Base station device and communication method

Abstract

To improve frequency utilization efficiency in a frequency band in which a usable bandwidth is preset under a dense environment in which many wireless LAN devices exist.SOLUTION: A first base station device comprises a transmission and reception unit which transmits and receives a radio signal, a resource allocation unit which determines allocation of frequency resources used in communication with a first terminal device, and a control information generation unit which generates control information. When the first base station device is communicating with the first terminal device using a first frequency channel and a second base station device is communicating with a second terminal device using a second frequency channel, the resource allocation unit allocates a part of the second frequency channel to communication with the first base station device and the first terminal device and the transmission and reception unit communicates with the first terminal device using a part of the first frequency channel and the second frequency channel.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a base station device and a communication method. [Background technology]

[0002] The Institute of Electrical and Electronics Engineers Inc. (IEEE) is currently working on the specification of IEEE802.11ax, which will achieve even faster speeds than the IEEE802.11 wireless LAN (Local Area Network) standard, and wireless LAN devices that comply with the draft specification are appearing on the market. Currently, standardization activities for IEEE802.11be, the successor to IEEE802.11ax, have begun. With the rapid spread of wireless LAN devices, the IEEE802.11be standardization is also examining how to further improve throughput per user in environments where wireless LAN devices are densely deployed.

[0003] In wireless LAN, frames can be transmitted using unlicensed bands that allow wireless communication without permission (license) from a country or region. Currently, the unlicensed bands mainly used are 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. In order for multiple wireless LAN devices to share the unlicensed bands, the available frequency bands are divided into a specified bandwidth. For example, if two access points are relatively close to each other, they cannot use the same frequency at the same time. However, if the unlicensed bands are divided into a specified bandwidth in advance, each access point can use a different band, and although the frequency bandwidth that can be used at one time is smaller, they can still communicate simultaneously.

[0004] Therefore, in the IEEE802.11 standard, the unlicensed band is divided into 20 MHz bandwidths and managed (see Non-Patent Document 1). In this case, different wireless LAN devices can simultaneously use different bands as described above. In addition, if there are no other wireless LAN devices communicating in the vicinity of a wireless LAN device, the wireless LAN device can expand the communication bandwidth and improve the communication speed by using channel bonding, which bundles the divided bands and uses them simultaneously. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] IEEE Std 802.11ac-2013,December 2013 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the fact that the bandwidth is fixed in advance means that the bandwidth that a wireless LAN device can use is limited to an integer multiple of the bandwidth. Also, if a nearby wireless LAN device has reserved a bandwidth of 20 MHz, other wireless LAN devices cannot use the 20 MHz bandwidth. This also applies when a wireless LAN device that has reserved a bandwidth of 20 MHz actually uses only a part of the 20 MHz bandwidth, which limits the frequency utilization efficiency of the entire system.

[0007] The present invention has been made in consideration of the above problems, and its purpose is to disclose a base station apparatus and a communication method that improves frequency utilization efficiency in a dense terminal environment where a large number of wireless LAN devices exist in a frequency band where the available bandwidth is preset. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, a base station apparatus and a communication method according to the present invention are as follows.

[0009] (1) That is, a base station device according to one embodiment of the present invention is a first base station device that performs wireless communication with a terminal device, and includes a transceiver unit that transmits and receives wireless signals, a resource allocation unit that determines an allocation of frequency resources to be used for communication with the first terminal device, and a control information generation unit that generates control information, wherein when the first base station device communicates with the first terminal device using a first frequency channel and a second base station device communicates with the second terminal device using a second frequency channel, the resource allocation unit allocates a portion of the second frequency channel to communication between the first base station device and the first terminal device, and the transceiver unit communicates with the first terminal device using the first frequency channel and a portion of the second frequency channel.

[0010] (2) Moreover, a base station device according to an aspect of the present invention is described in (1) above, wherein the second frequency channel is a frequency channel reserved by the second base station device.

[0011] (3) Moreover, a base station device according to one embodiment of the present invention is described in (2) above, wherein the control information generating unit generates first control information including information regarding a portion of the second frequency channel, and the transceiver unit transmits a frame including the first control information to the second base station device.

[0012] (4) Moreover, a base station device according to one embodiment of the present invention is described in (2) above, wherein the transceiver unit transmits a frame to the second base station device including information indicating a request for the second frequency channel.

[0013] (5) Furthermore, a base station device according to one embodiment of the present invention is described in (2) above, wherein the transceiver unit receives a frame transmitted by the second base station device and including information indicating permission to use the second frequency channel.

[0014] (6) Furthermore, a base station device according to one embodiment of the present invention is described in (2) above, wherein the control information generating unit further generates second control information requesting the second base station device to report channel quality of the second frequency channel at the second base station device, and the transceiver unit transmits the second control information to the second base station device and receives third control information from the second base station device, the third control information including information regarding the channel quality of the second frequency channel.

[0015] (7) Moreover, a base station device according to one embodiment of the present invention is described in (6) above, wherein the first base station device further includes a channel estimation unit that estimates channel quality of a frequency channel in the first base station device, the channel estimation unit estimates channel quality of the first frequency channel and channel quality of the second frequency channel, and the resource allocation unit decides to allocate a portion of the second frequency channel to communication between the first base station device and the first terminal device based on the estimated channel quality of the first frequency channel, the estimated channel quality of the second frequency channel, and information on channel quality included in the third control information.

[0016] (8) Moreover, a base station device according to one embodiment of the present invention is described in (1) above, wherein the transceiver unit transmits a trigger frame to at least one of the second base station device and the second terminal device, requesting transmission of a reference signal on the second frequency channel.

[0017] (9) Furthermore, a base station device according to one embodiment of the present invention is a second base station device that performs wireless communication with a terminal device, and includes a transceiver unit that transmits and receives wireless signals, and a resource allocation unit that determines an allocation of frequency resources to be used for communication with the second terminal device. When the second base station device is communicating with the second terminal device using a second frequency channel, when the transceiver unit receives first control information including information indicating that a first base station device will use a portion of the second frequency channel, the resource allocation unit excludes the portion of the second frequency channel from the allocation for communication with the second terminal device.

[0018] (10) Furthermore, a base station device according to one embodiment of the present invention is described in (9) above, wherein the second base station device further includes a channel estimation unit and a control information generation unit, and the transceiver unit receives second control information from the first base station device requesting a report of channel quality of a second frequency channel used by the second base station device for communication with a second terminal device, the channel estimation unit estimates the channel quality of the second channel in the second base station device, the control information generation unit generates third control information including information regarding the estimated channel quality of the second channel, and the transceiver unit transmits the third control information to the first base station device.

[0019] (11) Moreover, a base station device according to one embodiment of the present invention is described in (9) or (10) above, and the second frequency channel is a frequency channel reserved by the second base station device.

