JP6905580B2 - Wireless communication device - Google Patents

Description

Embodiments of the present invention relate to wireless communication devices.

In cellular systems, a Fractional Frequency Reuse (FFR) mechanism that reduces interference with adjacent base stations by partially repeating frequencies has begun to be introduced. In FFR, for example, the coverage area of a base station is divided into an area close to the base station and an area far from the base station, and different frequency channels are assigned to the near area and the distant area. The same frequency channel is used between adjacent base stations in an area close to the base station, and a different frequency channel is used between adjacent base stations in an area far from the base station. As a result, the throughput of the user is improved while suppressing the decrease in the frequency utilization efficiency.

Regarding the next-generation wireless LAN standard, IEEE802.11ax, AP cooperation technology is being studied as one of the access point differentiation technologies. Since IEEE802.11ax introduces an Orthogonal Frequency Division Multiple Access (OFDMA), there is a possibility of effective frequency utilization by applying FFR to a wireless LAN as one of the AP cooperation technologies. However, there has been no concrete proposal to apply FFR to wireless LAN.

Patent No. 5785329

IEEE Std 802.11ac (TM) -2013 IEEE Std. 802.11 (TM) -2012

An object of the present invention is to perform multiplex communication with a plurality of terminals by wireless communication devices having adjacent communication areas using the same frequency band with high frequency utilization efficiency.

The wireless communication device according to the embodiment of the present invention includes a terminal identifier of the first terminal designated as a target of frequency division multiplexing by another wireless communication device, and a first frequency assigned to the first terminal among a plurality of frequency components. Among the receiving unit that receives the information for specifying the component and the plurality of second terminals belonging to the own device, the second terminal having the same terminal identifier as the first terminal is selected, and the second terminal selected is the second terminal. A control unit that allocates one frequency component and a header in which the terminal identifier of the selected second terminal is set in the first field related to the first frequency component are transmitted in a band including the plurality of frequency components and selected. It includes a transmission unit that transmits the first frame addressed to the second terminal with the first frequency component.

The figure which shows the structure of the wireless communication system which concerns on 1st Embodiment. The figure which shows a plurality of RUs (resource units) secured in the continuous frequency domain of one channel. The figure which shows the allocation pattern of RU in the frequency bandwidth. The figure which shows the basic format example of a MAC frame. The figure explaining an example in which adjacent APs (access points) 1 and 2 each perform DL-OFDA transmission. The figure which shows the configuration example of the physical packet used in DL-OFDA. The figure which shows the example of the format of the field used to specify RU for each terminal. The figure which shows the situation that decoding fails due to a signal collision. The figure which shows the example of the terminal identifier assigned to each terminal. The figure explaining the example which sets the same value in a field by cooperation between adjacent APs. The figure which shows the example of the physical packet which AP1 and AP2 transmit by DL-OFDA. The figure which shows the operation sequence of the wireless LAN system which concerns on 1st Embodiment. The block diagram of AP which concerns on 1st Embodiment. Another block diagram of the AP according to the first embodiment. The block diagram of the terminal which concerns on 1st Embodiment. The flowchart of the operation of AP which concerns on 1st Embodiment. The flowchart of other operation of AP which concerns on 1st Embodiment. The figure which shows the format example of the trigger frame (TF). The figure which shows the setting example of Virtual AP. The figure which shows the operation sequence of the wireless LAN system in 2nd Embodiment. The figure which shows the example of the physical packet which UL-OFDA is transmitted. The figure which shows the example of transmitting TF using channel-based DL-OFDMA. The figure which shows the example of the allocation pattern of RU with respect to a frequency domain. The figure which shows the setting example of the field at the time of performing DL-MU-MIMO in a specific RU. The figure which shows the operation sequence of the wireless LAN system which concerns on 3rd Embodiment. The figure which shows the example of the physical packet which DL-OFDA & MU-MIMO is transmitted. Functional block diagram of an access point or terminal. The figure which shows the example of the whole configuration of a terminal or an access point. The figure which shows the hardware configuration example of the wireless communication device mounted on a terminal or an access point. Functional block diagram of a terminal or access point. The perspective view of the terminal which concerns on embodiment of this invention. The figure which shows the memory card which concerns on embodiment of this invention. The figure which shows an example of frame exchange of a contention period.

^{Specification framework document for IEEE Std 802.11 TM-} 2012 and IEEE Std 802.11ac ^TM- 2013, which are known as wireless LAN standards, and IEEE Std 802.11ax, the next-generation wireless LAN standard. ), IEEE 802.11-15 / 0132r17, all of which are incorporated herein by reference.

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

(First Embodiment)
FIG. 1 shows the configuration of the wireless communication system according to the first embodiment. This wireless communication system conforms to the IEEE802.11 standard, but a system conforming to other communication methods is also possible. AP1 and AP2 are arranged as a plurality of access points (APs). Three or more APs may be arranged.

Terminal 11, terminal 12, terminal 13, terminal 14, terminal 15, and terminal 16 belong to the wireless communication group (BSS: Basic Service Set) 1 formed by AP1 as a plurality of terminals (STA: Station). That is, the terminals 11 to 16 perform an association process with the AP1 and complete the exchange of parameters necessary for communication to establish a wireless link with the AP1. The state in which the terminal establishes a wireless link with AP1 may be expressed as the terminal being connected to AP1. The AP1 and the terminals 11 to 16 are each equipped with a wireless communication device. The wireless communication device mounted on the AP1 communicates with the wireless communication mounted on the terminals 11 to 16 in accordance with the IEEE802.11ax standard. Terminals other than terminals 11 to 16 may exist in BSS1. The terminal may be a terminal compliant with the IEEE802.11ax standard, or a legacy terminal (a terminal compliant with IEEE802.11b / a / g / n / ac).

Similarly, the terminal 21, the terminal 22, the terminal 23, the terminal 27, the terminal 28, and the terminal 29 belong to the wireless communication group (BSS: Basic Service Set) 2 formed by the AP2. That is, terminals 21 to 23 and terminals 27 to 29 establish a wireless link with AP2 by performing an association process with AP2. The AP2, the terminals 21 to 23, and the terminals 27 to 29 are each equipped with a wireless communication device. The wireless communication device mounted on the AP2 communicates with the wireless communication mounted on the terminals 21 to 23 and 27 to 29 in accordance with the IEEE802.11 standard. Terminals other than terminals 21-23 and 27-29 may exist in BSS2. The terminal may be a terminal compliant with the IEEE802.11ax standard, or a legacy terminal (a terminal compliant with IEEE802.11b / a / g / n / ac).

AP1 and AP2 are connected via a wireless network or a wired network. AP1 and AP2 may communicate with each other by a method according to the IEEE802.11 standard or other standards. AP1 and AP2 may be directly connected by a cable to perform wired communication. In the example of FIG. 1, AP1 and AP2 are connected by a wired network.

Among the communication areas E1 of AP1, terminals 11 to 13 belong to the area (neighborhood area) A1 close to AP1. Of the communication areas E1, terminals 14 to 16 belong to the area (far area) A2 far from AP1.

Similarly, in the communication area E2 of the AP2, the terminals 21 to 23 belong to the area (proximity area) B1 close to the AP2. Of the communication areas E2, terminals 27 to 29 belong to the area (far area) B2 far from AP2.

The neighborhood area A1 is an area where the signal from the adjacent AP (here, AP2) does not reach or the signal strength from the AP2 is low. That is, the neighborhood area A1 is an area in which the signal from AP2 does not interfere with the signal of AP1 or has little interference. In the distant area A2 of AP1, there is a part (called an overlapping area) that overlaps with the communication area of the adjacent AP2, where the reception strength of the signal from AP2 is high and it interferes with the signal from AP1. , There is a possibility that the signal from AP1 cannot be decoded correctly. In the distant area A2, other than the overlapping area, there is no interference with the AP2 or there is little interference as in the neighboring area. The neighborhood area B1 and the distant area B2 of the AP2 also have the same conditions as the neighborhood area A1 and the distant area A2 with respect to the interference with the adjacent AP, only the adjacent AP is changed to the AP1.

In the example of the figure, terminals 11 to 13 are present in the vicinity area A1 of AP1, and terminals 14 to 16 are present in the distant area A2. Terminals 21 to 23 are present in the vicinity area B1 of AP2, and terminals 27 to 29 are present in the distant area B2. Among the terminals belonging to AP2, the terminal 27 and the terminal 28 exist in the overlapping area.

Since the AP has basically the same function as the terminal (STA) except that it has a relay function, the AP is also a form of the terminal. In the example of FIG. 1, AP2 is not included in the communication area E1 of AP1 and AP1 is not included in the communication area E2 of AP2, but the communication between AP1 and AP2 is a radio of the same standard as the terminal. In the case of communication, communication between AP1 and AP2 may be performed by making the transmission power higher than that of the terminal.

AP1 is capable of OFDMA (Orthogonal Frequency Division Access) communication, which is frequency multiplex communication, with one or a plurality of terminals selected from a plurality of terminals 11 to 16. In OFDMA, a resource unit (RU) including one or a plurality of subcarriers is allocated to a terminal as a communication resource, and a plurality of terminals are simultaneously communicated with different RUs. Such OFDMA is particularly referred to as RU-based OFDMA. The RU may be referred to as a sub, a resource block, a frequency block, or the like. Uplink OFDMA is referred to as UL-OFDMA, and downlink OFDMA is referred to as DL-OFDM. In this embodiment, at least AP1 is capable of performing DL-OFDM.

Similarly, AP2 is capable of OFDMA (Orthogonal Frequency Division Access) communication with one or more terminals selected from a plurality of terminals 21 to 23 and 27 to 29. In this embodiment, AP2 is capable of performing at least DL-OFDMA of UL-OFDMA and DL-OFDM.

FIG. 2 shows resource units (RU # 1, RU # 2, ... RU # K) secured in a continuous frequency domain of one channel (described here as channel M). A plurality of subcarriers orthogonal to each other are arranged in the channel M, and a plurality of resource units including one or a plurality of continuous subcarriers are defined in the channel M. One or more subcarriers (guard subcarriers) may be arranged between resource units, but guard subcarriers are not essential. The bandwidth of one channel is, for example, 20 MHz, 40 MHz, 80 MHz, 160 MHz, and the like, but is not limited thereto. A plurality of 20 MHz channels may be combined into one channel. OFDMA communication is realized when a plurality of terminals use different resource units at the same time.

The number of subcarriers (number of tones) included in one resource unit may differ for each resource unit. For example, it is assumed that the variation of the number of subcarriers (number of tones) of one RU is 26, 52, 106, 242 subcarriers.

FIG. 3 shows a RU allocation pattern in a certain frequency bandwidth BW (here, 20 MHz width). For example, there are 26 patterns. It is assumed that the number of subcarriers included in the RU arranged at the center of the frequency bandwidth is fixed at 26. The numbers on the left side of each pattern in the figure indicate the allocation pattern number. The numbers in the squares in the figure indicate the number of subcarriers.

FIG. 4A shows an example of a basic format of a MAC frame. The MAC frame according to the present embodiment is based on such a frame format. This frame format includes MAC header, Frame body, and FCS fields. As shown in FIG. 4 (B), the MAC header includes fields of Frame Control, Duration / ID, Addless1, Addless2, Addless3, Quality Control, QoS Control, and HT (High Throughput) control.

Not all of these fields need to be present, and some fields may not be present depending on the type of frame. For example, the Addless3 field may not exist. Also, the QoS Control and / or HT Control fields may not be present. It is also possible that the frame body field does not exist. On the other hand, there may be other fields not shown in FIG. 4 (B). For example, there may be more Addless4 fields.

The destination address (Receiver Addless; RA) is entered in the Addless1 field, the source address (Transmitter Addless; TA) is entered in the Addless2 field, and the BSSID (BSSID), which is a BSS identifier, is entered in the Addless3 field according to the purpose of the frame. Basic Service Set Identifier) (In some cases, a wildcard BSSID that targets all BSSIDs by putting 1 in all bits) or TA is entered.

The Frame Control field includes two fields such as a type (Type) and a subtype (Subtype). There are a data frame, a management frame, and a control frame as the frame type of the MAC frame, and these are roughly classified in the Type field, and the fine type identification in the roughly classified frame is performed in the Subtype field. Trigger frames, which will be described later, may also be distinguished by a combination of type and subtype.

The Duration / ID field describes the media reservation time, and when a MAC frame addressed to another terminal is received, the medium is virtually busy from the end of the physical packet containing the MAC frame to the media reservation time. Is determined. Such a mechanism for virtually determining that the medium is busy, or a period during which the medium is virtually busy is called a NAV (Network Allocation Vector), as described above. The sequence number of the frame and the like are stored in the Sequence control field. The QoS field is used to perform QoS control for transmitting in consideration of the priority of the frame. The HT Control field is a field introduced in IEEE802.11n.

In the management frame, the information element (Information element; IE) to which a unique Identifier (Identifier) is assigned is framed.
Can be set in the Body field. One or more information elements can be set in the frame body field.

FCS (Frame Check Sequence) information is set in the FCS field as a checksum code used for frame error detection on the receiving side. As an example of FCS information, there is CRC (Cyclic Redundancy Code) and the like.

The technical problem to be solved by this embodiment will be described with reference to FIG. FIG. 5 shows an example in which AP1 performs DL-OFDMA communication with terminals 11 to 16 and AP2 performs DL-OFDMA communication with terminals 21 to 23 and 27 to 29. It is assumed that both AP1 and AP2 use channel 1 (Ch1) as the same frequency band. AP1 allocates resource units (RU) 1 to RU 6 to terminals 11 to 16. AP2 assigns RU1 to RU3 and RU7 to RU9 to terminals 21 to 23 and 27 to 29. The bandwidth of the channel can be various such as 20 MHz, 40 MHz, 80 MHz, 160 MHz, but here, 20 MHz is assumed. It is assumed that channel 1 includes RUs 1 to 9.

An operation example of DL-OFDMA transmission from AP1 to terminals 11 to 16 will be described. FIG. 6 shows a configuration example of a physical packet used in DL-OFDMA. It is assumed that AP1 transmits MAC frames (each of which is referred to as MAC frames 11 to 16) to terminals 11 to 16 by DL-OFDMA. AP1 transmits a physical packet including a legacy field, a SIG1 field, and a MAC frame transmitted by a RU for each terminal 11-16.
That is, a common SIG1 field is added to the MAC frames 11 to 16 addressed to the terminals 11 to 16. Then, a physical packet is configured by adding a legacy field defined in the IEEE802.11 standard to the beginning of the SIG1 field. Therefore, in the physical packets of terminals 11 to 16, the legacy field and the SIG1 field are common to terminals 11 to 16, and the MAC frame is set individually for each terminal. In addition, another field (for example, SIG2 field, STF (Short Training Field), LTF (Long Training Field), etc.) may be provided between the SIG1 field and each MAC frame for each RU.

Legacy fields include L-STF (Legacy-Short Training Field), L-LTF (Legacy-Long Training Field), and L-SIG (Legacy Signal Field). L-STF, L-LTF, and L-SIG are fields that can be recognized by terminals of legacy standards such as IEEE802.11a, and information such as signal detection, frequency correction (propagation path estimation), and transmission speed can be obtained, respectively. Stored.

Control information to be notified to terminals 11 to 16 is set in the SIG1 field. As an example of control information, information for designating RUs (here, RU1 to RU6) to be used for each terminal 11 to 16 is set. Specifically, the terminal identifier of the terminal (sometimes referred to as STAID) and the RU to be used are set in association with each other. The terminal identifier (STAID) may be an association ID (AID) assigned from AP1 in the association process, a part of the AID (Partial AID), or another identifier such as a MAC address. Further, in the SIG1 field, information necessary for decoding the MAC frame, for example, MCS (Modulation And Coding Scene) and other information may be set for each RU designated in the terminals 11 to 16. The SIG1 field includes, for example, the PHY HE-SIG-A field and the HE-SIG-B field examined in IEEE802.11ax.

FIG. 7 shows an example of the format of the field used to specify the RU for each terminal in the SIG1 field. The illustrated fields include a RU allocation Sub-field and a User specific field as defined within the PHY HE-SIG-B field considered in IEEE802.11ax. A value indicating the RU allocation pattern is set in the RU allocation field. For example, "00000000000" means an allocation pattern (9 multiple allocations) of 9 RUs in which one RU consists of 26 subcarriers. The nine RUs are assigned numbers (# 1 to # 9) according to predetermined rules. These RUs are represented as RU # 1 to RU # 9. User-specific fields include Userfield # 1 to Userfield # 9. The number of Userfields is variable, and here, it corresponds to the case where the value of the RU allocation field is "00000000000" (9 multiple allocations). RU # 1 to RU # 9 are associated with User field # 1 to User field # 9, respectively, and information (terminal allocation information) relating to a terminal to which RU # 1 to RU # 9 is assigned is set for each. For example, a terminal identifier (STAID) is set. In addition to STAID, information such as MCS may be set.
For example, when STA1 and MCS3 are set in Userfield # 1, RU # 1 is assigned to the terminal having STA1, and the MAC frame transmitted by RU # 1 is decoded by the MCS identified by MCS3. Means. In the following description, it is assumed that the SIG1 field includes the field of FIG. 7. However, the format for designating the RU to be assigned to each terminal is not limited to FIG. 7, and other formats may be used.

