Communication method and apparatus

Abstract

Provided in the embodiments of the present application are a communication method and an apparatus. The method is applied to the field of communications, and is applicable to communication scenarios in which the length of a cyclic prefix (CP) in a signal is unknown. The method comprises: a T node receiving a first radio frame, where the first radio frame comprises a first CP and a first training sequence (FTS), and the first radio frame may be a synchronization information block; and determining the length of the first CP on the basis of the FTS. Compared with attempting all possible CP lengths, performing synchronization and decoding on the basis of the first radio frame can reduce synchronization time, thereby improving decoding efficiency.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202411750312.4, filed on November 29, 2024, entitled "Communication Method and Apparatus", and to Chinese Patent Application No. 202510121717.X, filed on January 24, 2025, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more particularly to communication methods and apparatus. Background Technology

[0003] The cyclic prefix (CP) is a crucial component in wireless communication technology used to overcome multipath effects and achieve orthogonal frequency division multiplexing (OFDM). The CP's role is to prevent inter-symbol interference (ISI) and inter-carrier interference (ICI), ensuring that signals can be correctly decoded even when arriving via different paths. Since different CP lengths are suitable for different propagation environments—for example, signals with short CPs are suitable for multipath propagation environments with shorter delays, while signals with long CPs are suitable for multipath propagation environments with longer delays—the choice of CP length has a significant impact on the performance of the communication system.

[0004] In wireless communication systems, such as new radio (NR) 5G networks, wireless local area network (WLAN) systems, and short-range communication systems, the receiver needs to know the synchronization context (CP) length of the signal transmitted by the transmitter in order to perform correct synchronization and decoding. In some wireless communication systems, due to the variability of the transmission environment and the diversity of equipment configurations, the CP length in different radio frames may be different; that is, the CP length in a radio frame is unknown. Traditional synchronization measurement methods are inefficient when the CP length is unknown, resulting in long synchronization times and affecting system performance and user experience. Therefore, it is necessary to study solutions to reduce synchronization time when the CP length in the signal is unknown. Summary of the Invention

[0005] This application discloses a communication method and apparatus that can reduce synchronization time when the CP length in the signal is unknown.

[0006] Firstly, embodiments of this application provide a communication method applied to a terminal node (T node). This method can be implemented by the T node or components within the T node (e.g., circuits, processors, chips, or chip systems). The following description uses a T node implementation as an example. The method includes: the T node receiving a first radio frame, the first radio frame including a first cyclic prefix (CP) and a first training sequence (FTS); determining the length of the first CP based on the FTS; and reducing synchronization time and improving decoding efficiency by performing synchronization and decoding based on the first radio frame compared to trying all possible CP lengths. In this application, the first training sequence can also be referred to as a first training signal. The first radio frame can be a synchronization information block. The method of the first aspect can be applied to communication scenarios where the CP length in the signal is unknown. Alternatively, the method of the first aspect can be applied to communication scenarios where the CP length in the synchronization information block is unknown.

[0007] In one possible implementation, the length of the first CP is determined based on the FTS, including: determining the length of the first CP based on the sequence attributes of the FTS; this can reduce synchronization time and thus improve decoding efficiency. In this paper, sequence attributes can be replaced with sequence information, sequence features, or other names representing features of the sequence. The sequence attributes of the FTS can include at least one of the parameters of the FTS and the sequence type of the FTS.

[0008] Node T determines the length of the first CP based on the FTS, including: Node T determines the length of the first CP based on the FTS and a first mapping relationship. This first mapping relationship includes the mapping relationship between the FTS and the length of the first CP.

[0009] In one possible implementation, the length of the first CP is determined based on the sequence properties of the FTS, including: if the FTS is a first sequence, determining the length of the first CP to be 18 basic time units (Ts) or 128 basic time units, thereby narrowing the range of possible values ​​for the first CP length, for example reducing the four possible lengths of the first CP to two, thus reducing synchronization time; or, if the FTS is a second sequence, determining the length of the first CP to be 39 basic time units or 64 basic time units, thereby narrowing the range of possible values ​​for the first CP length, thus reducing synchronization time. The first sequence and the second sequence are different.

[0010] In one possible implementation, the length of the first CP is determined based on the sequence properties of the FTS, including: if the FTS is a first sequence, determining the length of the first CP to be 39 basic time units or 128 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time; or, if the FTS is a second sequence, determining the length of the first CP to be 18 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time.

[0011] In one possible implementation, the length of the first CP is determined based on the sequence properties of the FTS, including: if the FTS is a first sequence, determining the length of the first CP to be 64 basic time units or 128 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time; or, if the FTS is a second sequence, determining the length of the first CP to be 18 basic time units or 39 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time.

[0012] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS. This includes: if the FTS is the first sequence, the length of the first CP is determined to be 18 basic time units or 93 basic time units, thereby narrowing the range of possible values ​​for the first CP length, for example, reducing the four possible lengths of the first CP to two, thus reducing synchronization time; or, if the FTS is the second sequence, the length of the first CP is determined to be 39 basic time units or 64 basic time units, thereby narrowing the range of possible values ​​for the first CP length, thus reducing synchronization time. The first sequence and the second sequence are different.

[0013] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS, including: when the FTS is the first sequence, the length of the first CP is determined to be 39 basic time units or 93 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time; or, when the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time.

[0014] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS, including: when the FTS is the first sequence, the length of the first CP is determined to be 64 basic time units or 93 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time; or, when the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 39 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time.

[0015] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS. This includes: if the FTS is the first sequence, the length of the first CP is determined to be 18 basic time units or 101 basic time units, thereby narrowing the range of possible values ​​for the first CP length. For example, the four possible lengths of the first CP are reduced to two, thus reducing the synchronization time. Alternatively, if the FTS is the second sequence, the length of the first CP is determined to be 39 basic time units or 64 basic time units, thereby narrowing the range of possible values ​​for the first CP length and thus reducing the synchronization time. The first sequence and the second sequence are different.

[0016] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS, including: when the FTS is the first sequence, the length of the first CP is determined to be 39 basic time units or 101 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time; or, when the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time.

[0017] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS, including: when the FTS is the first sequence, the length of the first CP is determined to be 64 basic time units or 101 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time; or, when the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 39 basic time units, thereby narrowing the range of values ​​for the length of the first CP and thus reducing the synchronization time.

[0018] In one possible implementation, the length of the first CP is determined based on the sequence properties of the FTS, including: when the FTS is a first sequence, determining the length of the first CP to be one of the CP lengths in the first CP length set, thereby narrowing the range of possible values ​​for the first CP length and thus reducing synchronization time; or, when the FTS is a second sequence, determining the length of the first CP to be one of the CP lengths in the second CP length set, thereby narrowing the range of possible values ​​for the first CP length and thus reducing synchronization time. The intersection of the second CP length set and the first CP length set is an empty set. The union of the first CP length set and the second CP length set contains all possible lengths of the first CP.

[0019] In one possible implementation, the first CP follows the FTS in the first radio frame; this allows for a faster determination of the length of the CP following the FTS in the first radio frame, thereby reducing synchronization time.

[0020] In one possible implementation, the first radio frame further includes a second CP and a second training sequence (STS), with the second CP preceding the STS. The method further includes: the T node determining the length of the second CP based on the FTS, wherein in the first radio frame, the second CP precedes the second training sequence (STS) included in the first radio frame; this allows for faster determination of the length of the CP preceding the STS in the first radio frame, thereby reducing synchronization time. The second training sequence can also be referred to as a second training signal. Optionally, the length of the second CP differs from the length of the first CP. For example, the second CP may be longer than the first CP, thereby increasing the time for the T node to perform automatic gain control (AGC).

[0021] In one possible implementation, the length of the second CP is determined based on the FTS, including: the T node determines the length of the second CP based on the sequence attributes of the FTS; this can reduce synchronization time and thus improve decoding efficiency.

[0022] In one possible implementation, the length of the second CP is determined based on the sequence properties of the FTS, including: when the FTS is the first sequence, the T node determines that the length of the second CP is 34 basic time units or 128 basic time units, thereby narrowing the range of values ​​for the length of the second CP; or, when the FTS is the second sequence, the length of the second CP is determined to be 59 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the second CP.

[0023] In one possible implementation, the length of the second CP is determined based on the sequence properties of the FTS, including: when the FTS is the first sequence, the length of the second CP is determined to be 59 basic time units or 128 basic time units, thereby narrowing the range of values ​​for the length of the second CP; or, when the FTS is the second sequence, the length of the second CP is determined to be 34 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the second CP.

[0024] In one possible implementation, the length of the second CP is determined based on the sequence properties of the FTS, including: when the FTS is the first sequence, the length of the second CP is determined to be 34 basic time units or 97 basic time units, thereby narrowing the range of values ​​for the length of the second CP; or, when the FTS is the second sequence, the length of the second CP is determined to be 59 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the second CP.

[0025] In one possible implementation, the length of the second CP is determined based on the sequence properties of the FTS, including: when the FTS is the first sequence, the length of the second CP is determined to be 59 basic time units or 97 basic time units, thereby narrowing the range of values ​​for the length of the second CP; or, when the FTS is the second sequence, the length of the second CP is determined to be 34 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the second CP.

[0026] In one possible implementation, the length of the second CP is determined based on the sequence properties of the FTS, including: when the FTS is the first sequence, the T node determines the length of the second CP to be 34 basic time units or 110 basic time units, thereby narrowing the range of values ​​for the length of the second CP; or, when the FTS is the second sequence, the length of the second CP is determined to be 59 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the second CP.

[0027] In one possible implementation, the length of the second CP is determined based on the sequence properties of the FTS, including: when the FTS is the first sequence, the T node determines the length of the second CP to be 59 basic time units or 110 basic time units, thereby narrowing the range of values ​​for the length of the second CP; or, when the FTS is the second sequence, the length of the second CP is determined to be 34 basic time units or 64 basic time units, thereby narrowing the range of values ​​for the length of the second CP.

[0028] In one possible implementation, the length of the second CP is determined based on the sequence attributes of the FTS, including: when the FTS is the first sequence, the T node determines the length of the second CP to be 20 basic time units, 22 basic time units, or 128 basic time units; or, when the FTS is the second sequence, the length of the second CP is determined to be 44 basic time units or 64 basic time units; thereby narrowing the range of values ​​for the length of the second CP, and thus reducing the synchronization time.

[0029] In one possible implementation, the length of the second CP is determined based on the sequence attributes of the FTS, including: when the FTS is the first sequence, the T node determines the length of the second CP to be 44 basic time units or 128 basic time units; or, when the FTS is the second sequence, the length of the second CP is determined to be 20 basic time units, 22 basic time units or 64 basic time units; thereby narrowing the range of values ​​for the length of the second CP, and thus reducing the synchronization time.

[0030] In one possible implementation, the first radio frame further includes third indication information, which indicates the length of the first CP and the length of the second CP. Optionally, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 20 or 44 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 22 or 64 basic time units. Alternatively, when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 20 or 44 basic time units; when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 22 or 64 basic time units. Optionally, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 20 or 64 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 22 or 44 basic time units. Alternatively, when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 20 or 64 basic time units; when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 22 or 44 basic time units.

[0031] In one possible implementation, the first radio frame includes a synchronization information block, where one bit of the synchronization information in the synchronization information block is a third indication information; this can save bit overhead.