[0020] (12) Also, a communication method according to one embodiment of the present invention is a communication method of a first base station device that performs wireless communication with a terminal device, comprising the steps of transmitting and receiving a wireless signal, determining an allocation of frequency resources to be used for communication with the first terminal device, generating control information, and, when the first base station device communicates with the first terminal device using a first frequency channel and a second base station device communicates with a second terminal device using a second frequency channel, allocating a portion of the second frequency channel to communication between the first base station device and the first terminal device, and communicating with the first terminal device using the first frequency channel and a portion of the second frequency channel. Effect of the Invention

[0021] According to the present invention, frequencies can be efficiently utilized in a frequency band in which the available bandwidth is preset, even in a dense terminal environment in which a large number of wireless LAN devices exist, thereby contributing to improving the user throughput of wireless LAN devices. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating an example of communication according to an embodiment of the present invention. [Figure 4] FIG. 1 is a schematic diagram illustrating an example of division of a wireless medium according to one aspect of the present invention. [Diagram 5] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an aspect of the present invention. [Figure 6] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 7] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 8]FIG. 1 is a schematic diagram illustrating an example of an encoding method according to an aspect of the present invention. [Figure 9] FIG. 2 is a diagram illustrating an example of communication according to an embodiment of the present invention. [Figure 10] FIG. 2 is a diagram illustrating an example of communication according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The communication system in this embodiment includes a wireless transmitting device (access point device: Access point, base station device) and multiple wireless receiving devices (station devices: Station, terminal devices). A network configured with the base station device and the terminal devices is called a Basic Service Set (BSS: Basic service set, management range). The station device according to this embodiment can have the functions of an access point device. Similarly, the access point device according to this embodiment can have the functions of a station device. Therefore, hereinafter, when simply referring to a communication device, the communication device can refer to both a station device and an access point device.

[0024] The base station device and the terminal device in the BSS communicate based on CSMA / CA (Carrier sense multiple access with collision avoidance). In this embodiment, the base station device communicates with multiple terminal devices in infrastructure mode, but the method of this embodiment can also be implemented in ad-hoc mode in which terminal devices communicate directly with each other. In ad-hoc mode, the terminal devices form a BSS in place of the base station device. The BSS in ad-hoc mode is also called an Independent Basic Service Set (IBSS). In the following, the terminal devices that form an IBSS in ad-hoc mode can also be considered as base station devices.

[0025] In the IEEE802.11 system, each device can transmit multiple frame types with a common frame format. The transmission frames are defined in the physical (PHY) layer, medium access control (MAC) layer, and logical link control (LLC) layer.

[0026] The transmission frame of the PHY layer is called a physical protocol data unit (PPDU, physical layer frame). The PPDU is composed of a physical layer header (PHY header) that contains header information for signal processing in the physical layer, and a physical service data unit (PSDU, MAC layer frame), which is a data unit processed in the physical layer. The PSDU can be composed of an aggregated MPDU (A-MPDU), which aggregates multiple MAC protocol data units (MPDUs), which are the units of retransmission in the wireless section.

[0027] The PPDU is modulated according to a corresponding standard, for example, in the case of the IEEE802.11n standard, it is modulated into an Orthogonal Frequency Division Multiplexing (OFDM) signal.

[0028] The PHY header includes reference signals such as a short training field (STF) used for signal detection and synchronization, a long training field (LTF) used to acquire channel information for data demodulation, and control signals such as a signal (SIG) containing control information for data demodulation. STFs are classified into Legacy-STF (L-STF), High throughput-STF (HT-STF), Very high throughput-STF (VHT-STF), High efficiency-STF (HE-STF), Extremely high throughput-STF (EHT-STF), etc. according to the corresponding standard, and LTFs and SIGs are similarly classified into L-LTF, HT-LTF, VHT-LTF, HE-LTF, L-SIG, HT-SIG, VHT-SIG, HE-SIG, and EHT-SIG. VHT-SIG is further classified into VHT-SIG-A1, VHT-SIG-A2, and VHT-SIG-B. Similarly, HE-SIG is classified into HE-SIG-A1 to HE-SIG-A4 and HE-SIG-B. In addition, it can include a Universal SIGNAL (U-SIG) field that contains additional control information in anticipation of technical updates in the same standard.

[0029] The SIG may include information for demodulating the received frame, such as information indicating the modulation scheme and coding rate (MCS), the number of spatial data multiplexing (number of layers), the number of spatially multiplexed users, information indicating the presence or absence of space-time coding (e.g., information indicating the presence or absence of space-time coding transmit diversity), information indicating the destination of the frame, and information associated with the frame length of the frame (TXOP, etc.).

[0030] Furthermore, the PHY header can include information for identifying the BSS that is the source of the transmission frame (hereinafter, also referred to as BSS identification information). The information for identifying the BSS can be, for example, the SSID (Service Set Identifier) ​​of the BSS or the MAC address of the base station device of the BSS. The information for identifying the BSS can also be a value unique to the BSS (for example, BSS Color, etc.) other than the SSID or MAC address.

[0031] Since the PHY header including the SIG contains information necessary for data demodulation, it is desirable that the PHY header has a tolerance to transmission errors. It is also desirable that the PHY header is correctly received by wireless LAN devices other than the destination wireless LAN device. Considering the existence of wireless LAN devices with poor communication environments, it is desirable to set a modulation method and coding rate with high redundancy for the PHY header, especially for the SIG. The communication device can set a modulation method with a small modulation multi-level number, such as BPSK modulation, and a low coding rate for the PHY header.

[0032] MPDU is composed of a MAC layer header (MAC header) that contains header information for signal processing at the MAC layer, a MAC service data unit (MSDU) or frame body that is a data unit processed at the MAC layer, and a frame check sequence (FCS) that checks whether there are any errors in the frame. Multiple MSDUs can also be aggregated as an Aggregated MSDU (A-MSDU).

[0033] The frame types of MAC layer transmission frames are broadly classified into three types: management frames that manage the connection status between devices, control frames that manage the communication status between devices, and data frames that contain the actual transmission data. Each type is further classified into multiple subframe types. Control frames include acknowledgement (Ack) frames, request to send (RTS) frames, and clear to send (CTS) frames. Management frames include beacon frames, probe request frames, probe response frames, authentication frames, association request frames, and association response frames. Data frames include data frames and polling (CF-poll) frames. Each device can determine the frame type and subframe type of a received frame by reading the contents of the frame control field included in the MAC header.

[0034] The Ack may include a Block Ack, which is capable of notifying completion of reception of multiple MPDUs.

[0035] The beacon frame includes a field that describes the period (Beacon interval) at which the beacon is transmitted and the SSID. The base station device can periodically broadcast the beacon frame within the BSS, and the terminal device can identify the base station devices around the terminal device by receiving the beacon frame. The terminal device's identification of the base station device based on the beacon frame broadcast by the base station device is called passive scanning. On the other hand, the terminal device's exploration of the base station device by broadcasting a probe request frame within the BSS is called active scanning. The base station device can transmit a probe response frame in response to the probe request frame, and the contents of the probe response frame are equivalent to those of the beacon frame.

[0036] After recognizing a base station device, the terminal device performs a connection process with the base station device. The connection process is classified into an authentication procedure and an association procedure. The terminal device transmits an authentication frame (authentication request) to the base station device to which it wishes to connect. When the base station device receives the authentication frame, it transmits an authentication frame (authentication response) to the terminal device that includes a status code indicating whether the terminal device has been authenticated or not. By reading the status code written in the authentication frame, the terminal device can determine whether or not it has been authorized to be authenticated by the base station device. Note that the base station device and the terminal device can exchange authentication frames multiple times.

[0037] Following the authentication procedure, the terminal device transmits a connection request frame to the base station device to perform a connection procedure. When the base station device receives the connection request frame, it determines whether or not to permit the connection of the terminal device, and transmits a connection response frame to notify the result. The connection response frame contains a status code indicating whether or not the connection process is possible, as well as an association identifier (AID) for identifying the terminal device. The base station device can manage multiple terminal devices by setting different AIDs for each terminal device for which it has issued connection permission.

[0038] After the connection process is completed, the base station device and the terminal device perform actual data transmission. In the IEEE802.11 system, a distributed coordination function (DCF: Distributed Coordination Function), a centralized coordination function (PCF: Point Coordination Function), and their extended functions (enhanced distributed channel access (EDCA) and hybrid coordination function (HCF) are defined. The following describes an example in which a base station device transmits a signal to a terminal device using DCF.