When another field (for example, SIG2 field) is provided for each RU between the SIG1 field and each MAC frame, the MCS required for decoding the MAC frame is set in the SIG2 field instead of the SIG1 field. Configuration is also possible.

The AP1 transmits the legacy field and the SIG1 field in the channel width band (20 MHz), and transmits a MAC frame addressed to the terminal to which the RU is assigned for each RU specified in the SIG1 field.

The terminals 11 to 16 that have received the signal from the AP1 identify the RU to be decoded by the own terminal by decoding the SIG1 field after processing the legacy field. For example, each terminal confirms the value of the RU allocation Sub-field (RU allocation field) in FIG. 7 and specifies the RU allocation pattern. Here, it is recognized that the value of the RU allocation field is the above "00000000" (9 multiple allocations). Each terminal checks whether there is a User field in which the STAID of the own terminal is set among the plurality of User fields # 1 to User field # 9. When a User field in which the STAID of the own terminal is set is detected, it is recognized that the own terminal has been assigned the RU signal associated with the User field number. For example, when the terminal 13 detects that the STAID of the own terminal is set in Userfield # 3, it recognizes that RU # 3 has been assigned to the own terminal. In addition, information other than STAID (MCS, etc.) is detected from the Userfield in which the STAID of the own terminal is detected. Each terminal decodes the RU signal assigned to the own terminal by the detected MCS, decodes the subsequent payload, and receives the MAC frame addressed to the own terminal. In this example, in this way, the terminals 11 to 16 receive the MAC frames 11 to 16 addressed to their own terminals at the assigned RUs # 1 to RU # 6, respectively. The terminals 11 to 16 perform an inspection (CRC inspection, etc.) based on the FCS of the MAC frame, and if the inspection result is successful, a delivery acknowledgment frame (for example, an ACK frame, a BA (Block Ac) frame, etc.) is required. ) Is transmitted to AP1. The transmission of the ACK frame is performed by acquiring the access right to the wireless medium by using the carrier sense, for example, based on CSMA / CA.

Similarly, AP2 transmits a MAC frame (hereinafter referred to as MAC frames 21 to 23 and 27 to 29) to terminals 21 to 23 and 27 to 29 by DL-OFDMA. Specifically, a physical packet including a legacy field, a SIG1 field, and a plurality of MAC fields addressed to terminals 21 to 23 and 27 to 29 is transmitted. In the SIG1 field, information for designating RUs (here, RU1 to RU3 and RU7 to RU9, respectively) to be assigned to terminals 21 to 23 and 27 to 29 is set by using the format of FIG. 7. The terminals 21 to 23 and 27 to 29 that have received the signal transmitted downlink from the AP2 identify the RU assigned to the own terminal from the SIG frame 1 in the same manner as the terminals 11 to 16. Then, the payload transmitted by the RU is decoded, and MAC frames 21 to 23 and 27 to 29 addressed to the own terminal are received.

Here, since AP1 and AP2 use the same channel (Ch1), for example, terminals 27 and 28 in the overlapping area transmit DL-OFMDA when AP1 is transmitting DL-OFDMA. In some cases, or when AP1 and AP2 transmit DL-OFDMA at the same time, both signals may be received and decoding of the received signal may fail due to signal collision. This situation is shown in FIG. In this example, an operation example focusing on the terminal 16 and the terminal 28 is shown. "TX" means transmission and "RX" means reception.

The AP1 transmits a physical packet by DL-OFDMA (S1), and the terminal 16 receives the physical packet. The terminal 16 succeeds in receiving the MAC frame addressed to the own terminal and transmits the ACK frame (S2). The signal transmitted by AP1 is also received by the terminal 28 in the overlapping area. While receiving the signal from AP1, the terminal 28 also receives the signal of the physical packet transmitted by DL-OFDMA from AP2 (S3), and fails to decode the physical packet (decoding of the header, etc.) as a reception error. Although the terminal 28 has been focused on here, the same thing occurs in the terminal 27. Since the signals from the AP1 do not reach the terminals 21 to 23 and 29, the terminals 21 to 23 and 29 succeed in receiving the physical packet transmitted from the AP2. Further, since the terminals 11 to 15 belonging to BSS1 do not receive the signal from AP2, they also succeed in receiving the physical packet transmitted from AP1. In this way, when AP1 and AP2 adjacent to each other use the same channel, the terminal that does not receive the signal from the adjacent AP succeeds in receiving the physical packet transmitted by DL-OFDMA from the AP of its own BSS, but is adjacent. At the terminal to which the signal from the AP arrives, there is a possibility that the reception of the physical packet transmitted by DL-OFDMA from the AP of the own BSS may fail due to the signal collision. This leads to a decrease in frequency utilization efficiency.

In the present embodiment, the AP1 and the AP2 cooperate with each other by communicating with each other to improve the frequency utilization efficiency. Specifically, AP1 and AP2 select a terminal having the same STAID as a terminal to which the same RU is assigned, and set the terminal allocation information of the selected terminal in the User field corresponding to the RU. Further, for each of AP1 and AP2, for a RU that is not used by the other AP (AP2 for AP1 and AP1 for AP2), a terminal having an arbitrary STAID is selected, and the terminal allocation information of the selected terminal is used. Set to Userfield corresponding to RU. For the RU used by the other party's AP, terminal allocation information is acquired from the other party's AP, and the acquired terminal allocation information is set in the Userfield corresponding to the RU. Based on such settings, the values of the RU Allocation Sub-field and User specific field generated by AP1 and AP2 are the same. AP1 and AP2 each generate a SIG1 field containing a RU Allocation Sub-field and a User specific field, respectively. It should be noted that the values of the other fields in the SIG1 field are predetermined or coordinated in advance so that they are the same for AP1 and AP2. Then, each of AP1 and AP2 transmits the legacy field and the SIG1 field in the channel width band, and transmits the MAC frame by the RU assigned to the terminal by the own AP. Each AP does not transmit a frame in the RU to which the own AP has not assigned a terminal. Transmission from AP1 and AP2 is performed at the same time. A terminal that receives signals from both AP1 and AP2 (for example, terminals existing in overlapping areas such as terminals 28 and 27) receives signals from AP1 and AP2 at the same time. Even if these terminals receive signals transmitted from AP1 and AP2 at the same time, the legacy field and the SIG1 field can be decoded because the values common to AP1 and AP2 are set. Therefore, the RU assigned to the own terminal can be specified from the decoding result of the SIG1 field, and the MAC frame transmitted by the specified RU can be received. As a result, DL-OFDMA transmission can be successful even for terminals in overlapping areas, and frequency utilization efficiency can be improved.

Hereinafter, a specific example of this method will be shown. As shown in FIG. 9A, it is assumed that AP1 assigns ID1 to ID6 as STAIDs to STA11 to STA16. Further, as shown in FIG. 9B, it is assumed that AP2 assigns ID1 to ID3 and ID7 to ID9 as STAIDs to STA21 to STA23 and STA27 to S29. The STAIDs of STA11 to STA13 are the same as the STAIDs of STA21 to STA23. In this case, as shown in FIG. 5 described above, AP1 and AP2 allocate RU to the terminals in the own station, and DL-OFDA transmission is performed to STA11 to STA16, STA21 to STA23, and STA27 to S29, respectively. think of.

FIG. 10A shows a setting example of Userfield # 1 to Userfield # 9 in AP1. FIG. 10B shows a setting example of Userfield # 1 to Userfield # 9 in AP2.

In both AP1 and AP2, it is assumed that the same RU (here, RU # 1 to RU # 3) is used in the respective neighboring areas. AP1 and AP2 each set the same STAID for the User Field associated with these RUs. AP1 sets ID1 to ID3 (that is, STAID of terminals 11 to 13) in Userfield # 1 to Userfield # 3. Further, AP2 sets ID1 to ID3 (that is, STAID of terminals 21 to 23) in Userfield # 1 to Userfield # 3.

On the other hand, in both AP1 and AP2, for RUs (here, RUs # 4 to RU9) used in their respective distant areas, terminals are assigned to RUs not used by the other AP. In this example, AP1 sets ID4 to ID6 (that is, STAIDs of terminals 14 to 16) in Userfield # 4 to Userfield # 6. Further, AP2 cannot be used because RU # 4 to RU # 6 are used by AP1, but it is determined that AP1 does not use RU # 7 to RU # 9, and ID7 is assigned to Userfield # 7 to Userfield # 9. ~ ID 9 (that is, STAID of terminals 27 to 29) is set.

Further, in both AP1 and AP2, for the RU used only by the other AP, the terminal allocation information set in the RU (here, only STAID is assumed for the sake of simplicity) is acquired from the other AP and acquired. The terminal allocation information is set in the Userfield corresponding to the RU. In this example, AP1 sets ID7 to ID9 (that is, STAIDs of terminals 27 to 29) acquired from AP2 in Userfield # 7 to Userfield # 9. Further, AP2 sets ID4 to ID6 (that is, STAIDs of terminals 14 to 16) acquired from AP1 in Userfield # 4 to Userfield # 6. As a result, the RU Allocation Sub-field and User specific field produced by AP1 and AP2 become the same. Further, the same value is set for both AP1 and AP2 in the RU allocation Sub-field.

Here, only STAID is set as the terminal allocation information in Userfield, but other information such as MCS may be set. In this case as well, AP1 and AP2 cooperate with each other so that the same value is set for both AP1 and AP2 in all of Userfield # 1 to Userfield # 9.

Each of AP1 and AP2 transmits the same legacy field and the same SIG1 field in the channel width band, and subsequently, the RU specified by the own AP as the terminal belonging to the own station in the SIG1 field is addressed to the terminal. Send the MAC frame of.

An example of a physical packet transmitted by AP1 is shown in FIG. 11 (A). The horizontal axis is time and the vertical axis is frequency. Here, the frequencies are higher in the order of RU # 1 to RU # 9, but the frequency is not limited to this. The legacy field and the SIG1 field are transmitted in the channel width band (20 MHz), and the MAC frame is transmitted in the corresponding RU. If another field described above exists between the SIG1 field and the MAC frame, the field is also transmitted in the same RU as the MAC frame. MAC frames are not transmitted in RUs (RU # 7 to RU # 9) to which terminals are not assigned. “STA11” to “STA16” in the figure mean that they are MAC frames addressed to terminals 11 to 16. FIG. 11B shows an example of a physical packet transmitted by AP2. In AP2, since RU # 4 to RU # 6 are not assigned to terminals, MAC frames are not transmitted in these RUs.

A terminal in the overlapping area (assuming terminal 28, for example) receives signals from both AP1 and AP2 at the same time. The legacy field and SIG1 field transmitted from AP1 are the same signals as the legacy field and SIG1 field transmitted from AP2. Therefore, in the terminal 28, the legacy field and the SIG1 field can be normally decoded, and the RU allocation Sub-field and the User specific field can be detected (see FIG. 10B). The terminal 28 detects the STAID (= ID8) of its own terminal from Userfield # 8. Therefore, the signal transmitted by RU # 8 can be decoded and the MAC field addressed to the own terminal can be received. Since the MAC frame is not transmitted from AP1 in RU # 7 to RU # 9, signal collision in RU # 8 received by the terminal 28 does not occur.

As described above, AP1 and AP2 cooperate with each other, assign terminals having the same STAID to the same RU used by both, and set information in the physical header part (SIG1 field, etc.) between AP1 and AP2. By adjusting so that they are the same, high frequency utilization efficiency can be obtained even if AP1 and AP2 perform OFDMA using the same channel. That is, an FFR in which the same RU is used by a plurality of APs at the same time can be realized in a wireless LAN system.

FIG. 12 shows a sequence example of the operation of the wireless LAN system according to the present embodiment. When AP1 decides to perform DL-OFDMA transmission (DL-OFDMA transmission performed by using some RUs in common for both APs) in cooperation with AP2, the information necessary for cooperation (hereinafter referred to as "hereinafter") is transmitted to AP2. , Which may be referred to as FFR information) is transmitted (S11).

More specifically, AP1 determines the RU allocation pattern to use. Here, the above-mentioned 9-multiple pattern is selected. The RU (RU for turning on the FFR function. RU for FFR) to be used in common with AP2 is determined based on the number of terminals in the vicinity area A1 and the like. Here, it is determined that the terminals 11 to 13 exist in the vicinity area A1 and the data to be transmitted to these terminals exists, and the three RUs (here, RU # to RU # 3) are set to the FFR RU. To determine as. Further, AP1 determines that there is data to be transmitted to terminals 14 to 16 in the distant area A2, and determines RU # 4 to RU # 6 as RUs to be assigned to these terminals. As FFR information to be transmitted to AP2, AP1 includes a value indicating a RU allocation pattern, information for designating FFR RU (RU # 1 to RU # 3) (FFR on information), and RU (RU # 1 to RU #). Information (FFR correspondence information) for which terminal allocation information is specified is transmitted in association with 6). The terminal allocation information includes at least STAID and may include other information such as MCS. Here, the FFR on information includes the identifiers of RU # 1 to RU # 3. The FFR correspondence information includes information in which the identifiers of RU # 1 to RU # 6 and the terminal allocation information (ID1 to ID6, etc.) of terminals 11 to 16 are associated with each other.

Here, AP1 determines the RU allocation pattern and the RU for FFR, but as another method, it may be determined in advance by negotiation between AP1 and AP2, or it may be determined in advance by the system or specifications. good.

The AP2 grasps the FFR RU based on the FFR on information included in the FFR information received from the AP1. Here, it is grasped that RU # 1 to RU # 3 are RUs for FFR. AP2 assigns a terminal having STAID (ID1 to ID3) to RU # 1 to RU # 3 based on the FFR correspondence information, like AP1. Here, STA21 to STA23 having ID1 to ID3 are assigned as STAIDs to RU # 1 to RU # 3, respectively. Further, AP2 determines that AP1 does not use RU # 7 to RU # 9, and assigns STA27 to STA29 having ID7 to ID9 as STAIDs to RU # 7 to RU # 9. The AP2 transmits the terminal allocation information of the terminal assigned to the RU not used by the AP1 and the identifier of the RU as the FFR information to the AP1 (S13). Here, information in which the identifiers of RU # 7 to RU # 9 and the terminal allocation information (ID7 to ID9, etc.) of the terminals 27 to 29 are associated with each other is transmitted.

Upon receiving the FFR information from the AP2, the AP1 determines the execution timing of the DL-OFDMA, and transmits a DL-MU (Downlink Multi-User) notification frame including the execution timing information to the AP2 (S14). The execution timing of DL-OFDMA may be specified by the time, or may be specified by the elapsed time from the beginning or the end of the frame of the DL-MU start notification. One of a plurality of predetermined timing candidates may be specified. The execution timing may be specified by a method other than those listed here.

When the execution timing of DL-OFDMA arrives, AP1 and AP2 perform DL-OFDMA transmission (S15, S16). As a result, DL-OFDMA transmission is simultaneously performed by AP1 and AP2. AP1 transmits the physical packet shown in FIG. 11 (A), and AP2 transmits the physical packet shown in FIG. 11 (B). Here, the values of the RU allocation Sub-field and the User specific field in the physical packet transmitted by AP1 and AP2 are the same. Values other than these fields in the SIG1 field are the same for both AP1 and AP2. Also, the legacy field is the same for both AP1 and AP2.

The terminals 21 to 23 and 27 to 29 specified in the SIG1 field of the physical packet transmitted by the AP2 interpret the SIG1 field, identify the RU assigned to the own terminal, and decode the signal of the identified RU. , Receives MAC frames. In particular, the terminal 27 and the terminal 28 receive the physical packet signal from both AP1 and AP2 at the same time, but since the values in the SIG1 field are the same, the received signal can be correctly decoded (S18). In the figure, attention is paid to the terminal 28, and the situation in which the reception of the terminal 28 is successful is shown, but the reception signal is correctly decoded in the terminal 27 and the terminals 21 to 23 and 29 as well. Terminals 11 to 16 specified by the physical packet transmitted by AP1 also interpret the SIG1 field, identify the RU assigned to the own terminal, decode the signal of the specified RU, and receive the MAC frame ( S17). In the figure, attention is paid to the terminal 16, and the situation in which the reception of the terminal 16 is successful is shown, but the same applies to the terminals 11 to 15.

In the above-mentioned sequence example, some RUs among RUs # 1 to RU # 9 are used as FFR RUs, but all of RUs # 1 to RU # 9 can also be used as FFR RUs. It is also possible to assign a plurality of FFR RUs to one terminal. Further, both an FFR RU and a RU other than the FFR RU (usually referred to as a RU) may be assigned to one terminal.

Further, the AP2 transmits FFR information including the terminal allocation information of the terminal assigned to the RU (normal RU) other than the FFR RU in step 13 of FIG. 12, but the AP2 does not assign the terminal to the normal RU. In that case, the transmission of FFR information may be omitted. In this case, if AP1 does not receive FFR information from AP2 even after a certain period of time has passed since the transmission of FFR information from its own AP, AP1 determines that there is no terminal allocation to the normal RU in AP2. A DL-MU start notification frame may be transmitted.