[0032] In one possible implementation, the first radio frame further includes first indication information, which indicates the length of the first CP. After decoding the information carried in the first radio frame, the T node can verify the length of the first CP based on the first indication information to improve the reliability of decoding. The first indication information can be a bit in the synchronization information of the first radio frame. For example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 39 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 64 basic time units or 128 basic time units. Again, for example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 64 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 39 basic time units or 128 basic time units.

[0033] In one possible implementation, the first radio frame includes a synchronization information block, wherein one bit of the synchronization information in the synchronization information block is a first indication information, or in other words, the first indication information is one bit of the synchronization information in the synchronization information block.

[0034] In one possible implementation, the first sequence is a ZC sequence rooted with a first value, and the second sequence is a ZC sequence rooted with a second value, which is different from the first value; thus, the timing synchronization performance of the FTS is consistent when the FTS has different sequences.

[0035] In one possible implementation, the first sequence and the second sequence are conjugate sequences, which can reduce the workload of detecting sequences at the T node.

[0036] In one possible implementation, one or more time-domain symbols in the first radio frame are used as a physical broadcast channel (PBCH). The information carried by the PBCH includes second indication information, which is used to indicate the length of the first CP. Thus, the T node verifies the length of the first CP it has determined based on the second indication information, thereby improving the reliability of decoding.

[0037] In one possible implementation, the first radio frame further includes a third CP, the length of which is twice the length of the first CP. In the first radio frame, the first CP follows the FTS, and the third CP precedes the FTS. Thus, when the length of the third CP is 256 basic time units or close to 256 time units, peak detection on the first radio frame can yield three clusters of peaks, thereby determining the lengths of the first and third CPs. Optionally, the first radio frame also includes a second CP, which precedes the STS. For example, the first radio frame includes three CPs of different lengths: the first CP, the second CP, and the third CP. In the first radio frame, the STS precedes the FTS, the first CP follows the FTS, the second CP precedes the STS, and the third CP follows the STS and precedes the FTS.

[0038] In one possible implementation, the length of the first CP is determined based on the FTS, including: when the FTS is the first sequence, the T node determines the length of the first CP to be h basic time units or 128 basic time units, where h is 18, 39, or 64; when three clusters of peaks are obtained by peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be 128 basic time units; or, when two clusters of peaks are obtained by peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be h basic time units. This allows for rapid determination of the length of the first CP, thereby reducing synchronization time.

[0039] In one possible implementation, the length of the first CP is determined based on the FTS, including: when the FTS is the first sequence, the T node determines the length of the first CP to be h basic time units or 97 basic time units, where h is 18, 39, or 64; when peak detection of the first radio frame based on the FTS yields three clusters of peaks, the length of the first CP is determined to be 97 basic time units; or, when peak detection of the first radio frame based on the FTS yields two clusters of peaks, the length of the first CP is determined to be h basic time units. This allows for rapid determination of the length of the first CP, thereby reducing synchronization time.

[0040] In one possible implementation, the length of the first CP is determined based on the FTS, including: when the FTS is the first sequence, the T node determines the length of the first CP to be h basic time units or 110 basic time units, where h is 18, 39, or 64; when three clusters of peaks are obtained by peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be 110 basic time units; or, when two clusters of peaks are obtained by peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be h basic time units. This allows for rapid determination of the length of the first CP, thereby reducing synchronization time.

[0041] In one possible implementation, the length of the first CP is determined based on the sequence attributes of the FTS, including: if the FTS is a first sequence, the T node determines the length of the first CP to be the first CP length; or, if the FTS is a second sequence, the first CP length to be the second CP length; or, if the FTS is a third sequence, the first CP length to be the third CP length; or, if the FTS is a fourth sequence, the first CP length to be the fourth CP length. The first, second, third, and fourth sequences are four different sequences. The first, second, third, and fourth CP lengths are four different lengths. Since detecting which sequence the FTS is requires less time than trying different CP lengths for synchronization and decoding, the synchronization time can be reduced.

[0042] Secondly, embodiments of this application provide a communication method applied to a G node. This method can be implemented by the G node or components within the G node (e.g., circuits, processors, chips, or chip systems). The following description uses a G node implementation as an example. The method includes: the G node generating a first radio frame, the first radio frame including a first CP and an FTS; transmitting the first radio frame, the FTS being used by the receiving end of the first radio frame to determine the length of the first CP; thereby, the T node can determine the length of the first CP based on the FTS, thereby reducing synchronization time. The method of the first aspect can be applied to communication scenarios where the CP length in the signal is unknown. Alternatively, the method of the first aspect can be applied to communication scenarios where the CP length in the synchronization information block is unknown.

[0043] In one possible implementation, the sequence attribute of the FTS is used to determine the length of the first CP, or in other words, the sequence attribute of the FTS is used by the receiver to determine the length of the first CP. Thus, the T node can determine the length of the first CP based on the sequence attribute of the FTS, thereby reducing the synchronization time.

[0044] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 18 or 128 basic time units; or, the FTS is a second sequence, and the length of the first CP is 39 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0045] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 39 or 128 basic time units; or, the FTS is a second sequence, and the length of the first CP is 18 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0046] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 64 or 128 basic time units; or, the FTS is a second sequence, and the length of the first CP is 39 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0047] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 18 or 93 basic time units; or, the FTS is a second sequence, and the length of the first CP is 39 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0048] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 39 or 93 basic time units; or, the FTS is a second sequence, and the length of the first CP is 18 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0049] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 64 or 93 basic time units; or, the FTS is a second sequence, and the length of the first CP is 39 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0050] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 18 or 101 basic time units; or, the FTS is a second sequence, and the length of the first CP is 39 or 64 basic time units. Thus, the T node can reduce the range of values ​​for the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0051] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 39 basic time units or 101 basic time units; or, the FTS is a second sequence, and the length of the first CP is 18 basic time units or 64 basic time units; thus, the T node can reduce the range of values ​​for the length of the first CP according to the FTS, thereby reducing the synchronization time.

[0052] In one possible implementation, the FTS is a first sequence, and the length of the first CP is 64 basic time units or 101 basic time units; or, the FTS is a second sequence, and the length of the first CP is 39 basic time units or 64 basic time units; thus, the T node can reduce the range of values ​​for the length of the first CP according to the FTS, thereby reducing the synchronization time.

[0053] In one possible implementation, the first CP follows the FTS in the first radio frame; this allows for a faster determination of the length of the CP following the FTS in the first radio frame, thereby reducing synchronization time.

[0054] In one possible implementation, the first radio frame includes a second CP and an STS, with the second CP preceding the STS. The FTS is also used to determine the length of the second CP, or in other words, the FTS is also used by the receiver to determine the length of the second CP. This allows the length of the CP preceding the STS in the first radio frame to be determined more quickly, thereby reducing synchronization time.

[0055] In one possible implementation, the sequence attributes of the FTS are used to determine the length of the second CP, or in other words, the sequence attributes of the FTS are also used by the receiver to determine the length of the second CP; this can reduce synchronization time and thus improve decoding efficiency.

[0056] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 34 or 128 basic time units; or, the FTS is the second sequence, and the length of the second CP is 59 or 64 basic time units.

[0057] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 59 or 128 basic time units; or, the FTS is the second sequence, and the length of the second CP is 34 or 64 basic time units.

[0058] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 34 or 97 basic time units; or, the FTS is the second sequence, and the length of the second CP is 59 or 64 basic time units.

[0059] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 59 or 97 basic time units; or, the FTS is the second sequence, and the length of the second CP is 34 or 64 basic time units.

[0060] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 34 or 110 basic time units; or, the FTS is the second sequence, and the length of the second CP is 59 or 64 basic time units.

[0061] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 59 or 110 basic time units; or, the FTS is the second sequence, and the length of the second CP is 34 or 64 basic time units.

[0062] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 20, 22, or 128 basic time units; or, the FTS is the second sequence, and the length of the second CP is 44 or 64 basic time units.

[0063] In one possible implementation, the FTS is the first sequence, and the length of the second CP is 44 or 128 basic time units; or, the FTS is the second sequence, and the length of the second CP is 20, 22, or 64 basic time units.

[0064] In one possible implementation, the first radio frame also includes third indication information, which indicates the length of the first CP and the length of the second CP.

[0065] In one possible implementation, the first radio frame includes a synchronization information block, where one bit of the synchronization information in the synchronization information block is a third indication information; this can save bit overhead.

[0066] In one possible implementation, the FTS is a first sequence, and the length of the first CP is one of the CP lengths in the first CP length set, which can reduce the range of values ​​for the length of the first CP and thus reduce the synchronization time; or, the FTS is a second sequence, and the length of the first CP is one of the CP lengths in the second CP length set, which can reduce the range of values ​​for the length of the first CP and thus reduce the synchronization time.

[0067] In one possible implementation, the first radio frame further includes first indication information, which indicates the length of the first CP. For example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 39 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 64 basic time units or 128 basic time units. The intersection of the second CP length set and the first CP length set is an empty set. The union of the first CP length set and the second CP length set contains all possible lengths of the first CP.

[0068] In one possible implementation, the first radio frame includes a synchronization information block, wherein one bit of the synchronization information in the synchronization information block is a first indication information, or in other words, the first indication information is one bit of the synchronization information in the synchronization information block.

[0069] In one possible implementation, the FTS is a first sequence, and the length of the first CP is the same as the length of the first CP; or, the FTS is a second sequence, and the length of the first CP is the same as the length of the second CP; or, the FTS is a third sequence, and the length of the first CP is the same as the length of the third CP; or, the FTS is a fourth sequence, and the length of the first CP is the same as the length of the fourth CP. The first, second, third, and fourth sequences are four different sequences. The first, second, third, and fourth CP lengths are four different lengths. Since detecting which sequence the FTS is requires less time than trying different CP lengths for synchronization and decoding, the synchronization time can be reduced.

[0070] In one possible implementation, the first sequence is a ZC sequence rooted with a first value, and the second sequence is a ZC sequence rooted with a second value, which is different from the first value; thus, the timing synchronization performance of the FTS is consistent when the FTS has different sequences.

[0071] In one possible implementation, the first sequence and the second sequence are conjugate sequences, which can reduce the workload of detecting sequences at the T node.

[0072] In one possible implementation, one or more time-domain symbols in the first radio frame are used as PBCH, which carries information including second indication information. The second indication information is used to indicate the length of the first CP, thereby T node verifies the length of the first CP it has determined based on the second indication information, thereby improving the reliability of decoding.

[0073] In one possible implementation, the first radio frame also includes an STS and a third CP, the length of which is twice the length of the first CP; in the first radio frame, the first CP is after the FTS and the third CP is before the FTS; thus, when the T node obtains three clusters of peaks by performing peak detection on the first radio frame based on the FTS, the length of the first CP can be determined to be 128, 97, or 110 basic time units in order to reduce synchronization time.

[0074] Thirdly, embodiments of this application provide a communication method applied to a T-node. This method can be implemented by the T-node or components within the T-node (e.g., circuits, processors, chips, or chip systems). The following description uses a T-node implementation as an example. The method includes: the T-node receiving a synchronization information block, which includes a first CP and first indication information, the first indication information indicating the length of the first CP; using s basic time units as the length of the first CP, performing synchronization and decoding based on the synchronization information block; after decoding the synchronization information block to obtain the first indication information, determining whether the length of the first CP indicated by the first indication information is s basic time units, where s is an integer greater than 0. For example, s is any one of 18, 39, 64, or 128. Optionally, after determining that the length of the first CP indicated by the first indication information is s basic time units, determining that the decoding result is correct. Optionally, after determining that the length of the first CP indicated by the first indication information is not s basic time units, determining that the decoding result is incorrect, and trying other CP lengths, performing synchronization and decoding based on the synchronization information block. The method of this third aspect can be applied to communication scenarios where the length of the CP in the synchronization information block is unknown.

