Communication method and communication device

Abstract

The invention discloses a communication method and a communication device, relates to the technical field of communication, and can solve the problem that signals cannot be correctly demodulated due to superposition of multiple paths of signals. M RRUs in the plurality of RRUs can send M pieces of first information to the BBU, M is an integer greater than or equal to 1, any one piece of first information in the M pieces of first information comprises energy information and an identifier of one RRU, and the energy information indicates the energy of an input signal detected by the RRU; and the BBU controls channels of N RRUs in the plurality of RRUs to be in a turn-off state in the receiving direction based on the M pieces of first information, and N is an integer greater than or equal to 1. And the BBU receives a signal sent by a first RRU except the N RRUs in the plurality of RRUs, and the channel of the first RRU is in a normal working state in the receiving direction. In this way, the uplink signal sent by at least one RRU in the N RRUs can be prevented from conflicting with the uplink signal sent by the first RRU at the BBU.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and a communication device. Background Technology

[0002] Distributed wireless local area network (WLAN) is a type of WLAN that, in contrast to traditional centralized WLAN, refers to a WLAN system where access points (APs) are interconnected without traversing a wired backbone network. A distributed Wi-Fi system includes an Access Controller (AC), a central AP, and remote radio units (RRUs). The central AP can be a baseband unit (BBU). The BBU can connect to multiple RRUs.

[0003] If multiple RRUs send data to the BBU at the same time, signal collisions may occur at the BBU; if multiple RRUs receive signals from the BBU at the same time, it may lead to energy waste. Summary of the Invention

[0004] This application provides a communication method and a communication device that can solve the problem of incorrect demodulation of signals caused by the superposition of multiple signals.

[0005] In a first aspect, a communication system is provided, including a Base Unit (BBU) and multiple Remote Assisted Units (RRUs). The BBU includes multiple radio frequency (RF) channels, each RF channel being connected to a portion of the RRUs via a remote medium. Specifically: M RRUs are configured to send M first pieces of information to the BBU, where M is an integer greater than or equal to 1. Each of the M first pieces of information includes energy information and an RRU identifier, the energy information indicating the energy of an input signal detected by the RRU. The BBU is configured to control the channels of N RRUs among the multiple RRUs to be in a switched-off state in the receiving direction based on the M first pieces of information, where N is an integer greater than or equal to 1. The BBU is also configured to receive signals transmitted by a first RRU (excluding the N RRUs) among the multiple RRUs, the first RRU's channel being in a normal operating state in the receiving direction.

[0006] In this application, the radio frequency channel in the BBU can be understood as the channel between the power divider in the BBU and the baseband processing (baseband, BB module) in the BBU, and the channel in the RRU can be understood as the channel between the power divider in the BBU and the RRU after power division.

[0007] Therefore, this application can determine one of the M RRUs based on the first information reported by the M RRUs, that is, the channel of the first RRU is in normal working condition in the receiving (RX) direction, while the channels of the N RRUs are turned off. In this way, compared to the problem of signal conflict at the BBU when multiple terminals under multiple RRUs simultaneously send uplink signals to the BBU via the radio frequency channel, this application can, based on the first signal sent by the M RRUs, keep the channel of the first RRU in normal working condition and turn off the channels of the N RRUs in the receiving direction. This enables accurate identification and precise shutdown of RRUs at the granular level, avoiding signal conflict at the BBU between the uplink signal sent by at least one of the N RRUs and the uplink signal sent by the first RRU, thus improving the accuracy of the BBU in demodulating the uplink signal.

[0008] Furthermore, considering that even if one RRU in a single RF channel transmits an uplink signal, the noise from the paths of the other RRUs in that RF channel will be superimposed at the power divider in the BBU, increasing the superimposed signal noise figure and affecting the demodulation of the uplink signal transmitted by that single RRU. This application addresses this issue by receiving the uplink signal from the path of a first RRU and shutting down the paths of N RRUs in the RX direction. This avoids the influence of noise from the paths of N RRUs in the receiving direction on the uplink signal of the first RRU, improving the demodulation accuracy of the uplink signal from the first RRU by the BBU.

[0009] In one possible design, the N RRUs and the first RRU are connected to the same RF channel. Thus, when the BB module in the BBU selects an uplink signal from one RF channel for reception, if different RRUs on the same RF channel simultaneously have uplink signals to transmit, the BBU can shut down the RX direction channels of the N RRUs on that RF channel, while maintaining normal operation of the RX direction channel of the first RRU. This avoids signal conflict issues when the BBU receives uplink signals transmitted by RRUs on the same RF channel.

[0010] In one possible design, N RRUs and the first RRU are RRUs connected to at least two different RF channels. Specifically, this design could involve a total of N+1 RRUs connected to the BBU. When the BBU determines that the first RRU's channel is receiving normally based on M pieces of initial information, it can shut down the channels of the other N RRUs connected to the BBU. This way, the BBU can receive uplink signals from only one RRU on a single RF channel, avoiding signal conflicts that might occur at the BBU when at least one of the other N RRUs simultaneously transmits uplink signals to the first RRU.

[0011] In one possible design, the first RRU is the RRU corresponding to the first message received by the BBU. This can also be understood as the first RRU that detects energy information that meets the energy threshold first. When the BBU can directly use the RRU that first received the first message as the first RRU, it can ensure that the channel of the first RRU in the RX direction is not affected by the channels of the N RRUs.

[0012] In one possible design, M RRUs out of a set number of RRUs are those that transmit the first information within a preset time period; the first RRU is the one with the highest energy indicated by the energy information among the M RRUs. In this way, the BBU can ensure that the transmission in the RX direction of the RRU with the best signal quality within a certain period of time is not affected by the channels of the N RRUs.

[0013] In one possible design, the first RRU is the RRU whose channels among the M RRUs complete fine synchronization processing first under normal operating conditions. This design takes into account that if the BBU determines whether there is an uplink signal to be uploaded based solely on energy information, it will be inaccurate. There may be interference signals in the environment that are on the same frequency band as the uplink signal transmitted by the RRU, and the BBU will also detect the transmission of high-energy signals. This application combines energy information with fine synchronization processing to avoid the BBU receiving interference signals and also to ensure that the uplink signal of the selected first RRU is not conflicted with the signals of the N RRUs.

[0014] In one possible design, the BBU is used to control the channels of N RRUs to be turned off in the receiving direction when the efficient short training field HE-STF is detected in the signal transmitted by the first RRU.

[0015] In one possible design, the energy information indicated by the energy information for each of the M RRUs is greater than or equal to an energy threshold. This avoids the BBU receiving uplink signals transmitted by terminals under RRUs with poor signal quality, thus improving the transmission performance of the BBU in receiving uplink signals.

[0016] In one possible design, the BBU is also used to control the channels of N RRUs to return to normal operation upon receiving a complete signal frame from the first RRU. This ensures that the BBU can promptly restore uplink transmission of the N RRU channels while maintaining the transmission performance of the uplink signal received from the first RRU.

[0017] In one possible design, the communication system further includes multiple switching devices, each coupled to one of the multiple RRUs; the BBU includes multiple switching devices, or each of the multiple RRUs includes one of the multiple switching devices; the BBU also includes a controller for sending first control commands to the N switching devices coupled to the N RRUs respectively, the first control commands controlling the channel of one of the N RRUs to be in a receive-direction off state. Thus, through the transmission of the first control commands between the controller in the BBU and the N switching devices, the uplink transmission of the first RRU can be made unaffected by the uplink transmission of the N RRUs.

[0018] In one possible design, the controller is further configured to, upon determining that the BBU has received the complete signal frame transmitted by the first RRU, send a second control command to each of the N switching devices. This second control command controls one of the N RRUs to restore its channel to normal operation in the receiving direction. That is, when the controller determines that the uplink signal transmission of the first RRU is complete, it can promptly restore the channels of the N RRUs to normal operation in the RX direction through the transmission of the second control command between the controller and the N switching devices.

[0019] Secondly, a communication method is provided. The execution subject of this method can be a BBU (Base Station Unit), a component or device applied to the BBU (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the BBU's functions. In this method, the BBU includes multiple radio frequency (RF) channels, each RF channel being connected to a portion of multiple Remote Radio Units (RRUs) via a remote medium. The method includes: receiving M pieces of first information, where M is an integer greater than or equal to 1, each of the M pieces of first information including energy information and an RRU identifier, the energy information indicating the energy of an input signal detected by the RRU; based on the M pieces of first information, controlling the channels of N RRUs among the multiple RRUs to be in a deactivated state in the receiving direction, where N is an integer greater than or equal to 1; and receiving signals transmitted by a first RRU (excluding the N RRUs) among the multiple RRUs, the channels of the first RRU being in a normal operating state in the receiving direction.

[0020] For the beneficial effects of the second aspect, please refer to the explanation of the first aspect.

[0021] In one possible design, N RRUs and the first RRU are RRUs connected to the same RF channel.

[0022] In one possible design, N RRUs and the first RRU is an RRU connected to at least two different radio frequency channels.

[0023] In one possible design, the method further includes: upon receiving a complete signal frame sent by the first RRU, controlling the channels of N RRUs to resume normal operation.

[0024] In one possible design, receiving M first messages includes: receiving first messages sent by the first RRU; the first RRU is the RRU that receives the first messages first.

[0025] In one possible design, receiving M first messages includes: receiving M first messages sent by M RRUs within a preset time period; the first RRU is the RRU with the highest energy indicated by the energy information among the M RRUs.

[0026] In one possible design, before controlling the channels of N RRUs out of the multiple RRUs to be in the off state, the method further includes: performing fine synchronization processing on signals received from M RRUs; the first RRU is the RRU whose channels of the M RRUs are the first to complete the fine synchronization processing in normal operation.

[0027] In one possible design, controlling the channels of N RRUs out of a plurality of RRUs to be in a deactivated state includes: when the efficient short training field HE-STF is detected in the signal transmitted by the first RRU, controlling the channels of the N RRUs to be in a deactivated state in the receiving direction.

[0028] In one possible design, the energy information indicated by the energy information of each of the M RRUs is greater than or equal to the energy threshold.

[0029] Thirdly, a communication method is provided. The execution subject of this method can be an RRU, a component or device applied to the RRU (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the RRU's functions. The RRU is connected to a radio frequency channel in a BBU via a remote medium. The method includes: sending first information to the BBU, the first information including energy information and an RRU identifier, the energy information indicating the energy of an input signal detected by the RRU, and the first information used by the BBU to determine whether to control the RRU's channel to be in a closed state.

[0030] For the beneficial effects of the third aspect, please refer to the explanation of the first aspect.

[0031] In one possible design, the method further includes: sending a signal to the BBU; or receiving a control signal indicating that the RRU's channel is in a closed state in the receiving direction. This design can be understood as follows: the RRU reporting the first information to the BBU may be an RRU selected by the BBU to maintain its channel in a normal operating state; in this case, the BBU can receive the uplink signal sent by that RRU. Alternatively, the RRU reporting the first information to the BBU may not be selected by the BBU; if a switching device is included in the RRU, the RRU can receive a control signal sent by the BBU indicating that the RRU's channel is in a closed state in the receiving direction.

[0032] Fourthly, a communication system is provided, including a BBU and multiple RRUs. The BBU includes multiple radio frequency channels, each radio frequency channel being connected to a portion of the multiple RRUs via a remote medium. The BBU is configured to identify Q RRUs among the multiple RRUs whose signals are to be transmitted, where Q is an integer greater than or equal to 1. The BBU is also configured to transmit Z first instructions, wherein the Z first instructions indicate that Z RRUs (excluding the Q RRUs) are in a power-off state or a low-power state in the transmission direction, where Z is an integer greater than or equal to 1. The Z RRUs are configured to adjust to a power-off state or a low-power state in the transmission direction based on the Z first instructions.

[0033] Compared to existing technologies, when the radio frequency channel in the BBU transmits downlink (TX) signals, some RRUs under the radio frequency channel also transmit the downlink signal. This results in a certain degree of power waste when only some RRUs need to receive the downlink signal. Therefore, this application, based on the BBU identifying Q RRUs that need to transmit downlink signals, uses Z first quality parameters to put Z RRUs that do not need to transmit downlink signals into a shutdown or low-power state. This avoids the power waste caused by some RRUs that do not need to transmit downlink signals also transmitting the downlink signal.

[0034] Alternatively, the aforementioned BBU, used to identify Q RRUs among multiple RRUs that are to send signals, can be replaced with a BBU used to identify Z RRUs among multiple RRUs that are not sending signals.

[0035] In one possible design, Q RRUs and Z RRUs are connected to the same RF channel. This design can be understood as follows: when the BBU transmits a downlink signal through a RF channel, all RRUs under that RF channel will transmit the same content, i.e., all transmit the downlink signal. This ensures that when only the terminals under Q RRUs need to receive the downlink signal, the Z RRUs in that RF channel are in a powered-off or low-power state, avoiding the power waste caused by Z RRUs also transmitting the downlink signal.

