Signal identification method and communication device

Abstract

A signal identification method and a communication device are provided to solve the problem of data packet loss caused by the receiving device being unable to accurately synchronize with a target frame due to frame overlap in the signal transmission process; and can be applied to systems such as UWB-based wireless personal area network systems, Wi-Fi systems, and sensing systems. The method includes the step of a first device performing channel estimation based on an L-LTF sequence corresponding to a received signal frame to obtain a first channel estimation value, and determining whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the first channel estimation value and mark information of N subcarrier elements, wherein the first channel estimation value includes channel estimation values ​​corresponding to M subcarrier elements in the L-LTF sequence corresponding to the signal frame, and the mark information of N subcarrier elements includes sequence numbers of N subcarrier elements and amplitude and / or phase change values ​​corresponding to N subcarrier elements, and M and N are positive integers, M>1, and 1≤N≤M.

Description

Technology Field

[0001] delete

[0002] delete

[0003] This application relates to the field of communication, and in particular, to a signal identification method and a communication device. Background Technology

[0004] In wireless fidelity (Wi-Fi) systems, data transmission is completed based on the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) protocol, and a Listen-Before-Talk (LBT) mechanism is introduced to perform channel monitoring. Specifically, before transmitting data each time, a node needs to first monitor whether the channel is idle. If the channel is not idle, the node does not transmit data. To prevent data being transmitted by other nodes from being interrupted, a node can transmit data only when it is determined that the channel is idle.

[0005] Channel idle state detection can be implemented in the following two ways: one is energy detection (ED), where energy detection performs an energy evaluation on a received signal, and if the energy value is greater than the ED threshold, it indicates that the channel is occupied by a user. The other is carrier sense (CS), where carrier sense performs a correlation operation using the preamble sequence of the radio frame physical layer header of the received signal and a known sequence, and if correlated, determines whether the channel is idle using a threshold lower than the ED threshold—indicating that the channel is occupied by a user if the threshold exceeds the CS threshold; or if uncorrelated, determines whether the channel is idle using the ED.

[0006] However, when the aforementioned channel detection mechanism having random backoff characteristics is used between intra-frequency cells and / or within the same cell, if the transmitting device cannot detect a signal transmitted by another transmitting device through detection, the channel usage / idle state is misdetermined. Consequently, there may be two transmitting devices sending Wi-Fi frames over a wireless interface, causing a target frame to overlap with another non-target frame. However, the receiving device cannot guarantee that the target frame overlapping with the non-target frame will be parsed. As a result, data packet loss occurs. The problem to be solved

[0007] The present application provides a signal identification method and a communication device to solve the problem of data packet loss caused by the inability of a receiving device to accurately synchronize with a target frame due to frame overlap in a signal transmission process. means of solving the problem

[0008] To achieve the aforementioned objectives, the present application uses the following technical solutions.

[0009] According to a first embodiment, a signal identification method is provided. The method may be performed by a first device, or by a component of the first device, e.g., a processor, chip, or chip system of the first device, or by a logic module or software capable of implementing all or some functions of the first device. For the sake of explanation, an example in which the method is performed by the first device is used. The signal identification method comprises the steps of: the first device receiving a signal frame; the first device performing channel estimation based on a legacy long training field (L-LTF) sequence corresponding to the signal frame to obtain a first channel estimation value—the first channel estimation value includes channel estimation values ​​corresponding to M subcarrier elements in the L-LTF sequence corresponding to the signal frame—; The first device determines whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a first channel estimate value and mark information of N subcarrier elements—mark information of N subcarrier elements includes sequence numbers of N subcarrier elements and amplitude and / or phase change values ​​corresponding to N subcarrier elements, and M and N are positive integers, M>1, and 1≤N≤M.

[0010] Based on the signal identification method according to the first embodiment, the first device can identify an L-LTF sequence corresponding to a currently received signal frame by using the channel estimate value of the L-LTF sequence corresponding to the currently received signal frame and the mark information of the marked subcarrier element in the target L-LTF sequence. The first device can determine whether the current L-LTF sequence is a target L-LTF sequence marked by a specific mark method, and thus whether the current signal frame is a target frame can be identified more quickly or earlier. In the case of signal overlap, the reception of a non-target frame can be terminated in a timely manner, and the reception of a target frame can be restarted in advance, thereby reducing the signal packet loss rate and improving signal reception reliability. Additionally, a more reliable channel usage / idle state determination can also be formed based on whether the current signal frame is a target frame. In this way, the signal can be transmitted in a timely manner, thereby improving spectrum utilization.

[0011] In a possible design solution, the first device determines whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a first channel estimate value and mark information of N subcarrier elements, wherein the first device determines a first subcarrier element and a second subcarrier element based on sequence numbers of N subcarrier elements—the first subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the subcarrier element sequence number corresponds to the sequence numbers of N subcarrier elements, and the second subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the subcarrier element sequence number is adjacent to the sequence numbers of N subcarrier elements—; and the first device determines whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value. In this way, the first device can identify an L-LTF sequence based on Wi-Fi channel characteristics by using the channel estimate of a subcarrier element (second subcarrier element) adjacent to the sequence numbers of N subcarrier elements and the channel estimate of a de-marked subcarrier element (first subcarrier element) corresponding to the sequence numbers of N subcarrier elements, and thus it can be determined whether the current L-LTF sequence is a target L-LTF sequence marked with a specific mark method, and whether the current signal frame is a target frame can be identified more quickly or earlier.

[0012] In a possible design solution, determining whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value may include: the first device determining a second channel estimate value based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements; and when the absolute value of the second channel estimate value is less than a first threshold value, the first device determining that the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence; or when the absolute value of the second channel estimate value is greater than or equal to the first threshold value, the first device determining that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence.

[0013] The second channel estimate is the following first relationship: It satisfies the condition that when the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, the sequence number of which is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1 ≤ i ≤ N. In this way, the first device identifies an L-LTF sequence by de-marking the channel estimate value corresponding to the first subcarrier element, performing negative processing, and then summing the channel estimate value corresponding to the second subcarrier element. This method is simple, and in scenarios where channel conditions are good or noise is low, the identification of the L-LTF sequence can be completed quickly, thereby improving the identification speed.

[0014] In another possible design solution, the first device determining whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value may include the first device determining a second channel estimate value and a third channel estimate value based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements; and the first device determining whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on the second channel estimate value and the third channel estimate value.

[0015] The second channel estimate is the following second relationship: Satisfies; the third channel estimate is the following third relationship: It satisfies the condition that when the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is the third channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1 ≤ i ≤ N. In this way, based on identification based on the second channel estimate value, the first device may further determine whether the channel estimate value corresponding to the first subcarrier element is de-marked and the channel estimate value corresponding to the second subcarrier element is the sum of channel estimate values ​​obtained after the sum of co-directional amplitudes. Identifying by combining the second channel estimate value and the third channel estimate value can improve identification accuracy. In scenarios with poor channel conditions or high noise, identification of L-LTF sequences can also be implemented, thereby further improving signal identification reliability.

[0016] In a possible design solution, the first device determining whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a second channel estimate and a third channel estimate may include determining that the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence when the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is less than a second threshold; or determining that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence when the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is greater than or equal to the second threshold. In this way, the first device can identify an L-LTF sequence based on the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate. Based on ensuring signal identification reliability, the identification method can be simple and the signal identification speed can be improved.

[0017] According to a second embodiment, a signal identification method is provided. The method may be performed by a second device, or by a component of the second device, e.g., a processor, chip, or chip system of the second device, or by a logic module or software capable of implementing all or some functions of the second device. For the sake of illustration, an example in which the method is performed by the second device is used. The signal identification method comprises: the second device marks the amplitudes and / or phases of N subcarrier elements in a legacy long training field (L-LTF) sequence corresponding to a signal frame—the L-LTF sequence corresponding to the signal frame contains M subcarrier elements, M and N are positive integers, M > 1, and 1 ≤ N ≤ M—; and the second device transmits the signal frame to the first device.

[0018] Based on a signal identification method according to a second embodiment, the second device can mark an L-LTF sequence by performing a specific amplitude and / or phase change on a specific subcarrier element in the L-LTF sequence, and thus, an L-LTF sequence having a specific marking method can be used to form a signal frame for transmitting service data. This can ensure that the peak-to-average power ratio and fine frequency offset estimation of the signal are not fundamentally affected, and can also improve the degree of signal identification and the speed of signal identification.

[0019] In a possible design solution, when N subcarrier elements include subcarriers having consecutive sequence numbers, the amplitude and / or phase shift values ​​of subcarrier elements having adjacent sequence numbers are different. In this way, when the sequence numbers of the subcarrier elements selected for marking are consecutive, subcarrier elements having adjacent sequence numbers need to be marked in different ways to improve signal identification accuracy.

[0020] According to a third embodiment, a communication device is provided. The communication device includes a processing module and a transceiver module. The transceiver module is configured to receive a signal frame; the processing module is configured to perform channel estimation based on a legacy long training field (L-LTF) sequence corresponding to the signal frame to obtain a first channel estimation value, the first channel estimation value includes channel estimation values ​​corresponding to M subcarrier elements in the L-LTF sequence corresponding to the signal frame; the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the first channel estimation value and mark information of N subcarrier elements, the mark information of N subcarrier elements includes sequence numbers of N subcarrier elements and amplitude and / or phase change values ​​corresponding to N subcarrier elements, M and N are positive integers, M > 1, and 1 ≤ N ≤ M.

[0021] In a possible design solution, the processing module is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a first channel estimate value and mark information of N subcarrier elements, which may include: the processing module is configured to determine a first subcarrier element and a second subcarrier element based on sequence numbers of N subcarrier elements—the first subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the subcarrier element sequence number corresponds to the sequence numbers of N subcarrier elements, and the second subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the subcarrier element sequence number is adjacent to the sequence numbers of N subcarrier elements—; the processing module is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value.

[0022] In a possible design solution, the processing module is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value; the processing module is further configured to determine a second channel estimate value based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements; the processing module is further configured to determine that the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence when the absolute value of the second channel estimate value is less than a first threshold value; or the processing module is further configured to determine that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence when the absolute value of the second channel estimate value is greater than or equal to the first threshold value.

[0023] The second channel estimate is the following first relationship: It satisfies the condition that when the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, and the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1≤i≤N.

[0024] In another possible design solution, the processing module is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value; the processing module is further configured to determine a second channel estimate value and a third channel estimate value based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements; and the processing module is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on the second channel estimate value and the third channel estimate value.

[0025] The second channel estimate is the following second relationship: Satisfies; the third channel estimate is the following third relationship: It satisfies the condition that when the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is the third channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, and the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1≤i≤N.

[0026] In a possible design solution, the processing module is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a second channel estimate and a third channel estimate, which may include: the processing module is configured to determine that the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence when the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is less than a second threshold; or the processing module is configured to determine that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence when the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is greater than or equal to the second threshold.

[0027] Optionally, the transceiver module may include a receiving module and a transmitting module. The transmitting module is configured to implement the transmitting function of the communication device according to the third embodiment, and the receiving module is configured to implement the receiving function of the communication device according to the third embodiment.

[0028] Optionally, the communication device according to the third embodiment may further include a storage module. The storage module stores programs or instructions. When the processing module executes the programs or instructions, the communication device according to the third embodiment may be able to perform the method according to the first embodiment.

[0029] It should be noted that a communication device according to the third embodiment may be a terminal device or a network device, a chip (system) or other part or component that may be placed on a terminal device or a network device, or a device comprising a terminal device or a network device. This is not limited in the present application.

[0030] Additionally, regarding the technical effects of the communication device according to the third embodiment, reference is made to the technical effects of the method according to the first embodiment. Details are not described again in this specification.

[0031] According to a fourth embodiment, a communication device is provided. The communication device includes a processing module and a transceiver module. The processing module is configured to mark the amplitudes and / or phases of N subcarrier elements in a legacy long training field (L-LTF) sequence corresponding to a signal frame, wherein the L-LTF sequence corresponding to the signal frame includes M subcarrier elements, M and N are positive integers, M > 1, and 1 ≤ N ≤ M; and the transceiver module is configured to transmit the signal frame to a first device.

[0032] In a possible design solution, when N subcarrier elements include subcarriers having consecutive sequence numbers, the amplitude and phase change values ​​of subcarrier elements having adjacent sequence numbers are different.

[0033] Optionally, the transceiver module may include a receiving module and a transmitting module. The transmitting module is configured to implement the transmitting function of the communication device according to the fourth embodiment, and the receiving module is configured to implement the receiving function of the communication device according to the fourth embodiment.

[0034] Optionally, the communication device according to the fourth embodiment may further include a storage module. The storage module stores programs or instructions. When the processing module executes the programs or instructions, the communication device according to the fourth embodiment may be able to perform the method according to the second embodiment.

[0035] It should be noted that a communication device according to the fourth embodiment may be a terminal device or a network device, a chip (system) or other part or component that may be placed on a terminal device or a network device, or a device comprising a terminal device or a network device. This is not limited in the present application.

[0036] Additionally, regarding the technical effects of the communication device according to the fourth embodiment, reference is made to the technical effects of the method according to the second embodiment. Details are not described again in this specification.

[0037] According to a fifth embodiment, a communication device is provided. The communication device includes a processor. The processor is coupled to memory, and the processor is configured to execute a computer program stored in memory so as to enable the communication device to perform a method according to any one of the possible implementations of the first and second embodiments.