[0075] By employing the third method, after the T node decodes the synchronization information block to obtain the first indication information, it verifies whether the length of the first CP indicated by the first indication information is s basic time units; this can improve the reliability of decoding.

[0076] In one possible implementation, the first instruction information is contained within the synchronization information block.

[0077] In one possible implementation, the synchronization information block also includes an FTS; the method further includes: determining the length of the first CP based on the FTS; compared to trying all possible CP lengths, synchronizing and decoding based on the first radio frame can reduce synchronization time, thereby improving decoding efficiency.

[0078] In one possible implementation, the length of the first CP is determined based on the FTS, including: determining the length of the first CP based on the sequence attributes of the FTS; this can reduce synchronization time and thus improve decoding efficiency. In this paper, sequence attributes can be replaced with sequence information, sequence features, or other names representing features of the sequence. The sequence attributes of the FTS can include at least one of the parameters of the FTS and the sequence type of the FTS.

[0079] In one possible implementation, the method further includes: receiving a PBCH, the information carried by the PBCH containing second indication information, the second indication information being used to indicate the length of the first CP, thereby T node verifying the length of the first CP it has determined based on the second indication information, thereby improving the reliability of decoding.

[0080] Fourthly, embodiments of this application provide a communication method applied to a G node. This method can be implemented by the G node or components within the G node (e.g., circuits, processors, chips, or chip systems). The following description uses a G node implementation as an example. The method includes: the G node generating a synchronization information block, the synchronization information block including a first CP and first indication information, the first indication information indicating the length of the first CP; sending the synchronization information block; thereby enabling a T node, after decoding the synchronization information block and obtaining the first indication information, to verify whether the length of the first CP is the same as the length of the first CP used in decoding the synchronization information block; thus improving the reliability of decoding. The method of the fourth aspect can be applied to communication scenarios where the length of the CP in the synchronization information block is unknown.

[0081] In one possible implementation, the first instruction information is contained within the synchronization information block.

[0082] In one possible implementation, the synchronization information block also includes an FTS, which is used to determine the length of the first CP; thus, the T node can determine the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0083] In one possible implementation, the sequence attribute of the FTS is used to determine the length of the first CP, so that the T node can determine the length of the first CP based on the sequence attribute of the FTS, thereby reducing the synchronization time.

[0084] In one possible implementation, the method further includes: sending a PBCH, the information carried by the PBCH containing second indication information, the second indication information indicating the length of the first CP, so that the T node can verify the length of the first CP it has determined based on the second indication information, thereby improving the reliability of decoding. Sending the PBCH can be understood as sending information through the PBCH, which contains the second indication information.

[0085] Fifthly, embodiments of this application provide a communication method applied to a T-node. This method can be implemented by the T-node or components within the T-node (e.g., circuits, processors, chips, or chip systems). The following description uses a T-node implementation as an example. The method includes: the T-node receiving a synchronization information block, the synchronization information block including a first CP; and receiving a PBCH, the information carried by the PBCH including second indication information, the second indication information indicating the length of the first CP. Thus, the T-node can obtain the length of the first CP based on the second indication information, thereby reducing synchronization time. The method of the fifth aspect can be applied to communication scenarios where the length of the CP in the synchronization information block is unknown.

[0086] In one possible implementation, the synchronization information block also includes an FTS, which is used to determine the length of the first CP; thus, the T node can determine the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0087] In one possible implementation, the sequence attribute of the FTS is used to determine the length of the first CP, so that the T node can determine the length of the first CP based on the sequence attribute of the FTS, thereby reducing the synchronization time.

[0088] Sixthly, embodiments of this application provide a communication method applied to a G node. This method can be implemented by the G node or components within the G node (e.g., circuits, processors, chips, or chip systems). The following description uses a G node implementation as an example. The method includes: the G node sending a synchronization information block, the synchronization information block including a first CP; and sending a PBCH, the information carried by the PBCH including second indication information, the second indication information indicating the length of the first CP, so that a T node can obtain the length of the first CP based on the second indication information, thereby reducing synchronization time. The method of the sixth aspect can be applied to communication scenarios where the length of the CP in the synchronization information block is unknown.

[0089] In one possible implementation, the synchronization information block also includes an FTS, which is used to determine the length of the first CP; thus, the T node can determine the length of the first CP based on the FTS, thereby reducing the synchronization time.

[0090] In one possible implementation, the sequence attribute of the FTS is used to determine the length of the first CP, so that the T node can determine the length of the first CP based on the sequence attribute of the FTS, thereby reducing the synchronization time.

[0091] In a seventh aspect, embodiments of this application provide a communication device that has the function of implementing the behavior described in the first aspect method embodiment. The communication device may be a T-node, a component of the T-node (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the T-node. The functions of the communication device can be implemented in hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first wireless frame, the first wireless frame including a first CP and an FTS; the processing module is used to perform synchronization and decoding based on the first wireless frame.

[0092] In one possible implementation, the processing module, specifically used to determine the length of the first CP based on the sequence attributes of the FTS.

[0093] In one possible implementation, the processing module is specifically configured to determine the length of the first CP to be 18 basic time units or 128 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, determine the length of the first CP to be 39 basic time units or 64 basic time units.

[0094] In one possible implementation, the processing module is specifically used to determine the length of the first CP to be 39 basic time units or 128 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the first CP to be 18 basic time units or 64 basic time units.

[0095] In one possible implementation, the processing module is specifically configured to determine the length of the first CP to be 64 basic time units or 128 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, determine the length of the first CP to be 18 basic time units or 39 basic time units.

[0096] In one possible implementation, the processing module is specifically configured to determine the length of the first CP to be 18 basic time units or 93 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, to determine the length of the first CP to be 39 basic time units or 64 basic time units.

[0097] In one possible implementation, the processing module is specifically used to determine the length of the first CP to be 39 basic time units or 93 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the first CP to be 18 basic time units or 64 basic time units.

[0098] In one possible implementation, the processing module is specifically configured to determine the length of the first CP to be 64 basic time units or 93 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, determine the length of the first CP to be 18 basic time units or 39 basic time units.

[0099] In one possible implementation, the processing module is specifically configured to determine the length of the first CP to be 18 basic time units or 101 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, determine the length of the first CP to be 39 basic time units or 64 basic time units.

[0100] In one possible implementation, the processing module is specifically used to determine the length of the first CP to be 39 basic time units or 101 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the first CP to be 18 basic time units or 64 basic time units.

[0101] In one possible implementation, the processing module is specifically configured to determine the length of the first CP to be 64 basic time units or 101 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, determine the length of the first CP to be 18 basic time units or 39 basic time units.

[0102] In one possible implementation, the processing module is specifically used to determine the length of the first CP as a CP length from the first CP length set when the FTS is a first sequence; or, when the FTS is a second sequence, to determine the length of the first CP as a CP length from the second CP length set.

[0103] In one possible implementation, the processing module is further configured to determine the length of the second CP based on the FTS, in the first radio frame, before the STS included in the first radio frame.

[0104] In one possible implementation, the processing module, specifically used to determine the length of the second CP based on the sequence attributes of the FTS.

[0105] In one possible implementation, the processing module is specifically used to determine the length of the second CP to be 34 basic time units or 128 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 59 basic time units or 64 basic time units.

[0106] In one possible implementation, the processing module is specifically used to determine the length of the second CP to be 59 basic time units or 128 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 34 basic time units or 64 basic time units.

[0107] In one possible implementation, the processing module is specifically configured to determine the length of the second CP to be 34 basic time units or 97 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 59 basic time units or 64 basic time units.

[0108] In one possible implementation, the processing module is specifically configured to determine the length of the second CP to be 59 basic time units or 97 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 34 basic time units or 64 basic time units.

[0109] In one possible implementation, the processing module is specifically configured to determine the length of the second CP to be 34 basic time units or 110 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 59 basic time units or 64 basic time units.

[0110] In one possible implementation, the processing module is specifically used to determine the length of the second CP to be 59 basic time units or 110 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 34 basic time units or 64 basic time units.

[0111] In one possible implementation, the processing module is specifically configured to determine the length of the second CP to be 20 basic time units, 22 basic time units, or 128 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 44 basic time units or 64 basic time units.

[0112] In one possible implementation, the processing module is specifically configured to determine the length of the second CP to be 44 basic time units or 128 basic time units when the FTS is the first sequence; or, when the FTS is the second sequence, to determine the length of the second CP to be 20 basic time units, 22 basic time units, or 64 basic time units.

[0113] In one possible implementation, the processing module is specifically configured to determine the length of the first CP as h basic time units or 128 basic time units when the FTS is the first sequence, where h is 18, 39, or 64; determine the length of the first CP as 128 basic time units when three clusters of peak values ​​are obtained by peak detection of the first radio frame based on the FTS; or determine the length of the first CP as h basic time units when two clusters of peak values ​​are obtained by peak detection of the first radio frame based on the FTS.

[0114] In one possible implementation, the processing module is specifically configured to determine the length of the first CP as h basic time units or 97 basic time units when the FTS is the first sequence, where h is 18, 39, or 64; determine the length of the first CP as 97 basic time units when peak detection of the first radio frame based on the FTS yields three clusters of peaks; or determine the length of the first CP as h basic time units when peak detection of the first radio frame based on the FTS yields two clusters of peaks.

[0115] In one possible implementation, the processing module is specifically configured to determine the length of the first CP as h basic time units or 110 basic time units when the FTS is the first sequence, where h is 18, 39, or 64; determine the length of the first CP as 110 basic time units when peak detection of the first radio frame based on the FTS yields three clusters of peaks; or determine the length of the first CP as h basic time units when peak detection of the first radio frame based on the FTS yields two clusters of peaks.

[0116] In one possible implementation, the processing module is specifically configured to determine the length of the first CP as the first CP length when the FTS is a first sequence; or, determine the length of the first CP as the second CP length when the FTS is a second sequence; or, determine the length of the first CP as the third CP length when the FTS is a third sequence; or, determine the length of the first CP as the fourth CP length when the FTS is a fourth sequence.

[0117] For possible implementations of the communication device in the seventh aspect, please refer to the various possible implementations in the first aspect.

[0118] For the technical effects of the various possible implementations of the seventh aspect, please refer to the introduction of the technical effects of the various possible implementations of the first aspect.

[0119] Eighthly, embodiments of this application provide another communication device that has the function of implementing the behavior described in the second aspect of the method embodiments. The communication device may be a G-node, a component of the G-node (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the G-node. The functions of the communication device can be implemented in hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a first radio frame, the first radio frame including a first CP and an FTS; the transceiver module is used to transmit the first radio frame, the FTS being used to determine the length of the first CP.

[0120] For possible implementations of the communication device in the eighth aspect, please refer to the various possible implementations in the second aspect.

[0121] For the technical effects of the various possible implementations of the eighth aspect, please refer to the introduction of the technical effects of the various possible implementations of the second aspect.

[0122] Ninthly, embodiments of this application provide a communication device that has the function of implementing the behavior described in the third aspect of the method embodiment. The communication device may be a T-node, a component of the T-node (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the T-node. The function of the communication device can be implemented by hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a synchronization information block, the synchronization information block including a first CP and first indication information, the first indication information indicating the length of the first CP; the processing module is used to use s basic time units as the length of the first CP, and to perform synchronization and decoding based on the synchronization information block; after decoding the synchronization information block to obtain the first indication information, it determines whether the length of the first CP indicated by the first indication information is s basic time units, where s is an integer greater than 0.

