interference measurement control unit 103 of the base station 100 includes the Sender RS types field in the transmission instruction message in addition to the operation in the first embodiment. The jth bit of the Sender RS types field is set according to the type of the jth transmission relay station in the loop of item number 18 in FIG. 5 including the field. If the transmission relay station is non-transparent, the bit is set to 0. If the transmission relay station is transparent, the bit is set to 1. The interference measurement control unit 103 acquires the type of each transmission relay station from the wireless MAC processing unit 101.

  In step S112, the interference measurement control unit 103 of the base station 100 does not generate a report request message for each reception relay station, but generates a report request message common to all reception relay stations. The contents of the report request message include the antenna specification and sounding parameters received as parameters from the wireless MAC processing unit 101, the interference measurement schedule (reception relay station type and assigned radio resource) determined in step S111, and each transmission relay. Set according to station type.

An example of the transmission instruction message and the report request message generated in step S112 will be described with reference to FIGS. Here, assuming that n = 5, the measurement link requested by the wireless MAC processing unit 101, the basic CIDs and types of the relay stations 200-1 to 200-n, and the interference measurement scheduling results are as shown in FIG. And In step S111, it is assumed that the interference measurement control unit 103 allocates 3 OFDM symbols in the frame F _SOUNDING for sounding in order to process the request.

  FIG. 23 shows an example (part) of the transmission instruction message generated in step S112 in the second embodiment. In FIG. 23, the Sender RS types field is additionally shown in addition to the fields used in the first embodiment. Taking the first symbol (when i is 0) as an example, since the relay station 200-1 that is a relay station to be transmitted with the symbol is non-transparent, the Sender RS types field is set to 0. . Taking the third symbol (when i is 2) as an example, the Sender RS types field is set to 1 because the relay station 200-2, which is the relay station to be transmitted with the symbol, is transmissive. As in the case of the Antenna assignments field, when the value of the Number of CIDs field is 2 or more, the value of the Sender RS types field is a bit string indicating the type of each transmission relay station assigned to the symbol.

  FIG. 24 shows an example of the report request message generated by the base station 100 according to the second embodiment in step S112. According to FIG. 22C, there are three types of transmission relay station types and antenna combinations: (non-transparent type, relay link direction), (non-transparent type, access link method), and (transparent type, access link direction). There is. Therefore, three entries are generated for the value of the TLV value Receive antenna assignments, and the Sender RS type field and Sender RS antenna assignment field of each entry are set to values that indicate the type of relay station and antenna indicated by the entry, respectively. Is done. Taking the set of the second entry (in the case of i = 1) in FIG. 24 (non-transparent type, access link direction) as an example, the non-transparent relay station transmits with an antenna in the access link direction. In this case, it is required that the non-transmission type relay station uses an antenna in the access link direction, and the transmission type relay station uses an antenna in the relay link direction (FIG. 22, measurement links 2 to 4). Therefore, the Antenna for non-transparent RS field and the Antenna for transparent RS field of the entry are set to 1 and 0, respectively.

  In step S113, the interference measurement control unit 103 of the base station 100 transmits the report request message generated in step S112 to each receiving relay station via the wireless MAC processing unit 101 by multicast.

  The operations of the relay stations 200-1 to 200-n in the multi-hop wireless communication system according to the second embodiment when the report request message transmitted from the base station 100 is received in step S113 are the same as those shown in FIG. This is the same as the operation in the first embodiment described with reference to FIG. Here, it is assumed that the receiving relay station is the relay station 200-x.