[0036] In one possible design, Q RRUs and Z RRUs are RRUs connected to at least two different RF channels. This design could involve a total of Q plus Z RRUs connected to the BBU. If the BBU determines that Q RRUs out of the total number of RRUs need to transmit downlink signals, the remaining Z RRUs can be put into a shutdown or low-power state. The Q RRUs could be RRUs on a single RF channel or RRUs on different RF channels. Similarly, the Z RRUs could be RRUs on a single RF channel or RRUs on different RF channels.

[0037] In one possible design, Z RRUs are used to, based on Z first commands, adjust the front-end module (FEM) of each of the Z RRUs to a shutdown state in the transmission direction, or reduce the transmit power of the front-end module of each of the Z RRUs, or reduce the supply voltage of the front-end module of each of the Z RRUs. Considering that the FEM contains a power amplifier for transmitting downlink signals, this application can adjust the power amplifier in the FEM for transmitting downlink signals to a shutdown state, a low-power state, or a low-voltage state, so that the FEM cannot be used to transmit downlink signals.

[0038] In one possible design, the BBU is also used to determine whether the signal frame to be transmitted is a non-broadcast frame before sending the Z first instructions. It should be understood that if the signal frame to be transmitted by the BBU is a broadcast frame, there is no need to selectively shut down the RRUs connected to the BBU. If the signal frame to be transmitted by the BBU is a multicast or unicast frame, it is not necessary for the Z RRUs transmitting downlink signals to be in a powered-off or low-power state.

[0039] In one possible design, the BBU is also used to send Z second instructions after determining that a complete signal frame has been sent to Q RRUs. These Z second instructions instruct the Z RRUs to resume normal operation in the transmission direction. In this way, while avoiding the Z RRUs sending signal frames with the same content, the Z second instructions can promptly restore the Z RRUs to normal transmission in the TX direction.

[0040] In one possible design, the BBU includes a controller that is connected to a path of each of the plurality of RRUs; the controller is used to send a first instruction to each of the Z RRUs.

[0041] Fifthly, a communication method is provided. The execution subject of this method can be a BBU, a component or device applied to the BBU (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the BBU's functions. The BBU includes multiple radio frequency channels, each radio frequency channel being connected to some of the multiple RRUs through a remote medium. The method includes: determining Q RRUs among the multiple RRUs to which signals are to be transmitted, where Q is an integer greater than or equal to 1; and transmitting Z first instructions, where the Z first instructions indicate that Z RRUs other than the Q RRUs are in a power-off state or a low-power state in the transmission direction, where Z is an integer greater than or equal to 1.

[0042] For the benefits of the fifth aspect, please refer to the explanation of the fourth aspect.

[0043] In one possible design, Q RRUs and Z RRUs are RRUs connected to the same RF channel.

[0044] In one possible design, Q RRUs and Z RRUs are RRUs connected to at least two different radio frequency channels.

[0045] In one possible design, before sending the Z first instructions, the method further includes: determining that the signal frame to be sent is a non-broadcast frame.

[0046] In one possible design, the method further includes: after determining that a complete data frame has been sent to Q RRUs, sending Z second instructions, which instruct the Z RRUs to resume normal operation in the transmission direction.

[0047] Sixthly, a communication method is provided. The execution subject of this method can be an RRU, a component or device applied to the RRU (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the RRU's functions. The RRU is connected to a radio frequency channel in a BBU via a remote medium. The method includes: receiving a first instruction, the first instruction indicating that the RRU is in a power-off state or a low-power state in the transmission direction, and the RRU is an RRU that does not transmit signals; and adjusting the RRU to a power-off state or a low-power state in the transmission direction based on the first instruction.

[0048] For the beneficial effects of the sixth aspect, please refer to the explanation of the fourth aspect.

[0049] In one possible design, adjusting to a shutdown state or a low-power state in the transmission direction based on the first instruction includes: adjusting the RRU's front-end module to a shutdown state in the transmission direction based on the first instruction, or reducing the transmission power of the RRU's front-end module, or reducing the supply voltage of the RRU's front-end module. In another possible design, the method further includes: receiving a second instruction, the second instruction instructing the RRU to resume normal operation in the transmission direction.

[0050] In a seventh aspect, a communication device is provided, which is a BBU or a device within a BBU. The BBU includes multiple radio frequency channels, each of which is connected to a portion of the multiple remote root units (RRUs) via a remote medium. The communication device includes: a transceiver for receiving M first pieces of information, where M is an integer greater than or equal to 1, each of the M first pieces of information including energy information and an identifier of an RRU, the energy information indicating the energy of an input signal detected by an RRU; a controller for controlling the channels of N RRUs among the multiple RRUs to be in a closed state in the receiving direction based on the M first pieces of information, where N is an integer greater than or equal to 1; and a transceiver further for receiving signals transmitted by a first RRU other than the N RRUs among the multiple RRUs, the channels of the first RRU being in a normal operating state in the receiving direction.

[0051] In one possible design, it also includes multiple switching devices, each of which is coupled to one of the multiple RRUs; and a controller for sending a first control command to each of the N switching devices coupled to the N RRUs, the first control command being used to control the channel of one of the N RRUs to be in a closed state in the receiving direction.

[0052] In one possible design, N RRUs and the first RRU are RRUs connected to the same RF channel.

[0053] In one possible design, N RRUs and the first RRU is an RRU connected to at least two different radio frequency channels.

[0054] In one possible design, a transceiver is used to receive the first information sent by the first RRU; the first RRU is the RRU that receives the first information first.

[0055] In one possible design, the transceiver is used to receive M first messages sent by M RRUs within a preset time period; the first RRU is the RRU with the highest energy indicated by the energy information among the M RRUs.

[0056] In one possible design, the controller is also used to: perform fine synchronization processing on signals received from M RRUs; the first RRU is the RRU whose channel among the M RRUs completes fine synchronization processing first under normal operating conditions.

[0057] In one possible design, a controller is used to control the channels of N RRUs to be turned off in the receiving direction when the efficient short training field HE-STF is detected in the signal transmitted by the first RRU.

[0058] In one possible design, the energy information indicated by the energy information of each of the M RRUs is greater than or equal to the energy threshold.

[0059] In one possible design, the controller is also used to send a second control command to each of the N switching devices upon receiving a complete signal frame from the first RRU. The second control command is used to control the channel of one of the N RRUs to resume normal operation in the receiving direction.

[0060] Eighthly, a communication device is provided, applied to an RRU or a device within an RRU, wherein the RRU is connected to a radio frequency channel in a baseband processing unit (BBU) via a remote medium. The communication device includes: a transceiver for sending first information to the BBU, the first information including energy information and an identifier of the RRU, the energy information indicating the energy of an input signal detected by the RRU, and the first information used by the BBU to determine whether to control the RRU's channel to be in a state of being off in the receiving direction.

[0061] In one possible design, multiple switching devices are also included, each of which is coupled to one of the multiple RRUs; the switching devices are used to receive a first control command sent by the BBU, the first control command being used to control the RRU's channel to be in a closed state in the receiving direction.

[0062] In one possible design, the switching device is also used to receive a second control command sent by the BBU, which controls the RRU channel to return to normal operation in the receiving direction.

[0063] A ninth aspect provides a communication device applied to a BBU or a device within a BBU, the BBU including multiple radio frequency channels, each radio frequency channel being connected to a portion of multiple remote radio frequency units (RRUs) via a remote medium, the communication device including: a controller for determining Q RRUs among the multiple RRUs to transmit signals, where Q is an integer greater than or equal to 1; and a transceiver for transmitting Z first instructions, the Z first instructions indicating that Z RRUs among the multiple RRUs are in a power-off state or a low-power state in the transmission direction, where Z is an integer greater than or equal to 1.

[0064] In one possible design, Q RRUs and Z RRUs are RRUs connected to the same RF channel.

[0065] In one possible design, Q RRUs and Z RRUs are RRUs connected to at least two different radio frequency channels.

[0066] In one possible design, the controller is also used to determine whether the signal frame to be transmitted is a non-broadcast frame.

[0067] In one possible design, the transceiver is also used to send Z second instructions after determining that a complete data frame has been sent to Q RRUs. The Z second instructions instruct the Z RRUs to resume normal operation in the transmission direction.

[0068] In a tenth aspect, a communication device is provided, applied to an RRU or a device within an RRU, wherein the RRU is connected to a radio frequency channel in a baseband processing unit (BBU) via a remote medium. The communication device includes: a transceiver for receiving a first instruction indicating that the RRU is in a power-off state or a low-power transmission state in the transmission direction, wherein the RRU is an RRU that does not transmit data; and a controller for adjusting the RRU to a power-off state or a low-power transmission state in the transmission direction based on the first instruction.

[0069] In one possible design, the RRU also includes a front-end module; and a controller, which, based on a first instruction in the transmission direction, adjusts the front-end module to a shutdown state, or reduces the transmission power consumption of the front-end module, or reduces the supply voltage of the front-end module.

[0070] In one possible design, the transceiver is also used to receive a second instruction that instructs the RRU to resume normal operation in the transmission direction; the controller is also used to adjust the front-end module to normal operation in the transmission direction based on the first instruction, or to increase the transmission power consumption of the front-end module, or to increase the supply voltage of the front-end module.

[0071] Eleventhly, a computer-readable storage medium is provided, wherein computer instructions are stored therein, which, when executed on a communication device, cause the communication device to perform the method as described in the second aspect and any possible design of the second aspect, and / or, the method as described in the third aspect and any possible design of the third aspect, and / or, the method as described in the fifth aspect and any possible design of the fifth aspect, and / or, the method as described in the sixth aspect and any possible design of the sixth aspect.

[0072] In a twelfth aspect, a computer program product is provided that, when the computer program product is run on a communication device, causes the communication device to perform the method described in the second aspect and any possible design of the second aspect, and / or, the method described in the third aspect and any possible design of the third aspect, and / or, the method described in the fifth aspect and any possible design of the fifth aspect, and / or, the method described in the sixth aspect and any possible design of the sixth aspect.

[0073] It is understood that any of the communication devices, computer-readable storage media, or computer program products provided above can be applied to the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods, and will not be repeated here.

[0074] These or other aspects of this application will become more readily apparent in the following description. Attached Figure Description

[0075] Figure 1 This application provides a schematic diagram of a distributed WLAN system architecture.

[0076] Figure 2 This is a schematic diagram illustrating an application scenario of a hidden node provided in an embodiment of this application;

[0077] Figure 3 This is a schematic diagram of the architecture of a distributed WLAN system provided in an embodiment of this application;

[0078] Figure 4 A flowchart illustrating a communication method provided in an embodiment of this application;

[0079] Figure 5 A schematic diagram of the hardware structure of BBU and RRU in a distributed WLAN system provided for an embodiment of this application;

[0080] Figure 6 A schematic diagram of the structure of a power detector in an RRU provided in this application embodiment;

[0081] Figure 7 This application provides a schematic diagram of a selectable turn-off timing for RRU channels based on a first-come, first-served principle.

[0082] Figure 8 A timing diagram of RRU channel selection logic based on the strongest power criterion is provided for an embodiment of this application;

[0083] Figure 9 A timing diagram of RRU channel selection logic based on a fine synchronization criterion is provided for an embodiment of this application;

[0084] Figure 10 This is a schematic diagram of the architecture of a distributed WLAN system provided in an embodiment of this application;

[0085] Figure 11 This is a schematic diagram of the internal structure of a multifunctional mixer chip provided in an embodiment of this application;

[0086] Figure 12A schematic diagram of a distributed WLAN system provided in an embodiment of this application;

[0087] Figure 13 A flowchart illustrating a communication method provided in an embodiment of this application;

[0088] Figure 14 This is a schematic diagram of the architecture of a distributed WLAN system provided in an embodiment of this application;

[0089] Figure 15 A timing diagram illustrating the selection of an RRU channel in the TX direction in a distributed WLAN system, as provided in an embodiment of this application.

[0090] Figure 16 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0091] Figure 17 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0092] This application can be applied to the network architecture of distributed wireless local area networks (WLANs). Distributed WLANs, in contrast to traditional centralized WLANs, primarily refer to a method where access points (APs) in a WLAN are interconnected without traversing a wired backbone network. The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard defines a distributed system as the infrastructure used to connect APs. To establish a distributed WLAN, two or more APs need to be configured with the same service set identifier (SSID).