[0123] In one possible implementation, the synchronization information block also includes an FTS; the processing module is further used to determine the length of the first CP based on the FTS.

[0124] In one possible implementation, the processing module, specifically used to determine the length of the first CP based on the sequence attributes of the FTS.

[0125] For possible implementations of the communication device in the ninth aspect, please refer to the various possible implementations in the third aspect.

[0126] For the technical effects of the various possible implementations of the ninth aspect, please refer to the introduction of the technical effects of the various possible implementations of the third aspect.

[0127] In a tenth aspect, embodiments of this application provide another communication device that has the function of implementing the behavior described in the fourth aspect of the method embodiments. The communication device may be a G-node, a component of the G-node (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the G-node. The function of the communication device can be implemented in hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a synchronization information block, the synchronization information block including a first CP and first indication information, the first indication information indicating the length of the first CP; the transceiver module is used to transmit the synchronization information block.

[0128] In one possible implementation, the transceiver module is also used to send a PBCH, the information carried by the PBCH including second indication information, which is used to indicate the length of the first CP.

[0129] For possible implementations of the communication device in the tenth aspect, please refer to the various possible implementations in the fourth aspect.

[0130] For the technical effects of the various possible implementations of the tenth aspect, please refer to the introduction of the technical effects of the various possible implementations of the fourth aspect.

[0131] Eleventhly, embodiments of this application provide a communication device that has the function of implementing the behavior described in the fifth aspect of the method embodiments. The communication device may be a T-node, a component of the T-node (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the T-node. The function of the communication device can be implemented in hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a synchronization information block, the synchronization information block including a first CP; receive a PBCH, the information carried by the PBCH including second indication information, the second indication information indicating the length of the first CP; the processing module is used to determine the length of the first CP according to the second indication information contained in the PBCH.

[0132] For possible implementations of the communication device in the eleventh aspect, please refer to the various possible implementations in the fifth aspect.

[0133] For the technical effects of the various possible implementations of the eleventh aspect, please refer to the introduction of the technical effects of the various possible implementations of the fifth aspect.

[0134] In a twelfth aspect, embodiments of this application provide another communication device that has the functionality to implement the behavior described in the sixth aspect method embodiment. This communication device can be a G-node, a component of the G-node (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the G-node. The functionality of the communication device can be implemented in hardware or by hardware executing corresponding software, the hardware or software including one or more modules or units corresponding to the aforementioned functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a synchronization information block; the transceiver module is used to send the synchronization information block, the synchronization information block including a first CP; and to send a PBCH, the information carried by the PBCH including second indication information, the second indication information indicating the length of the first CP.

[0135] For possible implementations of the communication device in aspect 12, please refer to the various possible implementations in aspect 6.

[0136] For the technical effects of the various possible implementations of the twelfth aspect, please refer to the introduction of the technical effects of the various possible implementations of the sixth aspect.

[0137] In a thirteenth aspect, embodiments of this application provide another communication device, the communication device including one or more processors for processing data and / or signaling to enable the methods of any one of the first to sixth aspects described above to be implemented.

[0138] Optionally, the communication device further includes a memory that stores a computer program or instructions that, when executed by a processor, cause the communication device to perform the method described in any of the first to sixth aspects above. For example, the communication device may be a chip, the processor may be a processing unit within the chip, and the memory may be a random access memory or cache within the chip.

[0139] In this embodiment of the application, during the execution of the above method, the process of sending information (or signals) can be understood as a process of outputting information based on a computer program or instruction of the processor. When outputting information, the processor outputs the information to the transceiver so that the transceiver can transmit it. After being output by the processor, the information may undergo further processing before reaching the transceiver. Similarly, when the processor receives input information, the transceiver receives the information and inputs it into the processor. Furthermore, after the transceiver receives the information, the information may undergo further processing before being input into the processor.

[0140] Unless otherwise specified, or unless it contradicts its actual function or internal logic in the relevant description, the sending and / or receiving operations involved by the processor can generally be understood as processor-based computer program or instruction output.

[0141] In implementation, the processor described above can be a processor specifically designed to execute these methods, or it can be a processor that executes computer programs or instructions stored in memory to execute these methods, such as a general-purpose processor. For example, the processor can also be used to execute programs stored in memory, which, when executed, cause the communication device to perform the methods as shown in the first aspect or any possible implementation thereof.

[0142] In one possible implementation, the memory is located outside the aforementioned communication device. In another possible implementation, the memory is located inside the aforementioned communication device.

[0143] In one possible implementation, the processor and memory may be integrated into a single device; that is, the processor and memory may be integrated together.

[0144] In one possible implementation, the communication device further includes a transceiver for receiving or transmitting signals, etc.

[0145] In a fourteenth aspect, this application provides another communication device, which includes logic circuitry (or processing circuitry) and an interface (or interface circuitry) for inputting and / or outputting data; the logic circuitry is used to perform the methods described in any one of the first to sixth aspects above.

[0146] In a fifteenth aspect, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed on a computer, cause the computer to perform the methods described in any one of the first to sixth aspects above. The computer may be a T-node or a G-node.

[0147] In a sixteenth aspect, this application provides a computer program product that, when run on a computer, causes the computer to perform the method as described in any one of the first to sixth aspects above. For example, the computer program product includes a computer program that, when executed, causes the computer to perform the method as described in any one of the first to sixth aspects above.

[0148] In a seventeenth aspect, this application provides a chip including a communication interface and a processor; the communication interface is used for signal transmission and reception of the chip; the processor is used to execute computer programs or instructions, causing a communication device including the chip to perform the method of any one of the first to sixth aspects described above.

[0149] In the eighteenth aspect, this application provides a communication system, which includes the communication device of the seventh aspect and the communication device of the eighth aspect.

[0150] In a nineteenth aspect, this application provides a communication system, which includes the communication apparatus of the ninth aspect and the communication apparatus of the tenth aspect.

[0151] In a twentieth aspect, this application provides a communication system, which includes a communication device according to an eleventh aspect and a communication device according to a twelfth aspect. Attached Figure Description

[0152] Figure 1A is a schematic diagram of a star-flash short-range communication system provided in an embodiment of this application;

[0153] Figure 1B is a schematic diagram of the architecture of a star-flash short-range communication system provided in an embodiment of this application;

[0154] Figure 1C is a schematic diagram of a WLAN system provided in an embodiment of this application;

[0155] Figure 1D is a schematic diagram of a wireless communication system provided in an embodiment of this application;

[0156] Figure 2 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0157] Figure 3 is a schematic diagram of the frame structure of a synchronization information block provided in an embodiment of this application;

[0158] Figure 4 is a schematic diagram of the frame structure of a wireless frame provided in an embodiment of this application;

[0159] Figure 5 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0160] Figure 6 is a schematic diagram of the peak value obtained by peak detection at the T node provided in the embodiment of this application;

[0161] Figure 7A is a schematic diagram of the frame structure of a first wireless frame provided in an embodiment of this application;

[0162] Figure 7B is a schematic diagram of another first wireless frame structure provided in an embodiment of this application;

[0163] Figure 8 is a comparative diagram of some contents in two synchronization information blocks provided in the embodiments of this application;

[0164] Figure 9 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0165] Figure 10 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0166] Figure 11 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0167] Figure 12 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0168] Figure 13 is a schematic diagram of the structure of a communication device 130 provided in an embodiment of this application;

[0169] Figure 14 is a schematic diagram of another communication device provided in an embodiment of this application;

[0170] Figure 15 is a schematic diagram of another structure of the communication device provided in an embodiment of this application. Detailed Implementation

[0171] The terms "first" and "second," etc., used in the specification, claims, and drawings of this application are only used to distinguish different objects and not to describe a specific order. It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers does not imply the order of execution; the execution order of each process should be determined by its function and inherent logic. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0172] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described herein can be combined with other embodiments. In this application, message names are used only to distinguish different messages and should not be construed as limiting. That is, any message name in this application can be replaced with other names, and this application does not impose any limitations.

[0173] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items. For example, “A and / or B” can mean: the presence of only A, the presence of only B, and the presence of both A and B, where A and B can be singular or plural. The term “multiple” as used in this application refers to two or more. In the textual description of this application, the character “ / ” generally indicates that the preceding and following objects are in an “or” relationship.

[0174] It is understood that in the various embodiments of this application, "B corresponding to A" means that there is a correspondence between A and B, and B can be determined based on A. However, it should also be understood that determining (or generating) B based on (or on) A does not mean that B is determined (or generated) solely based on (or on) A; B can also be determined (or generated) based on (or on) A and / or other information.

[0175] It should be understood that in this application, the indication includes direct indication (also known as explicit indication) and implicit indication. Direct indication information A refers to information A being included; implicit indication information A refers to information A being indicated through the correspondence between information A and information B, and through direct indication information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0176] It should be understood that in this application, information C is used to determine information D, including both situations where information D is determined solely based on information C and situations where it is determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0177] In this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0178] In this application, the names of the messages (or information) in the following processes are merely examples. As communication technology evolves, the names of the messages (or information, etc.) in the following processes may change. However, no matter how the names change, as long as their meaning is the same as the function or meaning of the messages (or information, etc.) in this application, they all fall within the protection scope of this application.

[0179] Furthermore, in the embodiments of this application, "network element A sends information A to network element B" can be understood as network element B being the destination of information A or an intermediate network element in the transmission path between the destination and network element B, which may include sending information directly or indirectly to network element B. "Network element B receives information A from network element A" can be understood as network element A being the source of information A or an intermediate network element in the transmission path between the source and network element A, which may include receiving information directly or indirectly from network element A. Information may undergo necessary processing between the source and destination, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way and will not be elaborated further here.

[0180] The technical solutions of this application will now be described with reference to the accompanying drawings. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0181] To facilitate understanding of the detailed implementation of the embodiments of this application, the technical terms involved in the embodiments of this application are described below. These explanations are intended to make the embodiments of this application easier to understand and should not be regarded as limiting the scope of protection claimed by this application.

[0182] 1) Node: A node is a device with communication capabilities, including but not limited to one or more of the following: terminal devices, network devices, industrial equipment, or entertainment devices. Terminal devices can be called terminals, user equipment (UE), mobile stations, mobile terminals, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, transportation vehicles with wireless communication capabilities, communication modules, etc. The embodiments of this application do not limit the device form of the terminal. Terminals typically contain communication modules, circuits, or chips that perform corresponding communication functions. The terminal is also configured with program instructions for performing corresponding communication functions. Network devices include, but are not limited to, routers, switches, or base stations. Industrial equipment includes, for example, industrial robots and robotic arms. Leisure and entertainment equipment includes, for example, virtual reality (VR) devices, mixed reality (MR) devices, massage chairs, home theaters, game controllers, or 4D cinema cabins.

[0183] In certain application scenarios or network types, devices with similar communication capabilities may not be called nodes. However, for ease of description, in this application embodiment, devices with communication capabilities are collectively referred to as nodes.