[0039] In DCF, a base station device and a terminal device perform carrier sense (CS) to check the usage status of a wireless channel around the device before communication. For example, when a base station device, which is a transmitting station, receives a signal higher than a predetermined clear channel assessment level (CCA level) on the wireless channel, it postpones the transmission of a transmission frame on the wireless channel. Hereinafter, a state in which a signal of CCA level or higher is detected on the wireless channel is called a busy state, and a state in which a signal of CCA level or higher is not detected is called an idle state. In this way, CS performed by each device based on the power of a signal actually received (received power level) is called physical carrier sense (physical CS). The CCA level is also called a carrier sense level (CS level) or a CCA threshold (CCA threshold: CCAT). When a signal of CCA level or higher is detected, the base station device and the terminal device start an operation of demodulating at least a PHY layer signal.

[0040] In the following, when simply referring to carrier sense, this includes the case where virtual carrier sense described later is performed. In addition, when simply referring to carrier sense level, this also includes the case where the communication device indicates the minimum reception sensitivity indicating the received signal power at which the communication device demodulates at least the PHY layer signal. That is, when the communication device receives a frame, if the communication device observes that the received signal power of the frame is equal to or higher than the minimum reception sensitivity, the communication device needs to demodulate at least the PHY layer signal for the frame. This means that if the communication device observes that the received signal power is equal to or lower than the minimum reception sensitivity, the communication device does not need to demodulate the frame, and the communication device can transmit the frame. Therefore, the carrier sense level and the minimum reception sensitivity can be considered to have the same meaning.

[0041] The base station device performs carrier sensing for the period of the inter frame space (IFS) according to the type of transmission frame to be transmitted, and judges whether the wireless channel is in a busy state or an idle state. The period during which the base station device performs carrier sensing varies depending on the frame type and subframe type of the transmission frame that the base station device is going to transmit. In the IEEE802.11 system, multiple IFSs with different periods are defined, including a short inter frame space (SIFS: Short IFS) used for transmission frames assigned the highest priority, a polling inter frame space (PCF IFS: PIFS) used for transmission frames with a relatively high priority, and a distributed control inter frame space (DCF IFS: DIFS) used for transmission frames with the lowest priority. When the base station device transmits a data frame using DCF, the base station device uses DIFS.

[0042] After waiting for the DIFS, the base station device waits for a random backoff time to prevent frame collision. In the IEEE802.11 system, a random backoff time called a contention window (CW) is used. In CSMA / CA, it is assumed that a transmission frame transmitted by a certain transmitting station is received by a receiving station without interference from other transmitting stations. Therefore, if transmitting stations transmit transmission frames at the same timing, the frames collide with each other and the receiving station cannot receive the frames correctly. Therefore, frame collision is avoided by having each transmitting station wait for a randomly set time before starting transmission. When the base station device determines that the wireless channel is in an idle state by carrier sense, it starts counting down the CW, and only when the CW reaches 0 does it acquire the right to transmit and can transmit a transmission frame to the terminal device. Note that if the base station device determines that the wireless channel is in a busy state by carrier sense during the CW countdown, it stops the CW countdown. Then, when the wireless channel becomes idle, the base station device resumes the countdown of the remaining CW following the previous IFS.

[0043] A terminal device, which is a receiving station, receives a transmission frame, reads the PHY header of the transmission frame, and demodulates the received transmission frame. The terminal device can then read the MAC header of the demodulated signal to determine whether the transmission frame is addressed to the terminal device itself. The terminal device can also determine the destination of the transmission frame based on information written in the PHY header (for example, a group identification number (GID: Group identifier, Group ID) written in VHT-SIG-A).

[0044] When a terminal device judges that the received transmission frame is addressed to itself and demodulates the transmission frame without error, it must transmit an ACK frame indicating that the frame was received correctly to the base station device, which is the transmitting station. The ACK frame is one of the highest priority transmission frames that is transmitted only by waiting for the SIFS period (no random backoff time is taken). The base station device ends a series of communications by receiving the ACK frame transmitted from the terminal device. Note that if the terminal device does not receive the frame correctly, the terminal device does not transmit an ACK. Therefore, if the base station device does not receive an ACK frame from the receiving station for a certain period (SIFS + ACK frame length) after transmitting a frame, it terminates the communication as it has failed. In this way, the end of one communication (also called a burst) in the IEEE802.11 system is always determined by the presence or absence of the reception of an ACK frame, except in special cases such as the transmission of a notification signal such as a beacon frame or the use of fragmentation to divide the transmission data.

[0045] When the terminal device determines that the received transmission frame is not addressed to the terminal device itself, it sets a network allocation vector (NAV) based on the length of the transmission frame described in the PHY header, etc. The terminal device does not attempt communication during the period set in the NAV. In other words, the terminal device does not establish a wireless channel by the physical CS. Since the same operation as when the channel is judged to be busy is performed for the period set in the NAV, communication control by the NAV is also called virtual carrier sense (virtual CS). In addition to being set based on the information in the PHY header, the NAV is also set by the request to send (RTS) frame and the clear to send (CTS) frame, which are introduced to solve the hidden terminal problem.

[0046] In contrast to DCF, in which each device performs carrier sensing and autonomously acquires the transmission right, in PCF, a control station called a Point Coordinator (PC) controls the transmission right of each device within the BSS. In general, a base station device becomes the PC and acquires the transmission right for terminal devices within the BSS.

[0047] The communication period by PCF includes a contention free period (CFP) and a contention period (CP). During the CP, communication is performed based on the DCF described above, and during the CFP, the PC controls the transmission right. The base station device, which is the PC, broadcasts a beacon frame in which the CFP period (CFP Max duration) and the like are described in the BSS prior to PCF communication. Note that the PIFS is used for transmitting the beacon frame broadcast at the start of PCF transmission, and it is transmitted without waiting for the CW. The terminal device that receives the beacon frame sets the CFP period described in the beacon frame to the NAV. After that, until the NAV elapses or a signal (e.g., a data frame including CF-end) that broadcasts the end of CFP in the BSS is received, the terminal device can acquire the transmission right only when it receives a signal (e.g., a data frame including CF-poll) that signals the acquisition of the transmission right transmitted from the PC. During the CFP period, no packet collisions occur within the same BSS, so each terminal device does not take the random backoff time used in DCF.

[0048] A wireless medium can be divided into a number of resource units (RUs). FIG. 4 is a schematic diagram showing an example of a division state of a wireless medium. For example, in resource division example 1, a wireless communication device can divide a frequency resource (subcarrier, frequency tone, tone) which is a wireless medium into nine RUs. Similarly, in resource division example 2, a wireless communication device can divide a frequency resource which is a wireless medium into five RUs. Of course, the resource division example shown in FIG. 4 is merely an example, and for example, a number of RUs can be configured with different numbers of subcarriers. In addition, the wireless medium divided into RUs can include not only frequency resources but also spatial resources. A wireless communication device (e.g., an AP) can transmit frames to a number of terminal devices (e.g., a number of STAs) simultaneously by placing frames addressed to different terminal devices in each RU. The AP can write information indicating the division state of the wireless medium (resource allocation information) in the PHY header of a frame transmitted by the own device as common control information. Furthermore, the AP can write information indicating the RU in which the frame addressed to each STA is placed (resource unit assignment information) as unique control information in the PHY header of the frame transmitted by the AP itself.

[0049] Furthermore, multiple terminal devices (e.g., multiple STAs) can transmit frames simultaneously by placing frames in the assigned RUs and transmitting them. After receiving a frame (Trigger frame: TF) containing trigger information transmitted from the AP, multiple STAs can transmit frames after waiting for a predetermined period of time. Each STA can grasp the RU assigned to itself based on the information written in the TF. Furthermore, each STA can acquire an RU by random access based on the TF.