[0093] In densely populated environments such as student dormitories, offices, classrooms, hospital wards, and hotels, traditional centralized WLAN deployment solutions generally suffer from poor indoor signal quality, inability to access the network when multiple users are present, or slow network speeds and frequent disconnections when users are mobile, resulting in a poor user experience. Furthermore, as the number of deployed access points (APs) increases, the complexity of device management continues to rise, placing higher demands on customers' network management capabilities. Therefore, a distributed WLAN network architecture has been proposed. For example... Figure 1The diagram illustrates the structure of a distributed WLAN system 100. This distributed WLAN system can be, for example, a distributed Wi-Fi system. System 100 includes an Access Controller (AC) 101, distributed Access Points (DAPs) 102, and remote radio units (RRUs) 103. The distributed AP 102 can be understood as a central AP. An AC 101 can communicate with one central AP, and a central AP can communicate with multiple RRUs 103 via a remote medium. Each RRU 103 can provide wireless services to one or more terminals.

[0094] The AC101 is used as the management center AP and can be deployed in the network management center. The central AP is responsible for functions such as roaming handover, load balancing, spectrum analysis, and correlation control. For example, the central AP can automatically collect surrounding radio frequency resource parameters for judgment, automatically adjust radio frequency transmission power, and automatically select wireless channels to reduce interference, enabling the wireless network to adapt to changes in the wireless radio frequency environment and maintain optimal radio frequency resource status. The central AP can be deployed in equipment rooms, weak current shafts, corridors, or hallways. The RRU103 is responsible for air interface management and radio frequency control, and can provide high-power wireless signals. It can be ceiling-mounted, wall-mounted, or panel-mounted.

[0095] Distributed Wi-Fi architecture has the following significant advantages over traditional centralized WLAN deployment solutions:

[0096] 1) RRUs are deployed indoors with zero dead zones, while simultaneously improving wireless access performance;

[0097] 2) RRUs require no configuration; the AC only manages the central AP, saving on management nodes and costs.

[0098] 3) No re-association or re-authentication is triggered when the terminal roams, achieving "zero" roaming for the terminal;

[0099] 4) The central AP supports self-organizing networks and works with RRUs to complete the rapid deployment of low-cost networks.

[0100] In this distributed WLAN system, the problem of hidden nodes may occur.

[0101] A hidden node, also known as a stealth terminal, refers to a node that is within the coverage area of ​​the receiving node but outside the coverage area of ​​the sending node. For example... Figure 2The diagram illustrates an application scenario of a hidden node. Nodes A, B, and C all operate on the same channel. Node A can detect Node B, meaning Node B is within Node A's coverage area. Node B can detect both Node A and Node C, and Node C can also detect Node B, meaning Node B is also within Node C's coverage area. However, Nodes A and C cannot detect each other. In this case, Node C can be understood as "hidden" outside Node A's coverage area, but Node C is a hidden node that can potentially cause collisions with Node A's data transmissions. That is, when Node A sends data to Node B, Node C cannot detect any signal transmission; Node C considers the signal idle. However, if Node C also sends a signal to Node B at this time, the signals sent by Node A and C will collide or overlap at Node B. In other words, Node C is within Node B's coverage area as a receiving node, but outside Node A's coverage area as a sending node.

[0102] Having understood hidden nodes, this section provides an example to illustrate the potential problem of hidden nodes in a distributed WLAN system.

[0103] like Figure 3 The image shows a type of... Figure 1 The diagram illustrates the architecture of a distributed WLAN system 300. With the central access point (AP) serving as a base station (BBU), the BBU comprises multiple radio frequency chains (RF chains). Each RF chain can be connected to multiple remote root units (RRUs) via a multiplexer (e.g., multiplexer 302) and a remote medium. Each RRU can provide signal coverage for terminals.

[0104] The medium for remote connection can be, for example, optical fiber or network cable.

[0105] For example, the BBU includes a baseband (BB) module, a radio frequency integrated circuit (RFIC), a controller 301, and multiple radio frequency channels. For instance, the BB module can be a system-on-a-chip (SoC). For example, the multiple radio frequency channels include... Figure 3 The diagram shows RF channels 1 through RF channel n, a total of n RF channels, where n is an integer greater than or equal to 2. For example... Figure 3 As shown, each RF channel is coupled to a power divider, and each power divider is coupled to multiple multiplexers. Each multiplexer can be connected to an RRU via a remote medium. The number of RRUs connected to different RF channels in the n RF channels may be the same or different. For example, RF channel 1 is connected to x RRUs via a power divider, and the x RRUs include... Figure 3The diagram shows RRU_1_1 to RRU_1_x, where x is an integer greater than or equal to 1. RF channel n is connected to y RRUs via a power divider. The y RRUs include, for example, RRU_1_1 to RRU_1_x. Figure 3 The values ​​of RRU_n_1 to RRU_n_y are shown, where y is an integer greater than or equal to 1. The values ​​of x and y may be the same or different. If the value of x or y is equal to 1, it means that there is one RRU connected to one radio frequency channel. Figure 3 In the example, the number of RRUs connected to each RF passband is shown as at least 2.

[0106] The System-on-Chips (SoC) is primarily used for baseband signal processing. The RFIC (Radio Frequency Identifier) ​​is mainly used for up-conversion, down-conversion, filtering, and amplification of signals. The board-level controller, such as a complex programmable logic device (CPLD), is mainly used to transmit board-level control commands for the entire system. The power divider is responsible for splitting the RF signals and transmitting them to multiple RRUs via multiple multiplexers. The power divider can also receive RF signals of different frequencies transmitted through multiplexers, combine them, and then send them to the RF channel.

[0107] The RRU may include a multiplexer 303, a front-end module (FEM), a controller 304, and multiple antennas 305. The multiple antennas can be used to transmit or receive radio frequency signals of different frequencies; the multiplexer 303 can be used to combine or split the radio frequency signals transmitted by the multiple antennas; the FEM can be used to amplify the radio frequency signals to be transmitted or received; the controller 304, for example, is a CPLD, used to transmit board-level control commands for the entire system; and the antennas are used to transmit or receive radio frequency signals.

[0108] In some scenarios, the antenna selection scheme used in distributed WLAN systems is a channel-level antenna selection scheme. When a distributed Wi-Fi system transmits or receives signals, this antenna selection scheme can select the appropriate radio frequency (RF) channel within the BBU (Block Buffer Unit). For example, when the BBU receives signals in the receive (RX) direction, it can dynamically select the optimal uplink signal from the RF channel for processing, packet by packet, based on the signal strength detected by different RF channels.

[0109] Considering that multiple RRUs connected to a radio frequency channel are always in normal working order, if, in the RX direction, multiple terminals covered by RRUs connected to a single radio frequency channel need to send uplink data, a hidden node problem will exist between the terminals. That is, if terminals under different RRUs connected to a single radio frequency channel simultaneously send uplink signals, the uplink signals sent by terminals under different RRUs will overlap at the BBU, causing the overlapped signal to be unable to be correctly demodulated at the BBU.

[0110] Moreover, among the RRUs connected on the same RF channel, even if only one RRU has an uplink signal to send, the noise on the other RRU paths will be superimposed at the BBU multiplexer, making the superimposed signal noise figure larger and affecting the BBU's demodulation of the uplink signal.

[0111] Therefore, this application provides a communication method and a communication device, which can be applied to a distributed WLAN architecture. This method can determine whether each RRU after power splitting multiple RF channels should receive uplink signals, achieving RRU-level antenna selection resolution. For uplink signals, it can reduce the probability of data collisions in scenarios where RRUs concurrently transmit uplink signals, and mitigate the deterioration of the noise figure after multiplexing by the BBU-side multiplexer.

[0112] like Figure 4 The diagram illustrates a communication method provided in this application. This method can be applied to the RRU channel selection process in the receive (RX) direction. It allows the RRU to report the energy information of the uplink or input signals detected by the RRU to the BBU, enabling the BBU to determine which RRU channels to be shut down and which are normally receiving signals. In this way, the uplink signal received by the shut-down RRU channel cannot be transmitted to the BBU's radio frequency channel, thus preventing conflict with the uplink signal of the normally operating RRU channel. This method can be applied to a distributed WLAN architecture communication system, which includes a BBU and multiple RRUs. The BBU includes multiple radio frequency channels, each connected to a portion of the multiple RRUs via a remote medium. The method includes the following steps.

[0113] 401. M RRUs out of multiple RRUs send M first information messages to the BBU, where M is an integer greater than or equal to 1. Each of the M first information messages includes energy information and an RRU identifier. The energy information indicates the energy of the input signal detected by the RRU.

[0114] Accordingly, the BBU receives M first messages sent by M RRUs out of the multiple RRUs.

[0115] That is, the selection of RRU channels in the RX direction can rely on each RRU performing energy detection on the received uplink signal.

[0116] In some embodiments, when there is a signal input at the antenna port of the RRU, the RRU can perform energy detection on the input signal. When the RRU detects that the energy of the input signal is greater than or equal to an energy threshold, the RRU can send first information to the BBU, the first information including the energy information detected by the RRU and the identifier of the RRU.

[0117] In other words, the energy information indicated by the energy information of each of the M RRUs is greater than or equal to the energy threshold.

[0118] 402. Based on M pieces of first information, the BBU controls the channels of N RRUs out of multiple RRUs to be in the off state in the receiving direction, where N is an integer greater than or equal to 1.

[0119] In this application, the radio frequency channel can be understood as the channel between the power divider in the BBU and the BB module, and the RRU channel can be understood as the channel between the power divider in the BBU and the antenna in the RRU.

[0120] In this application, in order to ensure that the uplink signal transmitted by a terminal under one RRU is not affected by the terminals under other RRUs, it is sufficient to keep one RRU channel in normal receiving state in the RX direction.

[0121] Therefore, in some embodiments, the BBU can determine, based on M pieces of first information, that the channel of the first RRU among the M RRUs is in a normal working state in the receiving direction, and that the channels of the N RRUs other than the first RRU are in a deactivated state in the receiving direction. This is equivalent to N+1 being the total number of RRUs connected to the BBU.

[0122] In this way, the BBU will not be affected by the channels of the N RRUs when receiving the uplink signal sent by the first RRU. It also avoids the problem of data conflict at the BBU when at least two terminals under the same RRU are sending uplink signals at the same time.

[0123] Moreover, the BBU receiving the uplink signal sent by the first RRU will not be affected by noise on the paths of other RRUs.

[0124] This application does not limit how the BBU determines which RRU channels are in normal working condition and which are in a deactivated state. For example, the BBU may select and deactivate RRU channels according to a first-come, first-served principle, or it may select and deactivate RRU channels based on the strongest energy principle, or it may select and deactivate RRU channels based on a precise synchronization principle. Specific examples of these three methods will be illustrated below.

[0125] In some embodiments, the N RRUs and the first RRU are RRUs connected to the same radio frequency channel. This can be understood as M first messages being sent by M RRUs among multiple RRUs connected to the same radio frequency channel, and the BBU can determine the channel of the N RRUs to be turned off and the channel of the first RRU in normal operation under a radio frequency channel based on the M first messages.

[0126] This can be understood as follows: considering that the BB module on the BBU side can perform antenna selection at the RF channel level, when multiple RF channels receive uplink signals in the RX direction, the BB module can select only the uplink signal under one of the multiple RF channels for processing. However, this application considers that among multiple RRUs connected to the same RF channel, there may be cases where terminals under at least two RRUs simultaneously transmit uplink signals. If the BBU performs RRU channel selection and shutdown based on the first information reported by the RRUs connected to the same RF channel, the uplink signal of the first RRU channel in normal working condition under the same RF channel will not be interfered with by the uplink signals of other RRU channels.

[0127] In other words, the uplink signal received by the BB module in the BBU through the selected RF channel is only the uplink signal of one RRU channel. This avoids the problem of signal superposition caused by multiple RRUs connected to the selected RF channel sending uplink signals at the same time, which cannot be demodulated correctly.

[0128] In some embodiments, the N RRUs and the first RRU are RRUs connected to at least two different radio frequency channels. This can be because the M first messages are sent by M RRUs connected to at least one of the multiple radio frequency channels; that is, the M first messages could also be sent by M RRUs connected to a single radio frequency channel, or by M RRUs connected to multiple different radio frequency channels. The BBU can determine the channel of the first RRU that is in normal operation within one of the RRUs on one radio frequency channel based on the M first messages, and then shut down the channels of the remaining RRUs under that radio frequency channel, as well as the channels of all RRUs connected to the remaining radio frequency channels.

[0129] In this way, for the BB module in the BBU, it is not necessary to select the radio frequency channel. It is sufficient to directly select one of the multiple radio frequency channels and one of the first RRU channels to be in normal working state based on the M first information. Only the uplink signal transmitted by the channel of the first RRU of one radio frequency channel is fully received and processed. This can also avoid the problem of signal superposition caused by multiple RRUs connected to one radio frequency channel transmitting uplink signals at the same time, which cannot be demodulated correctly. At the same time, it avoids the problem of signal noise figure deterioration caused by noise superposition of multiple RRU channels.