[0184] 2) Grant Node (G Node) and Terminal Node (T Node): In some communication systems, nodes include grant nodes and terminal nodes. In this application, the grant node can be referred to as a G node, and the terminal node can be referred to as a T node. Below, G node represents the grant node, and T node represents the terminal node. The G node manages a certain number of T nodes, and the G node connects to these T nodes to jointly complete specific communication functions. The management of T nodes by the G node can be reflected in multiple dimensions, such as the G node allocating transmission resources and configuring communication domain parameters for the T nodes. As one possible implementation, the G node can send data scheduling information, while the T node can receive data scheduling information and send / receive data according to the data scheduling information. For example, in a short-range wireless communication system, the node that sends data scheduling information is the G node, and the node that receives data scheduling information and sends data according to the data scheduling information is the T node.

[0185] In some possible implementations, a G node and its connected T nodes belong to a communication domain. Optionally, the number of G nodes within a communication domain can be one or more. For example, a single G node and its connected T nodes together constitute a communication domain. Alternatively, a communication domain includes one G node (or master node) and at least one T node (or slave node), wherein the G node schedules the T nodes to enable data transmission between the nodes.

[0186] As an example, the G node is the access network device (e.g., a base station), and the T node is the terminal device (e.g., a mobile phone).

[0187] Terminal devices can be devices that provide voice / data, such as handheld devices with wireless connectivity, in-vehicle devices, etc. Currently, examples of terminals include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving vehicles, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, wearable devices, terminal devices in 5G networks, or future public land mobile communication networks. Terminal devices in a network (PLMN), etc., are not limited to this in the embodiments of this application.

[0188] By way of example and not limitation, in this embodiment, the terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific type of application function and require the use of other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0189] In this application embodiment, the access network device can be a radio access network (RAN) node (or device) that connects the terminal device to the wireless network. The access network device can also be called a network device or a radio access network device; for example, the access network device can be a base station. A base station can broadly encompass, or be replaced by, various names including: RAN node, Node B, evolved Node B (eNB), next-generation Node B (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master station, auxiliary station, motor slide retainer (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), radio unit (RU), positioning node, etc. A base station can be a macro base station, micro base station, relay node, donor node, or similar entities, or combinations thereof. A base station can also refer to a communication module, modem, or chip installed within the aforementioned equipment or apparatus. A base station can also be a mobile switching center, equipment performing base station functions in D2D, V2X, and M2M communications, network-side equipment in 6G networks, and equipment performing base station functions in future communication systems. A base station can support networks using the same or different access technologies. Optionally, a RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). The embodiments of this application do not limit the specific technologies or equipment forms used in the network equipment.

[0190] As another example, the G node is the access point (AP), and the T node is the station (STA).

[0191] An Access Point (AP) is a device with wireless communication capabilities that supports communication, sensing, or power transmission using WLAN standards. It has the function of communicating, sensing, or transmitting power with other devices in a WLAN network (such as non-access point stations (non-AP STAs) or other access points). It can also have the function of communicating, sensing, or transmitting power with other devices. An access point acts as a bridge connecting wired and wireless networks, its main function being to connect clients of various wireless networks together and then connect the wireless network to the Ethernet. In a WLAN system, an access point can be called an Access Point Station (AP STA). This wireless communication device can be a complete device, or it can be a chip, processing system, or functional module installed in a complete device. Devices with these chips, processing systems, or functional modules can implement the methods and functions of the embodiments of this application under the control of the chips, processing systems, or functional modules. The AP in the embodiments of this application is a device that provides services to non-AP STAs and can support the 802.11 series standards or subsequent standards. For example, an access point can be an access point for a terminal (such as a mobile phone) to enter a wired (or wireless) network, mainly deployed in homes, buildings, and parks, with a typical coverage radius of tens to hundreds of meters. Of course, it can also be deployed outdoors. Another example is that an AP can be a communication entity such as a communication server, router, switch, or bridge; APs can include various forms of macro base stations, micro base stations, and repeater stations. Of course, an AP can also be a chip, processing system, or module within the above-mentioned devices, thereby implementing the methods and functions of the embodiments of this application.

[0192] A Station on a Wi-Fi STA (Stationary Access Point) is a device with wireless communication capabilities that supports communication, sensing, or power transmission using WLAN standards. It has the ability to communicate, sense, or transmit power with other non-AP STAs or access points in a WLAN network. In a WLAN system, a station can be called a non-access point station (non-AP STA). In this application, unless otherwise specified, a station (i.e., STA) refers to a non-AP STA. For example, an STA is any user communication device that allows a user to communicate with an AP (Access Point) or sense or transmit power, and thus communicate with the WLAN. This wireless communication device can be a complete device, or it can be a chip, processing system, or functional module installed in a complete device. Devices with these chips, processing systems, or functional modules can implement the methods and functions of the embodiments of this application under the control of the chips, processing systems, or functional modules. For example, an STA can be a wireless communication chip, a wireless sensor, or a wireless communication terminal, and can also be referred to as a user. For example, the STA can be a mobile phone supporting Wi-Fi communication, a tablet computer supporting Wi-Fi communication, a set-top box supporting Wi-Fi communication, a smart TV supporting Wi-Fi communication, a smart wearable device supporting Wi-Fi communication, an in-vehicle communication device supporting Wi-Fi communication, and a computer supporting Wi-Fi communication. Of course, the STA can also be a chip, processing system, or module in the above-mentioned various types of devices, thereby implementing the methods and functions of the embodiments of this application.

[0193] 3) Synchronization: Synchronization refers to the process of establishing time and / or frequency synchronization between nodes or devices. Time synchronization aligns the signal reception time with the transmission time, while frequency synchronization aligns the carrier frequency of the received signal with the carrier frequency of the transmitted signal. In other words, synchronization primarily addresses time and frequency offset issues, ensuring that the receiver can accurately decode the signal sent by the transmitter. Synchronization mechanisms are often the foundation for inter-device communication.

[0194] For example, one of the G node and T node (i.e., the sender) transmits a specific sequence, which is then detected by the receiver. For downlink, the G node sends the specific sequence, and the T node receives it; for uplink, the T node sends the specific sequence, and the G node receives it. Afterward, the receiver adjusts its own timing and carrier frequency based on the time and frequency of the detected specific sequence, or notifies the sender to make adjustments.

[0195] 4) Sequence: A sequence is an ordered set of numbers or elements. Specific sequences can perform specific functions in different scenarios by utilizing their structure and properties. Sequences play a crucial role in communication and sensing technologies, enabling corresponding communication and / or sensing functions by carrying specific sequences within signals and / or data.

[0196] For example, in a communication system, a terminal device needs to access the network after powering on, but it doesn't know the network's prior information and cannot receive information normally. Therefore, the terminal device (e.g., a mobile phone) first needs to perform a network search to determine the frequency resources and timing information used by the network. To enable the terminal device to obtain this information, network devices (e.g., access network devices) periodically send synchronization signals carried on a synchronization channel. These synchronization signals are generated based on one or more predefined sequences. Correspondingly, the terminal device can search for synchronization signals at multiple preset frequency points based on predefined possible synchronization sequences. When it finds a specific synchronization signal, it considers itself to have found the network, and can then perform time synchronization and frequency offset estimation and compensation, and continue to attempt to receive subsequent signals and system broadcast information. It can be seen that the sequence plays a crucial role in the initial synchronization process; its detection performance, resistance to frequency offset, interference, and noise determine whether the terminal device can successfully access the network and how quickly it can do so. The detection performance of the sequence can be mainly characterized by its correlation. Correlation includes autocorrelation and cross-correlation.

[0197] Autocorrelation reflects the degree to which two identical sequences match each other at different relative positions. Cross-correlation reflects the degree to which two different sequences match each other at different relative positions. In communication systems, autocorrelation determines whether the starting position of a sequence can be accurately detected; cross-correlation determines the probability of misidentifying a sequence as another sequence.

[0198] After obtaining the system information required for access, the terminal device will attempt to communicate with the network, notify the network of its existence, and cooperate with the network to complete the subsequent access process. Therefore, similar to downlink synchronization, the terminal device can send a specific uplink synchronization signal from the network's reserved random access resources. This uplink synchronization signal is generated by the uplink synchronization sequence. The network device detects the uplink synchronization signal on each reserved random access resource to determine if any terminal device is requesting network access. Furthermore, in synchronization systems such as 4G or 5G mobile communication technologies, the access network device, while detecting the uplink synchronization signal, also estimates the uplink timing advance parameter and subsequently informs the terminal device. The terminal device adjusts its uplink transmission timing based on this parameter, enabling uplink transmissions from multiple terminal devices to be synchronized at the frame, subframe, time slot, or symbol level—that is, the uplink signals from multiple terminal devices arrive at the network device simultaneously within a certain error boundary. Thus, it can be seen that the uplink synchronization sequence also determines the performance of uplink random access request detection and uplink timing synchronization parameter estimation. Sequences are widely used in various scenarios of communication systems, and will not be described in detail here.

[0199] Currently, the main sequences used in the field of communications include zadoff-chu (ZC) sequences, m sequences, Golden sequences, and Golay sequence pairs.

[0200] Among them, the ZC sequence is a commonly used series of downlink master synchronization sequences in long term evolution (LTE) technology, which has perfect autocorrelation characteristics and good cross-correlation characteristics.

[0201] The ZC sequence can be represented by the following formula:

[0202] Where, x u (n) represents the nth element of the ZC sequence. u represents the root (or root index) of the ZC sequence. N represents the length of the ZC sequence. For example, N is 161.

[0203] As a commonly used series of downlink master synchronization sequences in new radio (NR) technology, the m-sequence employs a frequency domain cyclic shift design when generating synchronization signals, therefore its autocorrelation and cross-correlation properties are not zero.

[0204] Golden sequences are generated from two m-sequences and have properties similar to the m-sequences. They are generally used for scrambling in communication.

[0205] Golay sequence pairs, as one of the earliest proposed binary sequence pairs, possess complementary properties, meaning that both autocorrelation and cross-correlation properties of Golay sequence pairs are perfect. However, the number of Golay sequences is small, making them prone to repetition. Similarly, Golay sequence sets (including multiple Golay sequences) also suffer from similar problems. Furthermore, the complementarity of Golay sequences is disrupted in the presence of Doppler frequency shift.

[0206] 5) Time unit in the embodiments of this application:

[0207] The time units involved in the embodiments of this application may include radio frames and symbols. A radio frame includes an integer number of symbols.

[0208] The symbols include, but are not limited to: orthogonal frequency division multiplexing (OFDM) symbols, sparse code multiplexing access (SCMA) symbols, filtered orthogonal frequency division multiplexing (F-OFDM) symbols, and non-orthogonal multiple access (NOMA) symbols, etc., and this application does not limit them.

[0209] Unless otherwise specified, all time units (or time lengths) in the physical layer are multiples of the basic time unit Ts. The basic time unit Ts can be defined as: Ts = 1 / fs. fs represents the physical layer reference frequency. Ts represents the basic time unit. The specific value of fs is not limited, and correspondingly, the value of Ts is also not limited. For example, the physical layer reference frequency fs is 30.72MHz.

[0210] 6) Conjugate: This refers to attributes that share certain common characteristics in their relationship, but also exhibit opposite features in some aspects. For example, a+bi and a-bi are conjugate complex numbers.