[0038] In a possible design solution, the communication device according to the fifth embodiment may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used by the communication device according to the fifth embodiment to communicate with another communication device.

[0039] In the present application, a communication device according to the fifth embodiment may be a first device according to the first embodiment or a second device according to the second embodiment, or a chip (system) or other part or component that may be placed in the first device or the second device, or a device comprising the first device or the second device.

[0040] Additionally, regarding the technical effects of the communication device according to the fifth embodiment, reference is made to the technical effects of the method according to any one of the possible implementations of the first and second embodiments. Details are not described again in this specification.

[0041] According to a sixth embodiment, a communication system is provided. The communication system includes a first device and a second device. The first device is configured to perform a signal identification method according to a first embodiment, and the second device is configured to perform a signal identification method according to a second embodiment.

[0042] According to a seventh embodiment, a computer-readable storage medium is provided. The computer-readable storage medium comprises computer programs or instructions; and when the computer programs or instructions are executed on a computer, the computer is able to perform a method according to any one of the possible implementations of the first and second embodiments.

[0043] According to the eighth embodiment, a computer program product is provided. The computer program product includes a computer program or instructions; and when the computer program or instructions are executed on a computer, the computer is able to perform a method according to any one of the possible implementations of the first embodiment and the second embodiment. Brief explanation of the drawing

[0044] FIG. 1 is a diagram of a signal collision scenario according to an embodiment of the present application. FIG. 2 is another diagram of a signal collision scenario according to an embodiment of the present application. FIG. 3 is another diagram of a signal collision scenario according to an embodiment of the present application. FIG. 4 is a structural diagram of the overlap between a target frame and a non-target frame according to an embodiment of the present application. FIG. 5 is a structural diagram of a Wi-Fi frame in the 802.11ac protocol according to an embodiment of the present application. FIG. 6 is a structural diagram distinguishing between intra-frequency cells based on BSS colors according to an embodiment of the present application. FIG. 7 is a diagram of the architecture of a Wi-Fi communication system according to an embodiment of the present application. FIG. 8 is a schematic flowchart of a signal identification method according to an embodiment of the present application. FIG. 9 is a structural diagram of an OFDM train structure defined in the 802.11 2012 standard protocol according to an embodiment of the present application. FIG. 10 is a diagram showing the change in unmarked and marked first channel estimated values ​​according to an embodiment of the present application. FIG. 11 is another variation of the unmarked and marked first channel estimated values ​​according to an embodiment of the present application. FIG. 12 is another variation of the unmarked and marked first channel estimated values ​​according to an embodiment of the present application. FIG. 13 is another variation of the unmarked and marked first channel estimated values ​​according to an embodiment of the present application. FIG. 14 is a diagram of a scenario for distinguishing between intra-frequency cells according to an embodiment of the present application. FIG. 15 is a diagram of a scenario for distinguishing different users in the same cell according to an embodiment of the present application. FIG. 16 is a diagram of a scenario of parallel transmission in intra-frequency cells according to an embodiment of the present application. FIG. 17 is a structural diagram of an alternative transmission of signals in intra-frequency cells according to an embodiment of the present application. FIG. 18 is a structural diagram of parallel transmission of signals in intra-frequency cells according to an embodiment of the present application. FIG. 19 is a diagram of the structure of a communication device according to an embodiment of the present application. FIG. 20 is a drawing of the structure of another communication device according to an embodiment of the present application. Specific details for implementing the invention

[0045] For ease of understanding, the relevant technologies in the embodiments of the present application are described below first.

[0046] In CSMA / CA, the node needs to perform a random backoff process before each transmission. For example, the node randomly generates a random backoff count value based on specified parameters, such as a contention window value. In the random backoff process, the node detects the channel in slots of 9 microseconds (μs). If the channel is detected as idle, the node performs a backoff once, that is, decreases the counter value by 1. If the channel is detected as active, the node pauses the counter until the counter value reaches 0, after which the node can transmit data.

[0047] CSMA / CA uses the following two methods for channel idle state detection:

[0048] (1). Energy Detect (ED): The receiver performs an energy evaluation on the received signal. If the energy value is greater than the ED threshold, for example, -62 decibels relative to one milliwatt (dBm) / 20 megahertz (MHz), it indicates that the channel is occupied by a user and the channel is in use. If the energy value is less than the ED threshold, it indicates that the channel is not occupied by a user and the channel is idle.

[0049] (2). Carrier Detect (CS): The receiver performs a correlation operation using the known sequence and fixed sequence (i.e., preamble) of the physical layer header of the radio frame of the received signal, and if correlated, determines whether the channel is idle using a threshold lower than the ED threshold, and if the threshold exceeds the CS threshold (e.g., -82 dBm / 20 MHz), indicates that the channel is occupied by a user; or if not correlated, determines whether the channel is idle using the ED threshold.

[0050] However, there is a probability of signal collision based on the aforementioned random backoff detection mechanism that causes a target frame to overlap with another non-target frame. However, the receiving device cannot guarantee that a target frame overlapping with a non-target frame will be parsed. As a result, data packet loss occurs.

[0051] The following provides explanations with reference to the diagrams of three possible scenarios in which signal collisions occur.

[0052] Scenario 1: As illustrated in Fig. 1, different channels are cross-arranged, intra-frequency cells use the same channel, intra-frequency cells are separated by more than two other frequency cells, and are typically deployed in a campus office scenario. Channel 1 is used as an example. Access point (AP) 1 and AP 2 transmit data using Channel 1, and the cell where AP 1 is located and the cell where AP 2 is located are intra-frequency cells. In this case, AP 1 needs to transmit downlink services to station (STA) 1, and STA 2 within the cell where AP 2 is located needs to transmit uplink services to AP 2. However, the received signal strength indicator (RSSI) between STA 2 and AP 1 is less than -82 dBm, and STA 2 and AP 1 cannot tell each other who is transmitting the signal. In this case, regardless of whether STA 2 and AP 1 perform ED detection or CS detection, both STA 2 and AP 1 determine that the channel is idle and both STA 2 and AP 1 transmit signals over the wireless interface. That is, when AP 1 transmits a signal, STA 2 also transmits a signal. As a result, intra-frequency parallel interference occurs, signal collisions occur, and data packet loss is caused.

[0053] Scenario 2: As illustrated in Fig. 2, STA 1 and STA 2 are located in the cell where AP 1 is situated, and there is an obstacle between STA 1 and STA 2. In the case where there is a thick wall between STA 1 and STA 2, as a result, there is significant energy loss of the signals between STA 1 and STA 2, and STA 1 and STA 2 cannot know who is transmitting the signal. In this case, if both STA 1 and STA 2 transmit services to AP 1, a signal collision also occurs. In this case, STA 1 and STA 2 are each other's hidden nodes, and since neither STA 1 nor STA 2 can detect each other through detection, they determine that the channel is idle. Consequently, a signal collision occurs, causing data packet loss.

[0054] Scenario 3: As illustrated in FIG. 3, when a data packet from Transmitter 2 arrives, Transmitter 1 is already transmitting a data packet, and Transmitter 2 needs to perform channel idle state detection before transmitting the data packet. However, Transmitter 2 is missing the preamble synchronization header. In this case, when performing channel detection in distributed inter-frame spacing (DIFS), Transmitter 2 cannot correlate the preamble and therefore uses an ED threshold (e.g., -62 dBm) to determine whether the channel is idle. When the energy value of the detected signal is less than -62 dBm, the channel is determined to be idle. As a result, a misjudgment occurs, and consequently, a collision occurs.

[0055] In all three of the aforementioned scenarios, there is a signal collision problem. A signal collision means that two frames received by the receiver overlap each other, which can also be referred to as a message in message (MIM). As illustrated in Fig. 4, the target frame overlaps with the interference frame (which can also be referred to as a non-target frame), and the signal power of the target frame is much greater than that of the interference frame. Since the receiver synchronizes with the interference frame first, the receiver has already entered the reception procedure at moment t1, and frame synchronization can only be performed again after the decoding of the entire interference frame is completed. In this case, the preamble of the target frame is already missing, so the target frame cannot be locked, thereby causing data packet loss; the interference frame is also interfered with by the high-power target frame and cannot be decoded correctly. Consequently, data packet loss occurs.

[0056] Currently, MIM can be resolved using the capture effect. In the process of synchronizing to a non-target frame, a change in signal energy may be detected. If it is detected that the signal power change reaches a specific threshold (where the power difference between frames is required to be greater than 10 dB), reception of the currently captured signal frame may be stopped, and the signal frame is recaptured or resynchronized on the wireless interface. As illustrated in FIG. 4, if the receiver machine receives an interference frame at moment t1 and detects a power change ΔP after Δt, the receiver machine immediately stops receiving the interference frame and recaptures or resynchronizes the physical layer header of the wireless interface signal.

[0057] However, when the target frame is acquired using a capture effect, there are the following three problems:

[0058] (1). The power difference between the received target frame and the non-target frame must be at least 10 dB, and signals with a power difference of 0 dB to 10 dB cannot be identified.

[0059] (2). For Wi-Fi frames in 802.11n / ac / ax protocols, there are high throughput (HT), very high throughput (VHT), and high efficiency short training field (HE-STF) sub-fields, which are used for secondary auto gain control (AGC). When a power change occurs in the aforementioned sub-fields, the receiver machine cannot determine the power change, and consequently, the power capture function cannot be used.

[0060] For example, Fig. 5 is a structural diagram of a Wi-Fi frame in the 802.11ac protocol. As shown in Fig. 5, the structure of the Wi-Fi frame includes an 8-μs legacy short training field (L-STF), an 8-μs legacy long training field (L-LTF), a 4-μs legacy signal field (L-SIG), an 8-μs VHT-SIG-A, a 4-μs VHT-STF—where the VHT-LTF symbol length of each VHT-LTF is 4 μs—a 4-μs VHT-SIG-B, and a data portion. When a target frame arrives during the VHT-STF period of a non-target frame, the receiver machine cannot determine the power change. If the frame length is 1 ms and the duration of the VHT-STF is 4 μs, the probability that the receiver machine will be affected is 4%. In industrial scenarios, data packet lengths are approximately 300 μs, and packet loss rates are up to 1%. Consequently, this causes significant impact.

[0061] It should be noted that each sub-field within a Wi-Fi frame can also be referred to as a field.

[0062] (3). Currently, for most receiver machines, the processing priority of L-SIG, VHT-SIG-A, HT-SIG, and HE-SIG-A within the frame is high, and the reset time after encountering a target frame with a large signal is long. As a result, the physical layer synchronization header of the target frame with a large signal is missing, and packet loss occurs in the target frame.

[0063] Additionally, a basic service set (BSS) color field is introduced into the 802.11ax protocol. In the wireless interface data transmission process, the BSS color field is carried in the form of 6 bits in the high efficiency (HE) format within the high efficiency signal field A (HE-SIG-A) in the physical layer (PHY) header of the physical layer protocol data unit (PPDU). BSS color fields with different values ​​can represent different cells in intra-frequency cells, and the receiver machine can determine, based on the received BSS color, whether the received BSS color matches a pre-negotiated BSS color; if the received BSS color does not match the pre-negotiated BSS color, it can reacquire a Wi-Fi frame from the wireless interface.

[0064] As illustrated in FIG. 6, when STA 1 receives service data from AP 1, the cell where AP 1 is located and the cell where AP 2 is located are intra-frequency cells, and the BSS color field in the signal transmitted by AP 1 is different from the BSS color field in the signal transmitted by AP 2. For example, the BSS color field in the signal frame transmitted by AP 1 is blue, and the BSS color field in the signal frame transmitted by AP 2 is green. When STA 1 receives service data from AP 1, STA 1 can determine whether to continue receiving the signal frame by identifying whether the BSS color field in the received signal frame is blue. If STA 1 decides not to continue receiving the signal frame, STA 1 discards the currently received signal frame and recaptures the blue BSS color on the wireless interface.

[0065] However, BSS color can only be used by terminal devices in the 802.11ax protocol, and while it can be used to distinguish between users in different cells, it cannot be used to distinguish users within the same cell. Furthermore, for the receiver machine, a cell can only be identified after the parsing of HE-SIG-A is complete, and frames that overlap earlier than HE-SIG-A cannot be identified. Therefore, the MIM problem cannot be avoided using BSS color, and consequently, data packet loss occurs.

[0066] Accordingly, the embodiments of the present application provide a signal identification method capable of solving the problem of data packet loss caused by frame overlap in the signal transmission process, which prevents a receiving device from accurately synchronizing with a target frame. The signal identification method is applicable to industrial scenarios with high requirements for the reliability and sensitivity of Wi-Fi signals, such as the control of wireless workshop reconfiguration devices, automated guided vehicles (AGVs), uncrewed aerial vehicles of steel, and mechanical arm devices of vehicle manufacturers, and, as other examples, home gaming scenarios such as real-time combat mobile phone precision control games, and semi-virtual reality (VR) / augmented reality (AR) real-time immersive games. It should be noted that the signal frames in the embodiments of the present application are Wi-Fi frames.

[0067] The technical solutions of the present application will be described below with reference to the attached drawings.

[0068] The technical solutions in the embodiments of the present application may be applied to various communication systems, for example, 4th generation (4G) mobile communication systems such as Wi-Fi systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle Internet communication systems, 4th generation (4G) mobile communication systems such as long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, and future communication systems such as worldwide interoperability for microwave access (WiMAX) communication systems, new radio (NR) systems, 5th generation (5G) mobile communication systems, and 6th generation (6G) mobile communication systems.