If the AP2 wants to use a RU different from the FFR RU determined by the AP1 as the FFR RU, the AP2 may transmit a frame requesting the redetermination of the FFR RU to the AP1. At this time, the AP2 may specify the FFR RU that the own AP wants to use in the frame. When the AP1 receives the frame, it redetermines the FFR RU and repeats the same sequence as in FIG.

FIG. 13A is a functional block diagram of a wireless communication device mounted on AP1 or AP2 (hereinafter referred to as AP). The AP wirelessly communicates with a terminal in the BSS formed by the AP. Here, the configuration in which the AP communicates with the adjacent AP by using the same communication method as the terminal is shown.

The wireless communication device of the AP includes a control unit 101, a transmission unit 102, a reception unit 103, antennas 12A, 12B, 12C, 12D, and a buffer 104. The number of antennas is four here, but at least one antenna may be provided. The control unit 101 corresponds to a control unit or a baseband integrated circuit that controls communication with a terminal, and the transmission unit 102 and the reception unit 103 form a wireless communication unit or an RF integrated circuit that transmits and receives frames via an antenna. .. All or part of the processing of the control unit 101 and the processing of the digital area of the transmission unit 102 and the reception unit 103 may be performed by software (program) running on a processor such as a CPU, or by hardware. It may be done by both software and hardware. The AP may include a processor that performs all or part of the processing of the control unit 101, the transmission unit 102, and the reception unit 103.

The buffer 104 is a storage unit for passing a frame or the like between the upper layer and the control unit 101. The buffer 104 may be a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM. The upper layer may store the frame received from another network in the buffer 104 for relaying to the terminal side belonging to the own BSS. Further, the upper layer may receive the frame received from the terminal side or its payload from the control unit 101 via the buffer 104. The upper layer may perform communication processing higher than the MAC layer, such as TCP / IP and UDP / IP. Alternatively, TCP / IP and UDP / IP processing may be performed by the control unit 101, and the upper layer may perform processing of an application layer higher than that.
The operation of the upper layer may be performed by processing software (program) by a processor such as a CPU, may be performed by hardware, or may be performed by both software and hardware.

The control unit 101 mainly performs processing of the MAC layer and a part of processing of the physical layer (for example, processing related to OFDMA). The control unit 101 controls communication with the terminal by transmitting and receiving frames via the transmission unit 102 and the reception unit 103. Further, the control unit 101 exchanges information (FFR information) necessary for cooperation of multi-user transmission such as DL-OFDM by communicating with an adjacent AP via the transmission unit 102 and the reception unit 103. Further, the control unit 101 periodically transmits a beacon frame for notifying the BSS (Basic Service Set) attribute of the AP, synchronization information, and the like. Further, the control unit 101 may include a clock generation unit that generates a clock, and may manage the internal time by using the clock generated by the clock generation unit. The control unit 101 may output the clock created by the clock generation unit to the outside. Alternatively, the control unit 101 may generate an external clock generation unit, receive a clock input, and use the clock to manage the internal time.

The control unit 101 receives an association request from a terminal, performs an association process, and exchanges necessary information such as abilities and attributes with each other to establish a wireless link with the terminal. The capability information may include information on whether or not DL-OFDMA can be performed. Further, the ability information may include information on RU allocation patterns that can be implemented by the terminal, information on available RUs, and the like. If necessary, the control unit 101 may perform an authentication process with the terminal in advance. The control unit 101 grasps the state of the buffer 104 by periodically checking the buffer 104. Alternatively, the control unit 101 may confirm the state of the buffer 104 by an external trigger.

The transmission unit 102 adds a physical header to the frame to be transmitted to generate a physical packet, and further performs physical layer processing such as coding and modulation processing. The transmission unit 102 performs DA conversion, filter processing for extracting desired band components, frequency conversion (up-conversion), etc. on the modulated physical packet, amplifies the signal obtained by these with a preamplifier, and 1 Emit as radio waves into space from one or more antennas. The transmission unit 102 may acquire information necessary for generating a part or all of the physical header from the control unit 101. A part or all of the physical header may be added by the control unit 101. An operation example in the case of OFDMA transmission will be described later.

The signal received by the antenna is received by the receiving unit 103 in a low noise amplifier (LNA: Low).
It is amplified by Noise Amplifier), frequency-converted (down-converted), and a desired band component is extracted by a filtering process. The extracted signal is further converted into a digital signal by AD conversion, and after undergoing physical layer processing such as demodulation, error correction decoding, and physical header processing, a frame is input to each control unit 101. The control unit 101 may perform all or part of the processing of the physical header. When performing UL-OFDMA as in other embodiments described later, by separating the signals transmitted from each of the plurality of terminals for each RU, a frame (data frame, ACK frame, etc.) for each terminal is used. Is extracted.

When the control unit 101 receives a frame that requires a delivery confirmation response, the control unit 101 generates a delivery confirmation response frame (ACK frame, BA frame, etc.) based on the inspection result of the received frame, and the generated delivery confirmation response frame. Is transmitted via the transmission unit 102. When frames are transmitted from a plurality of terminals by UL-OFDMA described later, the Multi-Station BA frame considered in IEEE802.11ax may be transmitted as a delivery confirmation response frame.

As a first operation example of the AP according to the present embodiment (corresponding to the operation example of the AP1 in FIG. 12), the control unit 101 decides to perform DL-OFDMA at an arbitrary timing. The control unit 101 determines the RU allocation pattern (see FIG. 3), and also determines the RU for FFR from the plurality of RUs included in the determined RU allocation pattern. From the terminals (OFDA compatible terminals) for which a wireless link has been established, one or a plurality of terminals to be subjected to DL-OFDMA are selected. Further, the control unit 101 assigns a RU (FFR RU or other RU (normal RU)) to the selected terminal. Here, the FFR RU and the normal RU are assigned, but only the FFR RU may be assigned. Here, the terminal is selected first, but a plurality of RUs (FU for FFR, normal RU) may be selected first, and then the terminal to which the RU is assigned may be selected.

The terminal to which the FFR RU is assigned is, for example, a terminal in the vicinity area, and the terminal to which the normal RU is assigned is a terminal in the distant area. Which area the terminal belongs to may be determined by any method. For example, the judgment may be made by comparing the received power from the terminal with the threshold value. Alternatively, when the AP is equipped with GPS (Global Positioning System), the determination may be made using GPS. Further, the control unit 101 may estimate the distance to the terminal and make a judgment based on the estimated distance. However, the FFR RU may be assigned to a terminal in a distant area (for example, a terminal existing on the opposite side of an adjacent AP and not belonging to an overlapping area). It is also possible to assign a normal RU to a terminal in a nearby area.

The control unit 101 determines other parameters such as MCS and packet length (PPDU length, etc.) for each selected terminal as necessary.

The control unit 101 transmits FFR information to the partner AP via the transmission unit 102. The FFR information includes, for example, FFR on information (information specifying the FFR RU), FFR correspondence information (RU (FFR RU and normal RU) identifier, and terminal allocation information (STAID) of the terminal to which the RU is assigned. Etc.) and the value of the RU allocation pattern.

When the control unit 101 receives the FFR information from the other party's AP, the control unit 101 determines the execution timing of the DL-OFDMA and transmits the DL-MU start notification for which the execution timing is specified. When the execution timing (predetermined timing) specified in the DL-MU start notification arrives, the control unit 101 executes DL-OFDMA. Specifically, the control unit 101 sets the terminal allocation information (terminal identifier, etc.) of each terminal selected above in the field (Use field) related to the RU assigned to the terminal. Further, based on the FFR information received from the other party's AP, the terminal allocation information of the terminal to which the normal RU is assigned is set in the field (User field) related to the normal RU used by the other party's AP. Further, the value of the RU allocation pattern is set in the RU allocation field (RU allocation Sub-field). A SIG1 field is generated by setting a value (a value common to AP2) in other fields as well. The control unit 101 transmits a physical packet including a legacy field, a SIG1 field, and a MAC frame addressed to each terminal selected above. More specifically, the header including the legacy field and the SIG1 field is transmitted in the channel width band, and the MAC frame addressed to each selected terminal following the header is transmitted by the RU assigned to each terminal. Of the plurality of RUs included in the channel width band, transmission is not performed in the RU not assigned to any terminal by the control unit 101.

Here, by using the RU allocation field (RU allocation Sub-field), the RU is associated with each User field, but a method of directly setting the RU identifier to each User field is also possible. This also makes it possible to grasp the correspondence between the terminal and the RU. In this case, by cooperation between the own AP and the other AP, which RU identifier is set (or which terminal identifier is set) in which position Userfield is set (or which terminal identifier is set) is determined by negotiation between both APs. Alternatively, the setting rules may be set in advance.

As a second operation example of the AP according to the present embodiment (corresponding to the operation example of AP2 in FIG. 12), the control unit 101 determines to perform DL-OFDMA when FFR information is received from the other AP. The control unit 101 grasps the RU allocation pattern and the FFR RU based on the FFR information. The AP selects a terminal having the same terminal identifier as the terminal identifier of the terminal assigned to the same FFR RU by the other party's AP as the terminal to which the FFR RU is assigned from the terminals (OFDM compatible terminals) for which the wireless link has been established. ,select. Further, if necessary, a terminal to which a RU that is not used by the other party's AP is assigned among the normal RUs is selected. The control unit 101 assigns RUs (FFR RUs or normal RUs) to the selected terminals, respectively. Here, there are a terminal to which the FR RU is assigned and a terminal to which the normal RU is assigned, but there may be only a terminal to which the FFR RU is assigned. The control unit 101 determines other parameters such as MCS and packet length (PPDU length, etc.) for each selected terminal as necessary. At this time, for the terminal to which the FFR RU is assigned, the same value as the terminal to which the partner AP has assigned the FFR RU is determined. The control unit 101 transmits FFR information to the partner AP via the transmission unit 102. The FFR information includes information in which the identifier of the normal RU is associated with the terminal allocation information (STAID, etc.) of the terminal to which the normal RU is assigned.

When the control unit 101 receives the DL-MU start notification from the other party's AP, the control unit 101 executes the DL-OFDMA at the arrival of the execution timing (predetermined timing) specified in the DL-MU start notification. Specifically, the control unit 101 sets the terminal allocation information (terminal identifier, etc.) of each terminal selected above in the field (Use field) related to the RU assigned to each terminal. Further, based on the FFR information received from the other party's AP, the terminal allocation information of the terminal to which the normal RU is assigned is set in the field (User field) related to the RU (normal RU) used by the other party's AP. Further, the value of the above RU allocation pattern is set in the RU allocation field (RU allocation Sub-field). A SIG1 field is generated by setting a value (a value common to AP1) in other fields as well. The control unit 101 transmits a physical packet including a legacy field, a SIG1 field, and a MAC frame addressed to each terminal selected above. More specifically, the header including the legacy field and the SIG1 field is transmitted in the channel width band, and the MAC frame addressed to each selected terminal following the header is transmitted by the RU assigned to each terminal. Of the plurality of RUs included in the channel width band, transmission is not performed in the RU in which the control unit 101 is not assigned to any terminal.

The control unit 101 may access the storage device for storing the information notified to each terminal, the information notified from each terminal, or both of them, and read the information. The storage device may be an internal memory or an external memory, and may be a volatile memory or a non-volatile memory. In addition to the memory, the storage device may be an SSD, a hard disk, or the like.

The above-mentioned separation of the processing of the control unit 101 and the transmission unit 102 is an example, and a form different from the above-mentioned form is also possible. For example, the digital domain processing and the DA conversion may be performed by the control unit 101, and the processing after the DA conversion may be performed by the transmission unit 102. Similarly, the processing before the AD conversion is performed by the receiving unit 103, and the processing in the digital region including the processing after the AD conversion is performed by the control unit 101 for separating the processing of the control unit 101 and the receiving unit 103. You may. As an example, in the baseband integrated circuit according to the present embodiment, the control unit 101, the portion of the transmission unit 102 that performs physical layer processing, the portion that performs DA conversion, and the portion of the reception unit 103 that performs processing after AD conversion. The RF integrated circuit corresponds to a portion of the transmitting unit 102 that performs processing after the DA conversion and a portion of the receiving unit 103 that performs processing before the AD conversion. The wireless communication integrated circuit according to the present embodiment includes at least a baseband integrated circuit among the baseband integrated circuit and the RF integrated circuit. Processing between blocks or processing between baseband integrated circuits and RF integrated circuits may be separated by a method other than that described here.

FIG. 13A shows a configuration in which communication between APs is performed by the same communication method as that of the terminal, but communication between APs may be performed by another method such as wired communication. A configuration example in that case is shown in FIG. 13B. A transmission unit 105 and a reception unit 106 for inter-AP communication are provided. The wired IF 107 is connected to the wired network, outputs a frame or packet signal received from the transmitting unit 105 to the wired network, and passes the frame or packet signal received from the wired network to the receiving unit 106. The transmitting unit and the receiving unit 106 basically perform the same operations as the transmitting unit 105 and the receiving unit 106, except for the operation depending on the protocol. For example, the transmission unit 105 performs modulation, DA conversion, filtering, frequency conversion, amplification, and the like on the frame or packet passed from the control unit 101, and outputs the amplified signal to the wired IF 107. The receiving unit 106 performs amplification, frequency conversion, filtering processing, AD conversion, demodulation, and the like of the signal received from the wired IF 107 to acquire a frame or packet and passes it to the control unit 101.

FIG. 14 is a functional block diagram of a wireless communication device mounted on the terminal. The wireless communication devices mounted on the terminals 11 to 16, 21 to 23, and 27 to 29 in FIG. 1 have this configuration.

The wireless communication device includes a control unit 201, a transmission unit 202, a reception unit 203, at least one antenna 1, and a buffer 204. The control unit 201 corresponds to a control unit or a baseband integrated circuit that controls communication with the AP, and the transmission unit 202 and the reception unit 203 correspond to a wireless communication unit or an RF integrated circuit that transmits and receives frames. All or part of the processing of the control unit 201 and the processing of the digital area of the transmission unit 202 and the reception unit 203 may be performed by software (program) running on a processor such as a CPU, or by hardware. It may be done by both software and hardware. The terminal may include a processor that performs all or part of the processing of the control unit 201, the transmission unit 202, and the reception unit 203.

The buffer 204 is a storage unit for passing a frame or the like between the upper layer and the control unit 201. The buffer 204 may be a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM. The upper layer generates a frame to be transmitted to a device on another network such as another terminal, AP, or server and stores it in the buffer 204, or receives a frame from another terminal, AP, device, or the like. It is received from the control unit 201 via the buffer 204. The upper layer may perform communication processing higher than the MAC layer, such as TCP / IP and UDP / IP. Further, TCP / IP and UDP / IP may be processed by the control unit 201, and the upper layer may be processed by an application layer higher than this. The operation of the upper layer may be performed by processing software (program) by a processor such as a CPU, may be performed by hardware, or may be performed by both software and hardware.

The control unit 201 mainly processes the MAC layer. The control unit 201 controls communication with the AP by transmitting and receiving frames to and from the AP via the transmission unit 202 and the reception unit 203. Further, the control unit 201 may include a clock generation unit that generates a clock, and may manage the internal time by using the clock generated by the clock generation unit. The control unit 201 may output the clock created by the clock generation unit to the outside. Alternatively, the control unit 201 may generate an external clock generation unit, receive a clock input, and use the clock to manage the internal time.

As an example, the control unit 201 receives a beacon frame, grasps the BSS attributes and synchronization information of the AP, and then makes an association request to the AP to perform the association process. As a result, a wireless link is established with the AP by exchanging necessary information such as abilities and attributes of each other (may include ability information such as whether or not OFDMA can be performed). If necessary, an authentication process may be performed with the AP in advance. The control unit 201 grasps the state of the buffer 204 by periodically checking the buffer 204. Alternatively, the control unit 201 confirms the state of the buffer 204 by an external trigger. After confirming the existence of a frame such as a data frame to be transmitted to the AP, the control unit 201 acquires an access right (transmission right) to the wireless medium based on CSMA / CA or the like, and then transmits the frame to the transmission unit 202 and the antenna 1A. It may be transmitted via.

The transmission unit 202 adds a physical header to the frame input from the control unit 201 to generate a physical packet, and further performs physical processing such as coding and modulation processing. Further, the transmission unit 202 performs DA conversion, filter processing for extracting desired band components, frequency conversion (up-conversion), and the like on the modulated physical packet, and amplifies the signal obtained by these with a preamplifier. It is radiated as radio waves into the space from one or more antennas. When a plurality of antennas are provided, a transmission system may be provided for each antenna, physical layer processing may be performed for each transmission system, and the same signal may be transmitted at the same time. Alternatively, it is possible to control the directivity of transmission by using a plurality of antennas. The transmission unit 202 may acquire information necessary for generating a part or all of the physical header from the control unit 201. A part or all of the physical header may be added by the control unit 201.

The signal received by the antenna 1A is processed by the receiving unit 203. The received signal is amplified by LNA in the receiving unit 203, frequency-converted (down-converted), and a desired band component is extracted by file tarring processing. The extracted signal is further converted into a digital signal by AD conversion, undergoes physical layer processing such as demodulation, error correction decoding, and physical header processing, and then a frame such as a data frame is input to the control unit 201. .. The control unit 201 may perform all or part of the processing of the physical header.