[0130] 403. The first RRU, excluding N RRUs, sends a signal to the BBU. The channel of the first RRU is in normal working condition in the receiving direction.

[0131] Accordingly, the BBU receives the signal sent by the first RRU.

[0132] For multiple RRUs connected to a single RF channel, when the channels of N RRUs under a single RF channel are shut down, and only the channel of the first RRU in that RF channel is in normal working condition, the BBU can only receive the uplink signal sent by the first RRU connected to that RF channel. The uplink signal sent by the first RRU will not be affected by the uplink signals of the other shut-down RRU channels on that RF channel, thus avoiding the problem of signal superposition and incorrect demodulation of the uplink signals of multiple RRUs connected to a single RF channel at the power divider of that RF channel.

[0133] Similarly, if the RRU channels other than the first RRU channel on a radio frequency channel and the RRU channels of other radio frequency channels are shut down, the BBU will only receive the uplink signal transmitted from the first RRU connected to the same radio frequency channel. The uplink signal transmitted by the first RRU will not be affected by the other shut-down RRU channels on the same radio frequency channel and the RRU channels of other radio frequency channels connected to the same radio frequency channel. This avoids the problem of uplink signals from multiple RRU channels received on multiple radio frequency channels being superimposed in the BBU and unable to be demodulated correctly.

[0134] In some embodiments, the method may further include: when the BBU receives a complete signal frame transmitted by the first RRU, controlling the channels of the N RRUs to return to normal operation. That is, restoring these N RRUs to enter the normal reception process.

[0135] Even after resuming the normal receiving process, it can still loop through to other processes. Figure 4 The process shown involves selecting and shutting down the RRU's channels.

[0136] Regarding step 402, the following example illustrates the three criteria mentioned above by selecting and disabling channels of multiple RRUs connected by multiple radio frequency channels.

[0137] Method 1: First come, first served.

[0138] In some embodiments, the first RRU is the RRU corresponding to the first message received by the BBU.

[0139] In other words, if the BBU selects and disables multiple RRU channels corresponding to multiple radio frequency channels according to a first-come, first-served principle, it can be understood that when the BBU receives the first information sent by M RRUs, and the first received first information is sent by the first RRU, the BBU can determine that the channel of the first RRU is the RRU channel that should maintain normal operation. The BBU can disable the channels of the other RRUs among the multiple RRUs connected by multiple radio frequency channels, except for the first RRU, to ensure that the uplink signal sent by the first RRU is not affected by the channels of the other RRUs, thus avoiding signal superposition problems at the BBU.

[0140] Among them, the energy information indicated by the first RRU is greater than or equal to the energy threshold.

[0141] This can be understood as the BBU receiving the first information sent by the first RRU first, or as the first RRU among multiple RRUs connected by multiple radio frequency channels detecting that the energy of the input signal is greater than or equal to the energy threshold first. Furthermore, when the first RRU determines that the energy of the input signal is greater than or equal to the energy threshold, it sends the first information to the BBU. This first information includes the energy information of the first RRU and the identifier of the first RRU. In this application, the RRU identifier (ID) can also be referred to as the RRU serial number or number, etc.

[0142] For example, such as Figure 5 The diagram shown is a schematic of the hardware structure of the BBU and RRU in a distributed WLAN system 500 provided in this application, which can be used to implement the above. Figure 4 The method flow is shown.

[0143] like Figure 5 As shown, in Figure 3 Based on the architecture of the distributed WLAN system shown, the distributed WLAN system also includes multiple switching devices (which can also be understood as switching units). The number of switching devices is the same as the number of multiplexers in the BBU, or the same as the number of RRUs in the distributed Wi-Fi system. Each switching device is used to control the channel of one RRU to turn off or on. These multiple switching devices can be board-level switches deployed on the BBU side or board-level switches deployed on multiple RRU sides.

[0144] Figure 5 In the architecture of the distributed WLAN system shown, multiple switching devices are deployed on the BBU side, with each switching device positioned between a power divider and a multiplexer. The controller 301 in the BBU may include multiple general-purpose input / output (GPIO) interfaces, each coupled to a switching device. Each GPIO interface is used to send a control signal to a switching device, instructing it to either shut down the channel of the corresponding RRU or restore the RRU channel to normal operating condition.

[0145] 1) Energy detection and feedback of primary information.

[0146] like Figure 5 As shown, each RRU also includes an energy detection unit, which detects the energy of the input signal to the RRU. The controller 301 on the BBU side can also be coupled to multiple multiplexers in the BBU via multiple GPIO interfaces (different from the multiple GPIOs in controller 301 coupled to multiple switching devices), with each GPIO interface coupled to one multiplexer. Since one multiplexer can be coupled to one RRU via a remote medium, it is equivalent to each GPIO also being coupled to one RRU. When there is a signal input at the RRU's antenna port, the energy detection unit can detect the energy of the input signal. The RRU sends the energy detected by the energy detection unit to the BBU as energy information. For example, the energy can be power or signal strength. The following explanation uses power as an example.

[0147] The energy detection unit can be, for example, a power detection unit, where the energy information can be the power information of the RRU input signal, and the energy threshold can be a power threshold. The power detection unit can be, for example, a power detector. Figure 6The diagram shows a power detector in an RRU. The power detector includes a power divider 61, a filter 62, a detector 63, and a comparator 64. The comparator 64 can be coupled to the controller 304 on the RRU side. When a signal is input to the antenna port of any RRU, it is filtered by the power divider 61 and the filter 62 before being input to the detector 63. The detector 63 detects the power of the input signal, obtains its power magnitude, and inputs this magnitude to the comparator 64 for comparison. When the comparator 64 determines that the power of the input signal is greater than or equal to a power threshold, it outputs a high-level signal to the controller 304. This high-level signal can be understood as a trigger signal; the controller 304 can determine, based on the high-level signal, that it needs to report the first piece of information to the BBU. At this time, controller 304 can send first information to controller 301 on the BBU side via multiplexer 303 on the RRU side, the remote medium, and multiplexer 302 in the BBU coupled to the RRU. The first information includes indication information of the power level of the input signal and the RRU identifier. The power level of the input signal can be sent to controller 304 by detector 63. The RRU identifier is configured in controller 304. This completes the power detection of the RRU and the transmission of the first information.

[0148] In the case where the RRU includes multiple antennas, the power of the input signal can be understood as the sum of the power of the multiple antennas.

[0149] In this application, controller 301 and controller 304 may be, for example, a CPLD or a field-programmable gate array (FPGA).

[0150] 2) Response shutdown.

[0151] In some embodiments, when the controller 301 determines that the first RRU is in a normal operating state, the controller 301 may send a first control command to the remaining N switching devices coupled to the N RRUs respectively. The first control command is used to control the channel of one of the N RRUs to be in a receiving direction off state.

[0152] For example, after an RRU reports its first information to a BBU, the GPIO interface of the controller 301 in the BBU can receive the reported first information via a remote medium and a multiplexer in the BBU, and select and shut down the RRUs based on a first-come, first-served principle. If the controller 301 receives the first information from M RRUs, and the controller 301 uses a first-come, first-served principle, after receiving the first first information, the controller 301 can determine the RRU that received the first information first, for example, RRU_1_1, based on the RRU identifier in the first received information. It then selects RRU_1_1 to maintain normal operation and shuts down the channels of RF channel 1 other than RRU_1_1 (RRU_1_2 to RRU_1_x) and all other RRU channels of RF channels 2 to n. Specifically, the controller 301 can send a first control command to the switching devices in the BBU that are coupled to RRU_1_2 to RRU_1_x, as well as the switching devices coupled to RRUs under the other RF channels 2 to n in the BBU, to control the switching devices coupled to the other N RRUs except RRU_1_1 to turn off.

[0153] For example, suppose that the number of RRUs connected to each of the n radio channels is the same, for example, the number of RRUs connected to each radio channel is x. Here, the N RRUs can be understood as (x·n-1). Suppose that the number of RRUs connected to each of the n radio channels is not exactly the same, for example, x is not equal to y. Here, the N RRUs can be understood as (x+…+y-1).

[0154] In some embodiments, the switching device may be provided with a control interface. The first control command can be understood as a level signal. The switching device can control whether the control interface is turned on or off based on the received level signal. For example, when the control interface of the switching device receives a low-level signal, the control interface is turned off, and the channel of the RRU corresponding to the switching device is turned off. At this time, when the RRU channel reports an uplink signal, the uplink signal is discarded when it is transmitted to the switching device and cannot be transmitted to the RF channel.

[0155] At this time, since the control interface of the switching device coupled to RRU_1_1 does not receive a low-level signal and remains in a high-level state, the switching device coupled to RRU_1_1 is conducting and can be used to transmit the uplink signal received from RRU_1_1 to RF channel 1 through the power divider.

[0156] 3) Resume reception.

[0157] In some embodiments, when the BBU receives a complete signal frame sent by the first RRU, it controls the channels of N RRUs to return to normal operation.

[0158] In some embodiments, when the controller 301 determines that the BBU has received the complete signal frame sent by the first RRU, it sends a second control command to each of the N switching devices. The second control command is used to control the channel of one of the N RRUs to resume normal operation in the receiving direction.

[0159] For example, if the BB module on the BBU side determines that it has received the complete signal frame sent by RRU_1_1, the BB module can send an indication message to the controller 301, indicating that the complete signal frame sent by RRU_1_1 has been received. The controller 301 can then send a second control command (e.g., a high-level signal) to the switching devices coupled to RRU_1_2 to RRU_1_x connected to RF channel 1, and to the switching devices coupled to the remaining RRUs connected to RF channels 2 to n, to control the switching devices to turn on. In this way, the channels of RRU_1_2 to RRU_1_x, and the channels of the RRUs connected to RF channels 2 to n, can resume normal reception.

[0160] For example, such as Figure 7 The diagram shows a timing sequence for selecting and turning off RRU channels using a first-come, first-served principle. Figure 7 As shown, the uplink signals sent by RRU_1_x include the following fields: legacy short training field (L-STF), legacy long training field (L-LTF), legacy signal field (L-SIG), repeated legacy signal field (RL-SIG), high efficiency signal field A (HE-SIG-A), high efficiency short training field (HE-STF), high efficiency long training field (HE-LTF), high efficiency data (HE-DATA), and packet end (PE).

[0161] Assume that the RRUs connected to RF channel 1 include RRU_1_1, RRU_1_2, and RRU_1_3; the RRUs connected to RF channel 2 include RRU_2_1, RRU_2_2, and RRU_2_3, ...; and the RRUs connected to RF channel n include RRU_n_1, RRU_n_2, and RRU_n_3. If only the RRUs connected to RF channel 1 have uplink signals to transmit, and RRU_1_1 receives the uplink signal before RRU_1_2 and RRU_1_3, RRU_1_1 will transmit the uplink signal to RF channel 1 first. If RRU_1_1 detects that the power of its input signal is greater than or equal to a power threshold, RRU_1_1 will also be the first to send information to the BBU controller 301 before RRU_1_2 and RRU_1_3. If the BBU controller 301 receives the first message sent by RRU_1_1 first, the controller 301 determines that the channel of RRU_1_1 should remain in normal working condition, and the channels of the other N RRUs besides RRU_1_1 should be turned off. When the controller 301 determines to turn off the channels of RRU_1_2 and RRU_1_3, as well as the channels of the remaining RF channels 2 to n, RF channel 1 may have already started receiving uplink signals from RRU_1_2 and RRU_1_3, or it may not have started receiving uplink signals from RRU_1_2 and RRU_1_3 yet. Figure 7 As shown, when the controller 301 sends the first control command to the switching devices 2 and 3 corresponding to RRU_1_2 and RRU_1_3, and sends the first control command to the switching device coupled to each RRU connected to the RF channels 2 to n, the RF channel 1 has received part of the L-STF content sent by RRU_1_1, has not yet received the uplink signal of RRU_1_2, and has received a small part of the signal content of RRU_1_3. Figure 7 The time 1 shown is the time when the controller 301 determines that the power of RRU_1_1 is greater than or equal to the power threshold, and the time 2 is the time when the controller 301 shuts down the channels of RRU_1_2 and RRU_1_3, as well as the channel of each RRU connected to RF channels 2 to n, through the first control command.

[0162] When the BB module in the BBU determines that it has received the complete signal frame of the uplink signal sent by RRU_1_1, that is, when it has received the entire contents of the last field PE of the uplink signal of RRU_1_1, the controller 301 can send a second control command at time 3 to switching devices 2 and 3, as well as the switching devices coupled to each RRU connected to RF channels 2 to n, instructing to turn on switching devices 2 and 3, as well as the switching devices coupled to each RRU connected to RF channels 2 to n. At this time, a small portion of the uplink signal of RRU_1_2 and RRU_1_3 may be received after the complete signal frame of RRU_1_1 has been received, but for the BB module to demodulate the uplink signal of RRU_1_1, the small portion of the uplink signal of RRU_1_2 and RRU_1_3 will not have a signal superposition effect on the complete signal frame of RRU_1_1.