[0069] Various aspects, embodiments, or features are presented in this application by describing a system that may include multiple devices, components, modules, etc. It should be recognized and understood that each system may include other devices, components, modules, etc., and / or may not include all devices, components, modules, etc. discussed with reference to the accompanying drawings. Additionally, combinations of these solutions may also be used.

[0070] Additionally, in the embodiments of this application, terms such as “Example” and “Example” are used to indicate that an example, illustration, or description is being provided. Any embodiment or design scheme described as an “Example” in this application should not be described as having more desirable or greater advantages than other embodiments or design solutions. Specifically, the term “Example” is used to present a concept in a particular way.

[0071] In the embodiments of this application, the subscript, e.g., W1, may occasionally be incorrectly written as a non-subscript form, e.g., W1. Unless differences are emphasized, the expressed meanings are consistent.

[0072] The network architectures and service scenarios described in the embodiments of this application are intended to more clearly explain the technical solutions in the embodiments of this application and do not constitute a limitation on the technical solutions provided in the embodiments of this application. A person skilled in the art will understand that, due to the evolution of network architectures and the emergence of new service scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0073] For ease of understanding of the embodiments of the present application, the Wi-Fi communication system illustrated in FIG. 7 is first used as an example to describe in detail a communication system to which the embodiments of the present application are applicable. For example, FIG. 7 is a diagram of the architecture of a Wi-Fi communication system according to an embodiment of the present application.

[0074] As illustrated in FIG. 7, a Wi-Fi communication system includes one or more network devices, such as network device 1 and network device 2, and one or more terminal devices, such as terminal device 1 and terminal device 2. Communication between network devices may be performed, communication between network devices and terminal devices may also be performed, and communication between terminal devices may also be performed. FIG. 7 illustrates an example of two network devices and two terminal devices. The number of network devices and the number of terminal devices are not limited to this embodiment of the present application.

[0075] The cell where network device 1 is located and the cell where network device 2 is located are intra-frequency cells. In the scenario illustrated in FIG. 1, network device 1 is AP 1 and network device 2 is AP 2. The cell where AP 1 is located and the cell where AP 2 is located are intra-frequency cells, and both AP 1 and AP 2 transmit signals using Channel 1. Terminal device 1 and terminal device 2 may be located in the same cell or in different cells. For example, terminal device 1 and terminal device 2 may be located in the cell where AP 1 is located; or terminal device 1 may be located in the cell where AP 1 is located and terminal device 2 may be located in the cell where AP 2 is located.

[0076] In a Wi-Fi communication system provided in such an embodiment of the present application, when one device (including a network device or a terminal device) transmits data to another device (including a network device or a terminal device), the device transmitting the data is a transmitting end, and the device receiving the data is a receiving end. The receiving end is configured to implement functions such as signal acquisition and processing, and the transmitting end is configured to implement functions such as signal generation and transmission.

[0077] In some possible cases, the transmitter may be used as a receiver to implement functions such as signal acquisition and processing, and the receiver may be used as a transmitter to implement functions such as signal generation and transmission. That is, a single physical device may be a transmitter, a receiver, or both a transmitter and a receiver.

[0078] The technical solutions provided in this application are applicable to wireless local area network (WLAN) scenarios and, for example, to Institute of Electrical and Electronics Engineers (IEEE) 802.11 system standards, e.g., 802.11a / b / g standards, 802.11n standards, 802.11ac standards, 802.11ax standards, or next-generation standards of 802.11ax standards, e.g., 802.11be standards, Wi-Fi 7, or extremely high throughput (EHT), or, as other examples, next-generation standards of 802.11be, Wi-Fi 8, or next-generation standards of Wi-Fi 8.

[0079] The embodiments of this application are described using examples of primarily deployed WLAN networks, particularly networks to which the IEEE 802.11 system standard applies. A person skilled in the art will readily understand that the embodiments accompanying this application may be extended to other networks using various standards or protocols, for example, Bluetooth, High Performance Radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard and mainly used in Europe), Wide Area Networks (WAN), Personal Area Networks (PAN), or other networks that may be known or developed in the future. Accordingly, regardless of the coverage used and the wireless access protocol used, the various embodiments provided in this application are applicable to any suitable wireless network.

[0080] In embodiments of the present application, the network device is a device located on the network side of a Wi-Fi communication system and having a wireless transceiver function, or a chip or chip system that may be placed on the device. The network device includes, but is not limited to, an AP in a wireless fidelity (Wi-Fi) system, e.g., a home gateway, a router, a server, a switch, or a bridge, an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NodeB, NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB, home NodeB, HNB), a baseband unit (BBU), a wireless relay node, a wireless backhaul node, a transmission reception point (TRP), or a transmission point (TP). Alternatively, the network device may be a gNB or transmission point (TRP or TP) in a 5G system, for example, a new radio (NR) system, or a single antenna panel or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node, for example, a baseband unit (BBU) or distributed unit (DU) constituting a gNB or transmission point, a road side unit (RSU) having base station functions, etc.

[0081] A terminal device is a terminal that accesses a Wi-Fi communication system and has a wireless transceiver function, or a chip or chip system that can be deployed in the terminal. The terminal device may also be referred to as a non-access point station (non-AP station, non-AP STA), STA, user device, access terminal, subscriber unit, subscriber station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. In the embodiments of the present application, the terminal device may be a mobile phone, a tablet computer (Pad), a computer having a wireless transceiver function, a VR terminal device, an AR terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a vehicle-mounted terminal, an RSU having a terminal function, etc. The terminal device in the present application may alternatively be a vehicle-mounted module, a vehicle-mounted assembly, a vehicle-mounted component, a vehicle-mounted chip, or a vehicle-mounted unit embedded in a vehicle as one or more components or units. The vehicle uses a vehicle-mounted module, a vehicle-mounted assembly, a vehicle-mounted component, a vehicle-mounted chip, or a vehicle-mounted unit embedded in the vehicle to implement the signal identification method provided in the present application.

[0082] It should be noted that the signal identification method provided in the embodiments of the present application is applicable to any two nodes illustrated in FIG. 7, e.g., between a network device and a terminal device, between network devices, and between terminal devices. For specific implementations, refer to the following method embodiments. Details are not described again herein.

[0083] It should be noted that the solutions in the embodiments of the present application may alternatively be applied to other communication systems, and that the corresponding names may alternatively be replaced with the names of corresponding functions in other communication systems.

[0084] It should be understood that FIG. 7 is merely a simplified drawing used as an example for convenience of understanding. The communication system may further include other network devices and / or other terminal devices not shown in FIG. 7.

[0085] Hereinafter, a signal identification method provided in embodiments of the present application will be described in detail with reference to FIGS. 8 to 18.

[0086] For example, FIG. 8 is a schematic flowchart of a signal identification method according to an embodiment of the present application. The signal identification method is applicable to communication between any two nodes of FIG. 1, FIG. 2, or FIG. 7.

[0087] As illustrated in FIG. 8, the signal identification method may include the following steps.

[0088] S801: A second device marks the amplitudes and / or phases of N subcarrier elements in an L-LTF sequence corresponding to a signal frame.

[0089] The second device may be any terminal device or any network device shown in FIG. 7. An L-LTF sequence corresponding to a signal frame includes M subcarrier elements, the L-LTF sequence is a frequency domain sequence, each signal frame corresponds to two identical L-LTF sequences, M and N are positive integers, M>1, and 1≤N≤M.

[0090] In this embodiment of the present application, marking a subcarrier element in an L-LTF sequence may also be referred to as coloring a subcarrier element or as marking or coloring an L-LTF sequence and indicates changing the amplitude and / or phase of a subcarrier element. For example, different devices may select different subcarrier elements in an L-LTF sequence to perform the same or different amplitude and / or phase changes, or select the same subcarrier element to use the same or different amplitude and / or phase changes, that is, the devices have different marking or coloring schemes for the L-LTF sequence, and thus signal frames transmitted by the devices correspond to different L-LTF sequences, and L-LTF sequences may be used to distinguish signals transmitted by the devices.

[0091] For example, the second device selects the amplitudes and / or phases of N subcarrier elements from M subcarrier elements for marking; that is, the second device selects N subcarrier elements and changes the amplitude values ​​and / or phase values ​​of the N subcarrier elements to mark the changed N subcarrier elements, thereby obtaining a marked or colored L-LTF sequence. For example, the process of marking or coloring a single subcarrier element can be expressed by the following formula: , here

[0092] m is the sequence number of the subcarrier element, and is the value of the marked m-th subcarrier element, and is the amplitude and / or phase change value of the m-th subcarrier element, and is the value of the unmarked m-th subcarrier element, m is a positive integer, and 0 ≤ m ≤ M-1. The second device performs marking or coloring processing on all subcarrier elements in the entire L-LTF sequence, wherein the amplitudes and / or phases of the selected N subcarrier elements are changed, i.e., and; that the phases and / or amplitudes of the remaining subcarrier elements are not changed, i.e., It can be understood that... Alternatively, in an L-LTF sequence, for N marked subcarrier elements, ; and for unmarked subcarrier elements, You can understand that...

[0093] A 20 MHz bandwidth is used as an example. The L-LTF sequence defined in the standard protocol contains 64 subcarrier elements, and the value of each subcarrier element within the sequence is 1, 0, or -1. For example, L[1, 64] below is an unmarked L-LTF sequence assigned to the second device:

[0094] L[1, 64]={0, 0, 0, 0, 0, 0, 1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, 1, 1, 1, -1, -1, 1, 1, -1, 1, 1, 1, 1, 0, 1, -1, -1, 1, 1, -1, 1, -1, -1, -1, -1, -1, -1, -1, 1, 1, -1, -1, -1, -1, 1, -1, -1, 1, -1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, where the sequence numbers of the subcarrier elements in the unmarked L-LTF sequence are 1 to 64. It can be understood that the number of subcarrier elements in an L-LTF sequence can be determined based on bandwidth. In this embodiment of the present application, the unmarked L-LTF sequence L[1, 64] above is used for illustrative purposes.

[0095] If the amplitude of the aforementioned 7th subcarrier element with a value of 1 changes, for example, if the amplitude is amplified twice, i.e., If so, the value of the marked 7th subcarrier element changes to 2. Alternatively, if the phase of the 7th subcarrier element changes, for example, if the phase is rotated by 180°, i.e., In this case, the value of the marked 7th subcarrier component changes to -1. Alternatively, if the amplitude and phase of the 7th subcarrier component change, for example, if the amplitude is amplified twice and the phase is rotated by 180°, i.e., In this case, the value of the marked 7th subcarrier element is changed to -2.

[0096] Where possible, the N subcarrier elements may be subcarrier elements having discontinuous sequence numbers in the M subcarrier elements, for example, subcarrier elements having sequence numbers 8, 21, 23, 28, 32, and 50 in L[1, 64], i.e., N=6. In this case, the amplitude and phase changes of the N subcarrier elements may be the same, different, partially the same, or partially different. This is not particularly limited to this embodiment of the application.

[0097] In other possible cases, N subcarrier elements may alternatively include subcarrier elements having adjacent sequence numbers, for example, N=5 and include subcarrier elements having sequence numbers 11, 12, 13, 26, and 51 in L[1, 64], or include subcarrier elements having sequence numbers 11, 12, 13, 14, and 15 in L[1, 64]. In this case, the amplitudes and phase change values ​​of two subcarrier elements having adjacent sequence numbers are different. That is, when the amplitudes and phases of two subcarrier elements having adjacent sequence numbers change together, the amplitudes and phase change values ​​may not be the same, but the two subcarrier elements having adjacent sequence numbers may have the same amplitude but different phases, or different amplitudes but the same phase, thus facilitating subsequent identification. For example, the amplitude and phase change values ​​of the subcarrier elements having sequence numbers 11 and 12 are different, and the amplitude and phase change values ​​of the subcarrier elements having sequence numbers 12 and 13 are different, but the amplitude and phase change values ​​of the subcarrier elements having sequence numbers 11 and 13 may be the same.

[0098] It should also be noted that the second device can mark subcarrier elements in the entire L-LTF sequence, that is, change the amplitudes and / or phases of M subcarrier elements. In this case, the amplitude and phase change values ​​of two subcarrier elements having adjacent sequence numbers may not be the same. When channel conditions are good, the second device can also mark only one subcarrier element in the L-LTF sequence.

[0099] In actual application, it can be understood that when subcarrier elements are selected for marking, subcarrier elements with a value of 0 need to be avoided as much as possible, and that it is necessary to ensure that the peak-to-average power ratio (PAPR) of the selected subcarrier element's signal is sufficiently small after the marking process. Furthermore, in extreme cases, the amplitude and phase changes of the subcarrier element It could be.

[0100] Additionally, the second device performs a frequency-domain to time-domain conversion on the marked L-LTF sequence and adds a cyclic prefix (CP) to the L-LTF sequence to form an L-LTF in the transmitted signal frame. The L-LTF contains two identical orthogonal frequency division multiplexing (OFDM) symbols.