[0050] An AP can simultaneously allocate multiple RUs to one STA. The multiple RUs can be configured with consecutive subcarriers or non-consecutive subcarriers. An AP can transmit one frame using the multiple RUs allocated to one STA, and can allocate multiple frames to different RUs for transmission. At least one of the multiple frames can be a frame including common control information for multiple terminal devices to which resource allocation information is to be transmitted.

[0051] One STA can be assigned multiple RUs by the AP. The STA can transmit one frame using the assigned multiple RUs. Also, the STA can assign multiple frames to different RUs and transmit them using the assigned multiple RUs. The multiple frames can be frames of different frame types.

[0052] An AP can assign multiple AIDs (Association IDs) to one STA. The AP can assign RUs to the multiple AIDs assigned to one STA. The AP can transmit different frames to the multiple AIDs assigned to one STA using the assigned RUs. The different frames can be frames of different frame types.

[0053] One STA can be assigned multiple AIDs (Associate IDs) by the AP. One STA can be assigned RUs for each of the assigned AIDs. One STA recognizes that all RUs assigned to the multiple AIDs assigned to the STA are RUs assigned to the STA itself, and can transmit one frame using the assigned RUs. One STA can also transmit multiple frames using the assigned RUs. At this time, the multiple frames can be transmitted with information indicating the AIDs associated with the assigned RUs written therein. One STA can transmit different frames for the assigned AIDs using the assigned RUs. The different frames can be frames of different frame types.

[0054] Hereinafter, the base station device and the terminal device are collectively referred to as a wireless communication device or a communication device. Information exchanged when a wireless communication device communicates with another wireless communication device is also referred to as data. In other words, the wireless communication device includes the base station device and the terminal device.

[0055] A wireless communication device has either or both of a function for transmitting a PPDU and a function for receiving a PPDU. FIG. 1 is a diagram showing an example of a PPDU structure transmitted by a wireless communication device. A PPDU conforming to the IEEE802.11a / b / g standard is configured to include an L-STF, an L-LTF, an L-SIG, and a Data frame (MAC Frame, a MAC frame, a payload, a data section, data, information bits, etc.). A PPDU conforming to the IEEE802.11n standard is configured to include an L-STF, an L-LTF, an L-SIG, an HT-SIG, an HT-STF, an HT-LTF, and a Data frame. A PPDU conforming to the IEEE802.11ac standard is configured to include an L-STF, an L-LTF, an L-SIG, a VHT-SIG-A, a VHT-STF, a VHT-LTF, a VHT-SIG-B, and a part or all of a Data frame. The PPDU considered in the IEEE802.11ax standard is a configuration that includes some or all of the following: L-STF, L-LTF, L-SIG, RL-SIG in which L-SIG is repeated over time, HE-SIG-A, HE-STF, HE-LTF, HE-SIG-B, and Data frames.The PPDU considered in the IEEE802.11be standard is a configuration that includes some or all of the following: L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, EHT-LTF, and Data frames.

[0056] The L-STF, L-LTF, and L-SIG enclosed by dotted lines in Fig. 1 are configurations commonly used in the IEEE 802.11 standard (hereinafter, L-STF, L-LTF, and L-SIG are also collectively referred to as L-header). For example, a wireless communication device compatible with the IEEE 802.11a / b / g standard can properly receive an L-header in a PPDU compatible with the IEEE 802.11n / ac standard. A wireless communication device compatible with the IEEE 802.11a / b / g standard can receive a PPDU compatible with the IEEE 802.11n / ac standard by regarding it as a PPDU compatible with the IEEE 802.11a / b / g standard.

[0057] However, wireless communication devices that comply with the IEEE 802.11a / b / g standards cannot demodulate the PPDU that complies with the IEEE 802.11n / ac standards, which follows the L-header, and therefore cannot demodulate information related to the transmitter address (TA: Transmitter Address), receiver address (RA: Receiver Address), or the Duration / ID field used to set the NAV.

[0058] IEEE 802.11 specifies a method of inserting Duration information into L-SIG as a method for wireless communication devices conforming to the IEEE 802.11a / b / g standards to appropriately set NAV (or to perform reception for a predetermined period of time). Information on the transmission rate in the L-SIG (RATE field, L-RATE field, L-RATE, L_DATARATE, L_DATARATE field) and information on the transmission period (LENGTH field, L-LENGTH field, L-LENGTH) are used by wireless communication devices conforming to the IEEE 802.11a / b / g standards to appropriately set NAV.

[0059] FIG. 2 is a diagram showing an example of a method of inserting Duration information into an L-SIG. In FIG. 2, a PPDU configuration corresponding to the IEEE802.11ac standard is shown as an example, but the PPDU configuration is not limited to this. A PPDU configuration corresponding to the IEEE802.11n standard and a PPDU configuration corresponding to the IEEE802.11ax standard may also be used. TXTIME includes information on the length of the PPDU, aPreambleLength includes information on the length of the preamble (L-STF+L-LTF), and aPLCPHeaderLength includes information on the length of the PLCP header (L-SIG). L_LENGTH includes a Signal Extension, which is a virtual period set to achieve compatibility with the IEEE802.11 standard, and an N related to L_RATE. opsIt is calculated based on aSymbolLength, which is information about the duration of one symbol (symbol, OFDM symbol, etc.), aPLCPServiceLength, which indicates the number of bits included in the PLCP Service field, and aPLCPConvolutionalTailLength, which indicates the number of tail bits of the convolutional code. The wireless communication device can calculate L_LENGTH and insert it into the L-SIG. The wireless communication device can also calculate L-SIG Duration. The L-SIG Duration indicates information about the duration obtained by adding up the duration of the PPDU including L_LENGTH and the duration of the Ack and SIFS that are expected to be transmitted from the destination wireless communication device in response to the PPDU.

[0060] FIG. 3 is a diagram showing an example of L-SIG Duration in L-SIG TXOP Protection. DATA (frame, payload, data, etc.) is composed of a MAC frame and part of the PLCP header or both. Also, BA is Block Ack or Ack. PPDU includes L-STF, L-LTF, and L-SIG, and can further include one or more of DATA, BA, RTS, and CTS. The example shown in FIG. 3 shows L-SIG TXOP Protection using RTS / CTS, but CTS-to-Self may also be used. Here, ,MAC Duration is the period indicated by the value of the Duration / ID field. Also, the Initiator can transmit a CF_End frame to notify the end of the L-SIG TXOP Protection period.

[0061] Next, a method for identifying a BSS from a frame received by a wireless communication device will be described. In order for a wireless communication device to identify a BSS from a frame received, it is preferable for the wireless communication device transmitting a PPDU to insert information for identifying the BSS (BSS color, BSS identification information, a value unique to the BSS) into the PPDU. Information indicating the BSS color can be described in HE-SIG-A.

[0062] The wireless communication device can transmit the L-SIG multiple times (L-SIG Repetition). For example, the receiving wireless communication device receives the L-SIG transmitted multiple times using MRC (Maximum Ratio Combining), thereby improving the demodulation accuracy of the L-SIG. Furthermore, when the wireless communication device has correctly received the L-SIG using MRC, the wireless communication device can interpret the PPDU including the L-SIG as a PPDU that complies with the IEEE802.11ax standard.

[0063] The wireless communication device can receive a part of a PPDU other than the PPDU (for example, a preamble, L-STF, L-LTF, PLCP header, etc., defined by IEEE802.11) even during a PPDU reception operation (also referred to as a dual reception operation). When the wireless communication device detects a part of a PPDU other than the PPDU during a PPDU reception operation, the wireless communication device can update a part or all of the information related to the destination address, the source address, the PPDU, or the DATA period.