Upon receiving the signal transmitted by DL-OFDMA from the AP, the receiving unit 203 detects a value indicating the RU allocation pattern from the RU allocation field in the SIG1 field of the physical header. It searches for the existence of a plurality of Userfields in which the terminal identifier of the own terminal is set, and if so, identifies the RU related to the Userfield based on the RU allocation pattern. The receiving unit 203 decodes the signal of the specified RU, acquires a frame, and passes it to the control unit 201. If the acquired frame is a frame that requires a delivery confirmation response, the control unit 201 generates a delivery confirmation response frame based on the inspection result of the frame and transmits the delivery confirmation response frame. The delivery confirmation response frame may be transmitted by single-user transmission or multi-user transmission with another terminal (UL-OFDMA, UL-MU-MIMO, etc.). The single user transmission may be performed after a predetermined fixed time from the completion of frame reception, or may be performed by acquiring the access right of the wireless medium by the carrier sense and the backoff operation according to CSMA / CA. A part of the DL-OFDA signal reception process described here may be performed by the control unit 201.

The control unit 201 may access the storage device for storing the information notified to the AP, the information notified from the AP, or both of them, and read the information. The storage device may be an internal memory or an external memory, and may be a volatile memory or a non-volatile memory. In addition to the memory, the storage device may be an SSD, a hard disk, or the like.

The above-mentioned separation of the processing of the control unit 201 and the transmission unit 202 is an example, and a form different from the above-mentioned form is also possible. For example, the digital domain processing and the DA conversion may be performed by the control unit 201, and the processing after the DA conversion may be performed by the transmission unit 202. Similarly, for the processing of the control unit 201 and the reception unit 203, the processing before the AD conversion is performed by the reception unit 203, and the processing of the digital area including the processing after the AD conversion is performed by the control unit 201. May be good. As an example, in the baseband integrated circuit according to the present embodiment, the control unit 201, the portion of the transmission unit 202 that performs physical layer processing, the portion that performs DA conversion, and the portion of the reception unit 203 that performs processing after AD conversion. The RF integrated circuit corresponds to a portion of the transmitting unit 202 that performs processing after the DA conversion and a portion of the receiving unit 203 that performs processing before the AD conversion. The wireless communication integrated circuit according to the present embodiment includes at least a baseband integrated circuit among the baseband integrated circuit and the RF integrated circuit. Processing between blocks or processing between baseband integrated circuits and RF integrated circuits may be separated by a method other than that described here.

FIG. 15A is a flowchart of a first operation example of the AP according to the first embodiment (corresponding to the operation of AP1 in FIG. 12).

When the AP decides to perform DL-OFDMA at an arbitrary timing, it determines the RU allocation pattern to be used (see FIG. 3), and from a plurality of RUs corresponding to the RU allocation pattern, the RU for FFR is obtained. Determine (S101).

The AP selects one or more terminals to be subjected to DL-OFDMA from the terminals for which a wireless link has been established (S102). Further, the AP assigns one or more RUs (at least the former of the FFR RU and the normal RU) to each terminal (S102).
The AP determines other parameters such as MCS and packet length (PPDU length, etc.) for each selected terminal as necessary.

The AP assigns FFR on information (identifier of RU for FFR), FFR correspondence information (information in which the identifier of RU is associated with the terminal allocation information (STAID, etc.) of the terminal to which the RU is assigned), and RU allocation. The value of the pattern is transmitted as FFR information to the AP of the cooperation partner (S103).

When the AP receives the FFR information from the other party's AP or after a certain period of time (S104), the AP transmits a DL-MU start notification frame in which the execution timing of the DL-OFDMA is specified (S105). The DL-MU start notification frame assumes a control frame, but may be a management frame or a data frame. When the execution timing (predetermined timing) specified in the DL-MU start notification arrives (S106), the AP executes DL-OFDMA (S107).

Specifically, the AP sets the terminal allocation information (terminal identifier, etc.) of each terminal selected above in the field (Use field) related to the RU assigned to the terminal. Further, based on the FFR information received from the other party's AP, the terminal allocation information of the terminal to which the RU is assigned is set in the field (User field) related to the RU (normal RU) used by the other party's AP. Further, the value of the RU allocation pattern is set in the RU allocation field (RU allocation Sub-field). Values (values common to AP2) are also set in other fields in the SIG1 field. The AP transmits a physical packet containing a legacy field, a SIG1 field, and a MAC frame addressed to each terminal selected above. More specifically, the header including the legacy field and the SIG1 field is transmitted in the channel width band, and the MAC frame addressed to each terminal following the header is transmitted by the RU assigned to each terminal. Of the plurality of RUs included in the channel width band, the RUs that the AP has not assigned to any terminal do not perform transmission.

FIG. 15B is a flowchart of a second operation example of the AP according to the first embodiment (corresponding to the operation of AP2 in FIG. 12).

Upon receiving the FFR information from the other party's AP, the AP decides to perform DL-OFDMA (S201).

The AP grasps the RU allocation pattern and the FFR RU based on the FFR information (S202).

The AP selects a terminal having the same terminal identifier as the terminal assigned to the same FFR RU by the other AP as the terminal to which the FFR RU is assigned from the terminals (OFDM compatible terminals) for which the wireless link has been established. (S203). Further, if necessary, a terminal to which a RU not used by the other party's AP is assigned is selected from the normal RUs (S203).

The AP determines other parameters such as MCS and packet length (PPDU length, etc.) for each selected terminal as necessary. At this time, the AP1 determines the same value as the terminal to which the FFR RU is assigned to the terminal to which the partner AP is assigned the same FFR RU. As the FFR information, the AP transmits the FFR correspondence information in which the identifier of the normal RU to be used and the terminal allocation information of the terminal to which the normal RU is assigned are associated with each other to the AP of the cooperation partner (S204).

The AP grasps the execution timing of DL-OFDMA by receiving the DL-MU start notification frame from the other party's AP (S205). When the execution timing (predetermined timing) specified in the DL-MU start notification arrives (S206), the AP executes DL-OFDMA (S207).

Specifically, the AP sets the terminal allocation information (terminal identifier, etc.) of each terminal selected above in the field (User field) related to the RU assigned to each terminal. Further, based on the FFR information received from the other party's AP, the terminal allocation information of the terminal to which the RU is assigned is set in the field (User field) related to the RU (normal RU) used by the other party's AP. Further, the value of the above RU allocation pattern is set in the RU allocation field (RU allocation Sub-field). By setting values (values common to AP1) in other fields, the same SIG1 field as the other AP is generated.
The AP transmits a physical packet containing a legacy field, a SIG1 field, and a MAC frame addressed to each terminal selected above. More specifically, the header including the legacy field and the SIG1 field is transmitted in the channel width band, and the MAC frame addressed to each terminal following the header is transmitted by the RU assigned to each terminal. Of the plurality of RUs included in the channel width band, transmission is not performed in the RU in which the AP is not assigned to any terminal.

As described above, according to the present embodiment, by executing FFR in cooperation between AP1 and AP2, DL-OFDMA can be performed with high frequency utilization efficiency by using the same channel for AP1 and AP2. That is, by assigning terminals having the same STAID in both AP1 and AP2 to the FFR RU used in both AP1 and AP2, the contents of the physical header portion (SIG1 field, etc.) are the same between AP1 and AP2. Can be done. As a result, the terminal that receives both the AP1 and AP2 signals can also decode the header portion, so that the frame transmitted by DL-OFDMA from the AP to which the own terminal belongs can be correctly received.
In this way, an FFR in which the same RU is used by a plurality of APs at the same time can be realized in a wireless LAN system.

In the present embodiment, an example of executing FFR between two APs is shown, but it is also possible to execute FFR between three APs. In this case, FFR can be carried out in the same manner as in the present embodiment by exchanging FFR information among the three APs and coordinating with each other. This also applies to the second embodiment and the third embodiment described later.

(Second embodiment)
In the first embodiment, FFR (Fractional Frequency Rose) was carried out in DL-OFDMA, but in this embodiment, FFR is carried out in UL-OFDMA. When performing UL-OFDMA, the AP transmits a frame (hereinafter, referred to as a trigger frame: TF) in which a plurality of terminals to perform UL-OFDMA and a RU to be used by these terminals are specified. A plurality of terminals that have received the TF transmit a MAC frame such as a data frame (more specifically, a physical packet including the MAC frame) at a predetermined RU at the same predetermined timing. As a result, UL-OFDMA is performed.

Similar to the first embodiment, AP1 assigns RU # 1 to RU # 6 to terminals 11 to 16, and AP2 assigns RU # 1 to RU # 3, RU # 7 to terminals 21 to 23 and 27 to 29. It is assumed that RU # 9 is assigned (see FIG. 5).

FIG. 16 shows an example of the TF format. TF is defined based on the general MAC frame format. The TF includes a Frame Control field, a Duration / ID field, an Addless1 field, an Addless2 field, a common information field (COMMOM Info field), and a plurality of terminal information fields (Per User Info field).

As an example, the type of the Frame Control field may be a value representing "control", and the value of the subtype may be a value newly defined for TF. However, the configuration in which the frame type of the TF is not "control" but "management" or "data" is not excluded.

In the Addres1 field, a broadcast address or a multicast address is set as an example as RA (Receiver Address: recipient address). In the Addless2 field, the MAC address or BSSID of the AP is set as TA (Transmitter Addless: source address).

In the common information field, information to be notified in common to a plurality of terminals selected as targets of UL-OFDMA is set. As an example, there are the time length of the frame or physical packet to be transmitted by uplink, the type of frame to be transmitted by uplink, the length of the L-SIG field in the physical header added to the frame to be transmitted by uplink, and the like. Further, the timing information of the uplink transmission may be set.

In each terminal information field, information to be notified individually to the terminal is set. For example, the terminal identifier (STAID) of the terminal designated as the target of UL-OFDMA, the identifier of the RU assigned to the terminal, and the like are set. In addition, information that specifies the MCS to be applied to the frame to be transmitted by the uplink may be set. When a specific RU is associated with each terminal information field, there may be a configuration in which the setting of the RU identifier is omitted.

(First operation example in this embodiment: The same trigger frame is transmitted from both APs by using the settings of the virtual AP)
FIG. 17 shows a sequence of operation examples of the wireless LAN system according to the present embodiment. As a premise, each of AP1 and AP2 is set to a virtual AP in which a plurality of BSSIDs can be set. Specifically, as shown in FIG. 18, in addition to the BSSID (referred to as “A”) of the own AP, the BSSID (“B”) of the AP2 is also set as the sub BSSID in the AP1. Similarly, in AP2, in addition to the BSSID (referred to as “B”) of the own AP, the BSSID (“A”) of AP1 is also set as a sub BSSID. Each terminal belonging to AP1 and AP2 can receive a frame in which the BSSID of an AP other than the AP (BSS) to which the terminal is connected is set in the Adsless2 field (TA field) as capacity information (Capacity information). Notify AP of availability. The terminal that has notified that the response is possible can receive a frame in which the BSSID of the adjacent AP is set in the TA field. Here, it is assumed that the terminals 11 to 16 notify AP1 and the terminals 21 to 23 and 27 to 29 notify AP2. This notification may be performed by setting the capability information in the association request frame transmitted at the time of association, or may be performed via another frame such as a probe search frame.

By coordinating with each other, AP1 and AP2 grasp the FFR RU, and acquire the terminal allocation information of the terminal to which the normal RU is normally assigned from the other AP.

More specifically, AP1 determines RU # 1 to RU # 3 as FFR RUs and assigns them to terminals 11 to 13. Further, RU # 4 to RU # 6 are assigned to the terminals 14 to 16 as normal RUs. AP1 provides FFR information that specifies RU (RU # 1 to RU # 3) for FFR (FFR on information), RU # 1 to RU # 6, and terminal allocation information (STAID, etc.) of each terminal. The associated FFR correspondence information is transmitted to AP2 (S21). In addition, AP1 and AP2 may share a rule regarding the correspondence between Per User Info1 to Per User InfoN and RU in the trigger frame (TF) in advance. For example, rules such as RU # 1 corresponding to Per User Info1 and RU # 2 corresponding to Per User Info2 are shared between APs. As a sharing method, one of AP1 and AP2 may decide the rule and notify the other AP of the rule. Alternatively, the rules may be defined by specifications or standards.

AP2 grasps that RU # 1 to RU # 3 are FFR RUs based on the FFR on information included in the FFR information received from AP1. AP2 assigns terminals 21 to 23 having the same STAID (ID1 to ID3) as AP1 to RU # 1 to RU # 3 based on the FFR correspondence information (S22). Further, AP2 assigns terminals 27 to 29 having ID7 to ID9 as STAIDs to RUs # 7 to RU # 9 which are not used by AP1. AP2 transmits information in which RUs # 7 to RU # 9 are associated with terminal allocation information (STAID, etc.) of terminals assigned to these RUs as FFR information to AP1 (S23).

The AP1 transmits a UL-MU (Uplink Multi-User) start notification frame that specifies the execution timing of the UL-OFDMA to the AP2 (S24).

AP1 and AP2 simultaneously transmit TFs when the UL-OFDMA execution timing arrives (S25, S26). More specifically, AP1 is the Per User of TF.
In Info1 to Per User Info6, terminal allocation information (STAID) and RU identifier of terminals 11 to 16 are set, and Per User Info7 to Per User
In Info9, the terminal allocation information and the RU identifier of the terminals 27 to 29 acquired from AP2 are set. Set the necessary information in other fields in TF. As a result, TF (hereinafter, TF1) is generated. Then, AP1 transmits the generated TF1. More precisely, AP1 transmits a physical packet in which a physical header including a legacy field (L-STF, L-LTF, L-SIG) is added to TF1. The physical header and TF1 are transmitted in the channel width band (eg 20 MHz). In the physical header, another field may be added between the legacy field and TF1.

AP2 sets terminal allocation information (STAID, etc.) and RU identifier of terminals 21 to 23 and 27 to 29 in Per User Info1 to Per User Info3 and Per User Info7 to Per User Info9 of TF, respectively, and Per.
The terminal allocation information and the RU identifier of the terminals 14 to 16 acquired from AP1 are set in User Info4 to Per User Info6. In Addlesss2, the BSSID (MAC address) of AP1 is set instead of the BSSID (MAC address) of AP2. Set the required information in the other fields as well. As a result, TF (hereinafter, TF2) is generated. At this time, the other fields are also set to be the same as TF1 (for this reason, information may be exchanged between AP1 and AP2 as necessary). As a result, the values of all the fields of TF2 become the same as those of TF1. AP2 transmits the generated TF2. More precisely, AP2 transmits a physical packet in which a physical header including a legacy field (L-STF, L-LTF, L-SIG) is added to TF2. The physical header and TF2 are transmitted in the channel width band (eg 20 MHz). Similar to TF1, another field may be added between the legacy field and TF2 in the physical header. In this case, the added field should have the same value as the field added by AP1. Therefore, if necessary, information may be exchanged between AP1 and AP2 in advance.

The terminals 11 to 16 receive the TF1 transmitted from the AP1 and determine that the transmission source is the AP1 (TF1 is a frame to be received by the own terminal) by checking the TA set in the Address2 field. do. The terminals 11 to 16 specify the Per User field in which the STAID of the own terminal is set, and detect information such as RU used for uplink transmission from the specified field. The terminals 11 to 16 transmit a MAC frame such as a data frame (more specifically, a physical packet in which a physical header is added to the MAC frame) at a designated RU after a predetermined time from the completion of reception of the TF1 (S27). .. The physical header includes legacy fields, SIG1 fields, and so on. Arbitrary control information to be notified to AP1 is set in the SIG1 field. The format of the SIG1 field may be different from the format of the SIG1 field of the physical packet transmitted by DL-OFDMA in the first embodiment. The physical packets transmitted from the terminals 11 to 16 are shown in FIG. 19 (A). As a result, UL-OFDMA is performed between AP1 and terminals 11-16.

On the other hand, the terminals 21 to 23 and 29 receive the TF2 transmitted from the AP2 and confirm the TA stored in the Address2 field. From the TA, it is determined that the AP should be received from the settings of the Virtual AP, although it is an AP different from the AP to which the own terminal belongs. The terminals 21 to 23 and 29 specify the Per User field in which the STAID of the own terminal is set, and detect information such as RU used for uplink transmission from the specified field. The terminals 21 to 23 and 29 transmit a MAC frame such as a data frame (more specifically, a physical packet in which a physical header is added to the MAC frame) at a designated RU after a predetermined time from the completion of reception of the TF2 (physical packets). S28). On the other hand, the terminals 27 and 28 receive TF1 transmitted from AP1 and TF2 transmitted from AP2 at the same time, but their physical headers are the same, and the contents of TF1 and TF2 are also the same. Therefore, the terminals 27 and 28 can correctly decode the received signal. Therefore, the terminals 27 and 28 detect the RU or the like specified in the own terminal in the same manner as the terminals 21 to 23 and 29, and at the specified RU, a MAC frame (more specifically, a physical header is added to the MAC frame). The added physical packet) is transmitted. The physical header includes legacy fields, SIG1 fields, and so on. The physical packets transmitted from the terminals 21 to 23 and 27 to 29 are shown in FIG. 19 (B). As a result, UL-OFDMA is performed between AP2 and terminals 21-23 and 27-29.