[0163] The first-come, first-served principle of this application ensures that the signal reception of the RRU that receives the uplink signal first and whose signal energy is greater than or equal to the energy threshold is not affected by the channels of RRUs connected to the same RF channel or RRUs connected to other RF channels. It also avoids uplink signal conflicts caused by hidden terminals of terminals under RRUs connected to the same RF channel, and avoids noise figure deterioration caused by the superposition of multiple signals.

[0164] In some scenarios, Method 1, which uses a first-come, first-served principle to open one RRU channel and close the channels of the remaining RRUs, is suitable for situations without significant signal interference. For example, the scenario may have Wi-Fi signals, but no non-Wi-Fi interference signals such as microwave signals. This first-come, first-served principle ensures that the Wi-Fi signal of one RRU channel is not interfered with.

[0165] Method Two: The Criterion of Maximum Energy.

[0166] In some embodiments, M of the multiple RRUs are RRUs that send the first information within a preset time period, and the first RRU is the RRU with the highest energy indicated by the energy information among the M RRUs. It should be understood that the energy indicated by the energy information of each of the M RRUs that reports the first information is greater than or equal to an energy threshold.

[0167] This approach can be understood as follows: the controller 301 on the BBU side does not simply consider the RRU that receives the first information as the RRU that maintains normal operation. Instead, it can compare the first information reported by the M RRUs within a preset time period based on the principle of strongest energy, and then determine the channel of one RRU that maintains normal operation, as well as the channels of the N RRUs that need to be turned off.

[0168] Still with Figure 5 The hardware architecture and energy information shown are for example, with power output as the primary factor. Figure 8 The diagram illustrates a timing sequence for RRU channel selection based on the highest power criterion. Assume that RRUs connected to RF channel 1 include RRU_1_1, RRU_1_2, and RRU_1_3. Terminals connected to RRUs on RF channel 1 have uplink signals to transmit. Terminals connected to RRUs on RF channels 2 through n may or may not transmit uplink signals. When the first information reported by the first RRU received by the BBU-side controller 301 is from RRU_1_1, the controller 301 will continue to wait for a preset time period. Assuming that within this preset time period, the controller 301 receives first information from RRU_1_1, as well as from RRU_1_2 and RRU_1_3, the controller 301 can compare the power levels in these three RRU reports and determine that RRU_1_3 has the highest power level. At this time, controller 301 determines that the channel of the RRU maintaining normal operation is RRU_1_3, the channels of the RRUs to be turned off are the channels of RRU_1_1 and RRU_1_2, and the channels of all RRUs connected by RF channels 2 to n. For example, as Figure 8 As shown, RRU_1_1 receives the uplink signal first and detects a power level of -60dBm. It then reports the power level and identifier of RRU_1_1 to controller 301. Subsequently, RRU_1_3 and RRU_1_2 receive the uplink signal in sequence and report their corresponding power levels and identifiers to controller 301. RRU_1_3 detects an uplink signal power level of -40dBm, while RRU_1_2 detects an uplink signal power level of -50dBm. Controller 301 determines that RRU_1_3 reports the highest power level and therefore does not need to shut down the RRU channel. At this point, when controller 301 sends the first control command to the switching devices corresponding to these three RRUs, RF channel 1 may have already received some uplink signals from the RRUs, or it may not have started receiving uplink signals from some RRUs yet. For example, as... Figure 8 As shown, when controller 301 sends a control command to RRU_1_1 and RRU_1_2 to shut down the RRU channel at time 1, radio frequency channel 1 has already received part of the L-STF content in the uplink signal sent by RRU_1_3, has not yet received the uplink signal of RRU_1_2, and has already received a small part of the uplink signal of RRU_1_1.

[0169] When the BB module determines at time 2 that it has received the complete signal frame of RRU_1_3, that is, after receiving the PE field of the signal frame sent by RRU_1_1, it sends a second control command through the controller 301 to the corresponding switching device of RRU_1_1, the corresponding switching device of RRU_1_2, and all switching devices coupled to RF channels 2 to n, instructing the switching devices to be turned on, that is, to restore the channels of RRU_1_1, RRU_1_2, and RRUs connected to RF channels 2 to n to the normal receiving state.

[0170] This application's strongest energy criterion ensures that the signal reception of the RRU with the strongest energy is not affected by the channels of other RRUs within a certain period of time. This includes avoiding data conflicts caused by hidden nodes between RRUs connected on the same RF channel, and also avoiding noise figure deterioration caused by the superposition of multiple signals at the BBU.

[0171] In some scenarios, if the time intervals between data transmissions from terminals under different RRUs are short, and the energy differences of the uplink signals detected by different RRUs are small (all being considered strong signals), the BBU might have already received some signals from relatively weaker RRUs when it identifies the strongest RRU. In this case, the partial signals from the relatively weaker RRUs may or may not affect the proper demodulation of the signal from the strongest RRU. For example, whether the signal from the strongest RRU can be correctly demodulated depends on the number of RRUs transmitting the signal. If the BBU has already received partial signals from a smaller number of RRUs when identifying the strongest RRU, the demodulation of the signal from the strongest RRU may not be affected; however, if the BBU has already received partial signals from a larger number of RRUs when identifying the strongest RRU, the demodulation of the signal from the strongest RRU may be affected. This is because the first field L-STF in the signal frame occupies fewer bits, and demodulating the first field L-STF is relatively easy. A small number of signals sent by the RRU may not affect the BBU's correct demodulation of the signal sent by the most powerful RRU.

[0172] For example, such as Figure 8 As shown, before the BBU determines the most energetic RRU_1_3 at time 1, it has already received partial signals from the first field L-STF of RRU_1_1 and RRU_1_3, but has not yet received signals from other RRUs besides RRU_1_1 and RRU_1_3. In this case, the demodulation of the signal frame transmitted by RRU_1_3 by the BBU is not affected by the partial signals already received from RRU_1_1.

[0173] In some scenarios, Method 2, which uses the strongest energy criterion to determine which RRU channel is open and which is closed, is suitable for Wi-Fi scenarios where the transmitted data signal strength is high, while the interference signal strength from non-Wi-Fi signals in the environment is weak. Thus, even if a small portion of the interference signal is received by the BBU, such as a small portion of the signal from RRU_1_1, this small portion has a minimal impact on demodulating the signal from RRU_1_3, allowing the BBU to correctly demodulate the data field in the RRU_1_3 signal.

[0174] Method 3: Precise Synchronization Criteria.

[0175] In some embodiments, the first RRU is the RRU whose channels among the M RRUs complete fine synchronization processing first during normal operation.

[0176] In the first information sent by the M RRUs, the energy information corresponding to each RRU indicates that the energy is greater than or equal to the energy threshold.

[0177] This precise synchronization principle can be understood as follows: when the BBU receives the first signal from M RRUs, it may not immediately respond. That is, before controlling the channels of N RRUs to be in the receive-direction shutdown state, the BBU keeps all RRU channels connected by multiple radio channels in normal working condition for a period of time, during which time the BBU can continue to receive part of the uplink signals transmitted by the M RRUs. Once the BBU determines that the channel of the first RRU among the M RRUs has completed the precise synchronization process first in normal working condition, it controls the channels of the other N RRUs to be in the receive-direction shutdown state.

[0178] This precise synchronization criterion takes into account that when the BB in the BBU receives uplink signals, it first performs power statistics, then packet detection and precise synchronization. Packet detection and precise synchronization can be understood as determining whether a signal frame is in Wi-Fi format based on the content of the data packets in the received uplink signal. If the BB only determines whether an uplink signal is being transmitted based on its power level, it will be inaccurate, and there may also be interfering signals in the environment that are in the same frequency band. Therefore, this application uses the precise synchronization criterion to determine the first RRU, which can improve the accuracy of the BBU receiving uplink Wi-Fi signals.

[0179] In this context, precise synchronization can be understood as the receiver having determined the starting position of the data packet from the received signal. Specifically, the receiver can find the starting position of the data packet by performing cross-correlation operations on the received sequence. The starting position of the data packet can be understood as the position of the first symbol in the first field L-STF of the signal frame exemplified in this application.

[0180] In some embodiments, when the BBU detects HE-STF in the signal transmitted by the first RRU, it controls the channels of N RRUs to be turned off in the receiving direction.

[0181] Specifically, when the BB module receives the HE-STF signal sent by the first RRU, the BB sends a first control command to the switching devices corresponding to the N RRUs through the controller 301, instructing the switching devices corresponding to the N RRUs to turn off.

[0182] For example, still using Figure 5 The hardware architecture and energy information shown are for example, with power output as the primary factor. Figure 9 The diagram illustrates a timing sequence for RRU channel selection logic based on a precise synchronization criterion. Assume that RRUs connected to RF channel 1 include RRU_1_1, RRU_1_2, and RRU_1_3. Terminals connected to RRUs on RF channel 1 have uplink signals to transmit. Terminals connected to RRUs on RF channels 2 through n may or may not transmit uplink signals. RRU_1_1 receives the uplink signal first and detects that its power is greater than or equal to a power threshold. RRU_1_1 then sends its first information and the received uplink signal to the BBU. The first information includes an indication of RRU_1_1's power level and its identifier. Subsequently, RRU_1_3 and RRU_1_2 detect that their uplink signal power is greater than or equal to the power threshold and send their first information and uplink signals to the BBU. The BBU begins receiving the uplink signal from RRU_1_1 at time 1, and then sequentially begins receiving the uplink signals from RRU_1_3 and RRU_1_2. At time 2, the BB module in the BBU first completes fine synchronization based on a portion of the uplink signal from RRU_1_1. At this time, the BB module can temporarily refrain from sending the first control command to the switching devices corresponding to the other RRUs besides RRU_1_1 via the controller 301. Instead, at time 3, when it detects HE-STF in the signal sent by RRU_1_1, it uses the first control command to control the channels of the other N RRUs besides RRU_1_1 to be in a state of shutdown in the receiving direction.

[0183] This application's method of determining the first RRU to complete precise synchronization at time 2 and then delaying the process of shutting down the channels of the remaining N RRUs for a period of time (between time 2 and time 3) is based on the consideration that shutting down RRU channels would cause fluctuations in the signal power received by the BBU. Since the demodulation of the SIG field is highly sensitive to power, large power fluctuations would affect the accuracy of SIG field demodulation. Therefore, this application delays the process after detecting the precise synchronization signal at time 2, and then shuts down the channels of the remaining N RRUs at time 3 after detecting the HE-STF field, thus avoiding the impact of power fluctuations on SIG field demodulation.

[0184] According to the above Figure 9 As illustrated in the example description, the precise synchronization in this application can also be understood as having received the L-LTF in the signal frame, and determining the starting position of the signal frame when the signal frame is determined to be a Wi-Fi signal based on the content of the L-LTF.

[0185] Specifically, when the BBU determines that the signal frame is a Wi-Fi signal based on the content of the L-LTF, considering the interval between fields specified in the protocol, the position of the first symbol of the first field L-STF of the signal frame can be determined based on the position of the L-LTF field.

[0186] Thus, in this application, "first to complete fine synchronization" can be understood as "first to determine the start position of the signal frame from the received signals." Specifically, it can be understood that when the BBU determines that the signal correlation of the RRU meets the requirements based on the received L-LTF content through cross-correlation calculations and other methods, and first generates an indication that the signal is a Wi-Fi signal, it first determines the start position of the signal based on the position of the L-LTF field.

[0187] When the BB module determines at time 4 that it has received the complete signal frame of RRU_1_1, that is, after receiving the PE field of the signal frame sent by RRU_1_1, it sends a second control command through the controller 301 to the corresponding switching device of RRU_1_2, the corresponding switching device of RRU_1_3, and all switching devices coupled to RF channels 2 to n, instructing the switching devices to be turned on, that is, to restore the channel of RRU_1_2, the output channel of RRU_1_3, and the channel of RRU connected to RF channels 2 to n to the normal receiving state.

[0188] In some scenarios, the third method, which uses precise synchronization criteria, can be applied to situations where there is continuous interference from high-intensity, non-Wi-Fi signals, thus preventing the BBU from receiving interference signals from high-intensity, non-Wi-Fi signals.

[0189] In this way, this application can select the RRU channel based on the first information received from the M RRUs, as well as the first-come-first-served criterion, the strongest energy criterion, or the precise synchronization criterion, keeping one RRU channel in normal receiving state and shutting down the channels of the remaining RRUs. This can reduce data conflicts caused by the hidden terminal problem in the uplink RX direction and avoid the noise figure deterioration caused by the superposition of multiple signals at the BBU.