[0064] Ack and BA can also be called responses (response frames). In addition, a probe response, an authentication response, and a connection response can also be called responses. [1. First embodiment]

[0065] FIG. 5 is a diagram showing an example of a wireless communication system according to the present embodiment. The wireless communication system 3-1 includes a wireless communication device 1-1 and wireless communication devices 2-1 to 4. The wireless communication device 1-1 is also referred to as a base station device 1-1, and the wireless communication devices 2-1 to 4 are also referred to as terminal devices 2-1 to 4. The wireless communication devices 2-1 to 4 and the terminal devices 2-1 to 4 are also referred to as a wireless communication device 2A and a terminal device 2A, as devices connected to the wireless communication device 1-1. The wireless communication device 1-1 and the wireless communication device 2A are wirelessly connected, and are in a state in which they can transmit and receive PPDUs to each other. The wireless communication system according to the present embodiment includes a wireless communication system 3-2 in addition to the wireless communication system 3-1. The wireless communication system 3-2 includes a wireless communication device 1-2 and wireless communication devices 2-5 to 8. The wireless communication device 1-2 is also referred to as a base station device 1-2, and the wireless communication devices 2-5 to 8 are also referred to as terminal devices 2-5 to 8. Moreover, the wireless communication devices 2-5 to 8 and the terminal devices 2-5 to 8 are also referred to as wireless communication device 2B and terminal device 2B as devices connected to the wireless communication device 1-2. The wireless communication system 3-1 and the wireless communication system 3-2 form different BSSs, but this does not necessarily mean that the ESSs (Extended Service Sets) are different. An ESS indicates a service set forming a LAN (Local Area Network). In other words, wireless communication devices belonging to the same ESS can be considered to belong to the same network from a higher layer. Note that the wireless communication systems 3-1 and 3-2 can further include a plurality of wireless communication devices.

[0066] FIG. 6 shows wireless communication devices 1-1, 1-2, 2A, and 2B (hereinafter collectively referred to as wireless communication device 10-1, station device 10-1, or simply station device). 10 is a diagram showing an example of a device configuration. Wireless communication device 10-1 includes an upper layer unit (upper layer processing step) 10001-1, an autonomous distributed control unit (autonomous distributed control step) 10002-1, a transmitter (transmission step) 10003-1, a receiver (reception step) 10004-1, and an antenna unit 10005-1. The transmitter (transmission step) 10003-1 and the receiver (reception step) 10004-1 are also collectively referred to as a transmitter / receiver unit (transmission / reception step).

[0067] The upper layer unit 10001-1 is connected to other networks and can notify the autonomous distributed control unit 10002-1 of traffic-related information. The traffic-related information may be, for example, information addressed to other wireless communication devices, or control information included in a management frame or a control frame.

[0068] 7 is a diagram showing an example of the device configuration of the autonomous distributed control unit 10002-1. The autonomous distributed control unit 10002-1 includes a CCA unit (CCA step) 10002a-1, a backoff unit (backoff step) 10002b-1, and a transmission decision unit (transmission decision step) 10002c-1.

[0069] The CCA unit 10002a-1 can use either or both of information on the power of a signal received via a wireless resource and information on the received signal (including information after decoding) notified from the receiving unit to perform a state determination of the wireless resource (including a determination of whether the wireless resource is busy or idle). The CCA unit 10002a-1 can notify the backoff unit 10002b-1 and the transmission determination unit 10002c-1 of the state determination information of the wireless resource.

[0070] The backoff unit 10002b-1 can perform backoff using wireless resource state determination information. The backoff unit 10002b-1 generates a CW and has a countdown function. For example, the backoff unit 10002b-1 can execute a CW countdown when the wireless resource state determination information indicates idle, and can stop the CW countdown when the wireless resource state determination information indicates busy. The backoff unit 10002b-1 can notify the transmission determination unit 10002c-1 of the CW value.

[0071] The transmission decision unit 10002c-1 makes a transmission decision using either the wireless resource status decision information or the CW value, or both. For example, the transmission decision unit 10002c-1 can notify the transmission decision information to the transmission unit 10003-1 when the wireless resource status decision information indicates idle and the CW value is 0. Also, the transmission decision unit 10002c-1 can notify the transmission decision information to the transmission unit 10003-1 when the wireless resource status decision information indicates idle.

[0072] The transmitting unit 10003-1 includes a physical layer frame generating unit (physical layer frame generating step) 10003a-1 and a wireless transmitting unit (wireless transmitting step) 10003b-1. The physical layer frame generating unit 10003a-1 has a function of generating a physical layer frame (PPDU) based on transmission decision information notified from the transmission decision unit 10002c-1. The physical layer frame generating unit 10003a-1 performs error correction coding, modulation, precoding filter multiplication, etc. on the transmission frame sent from the upper layer. The physical layer frame generating unit 10003a-1 notifies the wireless transmitting unit 10003b-1 of the generated physical layer frame.

[0073] The frame generated by the physical layer frame generator 10003a-1 includes control information. The control information includes information indicating in which RU (here, RU includes both frequency resources and spatial resources) data addressed to each wireless communication device is allocated. The frame generated by the physical layer frame generator 10003a-1 also includes a trigger frame that instructs the wireless communication device, which is the destination terminal, to transmit a frame. The trigger frame includes information indicating the RU to be used when the wireless communication device instructed to transmit the frame transmits the frame.

[0074] The wireless transmission unit 10003b-1 converts the physical layer frame generated by the physical layer frame generation unit 10003a-1 into a radio frequency (RF) band signal to generate a radio frequency signal. The processing performed by the wireless transmission unit 10003b-1 includes digital-to-analog conversion, filtering, frequency conversion from the baseband band to the RF band, and the like.

[0075] The receiving unit 10004-1 includes a wireless receiving unit (wireless receiving step) 10004a-1 and a signal demodulating unit (signal demodulating step) 10004b-1. The receiving unit 10004-1 generates information about the received signal power from the RF band signal received by the antenna unit 10005-1. The receiving unit 10004-1 can notify the CCA unit 10002a-1 of the information about the received signal power and the information about the received signal.

[0076] The wireless receiver 10004a-1 has a function of converting an RF signal received by the antenna unit 10005-1 into a baseband signal and generating a physical layer signal (e.g., a physical layer frame). The processing performed by the wireless receiver 10004a-1 includes frequency conversion from the RF band to the baseband, filtering, and analog-to-digital conversion.

[0077] The signal demodulation unit 10004b-1 has a function of demodulating the physical layer signal generated by the wireless receiving unit 10004a-1. The processing performed by the signal demodulation unit 10004b-1 includes channel equalization, demapping, error correction decoding, and the like. The signal demodulation unit 10004b-1 can extract, for example, information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame from the physical layer signal. The signal demodulation unit 10004b-1 can notify the extracted information to the upper layer unit 10001-1. The signal demodulation unit 10004b-1 can extract any one or all of the information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame.

[0078] The antenna unit 10005-1 has a function of transmitting the radio frequency signal generated by the radio transmission unit 10003b-1 to the other wireless communication device 10-1 into the wireless space, and also has a function of receiving the radio frequency signal transmitted from the other wireless communication device 10-1.

[0079] The wireless communication device 10-1 can cause the wireless communication devices around the wireless communication device to set NAV for only the period by describing information indicating the period during which the wireless communication device uses the wireless medium in the PHY header or MAC header of the frame to be transmitted. For example, the wireless communication device 10-1 can describe information indicating the period in the Duration / ID field or Length field of the frame to be transmitted. The NAV period set in the wireless communication devices around the wireless communication device is called the TXOP period (or simply TXOP) acquired by the wireless communication device 10-1. The wireless communication device 10-1 that has acquired the TXOP is called a TXOP acquirer (TXOP holder). The frame type of the frame transmitted by the wireless communication device 10-1 to acquire the TXOP is not limited to any particular type, and may be a control frame (for example, an RTS frame or a CTS-to-self frame) or a data frame.