In AP1, in addition to the terminals belonging to the own AP, for example, uplink signals from terminals 27 and 28 existing in the overlapping area can be received, but RU # 8 and RU # 9 used by these terminals 27 and 28 are AP1. Since it is not used in the above, there is no problem in the reception operation in AP1. Further, the AP2 can also receive a signal from the terminal 16 or the terminal 15 depending on the terminal position, but the U # 5 and RU # 6 used by the terminal 16 or the terminal 15 and the like do not use the AP2, which is a problem. Does not occur.

(Second operation example in this embodiment: Different trigger frames are transmitted from both APs using channel-based DL-OFDMA)
In the above-mentioned operation example, FFR information is exchanged between AP1 and AP2, and BSSID of AP1 is used as the TA of the trigger frame generated by AP2, so that TF1 and TF2 generated by AP1 and AP2 are made into the same frame. .. As a result, even a terminal that receives TF1 and TF2 at the same time could normally receive TF1 or TF2. Alternatively, AP1 and AP2 may each utilize channel-based DL-OFDM to transmit different trigger frames. In channel-based OFDMA, a plurality of channels (for example, four channels of Ch1, Ch2, Ch3, and Ch4) are used simultaneously for transmission or reception. The terminal listens on each of the plurality of channels. In this case, it is not necessary to set the virtual AP for AP1 and AP2.

As before, FFR information is exchanged between AP1 and AP2. Also, different channels to be used in the channel-based DL-OFDMA are determined from each other. For example, AP1 decides to use channels 1 and 2, and AP2 decides to decide channels 3 and 4.

AP1 generates TF (hereinafter, TF11) in which terminal allocation information (STAID or the like) and RU identifier of terminals 11 to 16 are set in Per User Info1 to Per User Info6. The TA of TF11 is the BSSID of AP1. AP2 generates a TF (hereinafter referred to as TF12) in which terminal allocation information and RU identifiers of terminals 21 to 23 and 27 to 29 are set in Per User Info1 to Per User Info6. The TA of TF12 sets the BSSID of AP2. However, if the correspondence between the field and the RU is defined in advance without setting the RU identifier in the Per User Info field, the terminal allocation information of each terminal is assigned to the Per corresponding to the RU assigned to each terminal. Set it in the User Info field.

The allocation of RUs in AP1 and AP2 is the same as in the previous embodiments, for example, for terminals in the vicinity of AP1 and terminals in the vicinity of AP2, the same RU (RU for FFR) is used in both APs. Assign to. For terminals in the distant area of AP1 and terminals in the distant area of AP2, different normal RUs are assigned to both AP1 and AP2 (RUs are assigned so as not to overlap between APs). As a result, the signals transmitted from the respective neighboring areas of AP1 and AP2 do not reach the other AP (or even if they do, the received power is low), so that each AP is a terminal in the neighboring area belonging to the own AP. Can receive frames from. Further, since the signals transmitted from the distant areas of AP1 and AP2 use different RUs (normal RUs) for each AP, even if the signals arrive, they are received from the terminals in the distant areas belonging to the own AP. There is no problem in decoding the frame.

The AP1 transmits, for example, TF11 on channel 1 and an arbitrary frame on channel 2 (for example, the same frame as TF11 or a data frame addressed to a terminal in the neighboring area A1). TF11 is a frame instructing UL-OFDMA to be performed on channel 1. A physical header including a legacy field, a SIG1 field, and the like is added to the head side of these frames. In the SIG1 field on channels 1 and 2, for example, a channel allocation destination is set in each field (subfield) for channels 1 to 4. The allocation destination may be the STAID of a plurality of terminals that are the reception destinations of the TF transmitted on the corresponding channel. In the case of broadcasting, an ID defined for broadcasting (called a broadcast ID) may be used. In the case of broadcast ID, all terminals are the recipients. Here, the terminal identifiers (or broadcast IDs) of terminals 11 to 16 are set as the allocation destinations of channels 1 and 2, and the terminal identifiers (or broadcast IDs) of terminals 21 to 23 and 27 to 29 are assigned as the allocation destinations of channels 3 and 4. ) Is set (Note that AP1 grasps the allocation destinations of channels 3 and 4 from the FFR information acquired from AP2). Channels 3 and 4 may also transmit the same legacy and SIG1 fields as channels 1 and 2. An example of a physical packet transmitted by AP1 is shown in FIG. 20 (A). Here, the same TF11 is transmitted on channels 1 and 2. Channels 3 and 4 transmit legacy fields and SIG1 fields having the same contents as channels 1 and 2. Here, in the SIG1 field, the channel allocation destination is included in each field (subfield) for channels 1 to 4, but this is an example, and a configuration that does not include such information is also possible. .. It suffices if it contains the information necessary to decrypt the payload. AP1 transmits the same SIG1 field on channels 1 to 4, but such restriction is not necessary if the terminal can receive independently for each channel.

Similarly, AP2 transmits TF12 on channel 3 and an arbitrary frame (for example, the same frame as TF12 or a data frame addressed to a terminal in the neighboring area B1) on channel 4. TF12 is a frame instructing UL-OFDMA to be performed on channel 1. A physical header including a legacy field, a SIG1 field, and the like is added to the head side of these frames. The legacy field and SIG1 field are the same as those transmitted by AP1. In order to realize this, the rule for setting the terminal identifier in each field for channels 1 to 4 in the SIG1 field is shared in advance between AP1 and AP2. An example of a physical packet transmitted by AP2 is shown in FIG. 20 (B). Here, the same TF12 is transmitted on channels 3 and 4. Channels 1 and 2 transmit the legacy field and SIG1 field having the same contents as channels 3 and 4. Although AP2 transmits the same SIG1 field on channels 1 to 4, such restriction may not be necessary as long as the terminal can receive independently for each channel.

The terminals 11 to 16 belonging to AP1 detect the RU assigned to the own terminal by, for example, listening on channels 1 to 4 and decoding and analyzing the TF 11 received on channels 1 or 2, and UL-OFDMA. Transmission is performed (see FIG. 19 (A)). When a data frame is transmitted to an arbitrary terminal on channel 2, the terminal detects that the data frame has been sent from the SIG1 field to its own terminal on channel 2 and receives the data frame. conduct. Terminals 21 to 23 and 27 to 29 belonging to AP2 detect the RU assigned to their own terminal by, for example, listening on channels 1 to 4 and decoding and analyzing TF12 received on channels 3 or 4. , UL-OFDMA transmission (see FIG. 19B). When a data frame is transmitted to an arbitrary terminal on channel 4, the terminal detects that the data frame has been sent from the SIG1 field to its own terminal on channel 4, and also receives the data frame.

As described above, according to the present embodiment, UL-OFDMA can be performed with high frequency utilization efficiency using the same channel for AP1 and AP2. That is, when AP1 and AP2 transmit a trigger frame with the same content (more specifically, a physical packet with the same content) or transmit a trigger frame on different channels, the terminal existing in the overlapping area is also the AP to which the own terminal belongs. Can correctly receive the trigger frame sent from. Therefore, even in the case of UL-OFDMA, FFR in which the same RU is used by a plurality of APs at the same time can be realized with high frequency utilization efficiency.

(Third Embodiment)
In the first embodiment, high-efficiency FFR is realized by assigning terminals having the same STAID to the same RU (RU for FFR) among a plurality of RUs used by AP1 and AP2 in DL-OFDMA. In this embodiment, AP1 and AP2 use the same RU (RU for FFR) among a plurality of RUs used in DL-OFDMA, and downlink multi-user MIMO (Multi-Input and Multi-Autoput) (DL-MU). -By performing MIMO), highly efficient FFR is realized. That is, DL-MU-MIMO is performed with some RUs (RUs for FFR) among the plurality of RUs used in DL-OFDMA. This method is described as DL-OFDA & MU-MIMO.

In order to carry out DL-MU-MIMO using RU, it is necessary to use RU of 106 tones or more as an example. Therefore, as the RU allocation pattern, for example, the allocation patterns Nos. 16 to 23 in FIG. 3 can be used. In the following, the 23rd allocation pattern is assumed. FIG. 21 shows the allocation pattern of No. 23. As shown in the figure, the 106-tone RU is described as RU # 1 (or FFR RU), and the five 26-tone RUs are referred to as RU # 2, RU # 3, RU # 4, in order from the lowest frequency. Described as RU # 5 and RU # 6.

AP1 transmits DL-MU-MIMO to terminal 11 and terminal 12 by RU # 1 (DL-MU-MIMO transmission having a multiple number of 2), transmits to terminal 14 by RU # 2, and transmits to terminal 15 by RU # 3. Imagine a case. The transmission to the terminal 14 and the terminal 15 may be beamforming or omnidirectional transmission (omni transmission). In addition, AP2 transmits DL-MU-MIMO to terminal 21 with RU # 1 (DL-MU-MIMO transmission with 1 multiplex), terminal 23 with RU # 4, terminal 27 with RU # 5, and RU # 6. It is assumed that the terminal 28 is transmitted to the terminal 28. The transmission to the terminal 23, the terminal 27 and the terminal 28 may be beamforming or omnidirectional transmission (omni transmission). Here, the transmission target terminal of DL-MU-MIMO is a terminal in the neighborhood areas A1 and B1, but is not limited thereto.

Here, as the value to be set in the RU allocation Sub-field in FIG. 7, in the case of the 23rd pattern, "01000y ₂ y ₁ y ₀ " is possible. y ₂ y ₁ y ₀ can take a value in the range of 000 to 111. For y ₂ y ₁ y ₀ , a value corresponding to the number of multiples transmitted by the 106-tone RU (RU # 1) is set. In this example, since AP1 transmits two multiplex and AP2 transmits one multiplex using RU # 1, the value (“011”) representing the number of multiplex 3 is set to _{y 2} y ₁ y _0. That is, "0100011" is set in the RU allocation Sub-field. A setting example is shown in FIG. 22 (A). Both AP1 and AP2 set this value.

The User Special field following the RU allocation Sub-field is the User field # 1 to User field # 3 corresponding to the multiple number 3 and the User field # 4 to User corresponding to RU # 2 to RU # 6 of 26 tones, respectively. Includes field # 8. That is, as shown in FIG. 22 (B), three Userfields are used for 106-tone RU, and one Userfield is used for each of 26-tone RU # 2 to RU # 6. .. By changing the value of y ₂ y ₁ y _0, the number of Userfields (multiply number) for the RU of 106 tones changes. Such rules are commonly recognized by each AP and each terminal.

For the terminals 11 and 12 that are the targets of DL-MU-MIMO, the AP1 sets the terminal allocation information related to the terminal 11 to a predetermined User field # 1 among a plurality of User fields # 1 to # 3, and sets the terminal. The terminal allocation information regarding 12 is set in a predetermined User field # 2 among a plurality of User fields # 1 to # 3. The terminal allocation information includes, for example, STAID, information for identifying a stream, the number of streams, MCS, and the like. Further, AP1 sets the terminal allocation information regarding the terminal 14 in the User field # 4, and sets the terminal allocation information regarding the terminal 15 in the User field # 5. The terminal allocation information regarding the terminals 14 and 15 includes, for example, STAID, the number of streams, the presence / absence of beamforming, MCS, and the like.

AP2 sets terminal allocation information regarding the terminal 21 in a predetermined User field # 3 among a plurality of User fields # 1 to # 3 for the terminal 21 that is the target of DL-MU-MIMO. Further, AP2 sets terminal allocation information regarding the terminal 23, the terminal 27, and the terminal 28 in the User field # 6 to the User field # 8, respectively.

Further, the AP2 cooperates with the AP1 to provide information on the RUs (RU # 1, RU # 2, RU # 4, RU # 5) assigned by the AP1 to the terminal 11, the terminal 12, the terminal 14, and the terminal 15, and these. Acquires the terminal allocation information of the terminal of. Then, the terminal allocation information of the terminals 11 and 12 acquired from AP1 is set in the User fields # 1 and # 2 of the User fields # 1 to # 3 corresponding to RU # 1, respectively, and the terminal allocation information of the terminals 11 and 12 is set, and the RU # 4 and RU # are also set. The terminal allocation information of terminals 14 and 15 acquired from AP1 is also set in Userfield # 4 and # 5 corresponding to 5, respectively.

In addition, AP1 also contains information on RUs (RU # 1, RU # 4, RU # 5, RU # 6) assigned by AP2 to terminals 21, terminals 23, terminals 27, and terminals 28, and terminal allocation information for these terminals. And get. Then, the terminal allocation information of the terminal 21 acquired from AP2 is set in User field # 3 among User fields # 1 to # 3 corresponding to RU # 1, and RU # 4, RU # 5, and RU # are set. The terminal allocation information of the terminals 23, 27, and 28 acquired from AP2 is set in Userfield # 6, # 7, and # 8 corresponding to 6.

By the above operation, Userfield # 1 to # 8 set by AP1 and Userfield # 1 to # 8 set by AP2 become the same. Further, as described above, the same value is set for AP1 and AP2 in the RU allocation Sub-field.

FIG. 23 shows a sequence of operations of the wireless LAN system according to the present embodiment. When the AP1 decides to execute the DL-OFDMA & MU-MIMO transmission performed in cooperation with the AP2, the AP1 transmits data including information (FFR information) necessary for the cooperation to the AP2 (S31).

More specifically, AP1 determines a RU allocation pattern having a RU having a number of tones capable of MU-MIMO, and determines the RU having that number of tones as the RU for FFR. In addition, AP1 determines the maximum number of DL-MU-MIMOs to be performed in the FFR RU. A certain value may be added to the multiple number desired by AP1, or the desired multiple number is notified in advance by AP2, and the sum of the desired multiple number by the own AP and the notified multiple number is obtained. It may be the maximum multiple number. The AP1 determines a value to be set in the RU allocation Sub-field (hereinafter referred to as a pattern setting value) from the determined RU allocation pattern and the maximum number of multiplexes.

Here, as in the above-described example, AP1 selects the 23rd RU allocation pattern and determines RU # 1 in FIG. 21 as the FFR RU. Further, the maximum number of multiplexes is determined to be 3, and the pattern setting value is set to "0100011". Further, terminals 11 and 12 are selected as terminals for performing DL-MU-MIMO. Further, terminals 14 and 15 are selected as terminals to which RU # 2 and RU # 3, which are RUs (normal RUs) other than the FFR RU, are assigned, respectively.

Based on the above determination, AP1 generates FFR information and transmits the generated FFR information to AP2. Specifically, the AP1 transmits a pattern setting value (RU allocation pattern and maximum number of multiplexes) and information for specifying the FFR RU (RU # 1) (FFR on information). Further, the terminal allocation information of the terminals 11 and 12 that use RU # 1 and the terminal allocation information of the terminals 14 and 15 that allocate RU # 2 and RU # 3 are transmitted. Further, information indicating that the terminal 11 corresponds to Userfield # 1 and the terminal 12 corresponds to Userfield # 2 may be transmitted. The details of the terminal allocation information are as described above.

AP2 grasps the RU allocation pattern to be used this time based on the FFR information received from AP1, and also grasps that RU # 1 is the RU for FFR and the maximum number of multiplexes is 3.
Further, AP2 determines that RU # 2 and RU # 3 are used in AP1 and that the own AP can use RU # 4 to RU # 6. Further, the AP2 determines that since the AP1 has already assigned two terminals to the RU # 1, the own AP can assign only one terminal to the RU # 1. Therefore, it is assumed that AP2 decides to assign the terminal 21 to RU # 1. Alternatively, it is assumed that AP2 decides to assign the terminal 23, the terminal 27, and the terminal 29 to RU # 4 to RU # 6. AP2 transmits the terminal allocation information of the terminal 21 assigned to RU # 1 and the terminal allocation information of terminals 23, 27, 28 assigned to RU # 4 to RU # 6 as FFR information to AP1. (S32).

When the AP1 receives the FFR information from the AP2, the AP1 determines the execution timing of the DL-OFDMA & MU-MIMO, and transmits the DL-MU start notification frame for which the execution timing is specified to the AP2 (S33).

AP1 and AP2 perform DL-OFDA & MU-MIMO transmission when the execution timing of DL-OFDA & MU-MIMO execution timing arrives (S34, S35).
As a result, DL-OFDA & MU-MIMO transmission is simultaneously performed by AP1 and AP2.

24 (A) and 24 (B) show examples of physical packets transmitted by AP1 and AP2. The legacy field and SIG1 field (including RU allocation Sub-field and User Special field) of the physical packet transmitted by AP1 are the same as the physical packet transmitted by AP2. The legacy field and the SIG1 field are transmitted in the channel width band. In RU # 1, the SIG2 field and the MAC frame are transmitted from AP1 to the terminal 11 and the terminal 12 in spatial multiplexing (2 multiplexing), and the SIG2 field and the MAC frame are spatially multiplexed (1 multiplexing) from AP2 to the terminal 21. Is sent by.