  In step S123, the interference measurement control unit 203 of the relay station 200-x determines the antenna to be used for reception of the sounding signal based on the contents of the report request message received in step S121 and the transmission instruction message received in step S122. Make a decision. For each transmission instruction entry in the transmission instruction message, the interference measurement control unit 203 determines an antenna to be used for receiving a sounding signal transmitted based on the transmission instruction entry as follows. First, the interference measurement control unit 203 extracts the antenna used by the transmission relay station for transmitting the sounding signal and the type of the transmission relay station from the transmission instruction entry. These pieces of information are stored in the Antenna assignments field and the Sender RS types field, respectively. Next, the interference measurement control unit 203 refers to the Receive antenna assignments field of the report request message, and sends the sender RS type field indicating the type of the transmission relay station and the sender RS antenna indicating the antenna used by the transmission relay station to transmit the sounding signal. Searches for an entry whose assignment field matches the information from the transmission instruction entry. When the local station is non-transparent, the interference measurement control unit 203 refers to the antenna for non-transparent RS field value of the found entry, and determines the antenna to be used for receiving the sounding signal based on the transmission instruction entry. judge. When the local station is a transmission type, the interference measurement control unit 203 refers to the value of the Antenna for transparent RS field of the found entry, and determines an antenna to be used for reception of the sounding signal based on the transmission instruction entry. The interference measurement control unit 203 acquires the type of the own station from the wireless MAC processing unit 201.

  The operations of the relay stations 200-1 to 200-n in the multi-hop wireless communication system according to the second embodiment when receiving the sounding resource allocation message and the transmission instruction message transmitted from the base station 100 in step S114 are as shown in FIG. This is the same as the operation in the first embodiment described with reference to FIG.

  The operation of the base station 100 in the multi-hop wireless communication system according to the second embodiment when receiving the report response message transmitted from the relay stations 200-1 to 200-n in step S126 has been described with reference to FIG. The operation is the same as that in the first embodiment.

  As described above, according to the multi-hop wireless communication system according to the second embodiment, in addition to the effects of the first embodiment, the overhead of the interference measurement control MAC message can be reduced as compared with the first embodiment. it can. This is because the size of the report request message can be reduced because the antenna is specified for each relay station type, and the report request message can be transmitted to each receiving relay station by multicast instead of unicast.

  In the multi-hop wireless communication system according to the second embodiment, an example in which a non-transparent type and a transparent type are used as the type of relay station has been described. However, the present invention is not limited to this, A distinction may be used.

  As an example of the multi-hop wireless communication system according to the second embodiment, the type of the transmission relay station is included in the transmission instruction message, but the present invention is not limited to this. For example, the type of transmission relay station may be included in the report request message. This can be realized, for example, by including in the report request message a TLV value that includes data corresponding to the Sender RS types field of the transmission instruction message.

  As an example of the multi-hop wireless communication system according to the second embodiment, the transmission relay station includes information on the antenna to be used for transmitting the sounding signal in the transmission instruction message. However, the present invention is not limited to this. Absent. For example, it may be included in the report request message. For example, a TLV value that includes data corresponding to the Antenna assignments field of the transmission instruction message is included in the report request message, and the transmission relay station receives the multicast report request message and refers to the TLV value. Can be realized.

(Third embodiment)
In the second embodiment, an example in which the designation of an antenna to be used for receiving a sounding signal is designated for each type of transmission relay station and each used antenna to be transmitted is shown.

  However, in the measurement of interference between relay stations, it may be unnecessary to measure with any relay station type and antenna combination. FIG. 25 shows an example of a measurement necessity determination table. The table in FIG. 25 shows examples of combinations that require measurement. In FIG. 25, “◯” means a combination that requires interference measurement, and “−” means a combination that does not require interference measurement. For example, interference measurement is not required for a combination of non-transparent relay station / relay link direction antenna pairs. This is because the communication in the relay link, that is, the communication between the base station and the relay station, avoids interference by a multiple connection method such as OFDMA. On the other hand, interference measurement is required for combinations of non-transparent relay stations and antennas in the access link direction. This is because the communication on the access link, that is, the communication between the relay station and the mobile terminal station, may be performed simultaneously by a plurality of relay stations and interfere with each other.

  In the multi-hop wireless communication system according to the third embodiment, the base station and the relay station share information (a measurement necessity determination table) regarding combinations that require interference measurement. Further, the multi-hop wireless communication system according to the third embodiment generates and uses a transmission instruction message including the type of the transmission relay station together with information on the antenna to be used by the transmission relay station, and further operates the transmission relay station. A report request message including the minimum necessary information among antenna information to be used for measurement is generated and used for each set of mode, antenna used by the transmission relay station, and operation mode of the reception relay station. The multi-hop wireless communication system according to the third embodiment uses the information related to the combination that requires interference measurement to limit the content of the report request message to the minimum necessary content, and therefore the interference is more than that of the second embodiment. The overhead of the measurement control MAC message can be reduced.