[0080] The wireless communication device 10-1, which is a TXOP holder, can transmit frames to wireless communication devices other than the wireless communication device itself during the TXOP. If the wireless communication device 1-1 is a TXOP holder, the wireless communication device 1-1 can transmit frames to the wireless communication device 2A during the TXOP period. In addition, the wireless communication device 1-1 can transmit frames to the wireless communication device 2A during the TXOP period. During the TXOP period, the wireless communication device 1-1 can instruct the wireless communication device 2A to transmit a frame addressed to the wireless communication device 1-1. During the TXOP period, the wireless communication device 1-1 can transmit a trigger frame including information instructing the wireless communication device 2A to transmit a frame addressed to the wireless communication device 1-1.

[0081] The wireless communication device 1-1 may reserve a TXOP for all communication bands (e.g., Operation bandwidth) over which frames may be transmitted, or may reserve a TXOP for a specific communication band (Band), such as a communication band (e.g., Transmission bandwidth) over which frames will actually be transmitted.

[0082] The wireless communication device to which the wireless communication device 1-1 instructs to transmit a frame during the period of the acquired TXOP is not necessarily limited to the wireless communication device connected to the wireless communication device itself. For example, the wireless communication device can instruct a wireless communication device not connected to the wireless communication device itself to transmit a frame in order to make the wireless communication device in the vicinity of the wireless communication device itself transmit a management frame such as a Reassociation frame or a control frame such as an RTS / CTS frame.

[0083] In this embodiment, the signal demodulator of the station device can perform decoding processing and error detection on the received signal in the physical layer. Here, the decoding processing includes decoding processing on the error correction code applied to the received signal. Here, the error detection includes error detection using an error detection code (e.g., a cyclic redundancy check (CRC) code) that is previously added to the received signal, and error detection using an error correction code that originally has an error detection function (e.g., a low-density parity check code (LDPC)). The decoding processing in the physical layer can be applied to each coding block.

[0084] The upper layer transfers the result of the decoding of the physical layer in the signal demodulation section to the MAC layer. The MAC layer restores the MAC layer signal from the transferred result of the decoding of the physical layer. The MAC layer then performs error detection to determine whether the MAC layer signal transmitted by the station device that is the source of the received frame has been correctly restored.

[0085] The communication device according to the present embodiment can divide an available frequency band into frequency channels or channels with a predetermined bandwidth (Channel spacing). FIG. 9 is a schematic diagram showing an example of a frequency channel according to the present embodiment. As shown in FIG. 9, the communication device according to the present embodiment can divide an available frequency band into channels 901 each having a bandwidth of 20 MHz. In addition, the communication device according to the present embodiment can bundle a plurality of available frequency bands and use them as a channel 902 having a bandwidth of, for example, 40 MHz. Similarly, it is also possible to use channels with even wider bandwidths such as channels 903 and 904. Note that the method of dividing the frequency band is not limited to the example shown in FIG. 9. The frequency band can also be divided based on a bandwidth smaller than 20 MHz. It is also possible to set another channel between the divided channels. The channel can also be set as a guard band between the channels.

[0086] FIG. 10 is a schematic diagram showing an example of communication according to this embodiment. A communication device according to this embodiment can communicate with other communication devices using frequency channels. In the following, as shown in FIG. 10, an example will be described in which an access point device 1-1 communicates with a station device 2-1 using a channel 1001, and an access point device 1-2 communicates with a station device 2-5 using a channel 1002. For simplicity, an example will be described in which both channels 1001 and 1002 have a bandwidth of 20 MHz and are adjacent to each other, but it goes without saying that the method according to this embodiment is not limited to this example.

[0087] Under certain conditions, the access point device 1-1 can transmit a frame to the station device 2-1 using a part of the band of the channel 1002 in addition to the channel 1001. In other words, under certain conditions, the access point device 1-1 according to this embodiment can transmit a frame to the station device 2-1 by regarding the channel 1003 as an available frequency channel.

[0088] A frame transmitted by the access point device 1-1 using the channel 1003 can include information indicating that the channel 1003 is being used. The information can be, for example, information indicating a bandwidth occupied by the frame. If a frame transmitted via the channel 1003 is a frame that causes a response frame, for example, if the station device 2-1 that has received the frame returns a response frame, the response frame can be transmitted using the channel 1003. The station device 2-1 can also transmit the response frame using the channel 1001.

[0089] Here, the predetermined condition is not limited to anything. For example, a case may be considered in which the access point device 1-2 using the channel 1002 permits the access point device 1-1 to use at least a part of the band of the channel 1002. In this case, the access point device 1-2 can secure the channel 1002 by carrier sense, and then transmit a first frame including information indicating permission to use the channel 1002 to the access point device 1-1. Similarly, the station device 2-5 using the channel 1002 can also permit the access point device 1-1 to use at least a part of the band of the channel 1002, in which case the station device 2-5 can secure the channel 1002. Note that the access point device 1-2 can transmit the first frame using the channel 1002. That is, when the access point device 1-1 according to this embodiment intends to use a channel other than the channel 1001, it is necessary for the access point device 1-1 to be in a state in which it can decode frames, that is, in a receiving state, for example, in the channel 1002.

[0090] When the access point device 1-1 transmits a frame using the channel 1003, the restrictions on radio parameters such as the maximum allowable transmission power may differ between the channels 1001 and 1002 constituting the channel 1003. In this case, the access point device 1-1 can transmit a frame under the restrictions on the radio parameters imposed on all the channels constituting the channel 1003. The access point device 1-1 can also transmit a frame under the restrictions on the radio parameters imposed on the channel with the lowest center frequency (channel 1001 in the example of FIG. 10) among the channels constituting the channel 1003.

[0091] When the access point device 1-2 allows the access point device 1-1 to use the secured channel 1002, the access point device 1-2 may not transmit frames on the channel 1002. Moreover, under certain conditions, the access point device 1-2 may transmit frames to a communication device other than the access point device 1-1 (e.g., station device 2-5) using at least a part of the frequency band of the channel 1002 after allowing the access point device 1-1 to use the secured channel 1002. Here, the predetermined conditions may be determined by setting the allowable interference power of the station device 2-5 or the like as a threshold value.

[0092] The access point device 1-1 that has received the first frame can use the channel 1002. At this time, the access point device 1-1 can transmit a response frame corresponding to the first frame to the access point device 1-2. may include information indicating the time interval (time period) or frequency band in which the channel 1002 is used, or both.

[0093] The first frame including information indicating permission to use the channel 1002 transmitted by the access point device 1-2 may include information indicating a time interval (time period) during which the access point device 1-1 is permitted to use the channel 1002. The frame may include information indicating a frequency band during which the access point device 1-1 is permitted to use the channel 1002.

[0094] The access point device 1-1 according to this embodiment can request permission to use the channel 1002 from the access point device 1-2. In this case, the access point device 1-1 can transmit a second frame including information indicating a request for permission to use at least a part of the channel 1002 to the access point device 1-2 using the channel 1002. When the access point device 1-2 receives the second frame, it can transmit a third frame including information indicating whether or not the access point device 1-1 is permitted to use the channel 1002 to the access point device 1-1. The frame including the information indicating whether or not the access point device 1-1 is permitted to use the channel 1002 can be the first frame described above.