Here, the terminals 11 and 12 hold in advance spatial separation information (bit patterns) that are orthogonal to each other. Signals (preamble signals) having bit patterns orthogonal to each other are multiplexed in the SIG2 field of R1 # 1 transmitted by AP1. As a result, each of the terminals 11 and 12 extracts the signal by performing an operation on the signal in the SIG2 field based on the spatial separation information of the own terminal. The extracted signal is a signal whose amplitude and phase fluctuate depending on the propagation path. Each of the terminals 11 and 12 calculates the propagation path response based on this signal and the signal represented by the spatial separation information, and uses the propagation path response to separate the stream addressed to the own terminal after the SIG2 field. do. As a result, the MAC frame can be acquired. The stream separation method is not limited to this, and other methods are also possible. As the above spatial separation information, each row or each column of the orthogonal matrix can be used. In addition to the method of holding the space separation information in advance by the terminal, it is also possible to set the space separation information in the Userfield or the like for each terminal in the SIG1 field. Similarly, the SIG2 field transmitted by AP2 in RU # 2 also includes the same bit pattern as the spatial separation information held by the terminal 21.

The terminals 14 and 15 specified by the physical packet transmitted by the AP1 interpret the SIG1 field to identify the RU # 2 and RU # 3 assigned to the own terminal in the same manner as in the first embodiment. The signal of the specified RU is decoded and the MAC frame is received (S36). The SIG2 field transmitted by RU # 2 and RU # 3 may be, for example, a training field or another field. The terminals 11 and 12 receive the MAC frame by separating the stream of the own terminal from the signal transmitted by the RU # 1 by the above method.

On the other hand, the terminals 23, 27, and 28 specified by the physical packet transmitted by the AP2 interpret the SIG1 field in the same manner as in the first embodiment, and RU # 4, RU # 5 assigned to the own terminal. , RU # 6 is specified, the signal of the specified RU is decoded, and a MAC frame is received (S37). The SIG2 field transmitted by RU # 4, RU # 5, and RU # 6 may be, for example, a training field or another field. The terminal 21 receives the MAC frame by separating the stream of its own terminal from the signal transmitted by RU # 1 by the above method (S37). The terminal 27 and the terminal 28 receive the physical packet signal from both AP1 and AP2 at the same time, but since these legacy fields and the SIG1 field are the same, the received signal is correctly decoded and assigned to the own terminal. RU can be identified.

The 23rd RU allocation pattern used in the above example contains only one RU containing 106 or more tones, but an RU allocation pattern containing two or more of the RUs may be used. In that case, it is possible to perform DL-MU-MIMO in each of two or more RUs. For example, when the 24th RU allocation pattern in FIG. 3 is used, there are two 106-tone RUs (FFR RUs). Therefore, DL-MU-MIMO can be performed in each of the two FFR RUs. In this case, the RU allocation pattern is a pattern setting value that simultaneously represents the RU allocation pattern, the multiple number transmitted by the FFR RU on the left side (low frequency side), and the multiplex number transmitted by the FFR RU on the right side (high frequency side). It may be set to Sub-field.

For example, in the case of the 24th RU allocation pattern, the pattern setting value can be expressed in the format of _{"01y 2} y ₁ y ₀ z ₂ z ₁ z _0". y ₂ y ₁ y ₀ is a value in the range of 000 to 111, and z ₂ z ₁ z ₀ is a value in the range of 000 to 111. In y ₂ y ₁ y ₀ , a value corresponding to the maximum number of transmissions performed by the FFR RU on the left side is set, and in z ₂ z ₁ z ₀ , the maximum number of transmissions performed by the FFR RU on the right side is set. Set the value according to. For example, when the maximum multiply perfect number of the RU on the left side is 3, y ₂ y ₁ y ₀ is 011 and when the maximum multiply perfect number of the RU on the right side is 4, z ₂ z ₁ z ₀ is set to 100. do.

As described above, according to the present embodiment, AP1 and AP2 perform DL-MU-MIMO using the same RU (RU for FFR) among the plurality of RUs used in DL-OFDMA, and the physical header portion (SIG1). Make the contents of (field, etc.) the same between AP1 and AP2. As a result, the terminal that receives both the AP1 and AP2 signals can also decode the header portion and correctly receive the frame transmitted from the AP to which the own terminal belongs. Therefore, an FFR having high frequency efficiency can be realized in a wireless LAN system.

(Fourth Embodiment)
FIG. 25 is a functional block diagram of the base station (access point) 400 according to the present embodiment. This access point includes a communication processing unit 401, a transmitting unit 402, a receiving unit 403, antennas 42A, 42B, 42C, 42D, a network processing unit 404, a wired I / F 405, and a memory 406. .. The access point 400 is connected to the server 407 via a wired I / F 405. At least the former of the communication processing unit 401 and the network processing unit 404 has the same functions as the control unit described in the first embodiment. The transmitting unit 402 and the receiving unit 403 have the same functions as the transmitting unit and the receiving unit described in the first embodiment. Alternatively, the transmitting unit 402 and the receiving unit 403 correspond to the processing of the analog area of the transmitting unit and the receiving unit of the first embodiment, and the processing of the digital area of the transmitting unit and the receiving unit of the first embodiment communicates. It may correspond to the processing unit 401. The network processing unit 404 has the same function as the upper processing unit. Here, the communication processing unit 401 may internally hold a buffer for transferring data to and from the network processing unit 404. This buffer may be a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM.

The network processing unit 404 controls data exchange with the communication processing unit 401, data writing / reading with the memory 406, and communication with the server 407 via the wired I / F 405. The network processing unit 404 may perform communication processing higher than the MAC layer and processing of the application layer such as TCP / IP and UDP / IP. The operation of the network processing unit may be performed by processing software (program) by a processor such as a CPU, may be performed by hardware, or may be performed by both software and hardware.

As an example, the communication processing unit 401 corresponds to a baseband integrated circuit, and the transmitting unit 402 and the receiving unit 403 correspond to an RF integrated circuit that transmits and receives frames. The communication processing unit 401 and the network processing unit 404 may be configured by one integrated circuit (one chip). The digital region processing portion and the analog region processing portion of the transmission unit 402 and the reception unit 403 may be composed of different chips. Further, the communication processing unit 401 may execute communication processing higher than the MAC layer such as TCP / IP and UDP / IP. Further, although the number of antennas is four here, it is sufficient that at least one antenna is provided.

The memory 406 stores the data received from the server 407 and the data received by the receiving unit 403. The memory 406 may be, for example, a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM. Further, it may be SSD, HDD, SD card, eMMC or the like. The memory 406 may be outside the base station 400.

The wired I / F 405 sends and receives data to and from the server 407. In the present embodiment, the communication with the server 407 is performed by wire, but the communication with the server 407 may be performed wirelessly.

The server 407 is a communication device that receives a data transfer request requesting data transmission and returns a response including the requested data, and is assumed to be, for example, an HTTP server (Web server), an FTP server, or the like. However, it is not limited to this as long as it has a function of returning the requested data. It may be a communication device operated by a user such as a PC or a smartphone. Moreover, you may communicate with the base station 400 wirelessly.

When the STA belonging to the BSS of the base station 400 issues a data transfer request to the server 407, a packet related to the data transfer request is transmitted to the base station 400. The base station 400 receives this packet via the antennas 42A to 42D, and the receiving unit 403 executes the physical layer processing and the like, and the communication processing unit 401 executes the MAC layer processing and the like.

The network processing unit 404 analyzes the packet received from the communication processing unit 401.
Specifically, the destination IP address, destination port number, and the like are confirmed. When the data of the packet is a data transfer request such as an HTTP GET request, the network processing unit 404 determines that the data requested by this data transfer request (for example, the data existing in the URL requested by the HTTP GET request) is Check if it is cached in memory 406. The memory 406 stores a table in which a URL (or its reduced representation, for example, a hash value or an alternative identifier) is associated with data. Here, the fact that the data is cached in the memory 406 is expressed as the existence of the cached data in the memory 406.

When the cache data does not exist in the memory 406, the network processing unit 404 transmits a data transfer request to the server 407 via the wired I / F 405. That is, the network processing unit 404 transmits a data transfer request to the server 407 on behalf of the STA. Specifically, the network processing unit 404 generates an HTTP request, performs protocol processing such as adding a TCP / IP header, and passes the packet to the wired I / F 405.
The wired I / F 405 transmits the received packet to the server 407.

The wired I / F 405 receives a packet from the server 407 that is a response to the data transfer request. The network processing unit 404 grasps that the packet is addressed to the STA from the IP header of the packet received via the wired I / F 405, and passes the packet to the communication processing unit 401. The communication processing unit 401 executes the processing of the MAC layer for this packet, the transmitting unit 402 executes the processing of the physical layer, etc., and transmits the packet addressed to the STA from the antennas 42A to 42D.
Here, the network processing unit 404 associates the data received from the server 407 with the URL (or its reduced representation) and stores it in the memory 406 as cache data.

When the cache data exists in the memory 406, the network processing unit 404 reads the data requested by the data transfer request from the memory 406 and transmits this data to the communication processing unit 401. Specifically, an HTTP header or the like is added to the data read from the memory 406, protocol processing such as addition of a TCP / IP header is performed, and a packet is transmitted to the communication processing unit 401. At this time, as an example, the source IP address of the packet is set to the same IP address as the server, and the source port number is also set to the same port number as the server (the destination port number of the packet transmitted by the communication terminal). Therefore, from the viewpoint of STA, it looks as if it is communicating with the server 407. The communication processing unit 401 executes the processing of the MAC layer for this packet, the transmitting unit 402 executes the processing of the physical layer, etc., and transmits the packet addressed to the STA from the antennas 42A to 42D.

By such an operation, the frequently accessed data responds based on the cache data stored in the memory 406, and the traffic between the server 407 and the base station 400 can be reduced. The operation of the network processing unit 404 is not limited to the operation of the present embodiment. Any general cache proxy that fetches data from server 407 instead of STA, caches the data in memory 406, and responds to data transfer requests for the same data from the cached data in memory 406. For example, there is no problem with another operation.

The base station (access point) of the present embodiment can be applied as the base station of any of the above-described embodiments. The transmission of frames, data or packets used in any of the above embodiments may be performed using the cached data stored in memory 406. Further, the information obtained by the frame, data or packet received by the base station of any of the above-described embodiments may be cached in the memory 406. In any of the embodiments described above, the frame transmitted by the access point may include cached data or information based on the data. The information based on the data may be, for example, information on the size of the data or information on the size of the packet required for transmitting the data. It may also be information such as a modulation method required for data transmission. In addition, information on the presence or absence of data addressed to the terminal may be included.

The base station (access point) of the present embodiment can be applied as the base station of any of the above-described embodiments. In the present embodiment, the base station having a cache function has been described, but a terminal (STA) having a cache function can also be realized with the same block configuration as in FIG. 25. In this case, the wired I / F 405 may be omitted. Transmission of frames, data or packets by the terminal in any of the above embodiments may be performed using cached data stored in memory 406. Further, the information obtained by the frame, data or packet received by the terminal of any of the above-described embodiments may be cached in the memory 406. In any of the embodiments described above, the frame transmitted by the terminal may include cached data or information based on the data. The information based on the data may be, for example, information on the size of the data or information on the size of the packet required for transmitting the data. It may also be information such as a modulation method required for data transmission. In addition, information on the presence or absence of data addressed to the terminal may be included.

(Fifth Embodiment)
FIG. 26 shows an example of the overall configuration of a terminal (a terminal of a non-access point) or an access point. This configuration example is an example, and the present embodiment is not limited thereto. The terminal or access point includes one or more antennas 1 to n (n is an integer of 1 or more), a wireless LAN module 148, and a host system 149. The wireless LAN module 148 corresponds to the wireless communication device according to any one of the above-described embodiments. The wireless LAN module 148 includes a host interface, which is connected to the host system 149. In addition to being connected to the host system 149 via a connection cable, it may be directly connected to the host system 149. Further, the wireless LAN module 148 can be mounted on the board by solder or the like and connected to the host system 149 via the wiring of the board. The host system 149 communicates with an external device by using the wireless LAN module 148 and the antennas 1 to n according to an arbitrary communication protocol.
The communication protocol may include TCP / IP and a higher layer protocol.
Alternatively, TCP / IP may be mounted on the wireless LAN module 148, and the host system 149 may execute only the protocol of the upper layer. In this case, the configuration of the host system 149 can be simplified. This terminal is, for example, a mobile terminal, TV, digital camera, wearable device, tablet, smartphone, game device, network storage device, monitor, digital audio player, Web camera, video camera, project, navigation system, external adapter, internal It may be an adapter, a set-top box, a gateway, a printer server, a mobile access point, a router, an enterprise / service provider access point, a portable device, a handheld device, an automobile, or the like.
The wireless LAN module 148 (or wireless communication device) may have functions of other wireless communication standards such as LTE (Long Term Evolution) or LTE-Advanced (standards for mobile phones) in addition to 802.11. ..

FIG. 27 shows a hardware configuration example of the wireless LAN module. This configuration is applicable when the wireless communication device is mounted on either a non-access point terminal or an access point. That is, it can be applied as an example of a specific configuration of the wireless communication device in any of the above-described embodiments. In this configuration example, the number of antennas is only one, but two or more antennas may be provided. In this case, a plurality of sets of transmission system (116, 122 to 125), reception system (117, 132 to 135), PLL 142, crystal oscillator (reference signal source) 143, and switch 145 are arranged corresponding to each antenna. Each set may be connected to the control circuit 112. The PLL 142 and / or crystal oscillator 143 correspond to the oscillator according to this embodiment. When the AP-to-AP communication is performed by a wired method as shown in FIG. 13B, the wired IC may be configured by using a filter, a PLL, an amplifier, or the like and connected to the baseband IC 111 in the same manner as the RF IC.

The wireless LAN module (wireless communication device) is a baseband IC (Integrated).
It includes a Circuit) 111, an RF (Radio Frequency) IC 121, a balun 125, a switch 145, and an antenna 147.

The baseband IC 111 includes a baseband circuit (control circuit) 112, a memory 113, a host interface 114, a CPU 115, a DAC (Digital to Analog Converter) 116, and an ADC (Analog to Digital Converter) 117.

The baseband IC 111 and RF IC 121 may be formed on the same substrate. Further, the baseband IC 111 and the RF IC 121 may be composed of one chip. DAC116 and / or ADC117 may be located in the RF IC 121 or in another IC. Further, the memory 113 and / or the CPU 115 may be arranged in an IC different from the baseband IC.

The memory 113 stores data to be transferred to and from the host system. Further, the memory 113 stores information notified to the terminal or the access point, information notified from the terminal or the access point, or both of them. Further, the memory 113 may store a program necessary for executing the CPU 115 and may be used as a work area when the CPU 115 executes the program. The memory 113 may be a volatile memory such as SRAM or DRAM, or a non-volatile memory such as NAND or MRAM.

The host interface 114 is an interface for connecting to the host system. The interface may be anything such as UART, SPI, SDIO, USB, PCI Express and the like.

The CPU 115 is a processor that controls the baseband circuit 112 by executing a program. The baseband circuit 112 mainly processes the MAC layer and the physical layer. The baseband circuit 112, the CPU 115, or both correspond to a communication control device that controls communication, or a control unit that controls communication.

At least one of the baseband circuit 112 and the CPU 115 includes a clock generation unit that generates a clock, and the internal time may be managed by the clock generated by the clock generation unit.

The baseband circuit 112 performs physical header addition, coding, encryption, modulation processing (may include MIMO modulation) and the like as physical layer processing on the frame to be transmitted, for example, two types of digital baseband signals (which may include MIMO modulation). Hereinafter, a digital I signal and a digital Q signal) are generated.

The DAC 116 performs DA conversion of the signal input from the baseband circuit 112. More specifically, the DAC 116 converts the digital I signal into an analog I signal and the digital Q signal into an analog Q signal. In addition, there may be a case where a single system signal is transmitted as it is without quadrature modulation. When a plurality of antennas are provided and transmission signals of one system or a plurality of systems are distributed and transmitted by the number of antennas, a number of DACs or the like corresponding to the number of antennas may be provided.

The RF IC 121 is, for example, an RF analog IC, a high frequency IC, or both of them. The RF IC 121 includes a filter 122, a mixer 123, a preamplifier (PA) 124, a PLL (Phase Locked Loop) 142, a low noise amplifier (LNA), a balun 135, a mixer 133, and a filter 132.
Some of these elements may be located on baseband IC 111 or another IC. The filters 122 and 132 may be a band pass filter or a low pass filter.

The filter 122 extracts a signal in a desired band from each of the analog I signal and the analog Q signal input from the DAC 116. The PLL 142 uses an oscillating signal input from the crystal oscillator 143, and divides or multiplies the oscillating signal, or both, to generate a signal having a constant frequency synchronized with the phase of the input signal. The PLL 142 includes a VCO (Voltage Controlled Oscillator), and obtains a signal having a constant frequency by performing feedback control using the VCO based on an oscillation signal input from the crystal oscillator 143. The generated constant frequency signal is input to the mixer 123 and the mixer 133. The PLL 142 corresponds to an example of an oscillator that generates a signal having a constant frequency.

The mixer 123 up-converts the analog I signal and the analog Q signal that have passed through the filter 122 to a radio frequency by using a signal having a constant frequency supplied from the PLL 142. The preamplifier (PA) amplifies the radio frequency analog I and Q signals generated by the mixer 123 to the desired output power. The balun 125 is a converter for converting a balanced signal (differential signal) into an unbalanced signal (single-ended signal). The RF IC 121 handles balanced signals, but since the unbalanced signals are handled from the output of the RF IC 121 to the antenna 147, the balun 125 performs these signal conversions.