[0101] For example, FIG. 9 is a structural diagram of the OFDM train structure defined in the 802.11 2012 standard protocol. As shown in FIG. 9, the OFDM train structure includes an 8-μs L-STF, an 8-μs L-LTF, a 4-μs signaling field, and a data portion. The L-LTF includes a 1.6-μs CP (i.e., GI2) and two 3.2-μs OFDM symbols (i.e., T1 and T2). T1 and T2 are two repeated signals obtained by performing a frequency-domain to time-domain transformation on the L-LTF sequence. That is, T1 and T2 are obtained by performing the frequency-domain to time-domain transformation twice on the same L-LTF sequence. It can also be understood that T1 and T2 are obtained by performing the frequency-domain to time-domain transformation on two identical L-LTF sequences. For the formation of other time domain waveforms of the signal frame, refer to existing implementation processes. Details are not described in these embodiments of the present application.

[0102] It can be seen that L-LTF is used for fine frequency offset estimation and channel estimation. In this embodiment of the present application, after the L-LTF sequence forming the L-LTF is colored or marked, the marked L-LTF sequence is subjected to frequency-domain to time-domain conversion twice to form two repeated OFDM symbols, namely T1 and T2. Thus, the fine frequency offset estimation process is not affected. Furthermore, when the number of marked subcarrier elements is not large or the marking schemes are identical, the formed L-LTF has almost no effect on the PAPR of the signal. Additionally, when a marked subcarrier element is selected, an appropriate subcarrier element can be found through a search, so the impact on PAPR can be reduced to 1 dB to 2 dB.

[0103] It should be noted that for each transmitting device, an unmarked L-LTF sequence used by the transmitting device to transmit service data is fixed; and for the receiving end, the receiving end also stores the unmarked L-LTF sequence of each transmitting device. Additionally, the unmarked L-LTF sequences assigned to different transmitting devices may be the same or different.

[0104] S802: The second device transmits a signal frame to the first device. In response, the first device receives a signal frame from the second device.

[0105] The first device may be any terminal device or any network device shown in FIG. 7. The signal frame includes an L-LTF obtained by performing a frequency-domain to time-domain transformation on a marked L-LTF sequence. For the structure of the time-domain waveform of the signal frame, refer to the structure shown in FIG. 5 or FIG. 9. Details are not described further herein.

[0106] Accordingly, the first device receives a signal frame. After capturing the signal frame over the wireless interface, the first device synchronizes with the signal frame and enters the reception procedure. However, the currently synchronously received signal frame may be a signal frame transmitted by another device; that is, the signal frame may not be a signal frame transmitted by the second device in S802. For example, there is the MIM problem illustrated in FIG. 4. Therefore, the first device needs to determine whether the currently received signal frame is a target service transmitted by the target device; that is, it needs to determine whether the currently received signal frame is a signal frame transmitted by the second device, and thus quickly identify whether the current signal frame is a target frame. In the case where the currently received signal frame is not a target frame, reception may be stopped in a timely manner, and recapture of the target frame may be performed over the wireless interface. For specific implementation processes, refer to the following relevant descriptions in S803 and S804.

[0107] It can be understood that the transmitted signal frame changes during the transmission process, for example, signal attenuation. That is, while the received signal frame and the transmitted signal frame have a difference in power, the information carried in the received and transmitted signal frames does not change.

[0108] S803: The first device performs channel estimation based on an L-LTF sequence corresponding to a signal frame and obtains a first channel estimation value.

[0109] The first channel estimate includes channel estimate values ​​corresponding to M subcarrier elements in an L-LTF sequence corresponding to the currently received signal frame. That is, the first channel estimate includes M channel estimate values ​​corresponding to M subcarrier elements.

[0110] For example, in the process of receiving a signal frame, the first device parses the L-LTF in the signal frame and, for example, performs a time-domain-to-frequency-domain conversion process to obtain the L-LTF sequence in the signal frame. Because signal attenuation exists, the value of the subcarrier component in the received L-LTF sequence differs from the value of the subcarrier component in the transmitted L-LTF sequence. Therefore, the value of a single subcarrier component in the L-LTF sequence obtained by the first device through parsing can be expressed by the following formula: , here

[0111] is the original channel estimate of the m-th subcarrier element, and the original channel estimate can be understood as the channel estimate corresponding to the unmarked subcarrier element, or as the ratio of the received signal to the transmitted signal.

[0112] It can be understood that before parsing L-LTF, the first device first parses L-STF. L-STF can be used to implement functions such as signal detection, approximate frequency offset estimation, and symbol timing. For specific implementation processes, refer to existing relevant descriptions. Details are not described again in this specification.

[0113] Additionally, the first device performs channel estimation using the L-LTF sequence obtained through parsing to obtain a first channel estimation value, and the process of obtaining the channel estimation value of an arbitrary subcarrier element from the first channel estimation value can be implemented using the following formula:

[0114] .

[0115] That is, the channel estimate corresponding to any subcarrier element (m-th subcarrier element) in the first channel estimate is as follows:

[0116] .

[0117] It can be seen that if the amplitude and / or phase of a subcarrier element changes, the same change in amplitude and / or phase also occurs in the channel estimate value corresponding to the subcarrier element. That is, the channel estimate value of the marked subcarrier element in the first channel estimate value is identical to the original channel estimate value.

[0118] It should be noted that the channel estimate value may be a channel estimate amplitude value, a channel estimate phase value, or a channel estimate complex value (including channel estimate amplitude value and channel estimate phase value).

[0119] For example, if the second device changes the 28th amplitudes in the L-LTF sequence into the 31st subcarrier elements, for example, the amplitudes are amplified twice, i.e., And, the first device performs channel estimation for the L-LTF sequence, and the obtained first channel estimation value is shown in FIG. 10. The channel estimation values ​​of the 28th to 31st subcarrier elements in the L-LTF sequence are also correspondingly changed to twice the original channel estimation values. If the original channel estimation amplitude value of the 28th subcarrier element is 0.41501, the marked channel estimation amplitude value is 0.82984. In this case, the channel estimation value is the channel estimation amplitude value.

[0120] As another example, if the second device changes the 28th phases in an L-LTF sequence to the 31st subcarrier elements, for example, the phases are rotated by 180°, i.e., The first device performs channel estimation on the L-LTF sequence, and the obtained first channel estimation value is shown in FIG. 11. The channel estimation values ​​of the 28th to 31st subcarrier elements in the L-LTF sequence are also rotated by 180° compared to the original channel estimation values. If the original channel estimation phase value of the 28th subcarrier element is 68.3825°, the marked channel estimation phase value is -111.6165°. In this case, the channel estimation value is the channel estimation phase value.

[0121] It should be noted that for a subcarrier element with a value of 0, the channel estimate value corresponding to the subcarrier element is also 0. Therefore, in the first channel estimate values ​​shown in FIGS. 10 and FIGS. 11, the channel estimate value where the subcarrier element is 0 is not shown.

[0122] Additionally, FIGS. 10 and 11 are used to illustrate the relationship between the channel estimate value and the amplitude and / or phase change of the subcarrier elements. In actual application, in subcarrier elements having consecutive sequence numbers, when the amplitudes and phases of subcarrier elements having adjacent sequence numbers change simultaneously, the amplitude and phase change values ​​need to be different. For example, when only the amplitudes of the 28th to 31st subcarrier elements change, the amplitude change values ​​of the 28th and 29th subcarrier elements, or the 29th and 30th subcarrier elements, or the 30th and 31st subcarrier elements need to be different.

[0123] It can be understood that when phase and amplitude change simultaneously, the corresponding channel estimates obtained are channel estimate complex values.

[0124] S804: The first device determines whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on the first channel estimate value and the mark information of N subcarrier elements.

[0125] The mark information of N subcarrier elements includes the sequence numbers of N subcarrier elements and amplitude and / or phase change values ​​corresponding to the N subcarrier elements, i.e., the mark information of an L-LTF sequence marked by the second device. The target L-LTF sequence is an L-LTF sequence corresponding to a signal frame transmitted by the second device.

[0126] Mark information of N subcarrier elements can be obtained through pre-negotiation or pre-configuration between a first device and a second device. For example, when the first device is a network device and the second device is a terminal device, or when the first device is a terminal device and the second device is a network device, and the terminal device is associated with the network device, the terminal device may add the mark information of N subcarrier elements to an association frame, or the terminal device may obtain the mark information from a beacon frame transmitted by the network device, or the network device may transmit the mark information of N subcarrier elements to the terminal device using a newly added Wi-Fi 6 trigger frame. The method of negotiating the mark information of N subcarrier elements is not specifically limited to this embodiment of the present application.

[0127] Based on the Wi-Fi channel characteristics, the channel-estimated amplitude values ​​and channel-estimated phase values ​​of adjacent subcarrier elements in an unmarked L-LTF sequence are nearly continuous or nearly identical. As shown in FIG. 12, the channel-estimated amplitude value of subcarrier element (50) is 0.71571, the channel-estimated amplitude value of subcarrier element (51) is 0.706, and the difference between the channel-estimated amplitude values ​​of the two subcarrier elements is very small. This is also true for the channel-estimated amplitude value of subcarrier element (49) and the channel-estimated amplitude value of subcarrier element (50). As also shown in FIG. 13, the channel-estimated phase value of subcarrier element (50) is -82.2295°, the channel-estimated phase value of subcarrier element (49) is -80.2438°, and the difference between the channel-estimated phase values ​​of the two subcarrier elements is also very small. This is also true for the channel estimation phase value of the subcarrier element (50) and the channel estimation phase value of the subcarrier element (51). Accordingly, the first device can determine an L-LTF sequence corresponding to a signal frame based on the channel estimation value.

[0128] Additionally, from FIGS. 12 and 13, it can be seen that the channel-estimated amplitude values ​​and channel-estimated phase values ​​of at least two subcarrier elements having consecutive sequence numbers are essentially the same. Accordingly, in this embodiment of the application, a subcarrier element whose sequence number is adjacent to that of the m-th subcarrier element may be a subcarrier element whose sequence number is at least one different from or nearly identical to that of the m-th subcarrier element, and whose sequence number is at least one different from that of the m-th subcarrier element. For example, a subcarrier element adjacent to subcarrier element (50) may be any subcarrier element within 48 to 52 subcarrier elements. This is not particularly limited in this embodiment of the application. It can be understood that the channel-estimated amplitude value and channel-estimated phase value of a subcarrier element whose sequence number is one different from that of the m-th subcarrier element are closest to the channel-estimated amplitude value and channel-estimated phase value of the m-th subcarrier element. For convenience of explanation, in the following embodiments, a subcarrier element whose sequence number differs by 1 from that of the m-th subcarrier element is used as an adjacent subcarrier element for explanation.

[0129] In a possible design solution when channel conditions are good, the first device can determine, based on the first channel estimate value, whether there is a suddenly changed channel estimate value in the first channel estimate value, and whether the sequence number of the subcarrier element corresponding to the suddenly changed channel estimate value is the same as the sequence numbers of N subcarrier elements. If the sequence number of the subcarrier element corresponding to the suddenly changed channel estimate value is the same as the sequence numbers of N subcarrier elements, the first device can determine that the L-LTF sequence is the target L-LTF sequence and thus can continue to receive the signal frame corresponding to the L-LTF sequence. If the sequence number of the subcarrier element corresponding to the suddenly changed channel estimate value is different from the sequence numbers of N subcarrier elements, the first device can determine that the L-LTF sequence is not the target L-LTF sequence and thus immediately stop and terminate the reception of the current signal frame, reset all receiving modules, and re-receive the wireless interface signal until the target frame is received.

[0130] Alternatively, the first device may determine sequence numbers corresponding to the sequence numbers of N subcarrier elements in an L-LTF sequence corresponding to a signal frame based on whether the first subcarrier element is a subcarrier element and whether the channel estimation value corresponding to the first subcarrier element suddenly changes from the first channel estimation value. If the channel estimation value corresponding to each subcarrier element within the first subcarrier element suddenly changes, the L-LTF sequence may be determined to be a target L-LTF, and the first device may continue to receive the signal frame corresponding to the L-LTF sequence. If the channel estimation value corresponding to each subcarrier element within the first subcarrier element does not suddenly change or changes only partially, the L-LTF sequence may be determined not to be a target L-LTF, and the first device immediately stops and terminates the reception of the current signal frame, resets all receiving modules, and re-receives the wireless interface signal until the target frame is received.

[0131] For example, the sequence numbers of the N subcarrier elements are 8, 21, 23, 28, 32, and 50, i.e., N=6, and the amplitudes of the 6 subcarrier elements are amplified twice, and the phases are rotated by 180°, i.e., And, where m=8, 21, 23, 28, 32, 50. The first device determines subcarrier elements with sequence numbers 8, 21, 23, 28, 32, 50 in an L-LTF sequence corresponding to the currently received signal frame as the first subcarrier elements, that is, the first subcarrier elements are subcarrier elements with sequence numbers {8, 21, 23, 28, 32, 50}. If the channel estimation value of the first subcarrier element in the L-LTF sequence corresponding to the currently received signal frame changes abruptly as shown in FIGS. 12 and 13, the L-LTF sequence corresponding to the signal frame can be determined to be the target L-LTF.

[0132] In another possible design solution, the first device can determine whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence by using the following steps 1 and 2.

[0133] Step 1: The first device can determine a first subcarrier element and a second subcarrier element based on the sequence numbers of N subcarrier elements, wherein the first subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the sequence number of the subcarrier element corresponds to the sequence numbers of N subcarrier elements, and the second subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the sequence number of the subcarrier element is adjacent to the sequence numbers of N subcarrier elements.