[0095] The access point device 1-1 according to this embodiment can include, in the second frame, information indicating a time interval (time period) for using the channel 1002. The second frame can include information indicating a frequency band that the access point device 1-1 uses in the channel 1002.

[0096] The access point device 1-1 can transmit the second frame not as a frame addressed to one device but as a frame addressed to multiple devices. Here, the access point device 1-1 can transmit the second frame including information indicating multiple communication devices. It is preferable that the access point device 1-1 assumes that the multiple communication devices are communication devices that are using the channel 1002. This can be determined by the access point device 1-1 based on a propagation path estimation result associated with the channel 1002, as will be described later. The access point device 1-1 can also transmit the second frame as a broadcast frame.

[0097] An access point device (or station device) that receives a second frame transmitted as a frame addressed to multiple communication devices can determine whether or not the device itself is using channel 1002 or whether or not it has reserved channel 1002, and can transmit a third frame over channel 1002 to the communication device that sent the second frame.

[0098] The access point device 1-2 can transmit the first frame as a frame addressed to multiple devices, not to one device. The access point device 1-2 can transmit the first frame including information indicating multiple communication devices. The access point device 1-2 can transmit the first frame as a broadcast frame.

[0099] Prior to transmitting the first frame or the second frame, the access point device 1-1 and the access point device 1-2 can perform propagation path estimation associated with the channel 1002. For example, if the access point device 1-2 permits the access point device 1-1 to use the channel 1002, the frame transmitted by the access point device 1-1 using the channel 1002 will cause interference with the access point device 1-2 and the station device 2-5 that originally used the channel 1002. However, if the interference power is below a predetermined threshold (for example, the allowable interference power of each communication device), even if the access point device 1-1 is transmitting a frame using the channel 1002, the access point device 1-2 can also transmit a frame using the channel 1002.

[0100] Here, the allowable interference power is not limited to any particular value, but may be, for example, an interference power at which a frame can be correctly received (decoded without error) when a frame is received with a specified MCS (e.g., an MCS that can achieve 22.5 Mbps, which is one of the mandatory rates) and a specified transmission power (e.g., the upper limit of transmission power (antenna power) set by legal regulations, or EIRP). The allowable interference power may be set by each communication device, or may be set to a common value by communication devices in a connected state.

[0101] The access point apparatus 1-1 can transmit a fourth frame including information requesting the transmission of a reference signal (training field) for channel estimation to the access point apparatus 1-2 and the station apparatus 2-5. The access point apparatus 1-1 can transmit the fourth frame to a communication apparatus belonging to a BSS managed by the access point apparatus 1-2. At this time, the access point apparatus 1-1 can include, in the fourth frame, information associated with a training field transmitted by a communication apparatus that has received the fourth frame. The information associated with the training field can include a signal sequence set in the training field, an amount of phase rotation, and information indicating a radio resource from which the training field is transmitted.

[0102] The access point device 1-1 and the access point device 1-2 can also set a guard band between the channel 1001 and the channel 1002. The guard band can be newly set between the channel 1001 and the channel 1002. The guard band can also be set as a channel using a part of the bandwidth of the channel 1001 (for example, a band adjacent to the channel 1002) and a part of the bandwidth of the channel 1002 (for example, a band adjacent to the channel 1001).

[0103] The access point device 1-1 can use the guard band when transmitting a frame by using the first frame, the second frame, and the third frame. That is, the communication method performed when the access point device 1-1 uses the channel 1002 in the explanation so far can also be used when the access point device 1-1 uses the guard band for frame transmission.

[0104] In addition, since the guard band is a frequency band that is not normally used for communication, it is not necessarily necessary to secure the guard band by carrier sense prior to frame transmission. However, when the access point device 1-1 uses the guard band for frame transmission, carrier sense is required. When using the guard band, the access point device 1-1 according to this embodiment can perform carrier sense in advance to secure the guard band. For example, after securing the guard band, the access point device 1-1 can use a second frame to notify surrounding communication devices that the guard band will be used. At this time, unlike the case of using the channel 1002, the second frame can include information indicating that the access point device 1-1 has secured the guard band. The access point device 1-1 can transmit the second frame using the guard band.

[0105] The access point device 1-1 can transmit a trigger frame that triggers the transmission of a reference signal to other communication devices in the guard band. That is, the access point device according to this embodiment can transmit a reference signal having a wider signal bandwidth than the signal bandwidth of the reference signal transmitted in channel 1001, by using the band of channel 1001 and the guard band.

[0106] When implementing the above-described method, the access point device 1-1 can reserve radio resources in advance for setting the method. For example, the access point device 1-1 can set a time period in advance for setting the method by a beacon frame. Also, the access point device 1-1 can reserve radio resources in advance for setting the method for a predetermined period by a frame for reserving a TXOP.

[0107] The access point device according to the present embodiment can refuse to allow other communication devices to use the channel reserved by the access point device. For example, the access point device can transmit a frame including information indicating that the access point device does not permit other communication devices to use the channel reserved by the access point device. For example, the access point device can transmit a frame including information indicating that the access point device does not receive (or cannot receive) the second frame.

[0108] The access point device according to the present embodiment can indicate conditions for other communication devices to use a channel reserved by the access point device itself. For example, the access point device can report information associated with an allowable interference power when another communication device uses a channel reserved by the access point device itself. In addition, the access point device can report the conditions in advance by a beacon frame or a data frame.

[0109] The access point device 1-1 according to this embodiment can impose restrictions on frames transmitted on the channel 1002 reserved by the access point device 1-2. For example, the access point device 1-1 can determine whether to use the channel 1002 depending on the type of frame to be transmitted. Here, the frame type can be distinguished among a control frame, a management frame, and a data frame. The access point device 1-1 according to this embodiment can also determine whether to use the channel 1002 depending on the frame transmission method. For example, if the frame transmitted by the access point device 1-1 is addressed to multiple station devices, it can be set not to use the channel 1002.

[0110] The access point device 1-1 according to the present embodiment can determine whether to use the channel 1002 depending on the frequency band in which the channel 1002 is arranged. When the frequency band in which the primary channel is set is different from the frequency band in which the channel 1002 is arranged, the access point device 1-1 can be set not to use the channel 1002. Here, the frequency band can be distinguished among the 2.4 GHz band, the 5 GHz band, the 6 GHz band, and the 60 GHz band. Also, a plurality of frequency bands can be defined even in the 6 GHz band, and the access point device 1-1 according to the present embodiment can be set not to use the channel 1002 when the channel 1002 is set to 5.250 MHz when the primary channel is set to 5.150 MHz in the 5 GHz band.

[0111] The access point device 1-1 according to this embodiment can transmit OFDM signals in which different subcarrier intervals are set in the channels 1001 and 1002. In this case, the subcarriers of the OFDM signals transmitted in the channels 1001 and 1002 may be arranged contiguously or discontinuously. In this case, the access point device 1-1 can set the subcarrier interval set in the OFDM signal transmitted by the access point device 1-2 in the channel 1002 in the OFDM signal transmitted by the access point device 1-1 in the channel 1002. The access point device 1-1 can transmit a frame including information indicating the subcarrier interval to be set in the OFDM signal transmitted by the access point device 1-1 in the channel 1001.

[0112] When transmitting a frame on channel 1002, the access point device 1-1 according to this embodiment can transmit the frame in synchronization with the frame transmitted by the access point device 1-2 on channel 1002. Here, transmitting in synchronization includes a case where, when the frames transmitted by the access point device 1-1 and the access point device 1-2 are received by the communication device, the difference in reception timing is within the guard interval length set in the OFDM signal contained in the frame. In this case, the access point device 1-1 and the access point device 1-2 can perform a matching operation (calibration operation) prior to transmitting the frame. Here, the matching operation includes an operation of setting the difference in oscillation frequency to less than a predetermined value.