  The configuration of the multi-hop wireless communication system according to the third embodiment is the same as that of the first embodiment shown in FIG. The configurations of the base station 100 and the relay stations 200-1 to 200-n of the multi-hop wireless communication system according to the third embodiment are the same as those of the first embodiment shown in FIGS. Is the same.

  The interference measurement control unit 103 of the base station 100 and the interference measurement control unit 203 of the relay stations 200-1 to 200-n hold a measurement necessity determination table indicating combinations that require interference measurement. An example of the measurement necessity determination table is shown in FIG. The measurement necessity determination table is given in advance to the interference measurement control unit 103 of the base station 100 and the interference measurement control unit 203 of the relay stations 200-1 to 200-n.

  The interference measurement control MAC message used by the multi-hop wireless communication system according to the third embodiment is the same as that according to the second embodiment.

  Next, the operation of the multi-hop wireless communication system according to the third embodiment will be described in detail.

  The multi-hop wireless communication system according to the third embodiment when the wireless MAC processing unit 101 of the base station 100 requires interference measurement regarding the relay stations 200-1 to 200-n and requests interference measurement from the interference measurement control unit 103. The operation of the base station 100 is the same as that of the second embodiment except for the points described below.

  In step S112, the interference measurement control unit 103 of the base station 100 does not generate a report request message for each reception relay station, but generates a report request message common to all reception relay stations. The contents of the report request message include the antenna specification and sounding parameters received as parameters from the wireless MAC processing unit 101, the interference measurement schedule (reception relay station type and assigned radio resource) determined in step S111, and each transmission relay. Set according to station type. At that time, the interference measurement control unit 103 refers to the measurement necessity determination table when the type of the transmission relay station, the antenna used by the transmission relay station for transmission, and the type of the reception relay station are designated. Only for a combination in which a station cannot uniquely determine an antenna to be used for reception, information on the antenna to be used for reception corresponding to the combination is stored in the report request message.

  FIG. 26 shows an example of the report request message generated by the base station 100 according to the third embodiment in step S112. According to FIG. 22, there are three types of transmission relay station types and antenna combinations: (non-transparent type, relay link direction), (non-transparent type, access link method), and (transparent type, access link direction). However, referring to the measurement necessity determination table, for the (non-transmission type, relay link direction) set, if the reception relay station is non-transmission type, interference measurement is not necessary, and the reception relay station is transmission type. In this case, only measurement with an antenna in the access link direction is necessary. For this reason, the interference measurement control unit 103 does not include an entry for the set in the value of the TLV value Receive antenna assignments. Regarding the set of (non-transparent type, access link method), when the receiving relay station is a transparent type, there is a possibility of measuring in both the relay link direction and the access link direction. Include an entry for the set. When a non-transparent relay station transmits using an antenna in the access link direction, the non-transparent relay station is required to use an antenna in the access link direction, and the transparent relay station is required to use an antenna in the relay link direction (see FIG. 22 Measurement links 2-4). Therefore, the Antenna for non-transparent RS field and the Antenna for transparent RS field of the entry are set to 1 and 0, respectively. Similarly, an entry for the (transparent type, access link direction) pair is also included in the TLV value.

  Next, the operations of the relay stations 200-1 to 200-n in the multi-hop wireless communication system according to the third embodiment when the report request message transmitted from the base station 100 is received in step S113, except as described below. This is the same as the operation in the second embodiment described with reference to FIG. Here, it is assumed that the receiving relay station is the relay station 200-x.