[0134] For example, the sequence numbers of the N subcarrier elements are 8, 21, 23, 28, 32, and 50, i.e., N=6, and the amplitudes of the 6 subcarrier elements are amplified twice, and the phases are rotated by 180°, i.e., And, where m=8, 21, 23, 28, 32, 50. The first device determines subcarrier elements with sequence numbers 8, 21, 23, 28, 32, and 50 in an L-LTF sequence corresponding to the currently received signal frame as first subcarrier elements, that is, the first subcarrier elements are subcarrier elements with sequence numbers {8, 21, 23, 28, 32, 50}. In addition, the first device determines subcarrier elements adjacent to sequence numbers 8, 21, 23, 28, 32, and 50 in an L-LTF sequence corresponding to the currently received signal frame as second subcarrier elements. The subcarrier elements adjacent to 8, 21, 23, 28, 32, and 50 in the L-LTF sequence corresponding to the currently received signal frame may be corresponding subcarrier elements having a previous sequence number or corresponding subcarrier elements having a next sequence number. For example, the second subcarrier element is a subcarrier element having sequence number {7, 20, 22, 27, 31, 49}, or a subcarrier element having sequence number {9, 22, 24, 29, 33, 51}, or a subcarrier element having sequence number {7, 22, 24, 27, 31, 49}. This is not particularly limited to these embodiments of the present application.

[0135] Step 2: The first device can determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value.

[0136] Where possible, the first device has each channel estimate value at the channel estimate value corresponding to the first subcarrier element It can be divided into, that is, De-marking or color-fading processing can be performed on the first subcarrier element based on amplitude and / or phase change values ​​corresponding to N subcarrier elements that can be expressed as, where m=8, 21, 23, 28, 32, 50. The first device corresponds to each subcarrier element within the first subcarrier element. By determining whether it is basically the same as the channel estimate value of each subcarrier element within the second subcarrier element, it is possible to determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence.

[0137] For example, the second subcarrier element is a subcarrier element with sequence numbers {7, 20, 22, 27, 31, 49}, and the channel estimate value of each subcarrier element within the second subcarrier element is It is expressed as, and here =7, 20, 22, 27, 31, 49. The first device is cast By comparing with, determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence.

[0138] and , and , and , and , and , and and When they are basically identical or basically match, the first device can determine that the L-LTF sequence corresponding to the current signal frame is the target L-LTF sequence.

[0139] and , and , and , and , and , and and When they partially match or are completely different, the first device can determine that the L-LTF sequence corresponding to the current signal frame is not the target L-LTF sequence.

[0140] In other possible cases, the first device may determine a second channel estimate value based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements, wherein the second channel estimate value is the following first relationship: satisfies.

[0141] When the absolute value of the second channel estimate is smaller than the first threshold, the first device can determine that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence; or

[0142] When the absolute value of the second channel estimate is greater than or equal to the first threshold, the first device can determine that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence.

[0143] When the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, and the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1≤i≤N.

[0144] For example, the sequence numbers of N subcarrier elements are 8, 21, 23, 28, 32, and 50, In this case, the first subcarrier element is a subcarrier element with sequence numbers {8, 21, 23, 28, 32, 50}, the second subcarrier element is a subcarrier element with sequence numbers {7, 20, 22, 27, 31, 49}, and 1≤i≤6. Correspondingly, is the channel estimate corresponding to the i-th subcarrier element in {8, 21, 23, 28, 32, 50}. For example, is the channel estimate corresponding to subcarrier element 8, and is the channel estimate corresponding to subcarrier factor 21, and so on. is the amplitude and / or phase change value corresponding to the i-th subcarrier element in {8, 21, 23, 28, 32, 50}. For example, is the amplitude and / or phase change value corresponding to subcarrier element 8, i.e., And; is the amplitude and / or phase change value corresponding to the subcarrier element 21, i.e., It is people, etc. represents the opposite number of the corresponding channel estimate value obtained after the i-th subcarrier element within the first subcarrier element is de-marked.

[0145] In this case, since the sequence number of the subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, = and, here is the value of the i-th subcarrier element in {7, 20, 22, 27, 31, 49}. For example, is the channel estimate corresponding to subcarrier element 7, and is the channel estimate corresponding to the subcarrier factor 20, and so on.

[0146] In the case of N subcarrier elements, it should be noted that there are subcarrier elements having consecutive sequence numbers, and in the second subcarrier element, there exist subcarrier elements having sequence numbers identical to those of the N subcarrier elements.

[0147] It can be understood that when is a value close to 0, the subcarrier element can be determined to be a marked subcarrier element. Therefore, N formulas The second channel estimated value obtained by summing must also be a value close to 0. Second channel estimated value It can be a positive value, a negative value, or a complex value.

[0148] In this case, the first device is the second channel estimated value The absolute value of, that is It is possible to obtain and set a first threshold value based on the channel state. When is less than the first threshold, the first device can determine that the L-LTF sequence corresponding to the currently received signal frame is the target L-LTF sequence. Conversely, the L-LTF sequence is not the target L-LTF sequence.

[0149] In another possible design solution, the first device may also determine whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the channel estimate value of a subcarrier element corresponding to the sequence numbers of N subcarrier elements and the amplitude and / or phase change values ​​corresponding to the N subcarrier elements in the first channel estimate value. For example, the first device may compensate the first channel estimate value and then, based on the amplitude and / or phase change values ​​corresponding to the N subcarrier elements, compare the channel estimate value of a subcarrier element having a sequence number corresponding to the sequence numbers of N subcarrier elements in the compensated first channel estimate value with the values ​​of N subcarrier elements in a known L-LTF sequence (e.g., specified in a standard or determined by the transmitter and receiver through negotiation and communication). If the difference or ratio between the two values ​​is within a threshold range, it may be determined whether the L-LTF sequence corresponding to the current signal frame is a target L-LTF sequence. That is, the first device can identify whether the current signal is a target frame by comparing the compensated channel estimate value of a subcarrier element having a sequence number corresponding to the sequence numbers of the N subcarrier elements, based on amplitude and / or phase change values ​​corresponding to the N subcarrier elements, with the values ​​of the N subcarrier elements in an L-LTF sequence corresponding to a signal frame transmitted by the second device.

[0150] When channel conditions are poor or the signal-to-noise ratio is low, based on determining a second channel estimate value, the first device may further determine a third channel estimate value based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase fluctuation values ​​corresponding to N subcarrier elements, wherein the third channel estimate value is the following third relationship: It should be noted that it satisfies the third channel estimate value. It can be understood that the signal identification reliability and accuracy can be further improved by de-marking the subcarrier element considered to be marked in the L-LTF sequence corresponding to the current signal frame, obtaining the original channel estimate value of the marked subcarrier element, and adding and summing the original channel estimate value and the channel estimate value of the adjacent subcarrier element.

[0151] When the L-LTF sequence corresponding to the current signal frame is the target L-LTF sequence, It can be understood that it needs to be the sum of two values ​​with the same phases and the same amplitudes. Accordingly, the first device can determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence based on the second channel estimate value and the third channel estimate value.

[0152] For example, the absolute value of the third channel estimate The absolute value of the second channel estimate for The ratio of When it is smaller than this second threshold, the first device can determine that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence. Conversely, when the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is greater than or equal to the second threshold, the first device can determine that the L-LTF sequence corresponding to the signal frame is not the target L-LTF sequence.

[0153] The second threshold is a threshold greater than 0 and less than 1. The value of the second threshold may be set based on channel state, device computing capability, application scenario, etc. This is not particularly limited in these embodiments of the present application.

[0154] Based on the aforementioned steps S801 to S804, when it is determined that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence, the first device determines the signal frame as the target frame and can continue to receive the signal frame. Conversely, when it is determined that the L-LTF sequence corresponding to the signal frame is not the target L-LTF sequence, the first device determines that the signal frame is a non-target frame, immediately stops and terminates the reception of the current signal frame, resets all receiving modules, and can re-receive the wireless interface signal. In this case, if the target frame overlaps with the non-target frame, the signal frame on the wireless interface can be re-received in a timely manner so that the target frame can be quickly captured, the omission of the target frame can be avoided, and thereby the target frame can be quickly synchronized for reception.

[0155] It should be noted that when the receiving end consists of multiple antennas, each receiving antenna can identify a signal based on the relevant descriptions in S803 and S804, and an "or" operation may be performed on the identification result of each receiving antenna to determine whether a target signal is received. That is, if one antenna determines the target signal, the receiving end may represent the signal as the target signal.

[0156] Based on the signal identification method illustrated in FIG. 8, the second device can identify a method for marking the amplitude and / or phase change of a subcarrier element in an L-LTF sequence, so that the first device can identify a method for marking a subcarrier element in an L-LTF sequence corresponding to a currently received signal frame based on the mark information of the subcarrier element in the target L-LTF sequence, and can identify whether the current L-LTF sequence is a target L-LTF sequence marked by a target device with a specific mark method, thereby identifying whether the current signal frame is a target frame more quickly or earlier. In the case of signal overlap, the reception of a non-target frame is terminated in a timely manner, and the reception of a target frame is restarted in advance, so that the signal packet loss rate can be reduced and signal reception reliability can be improved.

[0157] Hereinafter, the signal identification method provided in the embodiments of the present application is described in detail with reference to application scenarios.

[0158] For example, the signal identification method provided in the embodiments of the present application can be applied to the diagram of the intra-frequency cell placement scenario illustrated in FIG. 14 and can be used to identify signals in intra-frequency cells. As illustrated in FIG. 14, in this scenario, four channels, namely channels 1 through 4, are arranged based on Wi-Fi. Cells of the same frequency use the same channel for transmission. There are four intra-frequency cells using the same channel. Each intra-frequency cell corresponds to one AP. For example, intra-frequency cells using channel 1 include cells 1 through 4 and correspond to APs 1 through 4. Cells of different frequencies do not affect each other. For example, signals transmitted by cells using channels 2 through 4 do not affect signals transmitted by cells using channel 1.

[0159] The first device is STA 1 in cell 1, and the second device is AP 1 in cell 1. In the process of transmitting a signal to STA 1, AP 1 receives a signal transmitted by the AP or STA in any one of cells 2 to 4, and a MIM is formed sequentially. In this case, STA 1 can distinguish signals from different intra-frequency cells by identifying an L-LTF sequence corresponding to the received signal frame and determining whether the signal frame is from AP 1.

[0160] For example, a 20 MHz bandwidth is used as an example. APs (APs 1 to 4) to which cells 1 to 4 belong transmit signals using L[1, 64] in S801 as an L-LTF sequence. For the same L-LTF sequence, APs 1 to 4 are marked using the subcarrier elements presented in Table 1. Each AP is selected to mark six subcarrier elements in L[1, 64], the sequence numbers of the selected six subcarrier elements are discontinuous, and the sequence numbers of the subcarrier elements selected and marked among the four APs do not overlap. For example, AP 1 selects a subcarrier element with sequence numbers {8, 21, 23, 28, 32, 50} from L[1, 64] for marking, and AP 2 selects a subcarrier element with sequence numbers {13, 15, 25, 42, 44, 58} from L[1, 64] for marking.

[0161] In addition, APs 1 through 4 all use the same marking scheme to mark the selected subcarrier element. For example, the marking scheme is one in which the amplitude is amplified twice and the phase is rotated by 180°, i.e., is. For AP 1, the value of m is 8, 21, 23, 28, 32, or 50. In this case, N=6, and the mark information of the N subcarrier elements is the sequence numbers of the 6 subcarrier elements {8, 21, 23, 28, 32, 50} and the amplitude and / or phase change values ​​of the 6 subcarrier elements. It may include.

[0162]

[0163] Since the L-LTF sequence L[1, 64] contains 64 subcarrier elements, it can be understood that when each AP selects the same number of subcarrier elements for marking, it is necessary to consider whether the number of intra-frequency cells at the frequency to which the AP belongs and the sequence numbers of the subcarrier elements selected by different APs overlap so that the number of selected subcarrier elements satisfies the requirements.

[0164] When AP 1 transmits a signal frame to STA 1, AP 1 needs to perform marking processing on the subcarrier element with sequence number {8, 21, 23, 28, 32, 50} in the L-LTF sequence by amplifying the amplitude twice and rotating the phase 180°, and then transmit the signal frame formed by the marked L-LTF sequence, i.e., the target frame, to STA 1. The subcarrier element with sequence number {8, 21, 23, 28, 32, 50} may be referred to as the target subcarrier element.

[0165] Additionally, STA 1 can parse a currently received signal frame to obtain an L-LTF sequence corresponding to the current signal frame, perform channel estimation using the L-LTF sequence obtained through parsing to obtain a first channel estimation value, and determine whether the marked subcarrier element is a subcarrier element with sequence numbers {8, 21, 23, 28, 32, 50} based on the mark information of the six subcarrier elements of AP 1 and the first channel estimation value.

[0166] When channel conditions are good, if possible, STA 1 can determine, based on the first channel estimate value, whether there is a suddenly changed channel estimate value in the first channel estimate value, and whether the sequence number of the subcarrier element corresponding to the suddenly changed channel estimate value is the sequence number of the target subcarrier element. If the sequence number of the subcarrier element corresponding to the suddenly changed channel estimate value is the sequence number of the target subcarrier element, for example, if the suddenly changed channel estimate value in the first channel estimate value is illustrated in FIG. 12 and FIG. 13, STA 1 can determine that the L-LTF sequence corresponding to the current signal frame is the target L-LTF sequence. If the sequence number of a subcarrier element corresponding to a suddenly changed channel estimate value is not the sequence number of a target subcarrier element, for example, STA 1 determines that the sequence number of a subcarrier element corresponding to a suddenly changed channel estimate value in the first channel estimate value is {13, 15, 25, 42, 44, 58} and does not match a subcarrier element with sequence number {8, 21, 23, 28, 32, 50}, and STA 1 may determine that the L-LTF sequence corresponding to the current signal frame is not the target L-LTF sequence.