[0211] 7) Waveforms and Symbols: In some possible schemes, physical layer signals, control information, and data information are transmitted using a CP-OFDM beam with a subcarrier spacing Δf = fs / 64 = 480 kHz. The CP-OFDM symbol contains a cyclic prefix (CP) and a valid data packet portion in the time domain. For example, the length of the valid data portion is 64 Ts. The length of the cyclic prefix is ​​an integer multiple of Ts. For example, the length of a regular CP is 5 Ts, the length of an extended CP is 14 Ts, and the time length of a CP-OFDM symbol is 69 Ts (including the regular CP) or 78 Ts (including the extended CP). In this paper, OFDM symbols are divided into OFDM symbols containing a CP (i.e., CP-OFDM symbols) and OFDM symbols not containing a CP. OFDM symbols not containing a CP can be simply referred to as OFDM symbols. Unless otherwise specified, an OFDM symbol can be either an OFDM symbol without a CP or a CP-OFDM symbol.

[0212] 8) Communication domain: This can refer to a system consisting of a group of communication nodes with communication relationships, and the communication connections between these nodes. A single communication device or equipment may exist in multiple communication domains.

[0213] For example, when a mobile phone and headset are communicating wirelessly, the mobile phone is located in communication domain a, which includes both the mobile phone and headset. In communication domain a, the mobile phone is the master node and the headset is the slave node. Then, when the mobile phone detects the cockpit domain controller (CDC) and establishes a wireless connection with it, the mobile phone is also located in communication domain b, which includes both the mobile phone and the CDC. In communication domain b, the CDC is the master node and the mobile phone is the slave node, obeying the CDC's commands. Of course, communication domain a and / or communication domain b can also include other slave nodes, such as car speakers, microphones, etc.

[0214] In this embodiment of the application, it is assumed that communication domain a includes node G and node T#1, but communication domain b does not include node T#1. Therefore, for node T#1, communication domain a can be referred to as this communication domain, while communication domain b can be referred to as other communication domains.

[0215] The preceding text introduced some terms, concepts, or processes involved in the embodiments of this application. The following text introduces the technical background involved in the embodiments of this application.

[0216] In wireless communication systems, the CP (Content Frame) is an effective means of eliminating multipath effects and implementing OFDM, and its length is crucial for accurate signal decoding. In existing wireless communication systems, such as 5G NR and Wi-Fi systems, the receiver needs to know the CP length of the transmitted signal for correct synchronization and decoding. Currently, existing designs typically assume that the CP length in the signal is known. However, in some wireless communication systems, due to the variability of the transmission environment and the diversity of equipment configurations, the CP length in different wireless frames may differ, meaning the CP length in a wireless frame is unknown. This presents new challenges to the synchronization mechanism. In these wireless communication systems, the receiver needs to achieve efficient and fast synchronization without knowing the CP length in order to accurately receive and decode the signal. Traditional synchronization measurement methods are inefficient when the CP is unknown, leading to prolonged synchronization time and affecting system performance and user experience. Therefore, it is necessary to study schemes to reduce synchronization time when the CP length in the signal is unknown.

[0217] Therefore, this application provides a communication method and apparatus that can reduce synchronization time when the CP length in the signal is unknown. In other words, using the communication method provided in this application, the receiving end can achieve synchronization more efficiently and quickly, so as to accurately receive and decode the signal. The communication method provided in this application is applicable to communication scenarios where the CP length in the signal is unknown. In communication scenarios where the CP length in the signal is unknown, the CP length in the wireless frame can be any of a variety of CP lengths.

[0218] The inventive concept of the communication method provided in this application is that the first training sequence (FTS) in the synchronization information block is used to determine the CP length, or in other words, the receiving end (e.g., T node) determines the CP length based on the FTS in the synchronization information block.

[0219] The technical solutions of this application embodiment can also be applied to various communication systems or networks, such as: WLAN communication systems, Starlight short-range communication systems, Wireless Fidelity (Wi-Fi) systems, Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Universal Mobile Telecommunication System (UMTS) systems, Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5th Generation (5G) systems or New Radio (NR) systems, Future Communications systems, Non-Terrestrial Networks (NTN) systems, Device-to-Device (D2D) communication systems, Machine-to-Machine (M2M) communication systems, Internet of Things (IoT) networks, or Vehicle-to-X (V2X) networks, etc. The communication systems described above are merely illustrative examples, and the applications of this application are not limited to these. This description is consistent with previous ones and will not be repeated below. Furthermore, the term "system" can be used interchangeably with "network." The StarScan short-range communication system can be referred to as a vehicle-mounted wireless short-range communication system.

[0220] This application supports IEEE protocols, such as IEEE 802.11be / Wi-Fi 7 / EHT, IEEE 802.11bn / UHR / Wi-Fi 8, IEEE Integrated mmWave / IMMW, IEEE 802.15 / UWB, or IEEE 802.11bf / sensing; this application may also support Spark Link / NearLink standard protocols.

[0221] Figure 1A is a schematic diagram of a StarScan short-range communication system provided in an embodiment of this application. As shown in Figure 1A, the StarScan short-range communication system includes G nodes and T nodes. G nodes are nodes that send data scheduling information in the StarScan short-range communication system, and T nodes are nodes that receive data scheduling information and send data according to the data scheduling information. Both G nodes and T nodes can be one or more. Typically, there is one G node and multiple T nodes. Taking an intelligent vehicle scenario as an example, one architecture of the StarScan short-range communication system is shown in Figure 1B. G nodes include the vehicle's domain control unit (DCU), and T nodes include the vehicle's screen and speakers, etc. The domain control unit is the core of each functional domain of the vehicle, formed by the centralized functional control logic, and is a high-performance processing unit strongly associated with a certain functional domain (e.g., cockpit domain, autonomous driving domain, etc.). Figure 1B is a schematic diagram of the architecture of a StarScan short-range communication system provided in an embodiment of this application. The technical solution of this application embodiment can be used in wireless short-range communication scenarios, and Figure 1A can be regarded as a schematic diagram of a wireless short-range communication scenario.

[0222] Figure 1C is a schematic diagram of a WLAN system provided in an embodiment of this application. Figure 1C shows a typical architecture of a basic service set (BSS) for a WLAN. Access points (APs) can connect to the internet, and multiple stations (STAs) (e.g., STA1, STA2, and STA3 shown in Figure 1C) are associated with the AP. Each STA accesses the internet through the AP. The number of APs and STAs shown in Figure 1C is merely an example; in a specific implementation, the number of APs or STAs may be more or less, and this embodiment of the application does not limit this. The AP in Figure 1C can be a multi-link device (MLD) supporting multiple links, and one or more STAs in Figure 1C can be non-AP MLDs supporting multiple links. In the WLAN system, the AP is a G node, and the STA is a T node. The technical solution of this embodiment of the application can be used in local wireless communication scenarios, and Figure 1C can be considered a schematic diagram of a local wireless communication scenario.

[0223] Figure 1D is a schematic diagram of a wireless communication system provided in an embodiment of this application. As shown in Figure 1D, the system includes one or more base stations (only one is shown) and multiple user equipment (UEs), wherein the number of base stations and UEs in the system is not limited. In the wireless communication system shown in Figure 1D, the base station is a G node and the UE is a T node. The technical solution of this application embodiment can be used in wide-area wireless communication scenarios, and Figure 1D can be regarded as a schematic diagram of a wide-area wireless communication scenario.

[0224] This application primarily describes embodiments applied to a short-range communication system. Those skilled in the art will readily understand that the various aspects of this application can be extended to other communication scenarios or networks employing various standards. For example, WLAN systems, Bluetooth, high-performance radio LANs (HIPERLANs) (a wireless standard similar to IEEE 802.11), wireless wide area networks (WWANs), wireless personal area networks (WPANs), or other networks currently known or to be developed in the future. In other words, the technical solutions of this application can be applied to short-range wireless communication systems, wide-area wireless communication systems, and other communication systems. Therefore, regardless of the coverage area and wireless access protocol used, the various aspects provided in this application can be applied to any suitable wireless network, such as a wireless network with an unknown CP length.

[0225] The communication system architecture or network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of communication system or network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application can also be applied to similar technical problems.

[0226] The communication method and apparatus provided in this application will be further described below with reference to the accompanying drawings. It is understood that this application uses T-nodes and G-nodes as examples of the execution entities in the interactive illustration, but this application does not limit the execution entities in the interactive illustration. For example, the method executed by the G-node in this application can also be implemented by a module (e.g., a circuit, chip, or chip system) in the G-node, or by a logic node, logic module, or software that can implement all or part of the functions of the G-node; the method executed by the T-node in this application can also be implemented by a communication module in the T-node or by a circuit or chip (e.g., a baseband chip, or a system-on-a-chip (SoC) chip containing a baseband chip, or a system-in-package (SIP) chip) in the terminal responsible for communication functions.

[0227] This application embodiment describes the method provided by the T node and the G node from both sides. However, during the transmission of signals, the T node and the G node can also forward the signals through other devices, such as forwarding devices to forward the signals between the T node and the G node. This application embodiment does not limit other devices besides the T node and the G node.

[0228] In this embodiment, "G node" can act as both a sender and a receiver. "T node" can also act as both a sender and a receiver. When "G node" acts as a sender, "T node" can act as a receiver. When "T node" acts as a sender, "G node" can act as a receiver. The following description uses G node as the sender and T node as the receiver as an example.

[0229] The communication method provided in the embodiments of this application is described below with reference to Figures 2, 5, and 9 to 12.

[0230] Figure 2 is a flowchart illustrating a communication method provided in an embodiment of this application. The descriptions of the T-node and G-node involved in Figure 2 can be found above and will not be detailed here. As shown in Figure 2, the method includes:

[0231] 201. Node G generates the first wireless frame.

[0232] The first radio frame includes a first CP and a first training sequence (FTS). The FTS is used to determine the length of the first CP. Alternatively, the FTS is used to determine the length of the first CP. The FTS can be a ZC sequence, an m-sequence, a Golden sequence, a Golay sequence, or other sequences; this application does not limit this. Some or all OFDM symbols in the first radio frame are CP-OFDM symbols. A CP-OFDM symbol contains a CP portion and a valid data packet portion in the time domain, with the CP portion being the end of the valid data packet portion. Alternatively, a CP-OFDM symbol contains a CP and a valid data packet in the time domain. For example, if a CP-OFDM symbol carries an STS, the structure of this CP-OFDM symbol can be represented as: [CP-STS, STS], where CP-STS is the end of the STS.

[0233] The lengths of the CPs in the first radio frame can be the same or different. In other words, the lengths of the CP portions of the CP-OFDM symbols in the first radio frame can be the same or different. In one possible design, the lengths of the CPs in the first radio frame are the same, and the first CP can be any CP in the first radio frame. In another possible design, the first radio frame contains two or more CPs of different lengths. The first CP is a CP at a predetermined position in the first radio frame. This predetermined position can be specified by standards supported by the T-node and G-node or configured by the G-node. For example, the CP at this predetermined position includes the CP of the first CP-OFDM symbol in the first radio frame, ordered chronologically, and the CPs of the third to the last CP-OFDM symbols. Another example is that the CP at this predetermined position includes the CPs of the third to the last CP-OFDM symbols in the first radio frame, ordered chronologically. When the first CP includes multiple CPs, the length of the first CP refers to the length of one of the CPs within the first CP. For example, the first CP includes the CPs of the third CP-OFDM symbol to the last CP-OFDM symbol in the first radio frame, ordered chronologically. The length of the CP of each of these CP-OFDM symbols is the length of the first CP. It should be understood that the T node determining the length of the first CP means determining the length of the CP at a predetermined position in the first radio frame. Optionally, the length of the CP at certain positions in the first radio frame can be an integer multiple of the length of the first CP. The multiple relationship between the length of the CP at certain positions in the first radio frame and the length of the first CP can be specified by the standards supported by the T node and G node or configured by the G node. For example, if the radio frame includes multiple OFDM symbols, the standards supported by the T node and G node specify that the length of the CP of the second CP-OFDM symbol in the radio frame, ordered chronologically, is twice the length of the first CP.