  In step S123, the interference measurement control unit 203 of the relay station 200-x determines the antenna to be used for reception of the sounding signal based on the contents of the report request message received in step S121 and the transmission instruction message received in step S122. Make a decision. For each transmission instruction entry in the transmission instruction message, the interference measurement control unit 203 determines an antenna to be used for receiving a sounding signal transmitted based on the transmission instruction entry as follows. First, the interference measurement control unit 203 extracts the antenna used by the transmission relay station for transmitting the sounding signal and the type of the transmission relay station from the transmission instruction entry. These pieces of information are stored in the Antenna assignments field and Sender RS types, respectively. Next, the interference measurement control unit 203 refers to the Receive antenna assignments field of the report request message, and searches for an entry in which the Sender RS antenna assignment field and the Sender RS antenna assignment field match the information from the transmission instruction entry. When the local station is non-transparent, the interference measurement control unit 203 refers to the value of the Antenna for non-transparent RS field of the found entry and determines an antenna to be used for the sounding signal based on the transmission instruction entry. . When the local station is a transmissive type, the interference measurement control unit 203 refers to the value of the Antenna for transparent RS field of the found entry, and determines an antenna to be used for the sounding signal based on the transmission instruction entry. If no matching entry is found, the interference measurement control unit 203 refers to the measurement necessity determination table and determines an antenna to be used in the combination of the information from the transmission instruction entry and the type of the own station. At this time, when the combination of information from the transmission instruction entry and the type of the local station is not required to be measured, the interference measurement control unit 203 does not measure the signal quality of the sounding signal transmitted by the transmission instruction entry. Judge that it is. The interference measurement control unit 203 acquires the type of the own station from the wireless MAC processing unit 201.

  The operations of the relay stations 200-1 to 200-n in the multi-hop wireless communication system according to the third embodiment when receiving the sounding resource assignment message and the transmission instruction message transmitted from the base station 100 in step S114 are as shown in FIG. This is the same as the operation in the second embodiment described with reference.

  The operation of the base station 100 in the multi-hop wireless communication system according to the second embodiment when receiving the report response message transmitted from the relay stations 200-1 to 200-n in step S126 has been described with reference to FIG. The operation is the same as in the second embodiment.

  As described above, according to the multi-hop wireless communication system according to the third embodiment, in addition to the effects of the second embodiment, the overhead of the interference measurement control MAC message can be reduced as compared with the second embodiment. it can. This is because the size of the report request message can be reduced by limiting the content of the report request message to the minimum necessary information by using the information on the combination that requires interference measurement.

  In the multi-hop wireless communication system according to the third embodiment, the measurement necessity determination table is given in advance to the interference measurement control unit 103 of the base station 100 and the interference measurement control unit 203 of the relay stations 200-1 to 200-n. However, the present invention is not limited to this example. For example, the base station 100 may dynamically create a measurement necessity determination table and notify the relay stations 200-1 to 200-n with a MAC message.

  As mentioned above, although embodiment of this invention was described, this invention is not limited only to these embodiment, In the range of the technical idea of this invention, these embodiment is combined and used. Some of the configurations may be changed.

This application claims the benefit of priority based on Japanese Patent Application No. 2009-176466 filed on Jul. 29, 2009, the entire disclosure of which is incorporated herein by reference.

Claims (22)