[0167] Additionally, when STA 1 determines that the sequence number of a subcarrier element corresponding to a suddenly changed channel estimate value is a target subcarrier element, STA 1 may further subdivide the suddenly changed channel estimate value into the amplitude and / or phase change values ​​of the target subcarrier element to obtain an unmarked channel estimate value, compare the channel estimate value with the channel estimate value of a subcarrier element adjacent to the channel estimate value, for example, the channel estimate value of a subcarrier element with sequence numbers {7, 20, 22, 27, 31, 49}, and determine whether the obtained unmarked channel estimate value matches the channel estimate value of the adjacent subcarrier element. For specific identification processes, refer to the relevant descriptions in step S803. Details are not described again herein.

[0168] In other possible cases, STA 1, based on the sequence number of the target subcarrier element, provides a first channel estimate for the channel estimate of a subcarrier element whose sequence number is identical to that of the target subcarrier element (i.e., the channel estimate corresponding to the first subcarrier element), for example, { , , , , , and }, and the channel estimate of a subcarrier element whose sequence number is adjacent to that of the target subcarrier element (i.e., the channel estimate corresponding to the second subcarrier element), for example, { , , , , , and } can be searched. Then, the value obtained by dividing the channel estimate of the subcarrier element having the sequence number of the target subcarrier element by the amplitude and / or phase change value of the target subcarrier element is individually compared with the channel estimate of the subcarrier element whose sequence number is adjacent to that of the target subcarrier element as follows:

[0169] , , , , , and and, here

[0170] = = = = And, the L-LTF sequence corresponding to the current signal frame can be determined to be the target L-LTF sequence.

[0171] Conversely, STA 1 can determine that the L-LTF sequence corresponding to the current signal frame is not the target L-LTF sequence.

[0172] In another possible case, STA 1 provides a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and a second channel estimate value based on the amplitude and / or phase change value of a target subcarrier element, e.g., can decide.

[0173] When the L-LTF sequence corresponding to the current signal frame is the target L-LTF sequence, that is, when the subcarrier element with sequence numbers {8, 21, 23, 28, 32, 50} in the L-LTF sequence corresponding to the current signal frame is the target subcarrier element, the second channel estimate value It can be understood that... Otherwise, if the signal frame currently received by STA 1 is a signal frame transmitted by AP 2, the second channel estimated value is changed to the sum of co-directional amplitudes, and the second channel estimated value is greater than 0.

[0174] In addition, STA 1 is the second channel estimate value You can obtain the absolute value of; When is less than the first threshold, it is determined that the L-LTF sequence corresponding to the current signal frame is the target L-LTF sequence. Conversely, STA 1 may determine that the L-LTF sequence corresponding to the current signal frame is not the target L-LTF sequence. For specific identification processes, refer to the relevant descriptions in steps S803 and S804. Details are not described again herein.

[0175] In another possible case, for example, when determining a second channel estimate value when channel conditions are poor or the signal-to-noise ratio is low, STA 1 determines a third channel estimate value, for example, based on the channel estimate value corresponding to the first subcarrier element, the channel estimate value corresponding to the second subcarrier element, and the amplitude and / or phase change value of the target subcarrier element. You can additionally decide on .

[0176] If the subcarrier elements with sequence numbers {8, 21, 23, 28, 32, 50} in the L-LTF sequence corresponding to the current signal frame are the target subcarrier elements, the third channel estimate value It can be understood that it needs to be twice the sum of positive amplitudes, for example, the sum of channel estimates corresponding to subcarrier elements with sequence numbers {7, 20, 22, 27, 31, 49}. Conversely, if the signal frame currently received by STA 1 is a signal frame transmitted by AP 2, the third channel estimate It is changed to half the sum of channel estimates corresponding to subcarrier elements with sequence numbers {7, 20, 22, 27, 31, 49}, for reverse amplitude cancellation.

[0177] In addition, STA 1 can perform a decision by combining the second channel estimate and the third channel estimate. For example, STA 1 is the absolute value of the third channel estimate The absolute value of the second channel estimate for The ratio of Makes decisions based on When is smaller than the second threshold and the value of the second threshold is [0, 1], STA 1 can determine that the L-LTF sequence corresponding to the current signal frame is the target L-LTF sequence. Conversely, When is greater than the second threshold, STA 1 may determine that the L-LTF sequence corresponding to the current signal frame is not the target L-LTF sequence. For specific identification processes, refer to the relevant descriptions in steps S803 and S804. Details are not described again herein.

[0178] Based on any one of the aforementioned decision processes, STA 1 may determine whether the current signal frame is a target frame based on determining whether the L-LTF sequence corresponding to the current signal frame is a target L-LTF sequence, and thus may determine whether to continue receiving the current signal frame. For example, when STA 1 determines that the L-LTF sequence corresponding to the current signal frame is not a target L-LTF sequence, STA 1 immediately stops receiving the current signal frame, recaptures the wireless interface, and synchronizes the signal frame of AP 1.

[0179] It can also be understood that STA 1 can identify a signal frame transmitted by any one of APs 2 to 4 or STAs 2 to 4 based on the aforementioned identification process, and that APs 2 to 4 or STAs 2 to 4 can also identify a target signal based on the aforementioned identification process. Details are not described in these embodiments of the application.

[0180] It should be noted that the sequence numbers of the subcarrier elements selected for different APs for marking presented in Table 1 do not overlap with each other. To distinguish signals from more cells, subcarrier elements having some overlapping sequence numbers may be selected for different APs for marking. As presented in Table 2 below, each of the subcarrier elements used by AP 1 and AP 2 for marking includes a subcarrier element (28), each of the subcarrier elements used by AP 2 and AP 3 for marking includes subcarrier elements (17, 37, and 52), and each of the subcarrier elements used by AP 3 and AP 4 for marking includes subcarrier elements (10 and 39).

[0181]

[0182] To distinguish signals from more cells, different APs may select different quantities of subcarrier elements for marking. As shown in Table 3 below, the quantity of subcarrier elements used by AP 1 for marking is 3, the quantity of subcarrier elements used by AP 2 for marking is 4, the quantity of subcarrier elements used by AP 3 for marking is 6, and the quantity of subcarrier elements used by AP 4 for marking is 5.

[0183]

[0184] Furthermore, misidentification may occur when different APs use the same marking scheme and a large number of subcarrier elements with overlapping sequence numbers. In this case, different APs can mark the subcarrier elements using different marking schemes, which results in a higher degree of signal identification, avoids misjudgment, and allows for the differentiation of more users. For example, the method by which AP 1 marks the subcarrier elements presented in Table 1, Table 2, or Table 3 is And, the method by which AP 2 marks the subcarrier elements presented in Table 1, Table 2, or Table 3 is And, the method by which AP 3 marks the subcarrier elements presented in Table 1, Table 2, or Table 3 is And, the method by which AP 4 marks a subcarrier element having a sequence number presented in Table 1, Table 2, or Table 3 is In addition, for any AP, different marking schemes may also be used for all selected subcarrier elements, or the same marking scheme may be used for some subcarrier elements. This is not particularly limited to these embodiments of the present application.

[0185] In the scenario illustrated in Fig. 14, APs to which different cells belong may use different specific mark schemes for the L-LTF sequence, so that the STA can distinguish signals from different cells based on the mark schemes corresponding to the target signals.

[0186] The signal identification method provided in this embodiment of the present application may also be applied to the scenario illustrated in FIG. 15 and may be used to distinguish signals transmitted by different users within the same cell. As illustrated in FIG. 15, the cell to which AP 1 belongs contains four different user devices STA 1 through STA 4. Since the problem of signal collision also exists when user devices within the same cell transmit signals, different users may also use different marking schemes for L-LTF sequences to distinguish the signals. For specific marking schemes, refer to the marking schemes of AP 1 through AP 4 in the scenario of FIG. 13. Details are not described further herein.

[0187] For example, STA 1 and STA 2 are the hidden nodes described in the scenario of FIG. 2. Thus, when STA 2 transmits a signal to AP 1, STA 1 determines that the channel is idle and therefore transmits a signal to AP 1, causing signal overlap. If the importance factor of the data transmitted by STA 1 at the current moment is higher, AP 1 can identify the currently received signal based on the mark information used by STA 1. For a specific signal identification process, refer to the relevant descriptions in S802 and S803, or the relevant descriptions for STA 1 identifying the signal transmitted by AP 1 in the scenario illustrated in FIG. 13. Details are not described again herein.

[0188] As another example, the signal identification method provided in this embodiment of the present application may be additionally applied to the scenario illustrated in FIG. 16. As illustrated in FIG. 16, Cell 1, to which AP 1 belongs, and Cell 2, to which AP 2 belongs, are intra-frequency cells, and the two cells are separated by a specific distance. When the RSSI between AP 1 and AP 2 is greater than the ED / CS threshold, AP 1 and AP 2 can listen to each other. However, because there is a specific distance between AP 1 and AP 2, the strength of the signal transmitted by AP 1 and detected by STA 1 is much stronger than the strength of the signal transmitted by AP 2 and detected by STA 1. Therefore, in this case, when signal overlap occurs, STA 1 can parse the signal transmitted by AP 1; when AP 1 transmits a signal to STA 1, AP 2 can also transmit a signal to STA 2, and the parsing of the signals does not affect each other.

[0189] However, in this case, when AP 2 transmits a signal to STA 2 first, AP 1 can detect through sensing that AP 2 is transmitting a signal; therefore, AP 1 determines that the channel is in use when sensing the channel, and thus AP 1 is backed off and transmits the signal after AP 2 has completed transmitting the signal. As illustrated in FIG. 17, the signal from Cell 1 and the signal from Cell 2 are transmitted alternately. In this case, only one AP transmits the signal at a time, which significantly reduces wireless interface utilization.

[0190] Accordingly, AP 1 and AP 2 may also mark L-LTF sequences using different marking methods. For specific marking methods, refer to the marking methods of AP 1 through AP 4 in the scenario of FIG. 13. Details are not described further in this specification. Accordingly, when receiving a signal transmitted by AP 2, AP 1 can identify the L-LTF sequence corresponding to the signal transmitted by AP 2 and determine whether the current signal is a signal from the cell (Cell 1) where AP 1 is located. If the current signal is not a signal from the cell where AP 1 is located, AP 1 can determine that the channel is idle and can transmit the signal without waiting for backoff. As illustrated in FIG. 18, the signal from Cell 1 and the signal from Cell 2 can be transmitted in parallel, that is, AP 2 can transmit the signal to STA 2, and AP 1 can also transmit the signal to STA 1. Similarly, STA 1 and AP 2 can also determine whether signals can be transmitted by detecting whether the current signals are signals transmitted from the cells where STA 1 and AP 2 are located. For specific signal identification processes, refer to the relevant descriptions in S803 and S804, or the relevant descriptions for STA 1 identifying signals transmitted by AP 1 in the scenario illustrated in FIG. 13. Details are not described again herein.

[0191] In the scenario illustrated in Fig. 16, it should be noted that after parsing the L-LTF, the receiver can determine whether the channel is idle, and then the receiver can start transmitting data.

[0192] In the scenario illustrated in FIG. 16, the signal identification method provided in this embodiment of the present application is used to form a smarter channel usage / idle state detection, and the problem that different intra-frequency cells cannot perform parallel data transmission due to a misjudgment that a channel is in use caused by clear channel assessment (CCA) can be avoided, and spectrum utilization can be improved.

[0193] In the embodiments described above, it can be understood that the methods and / or steps implemented by the first device may also be implemented by a component that can be used in the first device (e.g., a processor, a chip, a chip system, a circuit, a logic module, or software), and the methods and / or steps implemented by the second device may also be implemented by a component that can be used in the second device (e.g., a processor, a chip, a chip system, a circuit, a logic module, or software).

[0194] The foregoing primarily describes the solutions provided in this application. Correspondingly, this application further provides a communication device. The communication device is configured to implement the methods in the foregoing method embodiments. The communication device may be a first device in the method embodiments, a device comprising the first device, or a component that can be used in the first device, e.g., a chip or a chip system. Alternatively, the communication device may be a second device in the method embodiments, a device comprising the second device, or a component that can be used in the second device, e.g., a chip or a chip system.

[0195] It can be understood that, in order to implement the aforementioned functions, the communication device includes a corresponding hardware structure and / or software module for performing each function. A person skilled in the art should readily recognize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application may be implemented by hardware or a combination of hardware and computer software. Whether a function is performed by hardware or by hardware driven by computer software depends on the specific applications and design constraints of the technical solutions. A person skilled in the art may use different methods to implement the functions described for each specific application, but such implementation should not be considered to be outside the scope of the present application.

[0196] In the embodiments of the present application, division into functional modules may be performed on a communication device based on the aforementioned method embodiments. For example, each functional module may be obtained through division based on each corresponding function, or two or more functions may be integrated into a single processing module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. It should be noted that in the embodiments of the present application, the division into modules is an example and is merely a logical functional division. During actual implementation, another division method may be used.

[0197] For example, the communication device is a terminal device or a network device in the aforementioned method embodiments. FIG. 19 is a diagram of the structure of a communication device according to an embodiment of the present application. As shown in FIG. 19, the communication device (1900) includes a processing module (1901) and a transceiver module (1902).