[0234] Optionally, the first radio frame may also include a second training sequence (STS). As an example, the first radio frame includes a first CP, an FTS, and an STS; wherein, the FTS can be used for precise synchronization of time and / or frequency at both ends of the transceiver, estimation of precise frequency offset, channel calculation, noise estimation, etc., and the STS can be used for coarse synchronization of time and / or frequency at both ends of the transceiver, coarse adjustment of automatic gain control (AGC), and coarse frequency offset estimation, etc.

[0235] Optionally, one or more time-domain symbols in the first radio frame are used as the physical broadcast channel (PBCH), or in other words, one or more time-domain symbols in the first radio frame are PBCH. The information carried by the PBCH includes second indication information, which is used to indicate the length of the first CP. The T node uses this second indication information to verify the length of the first CP it has determined, thereby improving the reliability of decoding. For example, the second indication information contains two bits: when the second indication information is 00, the length of the first CP is 18 basic time units (Ts); when the second indication information is 01, the length of the first CP is 39 basic time units; when the second indication information is 10, the length of the first CP is 64 basic time units; and when the second indication information is 11, the length of the first CP is 128 basic time units.

[0236] In one possible implementation, the first radio frame includes a synchronization information block (hereinafter referred to as the synchronization block), which includes a first CP, an FTS, and an STS. The FTS and STS in the synchronization information block can be called synchronization preambles. As an example, the first radio frame is a synchronization information block, which includes an FTS, an STS, and synchronization information. The FTS occupies two OFDM symbols, or in other words, the FTS is carried on two OFDM symbols, or two OFDM symbols are used to transmit the FTS. The STS occupies one OFDM symbol, and the synchronization information occupies two OFDM symbols. As another example, the first radio frame is a radio frame including 14 OFDM symbols, and the synchronization information block in the first radio frame includes an FTS, an STS, and synchronization information. Optionally, the synchronization information carries the identity information of the G node (i.e., the transmitter), enabling the T node to quickly determine / identify the source of the data, thereby enabling control and scheduling within the communication domain. Figure 3 is a schematic diagram of the frame structure of a synchronization information block provided in an embodiment of this application. Referring to Figure 3, the synchronization information block includes FTS, STS and synchronization information. Each rectangle represents a CP-OFDM symbol or an OFDM symbol that does not contain CP. In the time domain, the OFDM symbol occupied by STS precedes the two OFDM symbols occupied by FTS, and the two OFDM symbols occupied by FTS precede the one OFDM symbol occupied by synchronization information.

[0237] In this application, the length of the wireless frame can be 125 microseconds or other lengths, and a wireless frame includes multiple OFDM symbols. This application uses a wireless frame with a length of 125 microseconds and including 14 OFDM symbols as an example for description. Figure 4 is a schematic diagram of the frame structure of a wireless frame provided in an embodiment of this application. As shown in Figure 4, the transmission time intervals (TTIs) #0 to #8, ordered chronologically, are all 1ms. Each TTI includes eight radio frames with a time domain length of 125 microseconds, namely radio frames #0 to #7. The first radio frame in TTI #0 (i.e., radio frame #0) and the first radio frame in TTI #8 both contain a synchronization information block and a PBCH (i.e., PBCH #1 and PBCH #2). The first radio frame in other TTIs does not contain a PBCH. The transmission period of the PBCH is 8ms. Radio frame #0 in TTI #0 is an example of the first radio frame. Radio frame #0 includes a synchronization information block and a PBCH. The synchronization information block includes FTS, STS, and synchronization information (i.e., synchronization information #1 and synchronization information #2). FTS occupies two OFDM symbols, STS occupies one OFDM symbol, synchronization information occupies two OFDM symbols, and PBCH occupies two OFDM symbols. The transmission period for the synchronization information block can be 1 ms, for example, the first radio frame in each TTI contains the synchronization information block, or it can be longer or shorter than 1 ms; this application does not impose any limitation on this. The transmission period for the PBCH can be 8 ms, or it can be longer or shorter than 8 ms; this application does not impose any limitation on this. Some or all of the 14 OFDM symbols in any radio frame are CP-OFDM symbols. For example, the first, second, fourth, and fifth OFDM symbols in the radio frame, ordered chronologically, are CP-OFDM symbols, and the other OFDM symbols do not contain CP.

[0238] 202. The G node sends the first wireless frame.

[0239] Accordingly, the T node receives the first radio frame. In some scenarios, multiple T nodes may receive the first radio frame. Since the operations performed by each T node that receives the first radio frame are similar, this embodiment of the application uses one T node as an example to describe the operations performed by the T node after receiving the first radio frame.

[0240] 203. Node T determines the length of the first CP based on FTS.

[0241] The T node determines the length of the first CP based on the FTS, including: determining the length of the first CP based on the sequence attributes of the FTS, or in other words, determining the length of the first CP based on the sequence information of the FTS, or in other words, determining the length of the first CP based on the sequence characteristics of the FTS. Compared to trying all possible CP lengths, synchronizing and decoding based on the first radio frame can reduce synchronization time and thus improve decoding efficiency.

[0242] The T node determines the length of the first CP based on the FTS, including: the T node determines the length of the first CP based on the FTS and a first mapping relationship. This first mapping relationship includes the mapping relationship between the aforementioned FTS and the length of the first CP. As an example, the first mapping relationship includes: the mapping relationship between FTS#1 and CP length #1, the mapping relationship between FTS#2 and CP length #2, the mapping relationship between FTS#3 and CP length #3, ..., the mapping relationship between FTS#f and CP length #f; where FTS#1-FTS#f represent f different FTSs, and CP length #1-CP length #f represent the lengths of f different first CPs. f is an integer greater than 1. For example, multiple different FTSs are ZC sequences with multiple different u values, and each ZC sequence is an FTS. The T node can determine the length of the first CP corresponding to the FTS based on the first mapping relationship.

[0243] In one possible implementation, the first radio frame includes an FTS and a STS, with the STS preceding the FTS. The first radio frame includes two CPs of different lengths: a first CP and a third CP. The first CP includes all CPs following the FTS and preceding the STS in the first radio frame. The third CP consists of CPs following the STS and preceding the FTS in the first radio frame, and its length is twice that of the first CP. After determining the length of the first CP, the T node can use twice the length of the first CP as the length of the second CP.

[0244] In one possible implementation, the first radio frame includes a First Transmission Schedule (FTS) and a Second Transmission Schedule (STS), with the STS preceding the FTS. The first radio frame includes three CPs of different lengths: a first CP, a second CP, and a third CP. The first CP includes all CPs in the first radio frame that follow the FTS; the second CP includes all CPs in the first radio frame that precede the STS; and the third CP includes all CPs in the first radio frame that follow the STS but precede the FTS. The length of the third CP is twice the length of the first CP. After determining the length of the first CP, the T node can use twice the length of the first CP as the length of the second CP. The T node can determine the length of the second CP based on the FTS. As an example, the T node determines the length of the second CP based on the sequence properties of the FTS. In this implementation, the second CP can be different from the first CP, and the second CP can be flexibly configured to allow the duration of the first radio frame to be a specific duration, such as 0.5 ms. For example, when designing the frame format of a wireless frame, after determining the lengths of the first CP and the third CP in the wireless frame, in order to make the duration of the wireless frame the target duration, the length of the second CP can be determined based on the lengths of the first CP, the third CP and the target duration, and the target duration is not limited.

[0245] The following section introduces several possible implementation methods for determining the length of the first CP based on FTS sequence attributes.

[0246] In one possible implementation #1, node T determines the length of the first CP based on the sequence properties of the FTS, including:

[0247] When the FTS is the first sequence, the length of the first CP is determined to be either 18 basic time units (Ts) or 128 basic time units. This narrows down the range of possible values ​​for the first CP length, for example, reducing the four possible lengths of the first CP to two, thereby reducing the synchronization time; or,

[0248] When the FTS is the second sequence, the length of the first CP is determined to be 39 basic time units or 64 basic time units, which can narrow the range of values ​​for the length of the first CP and thus reduce the synchronization time.

[0249] In one possible implementation #2, node T determines the length of the first CP based on the sequence properties of the FTS, including:

[0250] When the FTS is the first sequence, the length of the first CP is determined to be either 39 basic time units or 128 basic time units. This narrows the range of possible values ​​for the first CP length, thereby reducing the synchronization time; or,

[0251] When the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 64 basic time units, which can narrow the range of values ​​for the length of the first CP and thus reduce the synchronization time.

[0252] In one possible implementation #3, node T determines the length of the first CP based on the sequence properties of the FTS, including:

[0253] When the FTS is the first sequence, the length of the first CP is determined to be 64 basic time units or 128 basic time units. This narrows the range of possible values ​​for the length of the first CP, thereby reducing the synchronization time; or,

[0254] When the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 39 basic time units, which can narrow the range of values ​​for the length of the first CP and thus reduce the synchronization time.

[0255] In one possible implementation #4, determining the length of the first CP based on the sequence properties of the FTS includes:

[0256] When the FTS is the first sequence, determining the length of the first CP to be one of the CP lengths from the set of first CP lengths can narrow down the range of possible values ​​for the first CP length, thereby reducing synchronization time; or,

[0257] When the FTS is the second sequence, the length of the first CP is determined to be one of the CP lengths in the set of second CP lengths. This can narrow the range of values ​​for the length of the first CP and thus reduce the synchronization time.

[0258] The first CP length set includes one or more CP lengths. The second CP length set includes one or more CP lengths. The intersection of the second CP length set and the first CP length set is empty. The number and length of CP lengths included in the first CP length set are not limited. The number and length of CP lengths included in the second CP length set are not limited. The union of the first and second CP length sets contains all possible lengths of the first CP. For example, the first CP length set includes 18 and 128 basic time units, and the second CP length set includes 39 and 64 basic time units. Another example: the first CP length set includes 39 and 128 basic time units, and the second CP length set includes 18 and 64 basic time units. Yet another example: the first CP length set includes 64 and 128 basic time units, and the second CP length set includes 18 and 39 basic time units. The number of CP lengths in the first and second CP length sets can be the same or different. Taking the example where the number of CP lengths in the first CP length set is the same as the number of CP lengths in the second CP length set, after the T node determines that the length of the first CP is one of the CP lengths in the first CP length set, it can try all the CP lengths in the first CP length set and perform synchronization and decoding based on the first radio frame. Compared to trying all the CP lengths in the first CP length set and all the CP lengths in the second CP length set, performing synchronization and decoding based on the first radio frame reduces the workload by half. Similarly, after the T node determines that the length of the first CP is one of the CP lengths in the second CP length set, it can try all the CP lengths in the second CP length set and perform synchronization and decoding based on the first radio frame. Compared to trying all the CP lengths in the first CP length set and all the CP lengths in the second CP length set, performing synchronization and decoding based on the first radio frame reduces the workload by half.

[0259] In the above implementations #1 to #4, the 128 basic time units can be replaced with 93 or 101 basic time units. That is, the maximum length of the first CP can be either 93 or 101 basic time units.

[0260] The following section introduces several possible implementation methods for determining the length of the second CP based on FTS sequence attributes.