A multi-hop wireless communication system in which a relay station relays data between a base station and a mobile terminal station,
A transmission relay station that is a relay station that transmits a measurement signal for measuring signal quality between relay stations;
A reception relay station that is a relay station that receives the measurement signal from the transmission relay station and measures the signal quality;
A transmission instruction message including information for designating a transmission antenna, which is an antenna that the transmission relay station should use for transmitting the measurement signal, to the transmission relay station or to the transmission relay station and the reception relay station A control device for transmitting and transmitting to the reception relay station a reception instruction message including information for designating a reception antenna which is an antenna to be used by the reception relay station to receive the measurement signal;
A multi-hop wireless communication system. The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information designating a reception antenna for each reception relay station for each set of transmission relay station type and transmission antenna,
The reception relay station receives the type of the transmission relay station and the transmission antenna of the transmission relay station included in the transmission instruction message or the reception instruction message from the control apparatus, and reception from the control apparatus to the own station. Based on information included in the instruction message, a receiving antenna to be used for receiving a measurement signal transmitted from the transmission relay station is determined.
The multi-hop wireless communication system according to claim 1. The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information specifying a reception antenna for each type of the reception relay station for each set of transmission relay station type and transmission antenna,
The reception relay station includes a type of the transmission relay station, a transmission antenna of the transmission relay station, a type of the local station, and the control device included in the transmission instruction message or the reception instruction message from the control device. A receiving antenna used for receiving a measurement signal transmitted from the transmission relay station is determined based on information included in the reception instruction message from
The multi-hop wireless communication system according to claim 1. The reception relay station holds a measurement necessity determination table indicating a set of a transmission relay station type, a transmission antenna, a reception relay station type, and a reception antenna for which signal quality measurement is required, and the transmission relay station For measurement from the transmission relay station based on the type of station, the transmission antenna of the transmission relay station, the type of the local station, and the information included in the measurement necessity determination table or the reception instruction message Determine the receiving antenna used to receive the signal,
Based on the type of the transmission relay station and the transmission antenna of the transmission relay station, the type of the local station, and the measurement necessity determination table, a reception antenna used for receiving a measurement signal from the transmission relay station is When it is not possible to specify, the control device includes, in the reception instruction message, the information specifying the reception antenna for each type of the reception relay station for each set of the transmission relay station type and the transmission antenna.
The multi-hop wireless communication system according to claim 3. The type of the relay station is a distinction between a non-transmission type and a transmission type,
The multi-hop wireless communication system according to any one of claims 2 to 4.   The multi-hop wireless communication system according to claim 1, wherein the control device is the base station. A control device that controls measurement of signal quality between relay stations in a multi-hop wireless communication system in which a relay station relays data between a base station and a mobile terminal station,
A transmission instruction message including designation of a transmission antenna that is an antenna to be used by a transmission relay station to transmit a measurement signal for measuring signal quality between relay stations, and the measurement signal Control means for generating a reception instruction message including designation of a reception antenna that is an antenna to be used by the reception relay station to receive the measurement signal;
Communication means for transmitting the transmission instruction message generated by the control means to the transmission relay station, and transmitting the reception instruction message generated by the control means to the reception relay station;
Control device. The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information designating a reception antenna for each reception relay station for each set of transmission relay station type and transmission antenna,
In the reception relay station, the type of the transmission relay station and the transmission antenna of the transmission relay station included in the transmission instruction message or the reception instruction message from the control apparatus, and reception from the control apparatus to the own station Based on the information included in the instruction message, a receiving antenna used for receiving the measurement signal transmitted from the transmission relay station is determined.
The control device according to claim 7. The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information specifying a reception antenna for each type of the reception relay station for each set of transmission relay station type and transmission antenna,
In the reception relay station, the type of the transmission relay station, the transmission antenna of the transmission relay station included in the transmission instruction message or the reception instruction message from the control apparatus, the type of the own station, and the control apparatus Based on the information included in the reception instruction message from, the receiving antenna used for receiving the measurement signal transmitted from the transmission relay station is determined.
The control device according to claim 7. The reception relay station holds a measurement necessity determination table indicating a set of a transmission relay station type, a transmission antenna, a reception relay station type, and a reception antenna for which signal quality measurement is required, and the transmission relay station For measurement from the transmission relay station based on the type of station, the transmission antenna of the transmission relay station, the type of the local station, and the information included in the measurement necessity determination table or the reception instruction message The receiving antenna used to receive the signal is determined,
Based on the type of the transmission relay station and the transmission antenna of the transmission relay station, the type of the local station, and the measurement necessity determination table, a reception antenna used for receiving a measurement signal from the transmission relay station is When it is not possible to specify, the control means includes, in the reception instruction message, the information specifying the reception antenna for each type of the reception relay station for each combination of the transmission relay station type and the transmission antenna.
The control device according to claim 9. The type of the relay station is a distinction between a non-transmission type and a transmission type,
The control device according to any one of claims 8 to 10.   The control device according to claim 7, wherein the control device is the base station. A relay station that relays multi-hop communication data between a base station and a mobile terminal station,