The switch 145 is connected to the transmitting side balun 125 at the time of transmission, and is connected to the receiving side low noise amplifier (LNA) 134 or RF IC 121 at the time of reception. The control of the switch 145 may be performed by the baseband IC 111 or the RF IC 121, or another circuit for controlling the switch 145 may exist and the switch 145 may be controlled from the circuit.

The radio frequency analog I signal and analog Q signal amplified by the preamplifier 124 are balanced-unbalanced converted by the balun 125 and then radiated as radio waves from the antenna 147 into space.

The antenna 147 may be a chip antenna, an antenna formed by wiring on a printed circuit board, or an antenna formed by using a linear conductor element.

The LNA 134 in the RF IC 121 amplifies the signal received from the antenna 147 via the switch 145 to a level that can be demodulated while keeping noise low. The balun 135 unbalances-balances the signal amplified by the low noise amplifier (LNA) 134. The order of the balun 135 and the LNA 134 may be reversed. The mixer 133 down-converts the received signal converted into the balanced signal by the balun 135 into the baseband using the signal of a constant frequency input from the PLL 142. More specifically, the mixer 133 has means for generating carriers that are 90 ° out of phase with each other based on a constant frequency signal input from the PLL 142, and receives signals converted by the balun 135 at 90 ° to each other. It is orthogonally demodulated by the out-of-phase carrier wave to generate an I (In-phase) signal having the same phase as the received signal and a Q (Quad-phase) signal having a phase delayed by 90 ° from the I (In-phase) signal. The filter 132 extracts a signal of a desired frequency component from these I signal and Q signal. The I signal and Q signal extracted by the filter 132 are output from the RF IC 121 after the gain is adjusted.

The ADC 117 in the baseband IC 111 AD-converts the input signal from the RF IC 121. More specifically, the ADC 117 converts the I signal into a digital I signal and the Q signal into a digital Q signal. In some cases, only one system of signals may be received without orthogonal demodulation.

When a plurality of antennas are provided, the number of ADCs may be provided according to the number of antennas. Based on the digital I signal and the digital Q signal, the baseband circuit 112 performs physical layer processing (may include MIMO demodulation) such as demodulation processing, error correction code processing, and physical header processing to obtain a frame. The baseband circuit 112 processes the MAC layer on the frame. If the baseband circuit 112 implements TCP / IP, the baseband circuit 112 can also be configured to perform TCP / IP processing.

(Sixth Embodiment)
FIG. 28 is a functional block diagram of the terminal (STA) 500 according to the sixth embodiment. The STA 5 includes a communication processing unit 501, a transmitting unit 502, a receiving unit 503, an antenna 51A, an application processor 504, a memory 505, and a second wireless communication module 506. The base station (AP) may have a similar configuration.

The communication processing unit 501 has the same function as the control unit described in the first embodiment. The transmitting unit 502 and the receiving unit 503 have the same functions as the transmitting unit and the receiving unit described in the first embodiment. Alternatively, the transmitting unit 502 and the receiving unit 503 correspond to the processing of the analog area of the transmitting unit and the receiving unit described in the first embodiment, and the digital area of the transmitting unit and the receiving unit described in the first embodiment. The processing may correspond to the communication processing unit 501. Here, the communication processing unit 501 may internally hold a buffer for transferring data to and from the application processor 504. This buffer may be a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM.

The application processor 504 controls wireless communication via the communication processing unit 501, data writing / reading with the memory 505, and wireless communication via the second wireless communication module 506. The application processor 504 also executes various processes in the STA, such as Web browsing and multimedia processing such as video and music. The operation of the application processor 504 may be performed by processing software (program) by a processor such as a CPU, may be performed by hardware, or may be performed by both software and hardware.

The memory 505 stores the data received by the receiving unit 503 and the second wireless communication module 506, the data processed by the application processor 504, and the like. The memory 505 may be, for example, a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM. Further, SSD, HDD, SD card, eMMC and the like may be used. The memory 505 may be outside the access point 500.

As an example, the second wireless communication module 506 has the same configuration as the wireless LAN module shown in FIG. 26 or FIG. 27. The second wireless communication module 506 executes wireless communication by a method different from the wireless communication realized by the communication processing unit 501, the transmitting unit 502, and the receiving unit 503. For example, when the communication processing unit 501, the transmitting unit 502, and the receiving unit 503 are wireless communications conforming to the IEEE802.11 standard, the second wireless communication module 506 may be another wireless communication module 506 such as Bluetooth®, LTE, or Wireless HD. Wireless communication may be performed according to the wireless communication standard. Further, the communication processing unit 501, the transmission unit 502, and the reception unit 503 may execute wireless communication at 2.4 GHz / 5 GHz, and the second wireless communication module 506 may execute the radio frequency renewal at 60 GHz.

In this example, the number of antennas is one here, and the antennas are shared by the transmitting unit 502 / receiving unit 503 and the second wireless communication module 506. Here, the antenna may be shared by providing a switch for controlling the connection destination of the antenna 51A. Further, a plurality of antennas may be provided, and different antennas may be used by the transmitting unit 502 / receiving unit 503 and the second wireless communication module 506.

As an example, the communication processing unit 501 corresponds to a baseband integrated circuit, and the transmitting unit 502 and the receiving unit 503 correspond to an RF integrated circuit that transmits and receives frames. Here, the communication processing unit 501 and the application processor 504 may be configured by one integrated circuit (one chip). Further, a part of the second wireless communication module 506 and the application processor 504 may be configured by one integrated circuit (1 chip).

The application processor controls wireless communication via the communication processing unit 501 and wireless communication via the second wireless communication module 506.

(7th Embodiment)
29 (A) and 29 (B) are perspective views of the wireless terminal according to the present embodiment. The wireless terminal of FIG. 29 (A) is a notebook PC 301, and the wireless terminal of FIG. 29 (B) is a mobile terminal 321. The notebook PC 301 and the mobile terminal 321 are equipped with wireless communication devices 305 and 315, respectively. As the wireless communication devices 305 and 315, the wireless communication device mounted on the wireless terminal described above, the wireless communication device mounted on the access point, or both of them can be used. The wireless terminal equipped with the wireless communication device is not limited to a notebook PC or a mobile terminal. For example, TVs, digital cameras, wearable devices, tablets, smartphones, game devices, network storage devices, monitors, digital audio players, web cameras, video cameras, projects, navigation systems, external adapters, internal adapters, set-top boxes, gateways, etc. It can also be installed in printer servers, mobile access points, routers, enterprise / service provider access points, portable devices, handheld devices, automobiles, and the like.

Further, the wireless communication device mounted on the wireless terminal, the access point, or both of them can also be mounted on the memory card. FIG. 30 shows an example in which the wireless communication device is mounted on a memory card. The memory card 331 includes a wireless communication device 355 and a memory card main body 332. The memory card 331 utilizes the wireless communication device 335 for wireless communication with an external device (wireless terminal and / or access point, etc.). In FIG. 30, the description of other elements (for example, memory, etc.) in the memory card 331 is omitted.

(8th Embodiment)
In the present embodiment, in addition to the configuration of the wireless communication device (the wireless communication device of the access point, the wireless communication device of the wireless terminal, or both) according to any one of the above-described embodiments, the bus, the processor unit, and the external are added. It has an interface unit. The processor unit and the external interface unit are connected to the external memory (buffer) via the bus. Firmware runs in the processor section. By including the firmware in the wireless communication device in this way, it is possible to easily change the function of the wireless communication device by rewriting the firmware. The processor unit on which the firmware operates may be a control unit or a processor that performs processing of the control unit according to the present embodiment, or may be another processor that performs processing related to function expansion or modification of the processing. good. The processor unit on which the firmware operates may be provided by the access point, the wireless terminal, or both of them according to the present embodiment. Alternatively, the processor unit may be provided with an integrated circuit in a wireless communication device mounted on an access point or an integrated circuit in a wireless communication device mounted on a wireless terminal.

(9th Embodiment)
The present embodiment includes a clock generator in addition to the configuration of the wireless communication device (access point wireless communication device, wireless terminal wireless communication device, or both) according to any of the above-described embodiments. The clock generator generates a clock and outputs the clock from the output terminal to the outside of the wireless communication device. In this way, the clock generated inside the wireless communication device is output to the outside, and the host side is operated by the clock output to the outside, so that the host side and the wireless communication device side can be operated in synchronization with each other. It will be possible.

(10th Embodiment)
In the present embodiment, in addition to the configuration of the wireless communication device (the wireless communication device of the access point or the wireless communication device of the wireless terminal) according to any one of the above-described embodiments, the power supply unit, the power supply control unit, and the wireless power supply unit including. The power supply control unit is connected to the power supply unit and the wireless power supply unit, and controls to select the power supply to be supplied to the wireless communication device. By providing the wireless communication device with the power supply in this way, it is possible to perform a power consumption reduction operation in which the power supply is controlled.

(11th Embodiment)
The present embodiment includes a SIM card in addition to the configuration of the wireless communication device according to any one of the above-described embodiments. The SIM card is connected to a transmitting unit, a receiving unit, a control unit, or a plurality of these in a wireless communication device. In this way, by providing the SIM card in the wireless communication device, it is possible to easily perform the authentication process.

(12th Embodiment)
In this embodiment, in addition to the configuration of the wireless communication device according to any one of the above-described embodiments, a moving image compression / decompression unit is included. The moving image compression / decompression section is connected to the bus. As described above, by providing the moving image compression / decompression unit in the wireless communication device, it is possible to easily transmit the compressed moving image and decompress the received compressed moving image.

(13th Embodiment)
The present embodiment includes an LED unit in addition to the configuration of the wireless communication device (the wireless communication device of the access point, the wireless communication device of the wireless terminal, or both) according to any one of the above-described embodiments. The LED unit is connected to a transmitting unit, a receiving unit, a control unit, or a plurality of these. By providing the LED unit in the wireless communication device in this way, it is possible to easily notify the user of the operating state of the wireless communication device.

(14th Embodiment)
The present embodiment includes a vibrator unit in addition to the configuration of the wireless communication device (the wireless communication device of the access point, the wireless communication device of the wireless terminal, or both) according to any one of the above-described embodiments. The vibrator unit is connected to a transmission unit, a reception unit, a control unit, or a plurality of these. By providing the vibrator unit in the wireless communication device in this way, it is possible to easily notify the user of the operating state of the wireless communication device.

(15th Embodiment)
The present embodiment includes a display in addition to the configuration of the wireless communication device (access point wireless communication device, wireless terminal wireless communication device, or both) according to any of the above-described embodiments. The display may be connected to the control unit of the wireless communication device via a bus (not shown). By providing the display in this way and displaying the operating state of the wireless communication device on the display, it is possible to easily notify the user of the operating state of the wireless communication device.

(16th Embodiment)
In this embodiment, [1] a frame type in a wireless communication system, [2] a method of disconnecting a connection between wireless communication devices, [3] an access method of a wireless LAN system, and [4] a frame interval of a wireless LAN will be described.
[1] Frame types in communication systems Generally, as described above, frames handled on a wireless access protocol in a wireless communication system are roughly classified into three frames: a data frame, a management frame, and a control frame. It can be divided into types. These types are usually indicated by a header portion commonly provided between frames. As a display method of the frame type, one field may be capable of distinguishing three types, or a combination of two fields may be used to distinguish between the three types. In the IEEE802.11 standard, the frame type is identified by two fields, Type and Subtype, in the Frame Control field in the frame header part of the MAC frame. The data frame, the management frame, and the control frame are roughly classified in the Type field, and the subtypes in the roughly classified frames, for example, the Beacon frame in the management frame, are identified in the Subtype field.

The management frame is a frame used for managing a physical communication link with another wireless communication device. For example, there are frames used for setting communication with other wireless communication devices, frames for releasing (that is, disconnecting) communication links, and frames for power saving operation in wireless communication devices. ..

A data frame is a frame that transmits data generated inside a wireless communication device to another wireless communication device after establishing a physical communication link with the other wireless communication device. The data is generated in the upper layer of the present embodiment, and is generated by, for example, a user operation.

The control frame is a frame used for control when transmitting (exchanged) a data frame with another wireless communication device. When the wireless communication device receives a data frame or a management frame, the response frame transmitted to confirm the delivery belongs to the control frame. The response frame is, for example, an ACK frame or a BlockACK frame. The RTS frame and CTS frame are also control frames.

These three types of frames are processed as necessary in the physical layer and transmitted as physical packets via the antenna. In addition, the IEEE802.11 standard (the above-mentioned IEEE Std)
In (including extended standards such as 802.11ac-2013), there is an association process as one of the procedures for establishing a connection, but the Association Request frame and the Association Response frame used in it are the management frames, and the Association Request frame. Since the frame and the Association Response frame are unicast management frames, the receiving wireless communication terminal is requested to transmit the ACK frame which is the response frame, and this ACK frame is the control frame as described above.

[2] Method of disconnecting the connection between wireless communication devices There are an explicit method and an implicit method for disconnecting (releasing) the connection. As an explicit method, one of the wireless communication devices having established a connection transmits a frame for disconnection. In the IEEE802.11 standard, the Delivery frame corresponds to this and is classified as a management frame. Normally, the wireless communication device on the side that transmits the frame that disconnects the connection disconnects the connection when the frame is transmitted, and the wireless communication device that receives the frame that disconnects the connection receives the frame. judge. After that, if it is a non-base station wireless communication terminal, it returns to the initial state in the communication phase, for example, the state of searching for a BSS to be connected. When the wireless communication base station disconnects from a certain wireless communication terminal, for example, if the wireless communication base station has a connection management table that manages the wireless communication terminals that subscribe to its own BSS, the connection management Delete the information related to the wireless communication terminal from the table. For example, when the wireless communication base station assigns an AID to each wireless communication terminal that subscribes to its own BSS in the association process, the retained information associated with the AID of the wireless communication terminal that disconnected the connection is used. May be deleted and the AID may be released so that it can be assigned to another newly subscribed wireless communication terminal.

On the other hand, as an implicit method, frame transmission (transmission of data frame and management frame, or transmission of response frame to the frame transmitted by the own device) is detected from the wireless communication device of the connection partner with which the connection is established for a certain period of time. If not, the connection status is determined to be disconnected. There is such a method because, in the situation where the disconnection of the connection is determined as described above, the communication distance from the wireless communication device to which the connection is made is so large that the wireless signal cannot be received or decoded. This is because it is possible that the wireless link cannot be secured. That is, the reception of the frame that disconnects the connection cannot be expected.

A timer is used as a specific example of determining the disconnection by an implicit method. For example, when transmitting a data frame requesting a delivery confirmation response frame, a first timer (for example, a retransmission timer for a data frame) that limits the retransmission period of the frame is activated until the first timer expires (that is,). If the delivery confirmation response frame to the frame is not received (until the desired retransmission period elapses), retransmission is performed. The first timer is stopped when the delivery confirmation response frame to the frame is received.

On the other hand, when the first timer expires without receiving the delivery confirmation response frame, for example, it is confirmed whether the wireless communication device of the connection partner still exists (in the communication range) (in other words, whether the wireless link can be secured). At the same time, a second timer (for example, a retransmission timer for the management frame) that limits the retransmission period of the frame is activated. Like the first timer, the second timer retransmits if the delivery confirmation response frame to the frame is not received until the second timer expires, and when the second timer expires, it is determined that the connection has been disconnected. .. When it is determined that the connection has been disconnected, a frame for disconnecting the connection may be transmitted.

Alternatively, when a frame is received from the wireless communication device of the connection partner, the third timer is activated, and each time a frame is newly received from the wireless communication device of the connection partner, the third timer is stopped and the frame is started again from the initial value. When the third timer expires, a management frame is sent to check whether the wireless communication device of the connection partner still exists (in the communication range) (in other words, whether the wireless link is secured) as described above. At the same time, a second timer (for example, a retransmission timer for the management frame) that limits the retransmission period of the frame is activated. In this case as well, if the delivery confirmation response frame to the frame is not received until the second timer expires, retransmission is performed, and when the second timer expires, it is determined that the connection is disconnected. In this case as well, the frame for disconnecting the connection may be transmitted when it is determined that the connection has been disconnected.
The latter management frame for confirming whether the wireless communication device of the connection partner still exists may be different from the management frame in the former case. Further, as the timer for limiting the retransmission of the management frame in the latter case, the same timer as in the former case is used here as the second timer, but a different timer may be used.

[3] Access method of wireless LAN system For example, there is a wireless LAN system that assumes communication or competition with a plurality of wireless communication devices. In the IEEE802.11 wireless LAN, CSMA / CA (Carrier Sense Multiple Access with Carrier Availability) is the basis of the access method. In the method of grasping the transmission of a certain wireless communication device and transmitting after a fixed time from the end of the transmission, the transmission is performed simultaneously by a plurality of wireless communication devices that have grasped the transmission of the wireless communication device, and as a result, the transmission is performed. , Radio signals collide and frame transmission fails. By grasping the transmission of a certain wireless communication device and waiting for a random time from the end of the transmission, the transmission by a plurality of wireless communication devices grasping the transmission of the wireless communication device is stochastically dispersed. Therefore, if there is only one wireless communication device in which the earliest time is subtracted from the random time, the frame transmission of the wireless communication device is successful, and frame collision can be prevented. Since the acquisition of transmission rights is fair among a plurality of wireless communication devices based on a random value, the method adopting Carrier Availability is said to be a method suitable for sharing a wireless medium among a plurality of wireless communication devices. be able to.