[0190] This application is in Figure 3 Based on the distributed WLAN system architecture shown above, a schematic diagram of a distributed WLAN system architecture is also provided. As can be seen from the above, in... Figure 5 In the distributed WLAN system architecture shown, the energy detection unit of the RRU detects the signal energy input to the RRU, the controller 304 on the RRU side transmits the first information, the controller 301 in the BBU issues commands, and the board-level switching unit on the BBU side controls the channel on / off of the RRU. This application can also integrate these functions with greater integration into a single multi-functional mixer chip (or multi-functional mixer chip).

[0191] For example, Figure 10 This application provides an architectural diagram of a distributed WLAN system 1000, used for execution Figure 4 The flowchart of the communication method is shown. For example... Figure 10 As shown, in Figure 3 Based on the architecture of the distributed WLAN system shown, the BBU in the distributed Wi-Fi system also includes multiple multi-function mixer chips. The number of multi-function mixer chips is the same as the number of multiplexers in the BBU, or the same as the number of RRUs in the distributed Wi-Fi system, or each multi-function mixer chip in the BBU is located on the path of an RRU. Figure 10 As shown, each multifunction mixer chip in the BBU is coupled between a power divider and a multiplexer. Each multifunction mixer chip in the BBU can be used to implement the functions of the controller 301 and a switching device in the BBU of this application. Assuming that the number of RRUs connected to the BBU is N+1, the BBU includes N+1 multifunction mixer chips, each multifunction mixer chip includes N high-speed communication interfaces, such as GPIO, and each high-speed communication interface is coupled to a high-speed communication interface of each of the other N multifunction mixer chips in the BBU.

[0192] exist Figure 3Based on the architecture of the distributed WLAN system shown, each RRU in the distributed WLAN system also includes a multi-functional mixer chip. The multi-functional mixer chip in the RRU can be used to implement the functions of the energy detection unit and controller 304 of the RRU in this application.

[0193] An exemplary schematic diagram of the internal structure of a multi-functional mixer chip is shown below. Figure 11 As shown, its internal components include an amplifier 111, a multiplier 112, a local oscillator (LO) 113, a phase-locked loop (PLL) 114, a phase detector (PD) 115, a microcontroller unit (MCU) 116, a modem 117, and an interface 118 for high-speed analog communication with external devices. Specifically, the amplifier 111 amplifies the radio frequency signal input to the multi-function mixer chip; the multiplier 112 multiplies the carrier signal with the input signal to convert the signal to the target frequency; the local oscillator 113 generates a carrier signal, which is input to the PLL 114 for frequency multiplication and then outputs the carrier frequency required by the system; the MCU 116 provides logic control for the entire multi-function mixer chip; and the modem 117 modulates and demodulates external communication signals input to / output to the multi-function mixer chip.

[0194] This application presents a distributed WLAN system employing a multi-functional mixer chip, which can improve the data capacity of the RRU. Specifically, when the RRU transmits or receives signals, the multiplier in the multi-functional mixer chip can be used to frequency-convert the signal to be transmitted, supporting the transmission of multiple frequencies of signals on the RRU's antenna, or simultaneously transmitting multiple frequencies of signals received by the RRU's antenna on one RRU channel through frequency conversion. For example, the multiple frequencies here include 2.4G and 5G signals.

[0195] exist Figure 10 and Figure 11In the illustrated architecture, the channel selection process for the RRU in the RX direction is similar to that in the above embodiment. For example, taking the path of RRU_1_1 as an example, the detector in the multi-function mixer chip a of RRU_1_1 can detect the input power of the uplink signal received by RRU_1_1. If the detected uplink signal power is greater than or equal to a power threshold, the MCU in the multi-function mixer chip a receives this power indication and sends the power indication information corresponding to RRU_1_1 to the multi-function mixer chip b of the BBU via interface 118 and the remote medium. Simultaneously, the multi-function mixer chip a sends the identifier of RRU_1_1 when sending the power indication information, i.e., it sends first information, which includes the power indication information corresponding to RRU_1_1 and the identifier of RRU_1_1.

[0196] If the above first-come, first-served principle is adopted, when the multi-function mixer chip b coupled to RF channel 1 in the BBU first receives the first information through interface 118 and transmits it to the MCU in the multi-function mixer chip b in the BBU, the MCU can use the N+1 high-speed communication interfaces of the multi-function mixer chip b coupled to the other N RRUs to inform the other N multi-function mixer chips in the BBU to shut down the channels of their respective coupled RRUs. In this way, the BB module will only receive the uplink signal of RRU_1_1 sent by the multi-function mixer chip b coupled to RF channel 1. When the BB module in the BBU confirms that it has received the complete signal frame sent by RRU_1_1, the BB module can send an indication that the signal frame reception is complete to the multi-function mixer chip b. The multi-function mixer chip b then informs the other N multi-function mixer chips in the BBU through the N+1 high-speed communication interfaces coupled to the other N RRUs to open the channels of their respective coupled RRUs, and the channels of the N RRUs resume normal reception.

[0197] In some embodiments, the telemetry medium in this application may have two modes: digital telemetry or analog telemetry.

[0198] If a digital remote mode is used, the interface 118 of the multi-function mixer chip in this application can be a digital interface. For the multi-function mixer chip in the RRU, when the digital interface receives a power level indication from the MCU, it can send the power level indication to the data interface of the multi-function mixer chip in the BBU through the remote medium.

[0199] If an analog remote mode is used, the interface 118 in the multi-function mixer chip of this application may include an analog-to-digital converter (ADC) 118 and a digital-to-analog converter (DAC) 119. The ADC 118 and DAC 119 are used to perform digital-to-analog conversion and analog-to-digital conversion functions, respectively. For the multi-function mixer chip in the RRU, the DAC can receive a power level indication sent from the MCU, perform digital-to-analog conversion, and then send the power level indication to the multi-function mixer chip in the BBU through the remote medium, while simultaneously sending the RRU identifier, i.e., sending the first information. Correspondingly, the multi-function mixer chip in the BBU can receive the first information through the DAC, perform analog-to-digital conversion, and then send the power level indication and the RRU identifier to the MCU in the multi-function mixer chip in the BBU.

[0200] Thus, the method of deploying multi-functional mixer chips in the BBU and multiple RRUs in this application can ensure that the uplink signal transmission in the RX direction will not cause data conflict at the BBU while ensuring that the uplink signal transmission in the RX direction will be able to transmit uplink signals normally in one RRU channel. It also avoids the deterioration of the noise figure caused by the superposition of multiple signals.

[0201] This application may be applied to, for example Figure 1 In addition to the distributed WLAN system shown, it can also be applied to, for example, Figure 12 The distributed WLAN system shown is an example. Figure 12 As shown, the distributed WLAN system includes an AC (Access Controller), a central AP (BBU), multiple radio units (RUs), and multiple antenna units (AUs). The RRU in this application may include the functions of both RUs and AUs. The RU can be used to implement air interface management and radio frequency control functions beyond the antenna functions of the RRU, while the AU can be used to implement the antenna functions of the RRU. The BBU can be connected to multiple RUs via a power divider and a remote medium, and each RU can also be connected to multiple AUs via a power divider.

[0202] A BBU can include multiple RF channels, each RF channel can be connected to multiple RUs via a power divider, and each RU can be further connected to multiple AUs via a power divider, for example... Figure 12As shown, one radio frequency channel of the BBU is connected to three RUs via a remote medium. Each RU can communicate with four AUs in different rooms, and each AU can provide Wi-Fi signal coverage for at least one terminal in the room. When uplink signals are transmitted on different RUs under one radio frequency channel, the BBU will dynamically select one RU to turn on for uplink signal reception based on the signal strength detected by different channels, and turn off the remaining RUs. This can suppress hidden node interference between RUs and correctly receive the uplink signal transmitted by the selected RU.

[0203] While the antenna selection scheme described above allows for the selection of RUs connected to the RF channel to avoid hidden nodes between RUs, multiple AUs connected to the same RU are simultaneously turned on or off. This means that when the BBU determines the selected RU, the paths of all AUs connected to that RU are active and can be used for uplink signal reception. However, the BBU cannot directly distinguish the AUs connected to a single RU. If at least two AUs under a single RU are simultaneously transmitting uplink signals, the uplink signals from terminals under different AUs will collide or superimpose at the RU, resulting in a superimposed signal that cannot be correctly demodulated in the BBU. Furthermore, even if only one AU under the same RU has an uplink signal to transmit, the noise from the other AUs will be superimposed at the RU's power divider, increasing the noise figure of the superimposed signal received by the RU and affecting its uplink reception performance.

[0204] The communication method provided in this application can also be applied to, for example... Figure 12 The distributed Wi-Fi system shown is related to Figure 5 Similar to the distributed WLAN architecture shown, this application can also be used in... Figure 12 The distributed Wi-Fi system shown addresses the signal superposition problem in the aforementioned RU by adding multiple switching devices and energy detection units. For example, this application adds an energy detection unit to each AU after each RU power divider node to detect the energy of the uplink signal received by the AU. Furthermore, a switching device is coupled to each channel after power division by each RU power divider, meaning the number of switching devices in each RU is the same as the number of AUs connected to the RU. Alternatively, one switching device can be added to each AU. This allows the BBU to accurately select and shut down multiple AUs connected to a single RU, avoiding the signal superposition problem caused by hidden nodes in terminal devices under different RUs.

[0205] For example, the controller in the BBU can be coupled to multiple switching devices in the RU via a high-speed communication interface. The controller of the AU reports the energy information detected by the energy detection unit and the AU's identifier, and sends it to the controller in the BBU through the controller of the RU. The controller in the BBU can determine that the channel of one AU connected to a RU is in normal working condition based on the energy information reported by each AU and the AU's identifier (refer to the three criteria mentioned above for AU selection), and control the switching devices on the channels of that RU and the other AUs to turn off through a first control command (or, when the controller in the BBU is coupled to the switching devices in each AU, it directly controls the switching devices in the other AUs to turn off). In this way, each RU will only receive the uplink signal sent by one AU, avoiding signal superposition on the RU caused by uplink signals sent by multiple AUs.

[0206] When the RU determines that it has received a complete signal frame sent by the selected AU, it can send a second control command to the switching device corresponding to the AU with the off channel through the controller in the RU, so as to control the off RU channel to be in normal receiving state.

[0207] Similarly, this application can also achieve the above process by adding a multi-functional mixer chip to each AU under the BBU and RU.

[0208] Understandable, Figure 12 A combination of an AU and its corresponding RU can be considered as an RRU.

[0209] For example, Figure 12 The combination of an AU and its corresponding RU can be considered as Figure 3 , Figure 5 or Figure 10 One of the RRUs. Understandably, this is to reduce... Figure 3 The data conflict problem of multiple RRUs transmitting signals in the RX direction shown in the figure can be solved by this application. Figure 5 or Figure 10 The scheme shown in the diagram selects and disables channels of multiple RRUs to reduce the probability of data collisions in scenarios where multiple RRUs transmit signals in the RX direction. Similarly, when the combination of an AU and its corresponding RU is equivalent to an RRU, this application can also select and disable channels of multiple AUs, as illustrated in the example provided in this application. Figure 5 or Figure 10 This solution can reduce data conflict issues in scenarios where multiple AUs transmit signals in the RX direction.

[0210] In addition, in such Figure 1 or Figure 3In the distributed WLAN system shown, during the downlink (transmit, TX) direction, when each radio channel in the BBU transmits a downlink signal, the paths of the RRUs connected to each radio channel are all open. When one radio channel in the BBU has downlink data to send to some terminals under some RRUs, if the RRUs under each radio channel are in the open state, the paths of the RRUs not used for transmitting downlink signals will suffer from power waste. Moreover, all RRUs connected to the radio channel that needs to transmit downlink signals will broadcast the same content, which also results in power waste.

[0211] Therefore, this application provides a communication method in the TX direction where the path of the RRU to transmit downlink signals can be kept in normal working condition, while the paths of other RRUs that do not transmit signals are kept off. In this way, for multiple RRUs under one RF channel, the power consumption waste caused by RRUs that do not transmit signals transmitting downlink signals can be avoided, as well as the unnecessary power consumption caused by RRUs under other RF channels being in normal working condition can also be avoided.

[0212] like Figure 13 The diagram shown is a flowchart of a communication method provided in this application. This method can be applied to a distributed WLAN system, which includes a BBU and multiple RRUs. The BBU includes multiple radio frequency channels, and each radio frequency channel is connected to a portion of the multiple RRUs through a remote medium.