[0198] For example, the communication device (1900) is the first device in the above-described method embodiments.

[0199] The transceiver module (1902) is configured to receive a signal frame;

[0200] The processing module (1901) is configured to perform channel estimation based on a legacy long training field (L-LTF) sequence corresponding to a signal frame to obtain a first channel estimation value, and the first channel estimation value includes channel estimation values ​​corresponding to M subcarrier elements in the L-LTF sequence corresponding to the signal frame;

[0201] The processing module (1901) is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a first channel estimate value and mark information of N subcarrier elements, wherein the mark information of N subcarrier elements includes sequence numbers of N subcarrier elements and amplitude and / or phase change values ​​corresponding to N subcarrier elements, and M and N are positive integers, M>1, and 1≤N≤M.

[0202] In a possible design solution, the processing module (1901) is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element and amplitude and / or phase change values ​​corresponding to N subcarrier elements, wherein the first subcarrier element is a subcarrier element in the L-LTF sequence corresponding to the signal frame, and the subcarrier element sequence number corresponds to the sequence numbers of N subcarrier elements.

[0203] In another possible design solution, the processing module (1901) is:

[0204] A first subcarrier element and a second subcarrier element are determined based on the sequence numbers of N subcarrier elements— the first subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the sequence number of the subcarrier element corresponds to the sequence numbers of N subcarrier elements, and the second subcarrier element is a subcarrier element in an L-LTF sequence corresponding to a signal frame, and the sequence number of the subcarrier element is adjacent to the sequence numbers of N subcarrier elements—;

[0205] It is further configured to determine whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimate value.

[0206] In a possible design solution, the processing module (1901) is:

[0207] A second channel estimation value is further configured to be determined based on a channel estimation value corresponding to a first subcarrier element, a channel estimation value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements, and the second channel estimation value is further configured to satisfy the following first relationship: , here,

[0208] When the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, and the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1 ≤ i ≤ N;

[0209] When the absolute value of the second channel estimate is smaller than the first threshold, it is determined that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence; or

[0210] When the absolute value of the second channel estimate is greater than or equal to the first threshold, it is determined that the L-LTF sequence corresponding to the signal frame is not the target L-LTF sequence.

[0211] In another possible design solution, the processing module (1901) is:

[0212] The second channel estimate value and the third channel estimate value are further configured to determine based on a channel estimate value corresponding to a first subcarrier element, a channel estimate value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements, and the second channel estimate value is the following second relationship: Satisfies; the third channel estimate is the following third relationship: Satisfies, and here

[0213] When the sequence number of the i-th subcarrier element in the second subcarrier element is different from the sequence number of the subcarrier element in the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element in the second subcarrier element is the same as the sequence number of the subcarrier element in the N subcarrier elements, and, here is the second channel estimate, and is the third channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and is an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1 ≤ i ≤ N;

[0214] Based on the second channel estimate value and the third channel estimate value, it is further configured to determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence.

[0215] In a possible design solution, the processing module (1901) is:

[0216] When the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is less than the second threshold, it is determined that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence; or

[0217] It is further configured to determine that the L-LTF sequence corresponding to the signal frame is not the target L-LTF sequence when the ratio of the absolute value of the second channel estimate to the absolute value of the third channel estimate is greater than or equal to the second threshold.

[0218] For example, the communication device (1900) is the second device in the above-described method embodiments.

[0219] The processing module (1901) is configured to mark the amplitudes and / or phases of N subcarrier elements in a legacy long training field (L-LTF) sequence corresponding to a signal frame, wherein the L-LTF sequence corresponding to the signal frame includes M subcarrier elements, M and N are positive integers, M>1, and 1≤N≤M;

[0220] The transceiver module (1902) is configured to transmit a signal frame to the first device.

[0221] In a possible design solution, when N subcarrier elements include subcarriers having consecutive sequence numbers, the amplitude and phase change values ​​of subcarrier elements having adjacent sequence numbers are different.

[0222] Optionally, in this embodiment of the application, the transceiver module (1902) may include a receiving module and a transmitting module (not shown in FIG. 19). The transceiver module is configured to implement the transmitting and receiving functions of the communication device (1900).

[0223] Optionally, the communication device (1900) may further include a storage module (not shown in FIG. 19). The storage module stores programs or instructions. When the processing module (1901) executes the programs or instructions, the communication device (1900) may perform the function of the first device or the second device in the method shown in FIG. 8.

[0224] It should be understood that the processing module (1901) in the communication device (1900) may be implemented by a processor or a processor-related circuit component and may be a processor or a processing unit. The transceiver module (1902) may be implemented by a transceiver or a transceiver-related circuit component and may be a transceiver or a transceiver unit.

[0225] All relevant details of the steps in the aforementioned method embodiments may be cited in the functional descriptions of the corresponding functional modules. Details are not described again in this specification.

[0226] Since the communication device (1900) provided in these embodiments can perform the aforementioned signal identification method, for the technical effects that can be achieved by the communication device (1900), refer to the aforementioned method embodiments. Details are not described again in this specification.

[0227] For example, FIG. 20 is a diagram of the structure of another communication device according to an embodiment of the present application. The communication device may be a first device or a second device, or a chip (system) or other part or component that may be placed on the first device or the second device. As illustrated in FIG. 20, the communication device (2000) may include a processor (2001). Optionally, the communication device (2000) may further include a memory (2002) and / or a transceiver (2003). The processor (2001) is coupled to the memory (2002) and the transceiver (2003) and may be connected to the memory (2002) and the transceiver (2003), for example, via a communication bus.

[0228] Below, each component of the communication device (2000) will be described in detail with reference to FIG. 20.

[0229] The processor (2001) is the control center of the communication device (2000) and may be a single processor or a collective term for a plurality of processing elements. For example, the processor (2001) may be one or more central processing units (CPUs), application-specific integrated circuits (ASICs), or one or more integrated circuits configured to implement embodiments of the present application, for example, one or more digital signal processors (DSPs) or one or more field programmable gate arrays (FPGAs).

[0230] Optionally, the processor (2001) can perform various functions of the communication device (2000) by operating or executing a software program stored in memory (2002) and calling data stored in memory (2002).

[0231] During a specific implementation, in an embodiment, the processor (2001) may include one or more CPUs, for example, CPU 0 and CPU 1 as shown in FIG. 20.

[0232] During a specific implementation, in an embodiment, the communication device (2000) may also include a plurality of processors, for example, the processor (2001) and the processor (2004) shown in FIG. 20. Each of the processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). Here, the processor may be one or more devices, circuits and / or processing cores configured to process data (e.g., computer program instructions).

[0233] Memory (2002) is configured to store a software program for executing the solutions of the present application, and a processor (2001) controls the execution of the software program. For specific implementations, refer to the method embodiments described above. Details are not described again in this specification.

[0234] Optionally, the memory (2002) may be read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically eraseable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other compact disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital multifunction discs, Blu-ray discs, etc.), magnetic disc storage media or other magnetic storage devices, or any other medium that can be used to carry or store program code expected in the form of instructions or data structures and can be accessed by a computer. However, this is not limited thereto. The memory (2002) may be integrated with the processor (2001), may exist independently, or is coupled to the processor (2001) through an interface circuit (not shown in FIG. 20) of the communication device (2000). This is not particularly limited in this embodiment of the application.

[0235] The transceiver (2003) is configured to communicate with another communication device. For example, the communication device (2000) is a terminal device, and the transceiver (2003) may be configured to communicate with a network device or with another terminal device. As another example, the communication device (2000) is a network device, and the transceiver (2003) may be configured to communicate with a terminal device or with another network device.

[0236] Optionally, the transceiver (2003) may include a receiver and a transmitter (not individually shown in FIG. 20). The receiver is configured to implement a receiving function, and the transmitter is configured to implement a transmitting function.

[0237] Optionally, the transceiver (2003) may be integrated with the processor (2001), may exist independently, or may be coupled to the processor (2001) through an interface circuit (not shown in FIG. 20) of the communication device (2000). This is not particularly limited to this embodiment of the application.

[0238] Optionally, the processor (2001) is configured primarily to: process communication protocols and communication data, control the entire communication device, execute software programs, and process data of the software programs. The memory (2002) is configured primarily to store software programs and data. The transceiver (2003) may include a radio frequency circuit and an antenna. The radio frequency circuit is configured primarily to: perform conversion between baseband signals and radio frequency signals, and process radio frequency signals. The antenna is configured primarily to receive and transmit radio frequency signals in the form of electromagnetic waves. Input / output devices, e.g., a touchscreen, a display, or a keyboard, are configured primarily to: receive data entered by the user and output data to the user.

[0239] The processor (2001), transceiver (2003), and memory (2002) can be connected via a communication bus.

[0240] After the communication device is powered on, the processor (2001) can read the software program from the memory (2002), interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor (2001) performs baseband processing on the data to be transmitted and then outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal in the form of electromagnetic waves through the antenna. When data is transmitted to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor (2001). The processor (2001) converts the baseband signal into data and processes this data.

[0241] In another implementation, the radio frequency circuit and antenna may be deployed independently of the processor performing baseband processing. For example, in a distributed scenario, the radio frequency circuit and antenna may be deployed remotely, independently of the communication device.

[0242] The processor (2001) may be configured to perform baseband-related processing, for example, but not limited thereto; and the transceiver (2003) may be configured to perform radio frequency transmission or reception, for example, but not limited thereto. The aforementioned components may be placed individually on independent chips, or at least some or all of the components may be placed on the same chip. For example, the processor may be divided into an analog baseband processor and a digital baseband processor. The analog baseband processor and the transceiver may be integrated on the same chip, and the digital baseband processor may be placed on an independent chip. With the continuous development of integrated circuit technologies, an increasing number of components may be integrated on the same chip. For example, the digital baseband processor may be integrated on the same chip with multiple application processors (e.g., geometric processors and multimedia processors, but not limited thereto). The chip may be referred to as a system-on-chip. Whether components are placed independently on different chips or on one or more chips in an integrated manner generally depends on specific requirements of the product design. Specific implementation forms of the components are not limited in the embodiments of the present invention.

[0243] It should be noted that the structure of the communication device (2000) illustrated in FIG. 20 does not constitute a limitation on the communication device. The actual communication device may include more or fewer components than those illustrated in the drawing, combine some components, or have different arrangements of components.

[0244] Additionally, regarding the technical effects of the communication device (2000), reference is made to the technical effects of the communication method in the aforementioned method embodiments. Details are not described further in this specification.

[0245] An embodiment of the present application provides a communication system. The communication system includes the aforementioned first device and the aforementioned second device.

[0246] In some embodiments, the present application further provides a communication device. The communication device includes a processor configured to implement the method in any one of the aforementioned method embodiments.

[0247] In a possible implementation, the communication device further includes memory. The memory is configured to store necessary computer programs and data. The computer program may include instructions. A processor may call instructions from a computer program stored in memory and instruct the communication device to perform a method in any one of the aforementioned method embodiments. Of course, the communication device may not include memory.

[0248] In another possible implementation, the communication device further includes an interface circuit. The interface circuit is a code / data read / write interface circuit, and the interface circuit is configured to receive computer-executable instructions (computer-executable instructions may be stored in memory and read directly from memory or read through other components) and transmit computer-executable instructions to a processor.

[0249] In another possible implementation, the communication device further includes a communication interface, and the communication interface is configured to communicate with a module other than the communication device.

[0250] It can be understood that a communication device may be a chip or a chip system. When the communication device is a chip system, the communication device may include a chip or may include a chip and other individual components. This is not specifically limited in the embodiments of the present application.

[0251] The present application further provides a computer-readable storage medium. The computer-readable storage medium stores computer programs or instructions; and when the computer programs or instructions are executed by a computer, functions in any one of the aforementioned method embodiments are implemented.

[0252] The present application further provides a computer program product. When the computer program product is executed by a computer, the functions in any one of the aforementioned method embodiments are implemented.

[0253] A person skilled in the art will understand that, for the sake of convenience and simplicity of explanation, the detailed working processes of the aforementioned systems, devices, and units refer to the corresponding processes in the aforementioned method embodiments. Details are not described further in this specification.

[0254] It should be understood that in this specification, the term “and / or” describes only an association between associated objects and indicates that three relationships may exist. For example, A and / or B may represent the following three cases: where only A exists, where both A and B exist, and where only B exists, wherein A and B may be singular or plural. Additionally, the character “ / ” in this specification generally indicates an “or” relationship between associated objects, but may also indicate an “and / or” relationship. For details, refer to the context for understanding.

[0255] In this application, "at least one" means one or more, and "plural" means two or more. "At least one of the following items (fragments)" or similar expressions thereof means any combination of these items including any combination of singular items (fragments) or plural items (fragments). For example, at least one item (fragment) of a, b, or c may represent a, b, c, a and b, a and c, b and c, or a, b, and c, wherein a, b, and c may be singular or plural.

[0256] It should be understood that the sequence numbers of the aforementioned processes do not imply execution orders in the various embodiments of this application. Execution orders of the processes should be determined based on the functions and internal logic of the processes and should not be interpreted as any limitation on the implementation processes of the embodiments of this application.