A receiving antenna which is an antenna to be used for receiving a measurement signal transmitted from a transmission relay station for measuring signal quality between relay stations from a control device that controls measurement of signal quality between relay stations. In addition to the reception instruction message including information for specifying, or in addition to the reception instruction message, further includes information for specifying a transmission antenna that is an antenna to be used by the transmission relay station to transmit the measurement signal A communication means for receiving a transmission instruction message;
Control means for determining a receiving antenna used for receiving a measurement signal transmitted from the transmission relay station based on a message received by the communication means;
The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information designating a reception antenna for each reception relay station for each set of transmission relay station type and transmission antenna,
The control means includes a type of the transmission relay station and a transmission antenna of the transmission relay station included in the transmission instruction message or the reception instruction message from the control apparatus, and a reception instruction from the control apparatus to the own station. Based on the information included in the message, a receiving antenna used for receiving the measurement signal transmitted from the transmission relay station is determined.
Relay station. A relay station that relays multi-hop communication data between a base station and a mobile terminal station,
A receiving antenna which is an antenna to be used for receiving a measurement signal transmitted from a transmission relay station for measuring signal quality between relay stations from a control device that controls measurement of signal quality between relay stations. In addition to the reception instruction message including information for specifying, or in addition to the reception instruction message, further includes information for specifying a transmission antenna that is an antenna to be used by the transmission relay station to transmit the measurement signal A communication means for receiving a transmission instruction message;
Control means for determining a receiving antenna used for receiving a measurement signal transmitted from the transmission relay station based on a message received by the communication means;
The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information specifying a reception antenna for each type of the reception relay station for each set of transmission relay station type and transmission antenna,
The control means includes the type of the transmission relay station, the transmission antenna of the transmission relay station, the type of the local station, and the type of the local station included in the transmission instruction message or the reception instruction message from the control apparatus. Based on the information included in the reception instruction message, the receiving antenna used for receiving the measurement signal transmitted from the transmission relay station is determined.
Relay station. The control means holds a measurement necessity determination table indicating a set of a transmission relay station type, a transmission antenna, a reception relay station type, and a reception antenna for which measurement of signal quality is required, and the transmission relay station And the transmission antenna of the transmission relay station, the type of the local station, and the measurement signal from the transmission relay station based on the information included in the measurement necessity determination table or the reception instruction message To determine the receiving antenna used to receive
The relay station according to claim 14. The type of the relay station is a distinction between a non-transmission type and a transmission type,
The relay station according to any one of claims 13 to 15.   The relay station according to claim 13, wherein the control device is the base station. A control method for controlling measurement of signal quality between relay stations in a multi-hop wireless communication system in which a relay station relays data between a base station and a mobile terminal station,
A transmission relay station that transmits a measurement signal for measuring signal quality between relay stations generates a transmission instruction message including a designation of a transmission antenna that is an antenna to be used for transmission of the measurement signal;
A reception relay station that receives the measurement signal generates a reception instruction message including a designation of a reception antenna that is an antenna to be used for receiving the measurement signal;
Transmitting the reception instruction message to the reception relay station;
Transmitting the transmission instruction message to the transmission relay station;
Control method. The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information designating a reception antenna for each reception relay station for each set of transmission relay station type and transmission antenna,
The reception relay station includes the transmission instruction message or the type of the transmission relay station included in the reception instruction message, the transmission antenna of the transmission relay station, and the reception instruction message to the reception relay station. Based on the information, a receiving antenna used for receiving the measurement signal transmitted from the transmission relay station is determined.
The control method according to claim 18. The transmission instruction message or the reception instruction message includes the type of the transmission relay station,
The reception instruction message includes information specifying a reception antenna for each type of the reception relay station for each set of transmission relay station type and transmission antenna,
In the reception relay station, the type of the transmission relay station included in the transmission instruction message or the reception instruction message, the transmission antenna of the transmission relay station, the type of the own station, and the reception instruction message A receiving antenna to be used for receiving the measurement signal transmitted from the transmission relay station is determined based on the received information;
The control method according to claim 18. The reception relay station holds a measurement necessity determination table indicating a set of a transmission relay station type, a transmission antenna, a reception relay station type, and a reception antenna for which signal quality measurement is required, and the transmission relay station For measurement from the transmission relay station based on the type of station, the transmission antenna of the transmission relay station, the type of the local station, and the information included in the measurement necessity determination table or the reception instruction message The receiving antenna used to receive the signal is determined,
Based on the type of the transmission relay station and the transmission antenna of the transmission relay station, the type of the local station, and the measurement necessity determination table, a reception antenna used for receiving a measurement signal from the transmission relay station is If not specified, the reception instruction message includes the information specifying the receiving antenna for each type of the receiving relay station for each set of the transmitting relay station type and the transmitting antenna.
The control method according to claim 20. The type of the relay station is a distinction between a non-transmission type and a transmission type,
The control method according to any one of claims 18 to 21.

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