[0213] like Figure 14 The diagram shows an architecture of a distributed WLAN system. Figure 3 Unlike the distributed WLAN system architecture shown, this application allows the controller 301 in the BBU to be coupled to multiple multiplexers in the BBU via multiple high-speed communication interfaces, such as GPIOs. That is, the number of GPIOs in the controller 301 is the same as the number of RRUs. For each GPIO, the BBU can send a first control command to the RRU through one GPIO of the controller 301, indicating that the RRU is in a shutdown state or a low-power state. The BBU can also send a second control command to the RRU through one GPIO of the controller 301, indicating that the RRU returns to normal operation. On the RRU side, each RRU can... Figure 3 The diagram shows a controller 304, a multiplexer 303, an FEM, and multiple antennas. In this application, each controller 304 can be coupled to the FEM and is used to control the FEM to be in a shutdown state or a low-power state based on a first control command, or to control the FEM to return to a normal operating state based on a second control command.

[0214] Figure 14 The architecture shown and Figure 5The architecture shown can be the same architecture. If... Figure 5 The architecture shown is applied to Figure 13 In the method flow, Figure 5 The multiple switching devices shown are always in the ON state in the TX direction.

[0215] based on Figure 14 The architecture shown Figure 13 The method shown includes the following process.

[0216] 131. The BBU determines Q RRUs from multiple RRUs that need to send signals, where Q is an integer greater than or equal to 1.

[0217] In some embodiments, in the TX direction, reference Figure 14 In the distributed WLAN system architecture shown, when the BB module in the BBU determines the RRU that wants to send downlink signals, the BB module can send indication information to the controller 301 through the high-speed data interface between the BB module and the controller 301. The indication information indicates the identifiers of the Q RRUs that want to send signals.

[0218] For example, such as Figure 14 As shown, this high-speed data interface is a hardware-software interface (HSI). The controller 301 can be a CPLD or FPGA, etc.

[0219] For example, the indication information may be carried in the signaling indicating downlink transmission or uplink reception, such as the signaling adding at least 1 bit to indicate the identifier of the Q RRUs to be transmitted.

[0220] In some embodiments, the BB module sends indication information to the controller 301 via a high-speed data interface, indicating the identifiers of the Q RRUs whose signals are to be transmitted. Alternatively, the BB module can send indication information to the controller 301 via the high-speed data interface, indicating the identifiers of Z RRUs other than the identifiers of the Q RRUs whose signals are to be transmitted. These Z RRU identifiers are those of the RRUs that the BB module determines will not transmit downlink signals.

[0221] 132. The BBU sends Z first instructions, in which Z first instructions indicate that Z RRUs other than the Q RRUs are in a power off state or a low power state in the transmission direction, where Z is an integer greater than or equal to 1.

[0222] In some embodiments, a controller 301 in the BBU is coupled to a path of each of the plurality of RRUs, and the controller 301 is used to send a first instruction to each of the Z RRUs.

[0223] For example, the Z RRUs that the controller determines to receive the first instruction may be determined based on the identifiers of the Q RRUs that want to send downlink signals sent by the BB module, or it may be determined based on the identifiers of the Z RRUs that do not send downlink signals sent by the BB module.

[0224] For example, controller 301 can send Z first instructions through multiplexers corresponding to Z RRUs in BBU. Each of the Z first instructions is then transmitted to controller 304 on the RRU side via a remote medium, notifying RRU-side controller 304 to turn off or adjust the FEM of the RRU to a low-power state or low-voltage state in the TX direction.

[0225] The FEM mainly comprises two parts: a power amplifier (PA) for amplifying the TX signal and a low-noise amplifier (eLNA) for amplifying the RX signal. These two amplifiers are integrated within the FEM and connected to the RF path via a single-pole double-throw (SPD) switch. Considering that the same RF path can only operate in either the TX or RX state at a fixed time, the SPD switch can be used to switch and select between the PA and the eLNA. The FEM shutdown mentioned in this application primarily refers to shutting down the PA within the FEM used for amplifying the TX signal.

[0226] In some embodiments, before the BBU sends Z first instructions, the method further includes: determining that the signal frame to be sent is a non-broadcast frame.

[0227] For example, the signal frame to be sent may be a unicast frame or a multicast frame. That is, when the BB module in the BBU determines that the signal frame to be sent only needs to be sent to some terminals under multiple RRUs, in order to save power, the FEM in the RRU corresponding to the terminal that does not need to receive the signal frame can be turned off by the first instruction.

[0228] In some embodiments, Q RRUs and Z RRUs are RRUs connected to the same radio frequency channel.

[0229] This situation arises because, in existing technologies, multiple RRUs connected to the same RF channel transmit the same signal in the TX direction. However, when the signal frame to be transmitted is a unicast or multicast frame, the RRU corresponding to the terminal receiving the signal frame may only be a portion of the multiple RRUs connected to this RF channel, for example, Q RRUs. Z RRUs among the multiple RRUs connected to this RF channel do not need to transmit signal frames. For example, both Q and Z RRUs are connected to RF channel 1. Therefore, this application avoids the power waste caused by Z RRUs also transmitting signal frames by turning off or adjusting the FEM of these Z RRUs under this RF channel to a low-power state.

[0230] In some embodiments, Q RRUs and Z RRUs are RRUs connected to at least two different radio frequency channels.

[0231] This can be understood as follows: the Q RRUs that are to transmit signals can be RRUs connected to a single RF channel. Some of the Z RRUs that are not transmitting signals are connected to the same RF channel as the Q RRUs. However, the RF channels connected to another portion of the Z RRUs are different from those connected to the Q RRUs. For example, the Q RRUs are connected to RF channel 1, some of the Z RRUs are connected to RF channel 1, and the other portion of the Z RRUs are connected to at least one RF channel other than RF channel 1. For example, the at least one RF channel other than RF channel 1 includes RF channels 2 to n. This means that the FEMs of the RRUs connected to the remaining RF channels other than RF channel 1 are turned off or set to a low-power state. This avoids transmitting downlink signals through the RRUs not connected to RF channel 1 and the RRUs connected to RF channels 2 to n, thus saving power.

[0232] Alternatively, Q RRUs can be all RRUs connected to RF channel 1, and Z RRUs can be RRUs connected to RF channels 2 through n. In this case, the downlink signal to be transmitted is sent to the terminals under all RRUs connected to RF channel 1. This avoids the downlink signal being transmitted without passing through the RRUs connected to RF channels 2 through n, thus saving power.

[0233] Alternatively, the Q RRUs may be RRUs connected to multiple different RF channels. For example, some of the Q RRUs may be connected to RF channel 1, while others may be connected to RF channel 2. The Z RRUs may include the RRUs connected to RF channel 1, the RRUs connected to RF channel 2, and the RRUs connected to RF channels 3 through 1. This avoids transmitting downlink signals through the RRUs connected to RF channel 1, the RRUs connected to RF channel 2, and the RRUs connected to RF channels 3 through 1, thus saving power.

[0234] 133. Z RRUs adjust to the off state or low power state in the transmission direction based on Z first instructions.

[0235] In this way, when the BBU sends a downlink signal to the RRU, the Z RRUs will not send that downlink signal.

[0236] In some embodiments, when the BBU determines that it has sent a complete signal frame to Q RRUs, it sends Z second instructions, which instruct the Z RRUs to resume normal operation in the transmission direction.

[0237] For example, when the BB module in the BBU determines that a complete signal frame has been sent to Q RRUs, the BB module sends an indication message to the controller 301, instructing the controller 301 to send Z second instructions through the multiplexers corresponding to the Z RRUs in the BBU. Each of the Z second instructions is then transmitted to the controller 304 on the RRU side through the remote medium, notifying the RRU-side controller 304 to restore the normal working state of the FEM of the RRU in the TX direction, that is, to turn on the PA in the FEM or to increase the PA to a high power consumption state.

[0238] like Figure 15The diagram illustrates the timing of RRU channel selection in the TX direction of a distributed WLAN system. Taking an RRU connected to a single radio frequency channel as an example, assuming the BBU determines that the RRU to transmit downlink signals is RRU_1_1 in radio frequency channel 1, and the RRUs that do not need to transmit downlink signals include RRU_1_2 and RRU_1_3 in radio frequency channel 1, the controller 301 in the BBU, upon determining at time 1 that the RRU to transmit downlink signals is RRU_1_1, sends a first command to the controllers 304 of RRU_1_2 and RRU_1_3 to disable the FEM in RRU_1_2 and RRU_1_3. Thus, RRU_1_1 can normally transmit the downlink signals sent by radio frequency channel 1, while RRU_1_2 and RRU_1_3 do not transmit the downlink signals sent by radio frequency channel 1. When the BB module determines that it has completed sending the complete signal frame of the downlink signal, that is, after sending the content of the PE field, the BB module sends a second instruction to the controller 304 of RRU_1_2 and RRU_1_3 at time 2 through controller 301 to restore the FEM in RRU_1_2 and RRU_1_3 to normal working state.

[0239] Therefore, this application can turn off or switch to a low-power state of RRUs that do not need to transmit downlink signals when transmitting downlink signals through a designated RRU in the downlink TX direction, which can save power consumption of the distributed WLAN system.

[0240] If Figure 13 The method process is applied to Figure 10 In the illustrated architecture, this application can also perform RRU selection on the TX path in a distributed WLAN system based on a mixer architecture. First, the BB module sends a first command to the multi-function mixer chips corresponding to multiple RRUs in the BBU that are not transmitting downlink signals. Upon receiving the first command, the MCU in the multi-function mixer chip sends a first command to the multi-function mixer chip on the RRU side of the same path. Upon receiving the first command, the RRU-side multi-function mixer chip either shuts down the FEM or adjusts the FEM to a low-power state. After the downlink signal transmission ends, for the RRUs that are shut down or adjusted to a low-power state, the BB module issues a second command. The second command is transmitted via the multi-function mixer chip on the BBU side to the multi-function mixer chip on the RRU side, ultimately restoring the FEM device to normal operating status.

[0241] Similarly, in Figure 12In the distributed WLAN system shown, downlink (TX) signals can also exist, where different AUs connected to the same RU send the same downlink signal, resulting in a certain degree of power waste. That is, among the multiple AUs connected to an RU, some AUs do not need to send downlink signals to the terminal, but all AUs connected to an RU are in normal working condition. The downlink signal sent by the RU is wasted when it is transmitted from each AU connected to the RU. Therefore, in this application, to avoid the power waste caused by AUs connected to the RU sending the same downlink signal, the control unit 301 in the BBU can be coupled to the multiplexer after power division in each RU through multiple high-speed communication interfaces, such as GPIOs. That is, the number of GPIOs in the control unit 301 is the same as the number of AUs. For each GPIO, the BBU can send a first control command to the controller in an AU through one GPIO of the controller 301, indicating that the AU is in a shutdown state or a low-power state. The BBU can also send a second control command to the controller in an AU through one GPIO of the controller 301, indicating that the AU returns to normal working condition.

[0242] Understandable, Figure 12 A combination of an AU and its corresponding RU can be considered as an RRU.

[0243] For example, Figure 12 The combination of an AU and its corresponding RU can be considered as Figure 3 or Figure 14 One of the RRUs. Understandably, this is to reduce... Figure 3 The example shown illustrates that all RRUs connected to a single RF channel broadcast the same content, resulting in wasted power. This application addresses this issue by... Figure 14 The scheme shown in the paper selects and disables channels of multiple RRUs to avoid power waste in scenarios where RRUs that are not transmitting signals are transmitting signals in the TX direction. Similarly, when the combination of an AU and its corresponding RU is equivalent to an RRU, this application can also select and disable channels of multiple AUs, as illustrated in the example provided in this application. Figure 14 The proposed solution avoids the power consumption waste that occurs when an AU that does not send signals transmits signals in the TX direction.

[0244] and Figure 13The illustrated process is similar. The BB module in the BBU knows the identifiers of the AUs that want to transmit downlink signals. The BB module in the BBU can send the identifiers of R AUs that want to transmit signals or the identifiers of S AUs that do not transmit signals to the controller 301 in the BBU. The controller 301 can determine the S AUs that do not transmit signals based on the identifiers of the R AUs or the S AUs, and send S first instructions, instructing the S AUs (excluding the R AUs) to be in a power-off or low-power state in the transmission direction. R and S are integers greater than or equal to 1. The sum of R and S is the total number of AUs in the distributed WLAN system. Each of the S first instructions can be first sent by the controller 301 to the controller of the RU associated with the AU, and then sent by the RU controller to the controller of the AU. The controller of the AU controls the AU to be in a power-off or low-power state in the transmission direction.

[0245] Therefore, this application can turn off or switch to a low-power state of AUs that do not need to transmit downlink signals when transmitting downlink signals through a designated AU in the downlink TX direction, thereby saving power consumption of the distributed WLAN system.

[0246] Based on the above description of this application, in the distributed WLAN system solved by this application, the hidden node conflict problem between terminals under different RRUs in the RX direction, or the hidden node conflict problem between different AUs connected to the same RU, is addressed by adding energy detection and RRU identification reporting functions to each RRU after the power splitting node of the BBU, so that the BBU can accurately select different RRUs, or adding energy detection and AU identification reporting functions to each AU after the power splitting node of each RU, so that the BBU can accurately select AUs. Compared with the antenna-less selection scheme and the channel-level antenna selection scheme, this application has the advantages shown in Table 1.