[0257] It is understood that the systems, devices, and methods described in this application may be implemented in alternative ways. For example, the described device embodiments are merely examples. For example, the division into units is merely a logical functional division and may be different during actual implementation. For example, multiple units or components may be combined or integrated into other systems, or some features may be ignored or not performed. Additionally, the mutual couplings or direct couplings or communication connections shown or discussed may be implemented through some interfaces. Indirect couplings or communication connections between devices or units may be implemented electrically, mechanically, or in other forms.

[0258] The units described as separate parts may or may not be physically separate, and may be located in a single location or distributed across multiple network units. The parts indicated as units may or may not be physical units. Some or all of the units may be selected based on actual requirements to achieve the purposes of the solutions of the embodiments.

[0259] In addition, the functional units in the embodiments of the present application may be integrated into a single processing unit, or each of the units may exist physically alone, or two or more units may be integrated into a single unit.

[0260] All or part of the foregoing embodiments may be implemented by software, hardware, firmware, or any combination thereof. When a software program is used to implement the embodiments, the embodiments may be implemented wholly or partially in the form of a computer program product. A computer program product comprises one or more computer instructions. When computer program instructions are loaded and executed on a computer, the procedures or functions according to the embodiments of the present application are created wholly or partially. Such a computer may be a general-purpose computer, a dedicated computer, a computer network, or other programmable device. Computer instructions may be stored on a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave). A computer-readable storage medium may be any available medium accessible by a computer, or a data storage device such as a server or data center that incorporates one or more available media. Available media may be magnetic media (e.g., floppy disk, hard disk, or magnetic tape), optical media (e.g., DVD), semiconductor media (e.g., solid state disk (SSD)), etc. In embodiments of the present application, the computer may include the aforementioned devices.

[0261] Although this application has been described with reference to the embodiments, a person skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the attached drawings, the disclosed content, and the appended claims in the process of implementing this application claiming protection. In the claims, "comprising" does not exclude other components or other steps, and "a" or "one" does not exclude multiple cases. A single processor or another unit may implement the various functions listed in the claims. Some measures are described in different dependent claims, but this does not mean that these measures cannot be combined to produce a better effect.

[0262] Although this application has been described with reference to specific features and embodiments thereof, it is evident that various modifications and combinations thereof may be made without departing from the scope of this application. Accordingly, the specification and the accompanying drawings are merely exemplary descriptions of this application as defined by the appended claims and are to be considered as any or all of the modifications, variations, combinations, or equivalents covering the scope of this application. It is evident that a person skilled in the art may make various modifications and variations to this application without departing from the spirit and scope of this application. In such cases, this application is intended to cover such modifications and variations of this application, provided that they fall within the scope of protection defined by the claims of this application and their equivalents.

Claims

Claim 1 As a signal identification method, the method comprises the steps of: receiving a signal frame by a first device; performing channel estimation by the first device based on a legacy long training field sequence (L-LTF sequence) corresponding to the signal frame to obtain a first channel estimation value, wherein the first channel estimation value includes channel estimation values ​​corresponding to M subcarrier elements in the L-LTF sequence corresponding to the signal frame. and, by the first device, a step of determining whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the first channel estimation value and the mark information of N subcarrier elements—the mark information of the N subcarrier elements includes the sequence numbers of the N subcarrier elements and amplitude and / or phase change values ​​corresponding to the N subcarrier elements, wherein M and N are positive integers, M > 1, and 1 ≤ N ≤ M—and, by the first device, a step of determining whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the first channel estimation value and the mark information of N subcarrier elements, wherein the first device determines a first subcarrier element and a second subcarrier element based on the sequence numbers of the N subcarrier elements—the first subcarrier element is a subcarrier element in the L-LTF sequence corresponding to the signal frame, and the subcarrier element sequence number corresponds to the sequence numbers of the N subcarrier elements, and the second The subcarrier element is a subcarrier element in the L-LTF sequence corresponding to the signal frame, and the subcarrier element sequence number is adjacent to the sequence numbers of the N subcarrier elements.A method comprising the step of determining whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on a channel estimation value corresponding to a first subcarrier element, a channel estimation value corresponding to a second subcarrier element, and amplitude and / or phase change values ​​corresponding to N subcarrier elements in the first channel estimation value, by the first device. Claim 2 delete Claim 3 In claim 1, the step of determining whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence based on the first device, the first device, the first device, the first device, the channel estimate value corresponding to the first subcarrier element, the channel estimate value corresponding to the second subcarrier element, and the amplitude and / or phase change values ​​corresponding to the N subcarrier elements in the first channel estimate value, comprises the step of determining the second channel estimate value based on the first device, the channel estimate value corresponding to the first subcarrier element, the second subcarrier element, and the amplitude and / or phase change values ​​corresponding to the N subcarrier elements, wherein the second channel estimate value satisfies the following first relationship: , where the sequence number of the i-th subcarrier element within the second subcarrier element is different from the sequence number of the subcarrier element within the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element within the second subcarrier element is the same as the sequence number of the subcarrier element within the N subcarrier elements, and, here is the second channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element among the N subcarrier elements, and is a channel estimate value corresponding to the i-th subcarrier element in the second subcarrier element above, and A method comprising: an amplitude and / or phase change value corresponding to a subcarrier element in the N subcarrier elements, wherein the sequence number of the subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, wherein the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in the N subcarrier elements, and the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in the N subcarrier elements, wherein i is a positive integer and 1 ≤ i ≤ N; a step of determining by the first device that the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence when the absolute value of the second channel estimate value is smaller than a first threshold value; or a step of determining by the first device that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence when the absolute value of the second channel estimate value is greater than or equal to the first threshold value. Claim 4 In claim 1, the step of determining whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence based on the first device, the first device, the first device, the first device, the channel estimate value corresponding to the first subcarrier element, the channel estimate value corresponding to the second subcarrier element, and the amplitude and / or phase change values ​​corresponding to the N subcarrier elements in the first channel estimate value, comprises the step of determining the second channel estimate value and the third channel estimate value based on the first device, the channel estimate value corresponding to the first subcarrier element, the channel estimate value corresponding to the second subcarrier element, and the amplitude and / or phase change values ​​corresponding to the N subcarrier elements, wherein the second channel estimate value satisfies the following second relationship: ; and the above third channel estimate value satisfies the following third relationship: , where the sequence number of the i-th subcarrier element within the second subcarrier element is different from the sequence number of the subcarrier element within the N subcarrier elements, ; or when the sequence number of the i-th subcarrier element within the second subcarrier element is the same as the sequence number of the subcarrier element within the N subcarrier elements, and, here is the second channel estimate, and is the third channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element among the N subcarrier elements, and is a channel estimate value corresponding to the i-th subcarrier element in the second subcarrier element above, and A method comprising the step of determining whether an L-LTF sequence corresponding to the signal frame is a target L-LTF sequence by the first device based on the second channel estimate value and the third channel estimate value. Claim 5 In claim 4, the step of determining whether an L-LTF sequence corresponding to a signal frame is a target L-LTF sequence based on the second channel estimate value and the third channel estimate value by the first device comprises: a step of determining that the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence by the first device when the ratio of the absolute value of the second channel estimate value to the absolute value of the third channel estimate value is smaller than a second threshold value; or a step of determining that the L-LTF sequence corresponding to the signal frame is not a target L-LTF sequence by the first device when the ratio of the absolute value of the second channel estimate value to the absolute value of the third channel estimate value is greater than or equal to the second threshold value. Claim 6 delete Claim 7 delete Claim 8 As a communication device, the device comprises a processing module and a transceiver module, wherein the transceiver module is configured to receive a signal frame; the processing module is configured to perform channel estimation based on a legacy long training field (L-LTF) sequence corresponding to the signal frame to obtain a first channel estimation value, wherein the first channel estimation value includes channel estimation values ​​corresponding to M subcarrier elements in the L-LTF sequence corresponding to the signal frame; the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the first channel estimation value and mark information of N subcarrier elements, wherein the mark information of N subcarrier elements includes sequence numbers of the N subcarrier elements and amplitude and / or phase change values ​​corresponding to the N subcarrier elements, M and N are positive integers, M > 1, and 1 ≤ N ≤ M, and the processing module, based on the first channel estimation value and mark information of N subcarrier elements, the L-LTF corresponding to the signal frame Further configured to determine whether the sequence is a target L-LTF sequence, the processing module is configured to determine a first subcarrier element and a second subcarrier element based on the sequence numbers of the N subcarrier elements, wherein the first subcarrier element is a subcarrier element in the L-LTF sequence corresponding to the signal frame, and the subcarrier element sequence number corresponds to the sequence numbers of the N subcarrier elements, and the second subcarrier element is a subcarrier element in the L-LTF sequence corresponding to the signal frame, and the subcarrier element sequence number is adjacent to the sequence numbers of the N subcarrier elements;The device, wherein the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on a channel estimation value corresponding to the first subcarrier element, a channel estimation value corresponding to the second subcarrier element, and amplitude and / or phase change values ​​corresponding to the N subcarrier elements in the first channel estimation value. Claim 9 delete Claim 10 In claim 8, the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence based on a channel estimation value corresponding to the first subcarrier element, a channel estimation value corresponding to the second subcarrier element, and amplitude and / or phase change values ​​corresponding to the N subcarrier elements in the first channel estimation value, wherein the processing module is configured to determine a second channel estimation value based on a channel estimation value corresponding to the first subcarrier element, a channel estimation value corresponding to the second subcarrier element, and amplitude and / or phase change values ​​corresponding to the N subcarrier elements, and the second channel estimation value satisfies the following first relationship: , where the sequence number of the i-th subcarrier element within the second subcarrier element is different from the sequence number of the subcarrier element within the N subcarrier elements, ; or when the sequence number of the i-th subcarrier element within the second subcarrier element is the same as the sequence number of the subcarrier element within the N subcarrier elements, and, here is the second channel estimate, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element in N subcarrier elements, and is a channel estimate corresponding to the i-th subcarrier element in the second subcarrier element, and A device comprising: an amplitude and / or phase change value corresponding to a subcarrier element in N subcarrier elements, wherein the sequence number is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, wherein the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in N subcarrier elements, and the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in N subcarrier elements, i is a positive integer, and 1 ≤ i ≤ N; wherein the processing module is further configured to determine that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence when the absolute value of the second channel estimate value is less than the first threshold value; or wherein the processing module is further configured to determine that the L-LTF sequence corresponding to the signal frame is not the target L-LTF sequence when the absolute value of the second channel estimate value is greater than or equal to the first threshold value. Claim 11 In claim 8, the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence based on a channel estimation value corresponding to the first subcarrier element, a channel estimation value corresponding to the second subcarrier element, and amplitude and / or phase change values ​​corresponding to the N subcarrier elements in the first channel estimation value, wherein the processing module is configured to determine a second channel estimation value and a third channel estimation value based on a channel estimation value corresponding to the first subcarrier element, a channel estimation value corresponding to the second subcarrier element, and amplitude and / or phase change values ​​corresponding to the N subcarrier elements, and the second channel estimation value satisfies the following second relationship: ; and the above third channel estimate value satisfies the following third relationship: , where the sequence number of the i-th subcarrier element within the second subcarrier element is different from the sequence number of the subcarrier element within the N subcarrier elements, or; or when the sequence number of the i-th subcarrier element within the second subcarrier element is the same as the sequence number of the subcarrier element within the N subcarrier elements, and, here is the above-mentioned second channel estimate value, and is the above-mentioned third channel estimate value, and is a channel estimate value corresponding to the i-th subcarrier element in the first subcarrier element, and is an amplitude and / or phase change value corresponding to the i-th subcarrier element among the N subcarrier elements, and is a channel estimate value corresponding to the i-th subcarrier element in the second subcarrier element above, and The device is an amplitude and / or phase change value corresponding to a subcarrier element in the N subcarrier elements, wherein the sequence number of the subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in the second subcarrier element, the sequence number of the i-th subcarrier element in the first subcarrier element is the same as the sequence number of the i-th subcarrier element in the N subcarrier elements, the i-th subcarrier element in the second subcarrier element is a subcarrier element adjacent to the sequence number of the i-th subcarrier element in the N subcarrier elements, i is a positive integer, and 1 ≤ i ≤ N; the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is a target L-LTF sequence based on the second channel estimation value and the third channel estimation value. Claim 12 An apparatus according to claim 11, wherein the processing module is further configured to determine whether the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence based on the second channel estimate value and the third channel estimate value, wherein the processing module is further configured to determine that the L-LTF sequence corresponding to the signal frame is the target L-LTF sequence when the ratio of the absolute value of the second channel estimate value to the absolute value of the third channel estimate value is less than a second threshold; or wherein the processing module is further configured to determine that the L-LTF sequence corresponding to the signal frame is not the target L-LTF sequence when the ratio of the absolute value of the second channel estimate value to the absolute value of the third channel estimate value is greater than or equal to the second threshold. Claim 13 delete Claim 14 delete Claim 15 A communication device comprising a processor, wherein the processor is coupled to a memory; wherein the memory is configured to store a computer program; and wherein the processor is configured to execute the computer program stored in the memory so as to enable the communication device to perform a method according to any one of claims 1 and 3 to 5. Claim 16 A computer-readable storage medium, wherein the computer-readable storage medium stores computer programs or instructions; and when the computer programs or instructions are executed on a computer, the computer is able to perform a method according to any one of claims 1 and 3 through 5. Claim 17 A computer program stored on a computer-readable storage medium, wherein the computer program includes instructions; and when the instructions are executed on a computer, the computer is able to perform a method according to any one of claims 1 and 3 through 5.

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