[0113] In the above-described method, the field in which the information is described is not limited to any particular one. For example, the field in which the information is described can be described in the PHY layer (PHY header). By describing the information in the PHY header, the communication device can quickly read the information only by demodulation processing in the PHY layer. Also, the field in which the information is described can be described in the MAC layer (MAC header, MAC body). By describing the information in the MAC layer, the communication device can flexibly adjust the amount of information to be described.

[0114] According to the method described above, even if the frequency band is divided into predetermined frequency bands in advance, the access point device and the station device can flexibly change the frequency band that can be used for frame transmission, thereby making it possible to improve frequency utilization efficiency. [2. Common to all embodiments]

[0115] The communication device according to the present invention can communicate in a frequency band (frequency spectrum) called an unlicensed band, which does not require permission to use from a country or region, but the available frequency band is not limited to this. The communication device according to the present invention can also be effective in a frequency band called a white band (for example, a frequency band allocated for television broadcasting but unused in some regions) that is not actually used for the purpose of preventing interference between frequencies even though permission to use the band for a specific service is given by a country or region, and in a shared spectrum (shared frequency band) that is expected to be shared by multiple operators.

[0116] In addition, the communication device according to the present invention is not limited to a specific communication standard. For example, when a communication standard (e.g., a communication standard approved by ITU-R as IMT-Advanced or IMT-2020) that is mainly targeted at a frequency band called a licensed band, for which permission to use has been obtained from a country or region, is introduced into an unlicensed band, the communication device according to the present invention can also be effective in the communication standard.

[0117] The program that runs on the wireless communication device according to the present invention is a program that controls the CPU and the like (a program that makes a computer function) so as to realize the functions of the above-mentioned embodiments of the present invention. Information handled by these devices is temporarily stored in RAM during processing, and is then stored in various ROMs and HDDs, and is read, modified, and written by the CPU as necessary. Recording media for storing the programs include semiconductor media, The storage medium may be any of a hard disk (e.g., a ROM, a non-volatile memory card, etc.), an optical storage medium (e.g., a DVD, an MO, an MD, a CD, a BD, etc.), a magnetic storage medium (e.g., a magnetic tape, a flexible disk, etc.), etc. In addition, not only are the functions of the above-mentioned embodiments realized by executing the loaded program, but the functions of the present invention may also be realized by processing in cooperation with an operating system or other application programs, etc., based on instructions from the program.

[0118] In addition, when distributing the program on the market, the program can be stored in a portable recording medium and distributed, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device of the server computer is also included in the present invention. In addition, a part or all of the communication device in the above-mentioned embodiment may be realized as an LSI, which is typically an integrated circuit. Each functional block of the communication device may be individually formed into a chip, or a part or all of the functional blocks may be integrated into a chip. When each functional block is formed into an integrated circuit, an integrated circuit control unit that controls them is added.

[0119] In addition, the method of integration is not limited to LSI, but may be realized by a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit technology that can replace LSI appears due to the advancement of semiconductor technology, it is also possible to use an integrated circuit based on that technology.

[0120] The present invention is not limited to the above-mentioned embodiment. The wireless communication device of the present invention is not limited to application to a mobile station device, but can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning and washing machines, air conditioners, office equipment, vending machines, and other household appliances.

[0121] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs and the like that do not deviate from the gist of the present invention are also included in the scope of the claims. [Industrial Applicability]

[0122] The present invention is suitable for use in a base station device and a communication method. [Explanation of symbols]

[0123] 1-1, 1-2 Access point device 2-1~8 Station equipment 3-1, 3-2 Management scope 10001-1 Upper layer section 10002-1 Autonomous distributed control unit 10002a-1 CCA Department 10002b-1 Backoff section 10002c-1 Transmission decision unit 10003-1 Transmitter 10003a-1 Physical layer frame generator 10003b-1 Radio transmitter 10004-1 Receiver 10004a-1 Radio receiver 10004b-1 Signal demodulation section 10005-1 Antenna section

Claims

1. A first base station device that performs wireless communication with a terminal device, A transceiver unit for transmitting and receiving wireless signals; A resource allocation unit that determines an allocation of frequency resources to be used for communication with a first terminal device; a control information generating unit that generates control information; Equipped with the first base station device communicates with the first terminal device using a first frequency channel; When the second base station device is communicating with the second terminal device using the second frequency channel, The control information generator generates first control information including information regarding a portion of the second frequency channel; the transmission / reception unit transmits a frame including the first control information to the second base station device; the resource allocation unit allocates a portion of the second frequency channel to communication between the first base station device and the first terminal device; the transceiver unit communicates with the first terminal device using the first frequency channel and a portion of the second frequency channel; the second frequency channel is a frequency channel reserved by the second base station device; A first base station device.

2. the transmitting / receiving unit transmits a frame including information indicating a request for permission to use the second frequency channel to the second base station device; The first base station device according to claim 1 .

3. the transceiver receives a frame including information indicating permission to use the second frequency channel, the frame being transmitted by the second base station device; The first base station device according to claim 1 .

4. the control information generation unit further generates second control information requesting the second base station device to report a channel quality of the second frequency channel in the second base station device; the transceiver unit transmits the second control information to the second base station device, and receives third control information from the second base station device, the third control information including information on a channel quality of the second frequency channel. The first base station device according to claim 1 .

5. A channel estimation unit is further provided for estimating a channel quality of a frequency channel, the channel estimator estimates a channel quality of the first frequency channel and a channel quality of the second frequency channel; the resource allocation unit determines to allocate a part of the second frequency channel to communication between the first base station device and the first terminal device based on the estimated channel quality of the first frequency channel, the estimated channel quality of the second frequency channel, and information on channel quality included in the third control information. The first base station device according to claim 4 .

6. the transceiver unit transmits a trigger frame to at least one of the second base station device and the second terminal device, the trigger frame requesting transmission of a reference signal on the second frequency channel; The first base station device according to claim 1 .

7. A second base station device that performs wireless communication with a terminal device, A transceiver unit for transmitting and receiving wireless signals; a resource allocation unit that determines an allocation of frequency resources to be used for communication with the second terminal device, When the second base station device is communicating with the second terminal device using a second frequency channel, if the transceiver unit receives first control information including information indicating that a first base station device uses a part of the second frequency channel, the resource allocation unit excludes the part of the second frequency channel from allocation for communication with the second terminal device. A second base station device.

8. the second base station apparatus further includes a channel estimator and a control information generator; the transmission / reception unit receives, from the first base station device, second control information requesting a report of channel quality of a second frequency channel used by the second base station device for communication with a second terminal device; the channel estimator estimates a channel quality of the second frequency channel in the second base station device; the control information generator generates third control information including information on the estimated channel quality of the second frequency channel; The transmission / reception unit transmits the third control information to the first base station device. The second base station device according to claim 7.

9. the second frequency channel is a frequency channel reserved by the second base station device; The second base station device according to claim 7 or 8.

10. A communication method for a first base station device that performs wireless communication with a terminal device, comprising: transmitting and receiving wireless signals; determining an allocation of frequency resources to be used for communication with a first terminal device; generating control information; generating first control information including information on a portion of the second frequency channel when the first base station device is communicating with the first terminal device using a first frequency channel and the second base station device is communicating with a second terminal device using a second frequency channel; transmitting a frame including the first control information to the second base station device; allocating a portion of the second frequency channel to communication between the first base station device and the first terminal device; communicating with the first terminal device using the first frequency channel and a portion of the second frequency channel; having the second frequency channel is a frequency channel reserved by the second base station device; Communication methods.

Images