[0247] Table 1

[0248]

[0249] It is understood that, in order to achieve the functions in the above embodiments, the BBU and RRU include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0250] Figure 16 and Figure 17This is a schematic diagram illustrating the structure of possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the BBU or RRU in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be as follows: Figure 1 The central AP shown can also be as follows: Figure 1 The RRU shown can also be a module (such as a chip) applied to a central AP or RRU.

[0251] like Figure 16 As shown, the communication device 160 includes a processing unit 1610 and a transceiver unit 1620. The communication device 160 is used to implement the above-mentioned... Figure 4 and / or Figure 13 The method embodiments shown depict the functions of a terminal or base station.

[0252] When the communication device 160 is used to implement Figure 4 In the method embodiment shown, the BBU functions as follows: the transceiver unit 1620 receives M pieces of first information; it receives signals sent to the BBU from the first RRU (excluding N RRUs) among the plurality of RRUs, wherein the channel of the first RRU is in a normal working state in the receiving direction. The processing unit 1610 controls the channels of N RRUs among the plurality of RRUs to be in a deactivated state in the receiving direction based on the M pieces of first information.

[0253] When the communication device 160 is used to implement Figure 4 In the method embodiment shown, the RRU functions as follows: the transceiver unit 1620 is used to send first information; the processing unit 1610 is used to perform energy detection.

[0254] When the communication device 160 is used to implement Figure 13 In the method embodiment shown, the BBU functions as follows: the transceiver unit 1620 is used to send Z first instructions, in which the Z first instructions indicate that Z RRUs other than the Q RRUs are in a power-off state or a low-power state in the transmission direction; the processing unit 1610 is used to determine Q RRUs that are to transmit signals or Z RRUs other than the Q RRUs that are not to transmit signals.

[0255] When the communication device 160 is used to implement Figure 13 In the method embodiment shown, the RRU functions as follows: the processing unit 1610 is used to adjust to a shutdown state or a low-power state in the transmission direction based on a first instruction; the transceiver unit 1620 is used to send signals when the transmission direction is in a normal operating state.

[0256] For a more detailed description of the processing unit 1610 and the transceiver unit 1620, please refer to [the relevant documentation]. Figure 4 and Figure 13The relevant descriptions in the method embodiments shown.

[0257] like Figure 17 As shown, the communication device 170 includes a controller 1710 and an interface circuit 1720. The controller 1710 and the interface circuit 1720 are coupled to each other. It is understood that the interface circuit 1720 can be a transceiver or an input / output interface. Optionally, the communication device 170 may also include a memory 1730 for storing instructions executed by the controller 1710, or storing input data required for the controller 1710 to execute instructions, or storing data generated after the controller 1710 executes instructions.

[0258] When the communication device 170 is used to achieve Figure 4 or Figure 13 In the method shown, the controller 1710 is used to implement the functions of the processing unit 1610, and the interface circuit 1720 is used to implement the functions of the transceiver unit 1620.

[0259] In this application, entity A sends information to entity B, either directly or indirectly through other entities. Similarly, entity B receives information from entity A, either directly or indirectly through other entities. Entities A and B can be BBUs or RRUs, or modules of BBUs or RRUs. Information transmission and reception can be between BBUs and RRUs, for example, between two BBUs and RRUs; it can also be between nodes of two RRUs, such as between an RU and an AU; or it can be between different modules within a single device, such as between a BBU chip and other modules of the BBU, or between an RRU chip and other modules within the RRU.

[0260] It is understood that the processor in the embodiments of this application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor.

[0261] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or terminal. The processor and storage medium can also exist as discrete components in a base station or terminal.

[0262] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0263] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0264] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. "Including at least one of A, B, and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0265] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication system, characterized in that, The system includes a baseband processing unit (BBU) and multiple radio frequency remote units (RRUs). The BBU includes multiple radio frequency channels, each of which is connected to a portion of the RRUs via a remote medium. M of the plurality of RRUs are used to send M first information to the BBU, where M is an integer greater than or equal to 1. Each of the M first information includes energy information and an RRU identifier, and the energy information indicates the energy of the input signal detected by the RRU. The BBU is used to control the channels of N RRUs among the plurality of RRUs to be in a state of being off in the receiving direction based on the M first pieces of information, where N is an integer greater than or equal to 1; The BBU is also used to receive signals transmitted by a first RRU other than the N RRUs among the plurality of RRUs, wherein the channel of the first RRU is in normal working condition in the receiving direction.

2. The communication system according to claim 1, characterized in that, The N RRUs and the first RRU are RRUs connected to the same radio frequency channel.

3. The communication system according to claim 1, characterized in that, The N RRUs and the first RRU are RRUs connected to at least two different radio frequency channels.

4. The communication system according to any one of claims 1-3, characterized in that, The first RRU is the RRU corresponding to the first information received first by the BBU.

5. The communication system according to any one of claims 1-3, characterized in that, M of the plurality of RRUs are RRUs that send the first information within a preset time period; The first RRU is the RRU with the highest energy indicated by the energy information among the M RRUs.

6. The communication system according to any one of claims 1-3, characterized in that, The first RRU is the RRU whose channel of the M RRUs completes fine synchronization processing first under normal working conditions.

7. The communication system according to claim 6, characterized in that, The BBU is used to control the channels of the N RRUs to be in a state of being turned off in the receiving direction when it detects the efficient short training field HE-STF in the signal transmitted by the first RRU.

8. The communication system according to any one of claims 1-7, characterized in that, The energy indicated by the energy information for each of the M RRUs is greater than or equal to the energy threshold.

9. The communication system according to any one of claims 1-8, characterized in that, The BBU is also used to control the channels of the N RRUs to return to normal operation upon receiving a complete signal frame sent by the first RRU.

10. The communication system according to any one of claims 1-9, characterized in that, The communication system further includes multiple switching devices, each of which is coupled to one of the multiple RRUs; the BBU includes the multiple switching devices, or each of the multiple RRUs includes one of the multiple switching devices. The BBU also includes a controller, which is used to send a first control command to each of the N switching devices coupled to the N RRUs. The first control command is used to control the channel of one of the N RRUs to be in a closed state in the receiving direction.

11. The communication system according to claim 10, characterized in that, The controller is further configured to, upon determining that the BBU has received the complete signal frame sent by the first RRU, send a second control command to each of the N switching devices, wherein the second control command is configured to control the channel of one of the N RRUs to resume normal operation in the receiving direction.

12. A communication method, characterized in that, A device applied to a baseband processing unit (BBU) or the BBU, the BBU including multiple radio frequency (RF) channels, each RF channel being connected to a portion of multiple radio frequency remote units (RRUs) via a remote medium, the method comprising: Receive M first pieces of information, where M is an integer greater than or equal to 1, and any one of the M first pieces of information includes energy information and an RRU identifier, wherein the energy information indicates the energy of the input signal detected by the RRU; Based on the M first pieces of information, the channels of N RRUs among the plurality of RRUs are controlled to be in a state of being off in the receiving direction, where N is an integer greater than or equal to 1; The system receives signals transmitted by the first RRU (excluding the N RRUs) among the plurality of RRUs, and the channel of the first RRU is in normal working condition in the receiving direction.

13. The method according to claim 12, characterized in that, The N RRUs and the first RRU are RRUs connected to the same radio frequency channel.

14. The method according to claim 12, characterized in that, The N RRUs and the first RRU are RRUs connected to at least two different radio frequency channels.

15. The method according to any one of claims 12-14, characterized in that, The method further includes: Upon receiving a complete signal frame from the first RRU, control the channels of the N RRUs to resume normal operation.

16. The method according to any one of claims 12-14, characterized in that, The receiving of M first messages includes: receiving the first messages sent by the first RRU; The first RRU is the RRU that receives the first information first.

17. The method according to any one of claims 12-14, characterized in that, The receipt of M first pieces of information includes: Receive the M first messages sent by M RRUs within a preset time period; The first RRU is the RRU with the highest energy indicated by the energy information among the M RRUs.

18. The method according to any one of claims 12-14, characterized in that, Before controlling the channels of N RRUs out of the plurality of RRUs to be in the off state, the method further includes: The signals received from the M RRUs are subjected to fine synchronization processing; The first RRU is the RRU whose channel of the M RRUs completes fine synchronization processing first under normal working conditions.

19. The method according to claim 18, characterized in that, The control of the channels of N RRUs among the plurality of RRUs to be in the off state includes: When the efficient short training field HE-STF is detected in the signal transmitted by the first RRU, the channels of the N RRUs are controlled to be turned off in the receiving direction.

20. The method according to any one of claims 12-19, characterized in that, The energy indicated by the energy information for each of the M RRUs is greater than or equal to the energy threshold.

21. A communication method, characterized in that, A device applied to a radio frequency remote unit (RRU) or the RRU, wherein the RRU is connected to a radio frequency channel in a baseband processing unit (BBU) via a remote medium, the method comprising: The BBU sends first information, which includes energy information and the identifier of the RRU. The energy information indicates the energy of the input signal detected by the RRU. The first information is used by the BBU to determine whether to control the channel of the RRU to be in a closed state.

22. The method according to claim 21, characterized in that, The method further includes: Send a signal to the BBU; Alternatively, a control signal may be received, which indicates that the channel of the RRU is in a closed state in the receiving direction.

23. A communication system, characterized in that, The system includes a baseband processing unit (BBU) and multiple radio frequency remote units (RRUs). Each BBU includes multiple radio frequency channels, and each channel is connected to a portion of the RRUs via a remote medium. The BBU is used to determine Q RRUs among the plurality of RRUs that have signals to be transmitted, where Q is an integer greater than or equal to 1; The BBU is also used to send Z first instructions, wherein the Z first instructions indicate that Z RRUs other than the Q RRUs are in a power off state or a low power state in the transmission direction, and Z is an integer greater than or equal to 1; The Z RRUs are used to adjust the transmission direction to the shutdown state or the low-power state based on the Z first instructions.

24. The communication system according to claim 23, characterized in that, The Q RRUs and the Z RRUs are RRUs connected to the same radio frequency channel.

25. The communication system according to claim 24, characterized in that, The Q RRUs and the Z RRUs are RRUs connected to at least two different radio frequency channels.

26. The communication system according to any one of claims 23-25, characterized in that, The BBU is also used to determine that the signal frame to be sent is a non-broadcast frame before sending the Z first instructions.

27. The communication system according to any one of claims 23-26, characterized in that, The BBU is also used to send Z second instructions when it is determined that a complete signal frame has been sent to the Q RRUs, the Z second instructions instructing the Z RRUs to resume normal operation in the transmission direction.

28. The communication system according to any one of claims 23-27, characterized in that, The BBU includes a controller that is coupled to a path of each of the plurality of RRUs; The controller is used to send the first instruction to each of the Z RRUs.

29. A communication method, characterized in that, A device applied to a baseband processing unit (BBU) or the BBU, the BBU including multiple radio frequency (RF) channels, each RF channel being connected to a portion of multiple radio frequency remote units (RRUs) via a remote medium, the method comprising: Determine Q RRUs from the plurality of RRUs that have signals to be transmitted, where Q is an integer greater than or equal to 1; Send Z first instructions, wherein the Z first instructions indicate that Z RRUs other than the Q RRUs are in a power off state or a low power state in the transmission direction, and Z is an integer greater than or equal to 1.

30. The method according to claim 29, characterized in that, The Q RRUs and the Z RRUs are RRUs connected to the same radio frequency channel.

31. The method according to claim 29, characterized in that, The Q RRUs and the Z RRUs are RRUs connected to at least two different radio frequency channels.

32. The method according to any one of claims 29-31, characterized in that, Before sending the Z first instructions, the method further includes: determining that the signal frame to be sent is a non-broadcast frame.

33. The method according to any one of claims 29-32, characterized in that, The method further includes: If it is determined that a complete data frame has been sent to the Q RRUs, Z second instructions are sent, which instruct the Z RRUs to resume normal operation in the transmission direction.

34. A communication method, characterized in that, A device applied to a radio frequency remote unit (RRU) or the RRU, wherein the RRU is connected to a radio frequency channel in a baseband processing unit (BBU) via a remote medium, the method comprising: Receive a first instruction, which indicates that the RRU is in a power-off state or a low-power state in the transmission direction, wherein the RRU is an RRU that does not transmit signals; Based on the first instruction, the RRU is adjusted to the off state or the low power state in the transmission direction.

35. The method according to claim 34, characterized in that, The method further includes: The system receives a second instruction, which instructs the RRU to resume normal operation in the transmission direction.

36. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed on a communication device, cause the communication device to perform the method as described in any one of claims 12-22, 29-35.

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