[4] Wireless LAN Frame Interval The frame interval of the IEEE802.11 wireless LAN will be described. The frame intervals used in the IEEE802.11 wireless LAN are distributed coordination faction interframe space (DIFS), arbitration interframe space (AIFS), point coordination functionSemperencecept , Reduced interframe space (DIRFS) and the like.

The definition of the frame interval is defined as a continuous period in which the carrier sense idle should be confirmed and opened before transmission in the IEEE802.11 wireless LAN, and the exact period from the previous frame is not discussed. Therefore, the definition is followed in the description of the IEEE802.11 wireless LAN system here. In the IEEE802.11 wireless LAN, the time to wait for random access based on CSMA / CA is the sum of the fixed time and the random time, and it can be said that this definition is used to clarify the fixed time.

DIFS and AIFS are frame intervals used when attempting to start frame exchange during a contention period that competes with other wireless communication devices based on CSMA / CA. DIFS is used when there is no distinction of priority by traffic type, and AIFS is used when priority is provided by traffic type (Traffic Identity).

Since the operations related to DIFS and AIFS are similar, they will be described mainly using AIFS below. In the IEEE802.11 wireless LAN, access control including the start of frame exchange is performed at the MAC layer. Further, when QoS (Quality of Service) is supported when the data is passed from the upper layer, the traffic type is notified together with the data, and the data is classified into the priority at the time of access based on the traffic type. The class at the time of this access is called an access category (AC). Therefore, the AIFS value is provided for each access category.

PIFS is a frame interval for allowing access with priority over other competing wireless communication devices, and has a shorter period than either the value of DIFS or AIFS. SIFS is a frame interval that can be used when transmitting a control frame of a response system or when continuing frame exchange in a burst after acquiring an access right once. EIFS is a frame interval that is activated when frame reception fails (it is determined that the received frame is an error).

RIFS is a frame interval that can be used when a plurality of frames are continuously transmitted to the same wireless communication device in a burst after the access right is once acquired, and while RIFS is used, the transmission partner's wireless communication device can be used. Does not request a response frame for.

Here, FIG. 31 shows an example of frame exchange during a competing period based on random access in the IEEE802.11 wireless LAN.

It is assumed that when a data frame (W_DATA1) transmission request is generated in a certain wireless communication device, the medium is recognized as busy medium as a result of carrier sense. In this case, the AIFS for a fixed time is vacated from the time when the carrier sense becomes idle, and then the data frame W_DATA1 is transmitted to the communication partner when a random time (random backoff) is vacated. If, as a result of the carrier sense, it is recognized that the medium is not busy, that is, the medium is idle, a fixed time AIFS is provided from the time when the carrier sense is started, and the data frame W_DATA1 is communicated with the communication partner. Send to.

The random time is a pseudo-random integer derived from a uniform distribution between the content windows (CW) given as an integer from 0, multiplied by the slot time. Here, the CW multiplied by the slot time is called the CW time width.
The initial value of CW is given in CWmin, and each time it is retransmitted, the value of CW is increased until it reaches CWmax. Both CWmin and CWmax have values for each access category, similar to AIFS. In the wireless communication device of the transmission destination of W_DATA1, if the data frame is successfully received and the data frame is a frame requesting the transmission of the response frame, the occupation of the physical packet containing the data frame ends on the wireless medium. A response frame (W_ACK1) is transmitted after SIFS time from the time point. When the wireless communication device that has transmitted W_DATA1 receives W_ACK1, it transmits the next frame (for example, W_DATA2) after SIFS time from the end of occupancy of the physical packet containing W_ACK1 on the wireless medium if it is within the transmission burst time limit. can do.

AIFS, DIFS, PIFS and AIFS are functions of SIFS and slot time, but SIFS and slot time are defined for each physical layer. In addition, parameters such as AIFS, CWmin, and CWmax for which values are set for each access category can be set for each communication group (Basic Service Set (BSS) in the 802.11 wireless LAN), but default values are set. ..

For example, in the standardization of 802.11ac, SIFS is 16 μs and slot time is 9 μs, so that PIFS is 25 μs, DIFS is 34 μs, and the default value of the frame interval of access category BACKGROUND (AC_BK) in AIFS is 79 μs. The default frame spacing of BEST EFFORT (AC_BE) is 43 μs, the default frame spacing of VIDEO (AC_VI) and VOICE (AC_VO) is 34 μs, and the default values of CWmin and CWmax are 31 and 1023 for AC_BK and AC_BE, respectively. , AC_VI is 15 and 31, and AC_VO is 7 and 15. Note that EIFS is basically the sum of SIFS and DIFS and the time length of the response frame when transmitting at the slowest essential physical rate. In a wireless communication device capable of efficiently taking EIFS, the occupancy time length of the physical packet carrying the response frame to the physical packet that activated EIFS can be estimated, and the sum of SIFS, DIFS, and the estimated time can be used. can.

The frame described in each embodiment may refer to an IEEE802.11 standard or a compliant standard such as Null Data Packet, which is called a packet.

The terms used in this embodiment should be broadly interpreted. For example, the term "processor" may include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, and the like. In some circumstances, "processor" may refer to application-specific integrated circuits, field programmable gate arrays (FPGAs), programmable logic circuits (PLDs), and the like. A "processor" may refer to a combination of processing devices such as multiple microprocessors, a combination of DSPs and microprocessors, and one or more microprocessors that work with a DSP core.

As another example, the term "memory" may include any electronic component capable of storing electronic information. "Memory" includes random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable PROM (EEPROM), and non-volatile. It may refer to random access memory (NVRAM), flash memory, magnetic or optical data storage, which can be read by a processor. If the processor reads and writes information to the memory, or both, then the memory can be said to communicate electrically with the processor. The memory may be integrated into the processor, again which can be said to be in electrical communication with the processor. Further, the circuit may be a plurality of circuits arranged on a single chip, or may be one or more circuits distributed on a plurality of chips or a plurality of devices.

Further, in the present specification, "at least one of a, b and / or c" is not only a combination of a, b, c, ab, ac, bc, abc, but also a combination. It is an expression including a plurality of combinations of the same elements such as a-a, a-bb, a-a-b-b-c-c. Further, it is an expression that covers a configuration including elements other than a, b, and c, such as a combination of abc-d.

The present invention is not limited to the above embodiment as it is, and at the implementation stage, the components can be modified and embodied without departing from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

[Item 1]
A receiver that receives a terminal identifier of a first terminal designated as a target of downlink frequency division multiplexing by another wireless communication device and information that identifies a first frequency component assigned to the first terminal among a plurality of frequency components. When,
A control unit that selects a second terminal having the same terminal identifier as the first terminal from a plurality of second terminals belonging to the own device and assigns the first frequency component to the selected second terminal.
A header in which the terminal identifier of the selected second terminal is set in the first field related to the first frequency component is transmitted in a band including the plurality of frequency components, and the first frame addressed to the selected second terminal is transmitted. A wireless communication device including a transmission unit that transmits the first frequency component.
[Item 2]
The wireless communication device according to item 1, wherein the transmission unit transmits the header at a predetermined timing.
[Item 3]
The receiving unit receives the execution timing information of the downlink frequency multiplex transmission from the other wireless communication device, and receives the execution timing information.
The wireless communication device according to item 1 or 2, wherein the transmission unit transmits the header according to the execution timing information.
[Item 4]
The receiving unit identifies information that identifies a terminal identifier of another first terminal designated as a target for downlink frequency division multiplexing by the other wireless communication device and a second frequency component assigned to the other first terminal. And receive,
The control unit does not allocate the second frequency component to any of the plurality of second terminals.
The transmission unit transmits the header in which the terminal identifier of the other first terminal is further set in the second field related to the second frequency component in the band including the plurality of frequency components. The wireless communication device according to any one of the above.
[Item 5]
The control unit further selects a second terminal different from the second terminal to which the first frequency component is assigned among the plurality of second terminals, and assigns the third frequency component to the other second terminal.
The item 4 in which the transmission unit transmits the header in which the terminal identifier of the other second terminal is further set in the third field related to the third frequency component in the band including the plurality of frequency components. Wireless communication device.
[Item 6]
The wireless communication device according to any one of items 1 to 5, further comprising at least one antenna.
[Item 7]
A receiver that receives a terminal identifier of a first terminal designated as a target of downlink frequency division multiplexing by another wireless communication device and information that identifies a first frequency component assigned to the first terminal among a plurality of frequency components. When,
A control unit that selects a second terminal to which the first frequency component is assigned from among a plurality of second terminals belonging to the own device, and a control unit.
The terminal identifier of the first terminal is set in a predetermined first field among a plurality of fields related to the first frequency component, and the terminal identifier of the selected second terminal is set in a predetermined first field among the plurality of fields. A radio provided with a transmitter that transmits the headers set in the two fields in a band including the plurality of frequency bands, and spatially multiplexes the first frame addressed to the selected second terminal with the first frequency component. Communication device.
[Item 8]
The wireless communication device according to item 7, wherein the transmission unit transmits the terminal identifier of the selected second terminal and the information specifying the first frequency component to the other wireless communication device.
[Item 9]
The wireless communication device according to item 7 or 8, wherein the transmission unit transmits the header at a predetermined timing.
[Item 10]
The receiving unit receives the execution timing information of the downlink frequency multiplex transmission from the other wireless communication device, and receives the execution timing information.
The wireless communication device according to any one of items 7 to 9, wherein the transmission unit transmits the header according to the execution timing information.
[Item 11]
The receiving unit receives a terminal identifier of another first terminal designated as a target for the downlink frequency division multiplexing by the other wireless communication device and information for specifying a second frequency component assigned to the other first terminal. Receive and
The transmission unit transmits the header in which the terminal identifier of the other first terminal is further set in the third field related to the second frequency component in the band including the plurality of frequency components. The wireless communication device according to any one of the above.
[Item 12]
The control unit further selects a second terminal different from the second terminal to which the first frequency component is assigned among the plurality of second terminals, and determines a third frequency component to be assigned to the other second terminal. death,
The transmission unit transmits the header in which the terminal identifier of the other second terminal is further set in the fourth field related to the third frequency component in the band including the plurality of frequency components, and the first. 3. The wireless communication device according to item 11, which transmits a second frame addressed to a terminal with the third frequency component.
[Item 13]
The wireless communication device according to any one of items 7 to 12, further comprising at least one antenna.
[Item 14]
Identify the terminal identifiers of a plurality of first terminals designated by other wireless communication devices as targets for uplink frequency division multiplexing, and a plurality of different first frequency components assigned to the plurality of first terminals among the plurality of frequency components. A receiver that receives information and
A control unit that determines a plurality of different second frequency components to be assigned to a plurality of second terminals to be subjected to uplink frequency division multiplexing, and a control unit that determines a plurality of different second frequency components.
The terminal identifiers of the plurality of first terminals are set in a plurality of fields related to the plurality of first frequency components, and the terminal identifiers of the plurality of second terminals are set to a plurality of fields related to the plurality of second frequency components. A transmitter that transmits a frame instructing the uplink frequency multiplex transmission, which is set in the field and the address of the other wireless communication device is set in the source address field.
Wireless communication device equipped with.
[Item 15]
The wireless communication device according to item 14, further comprising at least one antenna.
[Item 16]
A receiver that receives information in the second frequency band used by another wireless communication device to transmit a first frame instructing that uplink frequency division multiplexing is performed in the first frequency band.
A second frame instructing a plurality of terminals belonging to the own device to perform uplink frequency multiplex transmission in the first frequency band is set in a third frequency band different from the second frequency band, and the first frame is used. The transmitter that sends at the same time,
Wireless communication device equipped with.
[Item 17]
The wireless communication device according to item 16, further comprising at least one antenna.

1, 2: Access point (AP)
101, 201: Control units 102, 105, 202: Transmission units 103, 106, 203: Reception unit 107: Wired IF
104: Buffer 111: Baseband IC
121: RF IC
113: Memory 114: Host interface 115: CPU
116: DAC
117: ADC
121: RF IC
122, 132: Filter 123, 133: Mixer 124, 134: Amplifier 125, 135: Balun 142: PLL
143: Crystal oscillator 147: Antenna 145: Switch 148: Wireless LAN module 149: Host system 301: Notebook PC
305, 315, 355: Wireless communication device 321: Mobile terminal 331: Memory card 332: Memory card main body 42A to 42D: Antenna 402: Transmission unit 403: Reception unit 401: Communication processing unit 404: Network processing unit 405: Wired I / F
406: Memory 407: Server 501: Communication processing unit 502: Transmission unit 503: Reception unit 51A: Antenna 504: Application processor 505: Memory 506: Second wireless communication module

Claims (8)

It ’s a wireless communication device,
The terminal identifier assigned by the other wireless communication device of the first terminal belonging to the other wireless communication device designated by the other wireless communication device as the target of downlink frequency division multiplexing, and the first of the plurality of frequency components. A receiver that receives information that identifies the first frequency component assigned to one terminal, and
Control to select a second terminal to which the first frequency component is assigned from among a plurality of second terminals belonging to the wireless communication device and to which a terminal identifier is assigned by the wireless communication device, which are different from the first terminal. Department and
The terminal identifier of the first terminal is set in a predetermined first field among a plurality of fields related to the first frequency component, and the terminal identifier of the selected second terminal is set in a predetermined first field among the plurality of fields. The receiver is provided with a transmitter that transmits the header set in the two fields in a band including the plurality of frequency components and spatially multiplexes the first frame addressed to the selected second terminal with the first frequency component. Receives the execution timing information of the downlink frequency multiplex transmission from the other wireless communication device.
The transmission unit is a wireless communication device that transmits the header according to the execution timing information. The receiving unit receives a terminal identifier of another first terminal designated as a target for the downlink frequency division multiplexing by the other wireless communication device and information for specifying a second frequency component assigned to the other first terminal. Receive and
The transmission unit transmits the header in which the terminal identifier of the other first terminal is further set in the third field related to the second frequency component in the band including the plurality of frequency components. The wireless communication device described. The control unit further selects a third terminal different from the second terminal to which the first frequency component is assigned from the plurality of second terminals, determines a third frequency component to be assigned to the third terminal, and determines the third frequency component to be assigned to the third terminal.
The transmission unit transmits the header in which the terminal identifier of the third terminal is further set in the fourth field related to the third frequency component in the band including the plurality of frequency components, and transmits the third terminal. The wireless communication device according to claim 2, wherein the second frame addressed to the user is transmitted by the third frequency component. The wireless communication device according to any one of claims 1 to 3, further comprising at least one antenna. It ’s a wireless communication device,
Of the terminal identifiers assigned by the other wireless communication device of the plurality of first terminals belonging to the other wireless communication device designated by the other wireless communication device as the target of uplink frequency division multiplexing, and the plurality of frequency components. A receiving unit that receives information that identifies a plurality of different first frequency components assigned to the plurality of first terminals, and
A control unit that determines a plurality of different second frequency components to be assigned to a plurality of second terminals different from the first terminal, which are targets of uplink frequency multiplex transmission.
The terminal identifiers of the plurality of first terminals are set in a plurality of fields related to the plurality of first frequency components, and the terminal identifiers of the plurality of second terminals are set to a plurality of fields related to the plurality of second frequency components. A transmitter that transmits a frame instructing the uplink frequency multiplex transmission, which is set in the field and the address of the other wireless communication device is set in the source address field.
Wireless communication device equipped with. The wireless communication device according to claim 5, further comprising at least one antenna. It ’s a wireless communication device,
The terminal identifier assigned by the other wireless communication device of one or more first terminals belonging to the other wireless communication device designated by the other wireless communication device as the target of uplink frequency division multiplexing, and the other wireless communication device. and information of the second frequency band used for transmitting the first frame to indicate that the communication device performs the uplink frequency multiplexed in a first frequency band to the first terminal, execution of the uplink frequency multiplexing A receiver that receives timing information and
The second frequency includes a header and a second frame instructing the second terminal to perform uplink frequency multiplex transmission in the first frequency band to one or more second terminals belonging to the wireless communication device. It is provided with a transmission unit that transmits according to the execution timing information in a third frequency band different from the band.
The transmitter transmits the header in the second frequency band in addition to the third frequency band.
The header has a first field for designating a terminal for receiving the first frame in the second frequency band and a second field for designating a terminal for receiving the second frame in the third frequency band. Including and
The transmitter sets the terminal identifier of the first terminal in the first field of the header according to the first rule, and sets the terminal identifier of the second terminal in the second field of the header according to the first rule. Set,
The first rule sets the terminal identifier of the first terminal in the first field of the header transmitted before the first frame by the other wireless communication device according to the execution timing information, and sets the terminal identifier of the first terminal in the second field. A wireless communication device that has the same rules as the rules for setting terminal identifiers. The wireless communication device according to claim 7, further comprising at least one antenna.

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