[0261] In one possible implementation #5, node T determines the length of the second CP based on the sequence properties of the FTS, including:

[0262] When the FTS is the first sequence, the length of the second CP is determined to be 34 basic time units or 128 basic time units. This narrows down the range of possible values ​​for the second CP length, for example, reducing the four possible lengths of the second CP to two, thereby reducing the synchronization time; or,

[0263] When the FTS is the second sequence, the length of the second CP is determined to be 59 basic time units or 64 basic time units, which can narrow the range of values ​​for the length of the second CP and thus reduce the synchronization time.

[0264] In one possible implementation #6, node T determines the length of the second CP based on the sequence properties of the FTS, including:

[0265] When the FTS is the first sequence, the length of the second CP is determined to be either 59 basic time units or 128 basic time units. This narrows the range of possible values ​​for the second CP length, thereby reducing the synchronization time; or,

[0266] When the FTS is the second sequence, the length of the second CP is determined to be 34 basic time units or 64 basic time units, which can narrow the range of values ​​for the length of the second CP and thus reduce the synchronization time.

[0267] In one possible implementation #7, node T determines the length of the second CP based on the sequence properties of the FTS, including:

[0268] When the FTS is the first sequence, the length of the second CP is determined to be either 64 basic time units or 128 basic time units. This narrows the range of possible values ​​for the second CP length, thereby reducing the synchronization time; or,

[0269] When the FTS is the second sequence, the length of the second CP is determined to be 34 basic time units or 59 basic time units. This can narrow the range of values ​​for the length of the second CP and thus reduce the synchronization time.

[0270] In one possible implementation #8, determining the length of the second CP based on the sequence properties of the FTS includes:

[0271] When the FTS is the first sequence, determining the length of the second CP to be one of the CP lengths from the set of third CP lengths can narrow down the range of possible values ​​for the second CP length, thereby reducing synchronization time; or,

[0272] When the FTS is the second sequence, the length of the second CP is determined to be one of the CP lengths in the set of fourth CP lengths. This can narrow the range of values ​​for the length of the second CP and thus reduce the synchronization time.

[0273] In one possible implementation #9, determining the length of the second CP based on the sequence properties of the FTS includes:

[0274] When the FTS is the first sequence, node T determines the length of the second CP to be 20 basic time units, 22 basic time units, or 128 basic time units; or,

[0275] When the FTS is the second sequence, the length of the second CP is determined to be 44 basic time units or 64 basic time units; this can narrow the range of values ​​for the length of the second CP, thereby reducing the synchronization time.

[0276] In one possible implementation #10, determining the length of the second CP based on the sequence properties of the FTS includes:

[0277] When the FTS is the first sequence, node T determines the length of the second CP to be either 44 basic time units or 128 basic time units; or...

[0278] When the FTS is the second sequence, the length of the second CP is determined to be 20 basic time units, 22 basic time units, or 64 basic time units; this can narrow the range of values ​​for the length of the second CP, thereby reducing the synchronization time.

[0279] In one possible design, the first radio frame further includes third indication information, which indicates the lengths of the first CP and the second CP. Optionally, the first radio frame includes a synchronization information block, where one bit of the synchronization information is the third indication information. As an example, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 20 or 44 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 22 or 64 basic time units. As another example, when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 20 or 44 basic time units; when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 22 or 64 basic time units. As another example, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 20 or 64 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 22 or 44 basic time units. As another example, when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 20 or 64 basic time units; when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 22 or 44 basic time units.

[0280] The third CP length set includes one or more CP lengths. The fourth CP length set includes one or more CP lengths. The intersection of the third and fourth CP length sets is an empty set. The number and length of CP lengths included in the third CP length set are not limited. The number and length of CP lengths included in the fourth CP length set are not limited. The union of the third and fourth CP length sets can contain all possible lengths of the second CP. For example, the third CP length set includes 34 and 128 basic time units, and the fourth CP length set includes 59 and 64 basic time units. Another example: the third CP length set includes 59 and 128 basic time units, and the fourth CP length set includes 34 and 64 basic time units. Yet another example: the third CP length set includes 64 and 128 basic time units, and the fourth CP length set includes 34 and 59 basic time units. The number of CP lengths in the third and fourth CP length sets can be the same or different. Taking the example where the number of CP lengths in the third CP length set and the number of CP lengths in the fourth CP length set are the same, after the T node determines that the length of the second CP is one of the CP lengths in the third CP length set, it can try all the CP lengths in the third CP length set and perform synchronization and decoding based on the first radio frame. Compared to trying all the CP lengths in both the third and fourth CP length sets, performing synchronization and decoding based on the first radio frame reduces the workload by half. Similarly, after the T node determines that the length of the second CP is one of the CP lengths in the fourth CP length set, it can try all the CP lengths in the fourth CP length set and perform synchronization and decoding based on the first radio frame. Compared to trying all the CP lengths in both the third and fourth CP length sets, performing synchronization and decoding based on the first radio frame reduces the workload by half.

[0281] In implementations #5 to #8, the 128 basic time units can be replaced with 97 or 110 basic time units. That is, the maximum length of the second CP can be either 97 or 110 basic time units.

[0282] The first sequence and the second sequence are different. The first and second sequences can be any two different sequences, and the T node can quickly and accurately identify them. In one possible design, the first and second sequences are two different types of sequences, thus accurately and quickly determining whether the FTS is the first or second sequence based on its type. For example, the first sequence is a ZC sequence, and the second sequence is an m-sequence. Another example is a Golay sequence, and the second sequence is an m-sequence. Yet another example is a Golay sequence, and the second sequence is a ZC sequence. In another possible design, the first and second sequences are different sequences of the same type, ensuring that the timing synchronization performance of the FTS is the same regardless of the length of the first CP. For example, the first sequence is a ZC sequence rooted in a first value, and the second sequence is a ZC sequence rooted in a second value, where the second value is different from the first value. For example, the first value is 1, and the second value is 160. Another example is the first value is 2, and the second value is 159. Optionally, the first and second sequences are conjugate sequences, which can reduce the computational cost of the T node when detecting the FTS. In the field of communications, it is a common technique for T-nodes to detect whether a received sequence is a specific sequence, and these techniques will not be listed here. For example, a T-node can detect a first sequence based on its autocorrelation or cross-correlation characteristics, and a second sequence based on its autocorrelation or cross-correlation characteristics. For instance, the first sequence is a ZC sequence rooted at a first value, and the second sequence is a ZC sequence rooted at a second value, which is different from the first value. The T-node determines whether the FTS (First Sequence) is the first or second sequence by detecting the root of the FTS. A ZC sequence is a complex sequence. One possible implementation for a T-node to detect whether the FTS is the first or second sequence is as follows: Optionally, the T-node divides the received signal (i.e., the first radio frame) into several signal segments, the length of which can be equal to the length of the FTS. The T-node calculates the cross-correlation value between each signal segment and the first sequence (or the second sequence). If any of the calculated cross-correlation values ​​between each signal segment and the first sequence (or the second sequence) has a significant peak exceeding a preset threshold, the FTS is determined to be the first sequence; otherwise, the FTS is determined to be the second sequence. The preset threshold can be set according to actual needs and is not limited here. If the FTS is the first sequence, then ideally, there will be a significant peak in the cross-correlation values ​​of each signal segment and the first sequence (or the second sequence), which indicates the location of the FTS in the received signal (i.e., the first radio frame). The T node can identify the specific starting position of the FTS in the received signal by detecting the peak in the cross-correlation values ​​of each signal segment and the first sequence. The process by which the T node calculates the cross-correlation value between a signal segment and the first sequence can be as follows: the T node multiplies the signal segment and the first sequence point by point and sums them, thus obtaining the cross-correlation value between the signal segment and the first sequence. This process is applied to multiple segments to generate a series of cross-correlation values.

[0283] In this embodiment, the T node determines the length of the first CP based on the FTS; compared to trying all possible CP lengths, synchronization and decoding based on the first radio frame can reduce synchronization time and thus improve decoding efficiency.

[0284] Figure 5 is a flowchart illustrating another communication method provided in an embodiment of this application. Based on the method in Figure 2, Figure 5 describes an implementation of determining the length of the first CP based on FTS. As shown in Figure 5, the method includes:

[0285] 501. Node G generates the first wireless frame.

[0286] The first radio frame includes a first CP, a STS, a third CP, an FTS, and synchronization information. The FTS is used to determine the length of the first CP. The length of the third CP is twice the length of the first CP. In the first radio frame, the STS precedes the FTS, the third CP follows the STS and precedes the FTS, and the first CP includes one or more CPs in the first radio frame that follow the FTS; for example, the first CP includes all CPs in the first radio frame that follow the FTS. The first radio frame can be a synchronization information block.

[0287] 502. The G node sends the first wireless frame.

[0288] Accordingly, node T receives the first radio frame.

[0289] When FTS is the first sequence, nodes 503A and T determine the length of the first CP to be 18 basic time units or 128 basic time units.

[0290] If the 504A and T nodes obtain three clusters of peak values ​​by performing peak detection on the first radio frame based on FTS, they determine that the length of the first CP is 128 basic time units; or, if the 504A and T nodes obtain two clusters of peak values ​​by performing peak detection on the first radio frame based on FTS, they determine that the length of the first CP is 18 basic time units.

[0291] One possible implementation of step 504A is as follows: If the T node obtains three clusters of peak values ​​greater than or equal to a first threshold by performing peak detection (or over-peak detection) on the first radio frame based on FTS, it determines the length of the first CP to be 128 basic time units; or, if it obtains two clusters of peak values ​​greater than or equal to the first threshold by performing peak detection on the first radio frame based on FTS, it determines the length of the first CP to be 18 basic time units. Each cluster of peak values ​​includes one or more peak values ​​greater than or equal to the first threshold. The three clusters of peak values ​​greater than or equal to the first threshold can be three similar clusters of peak values, and the number of peak values ​​in different clusters can be different. In transmission scenarios with very low multipath delay, each cluster of peak values ​​greater than or equal to the first threshold is considered as one peak value greater than or equal to the first threshold. The time-domain interval between any two clusters of peak values ​​greater than or equal to the first threshold is greater than an interval threshold, for example, the interval threshold is 128 basic time units, 192 basic time units, 224 basic time units, etc. The first threshold can be set according to actual requirements and is not limited here. The first threshold can be a standard specification supported by the T node and the G node or configured by the G node. In this application, the length of the OFDM symbol without a CP is 256 basic time units, or in other words, the length of the effective data packet portion of the CP-OFDM symbol is 256 basic time units. When the length of the first CP is 128 basic time units, the length of the third CP is twice the length of the first CP, which is 256 basic time units. Referring to Figure 7A, when the length of the third CP is 256 basic time units, the length of the third CP is equal to the length of the OFDM symbol without a CP, which is equivalent to the FTS being carried by 3 OFDM symbols, or in other words, equivalent to the FTS being an FTS of 3 OFDM symbols. Therefore, during peak detection, three clusters of peaks equal to the first threshold can be detected. When the length of the first CP is 93 or 101 basic time units, the length of the third CP is close to 256 basic time units, and during peak detection, three clusters of peaks equal to the first threshold can also be detected.

[0292] Figure 6 is a schematic diagram of the peak values ​​obtained by the T-node in peak detection according to an embodiment of this application. As shown in Figure 6, when the length of the third CP is 256 basic time units, the T-node can obtain three clusters of peak values ​​greater than or equal to the first threshold during peak detection. Generally, if the FTS carries 3 OFDM symbols, when the reflected signal of the first radio frame is weak, the T-node can detect three clusters of peak values ​​greater than or equal to the first threshold during peak detection; when the reflected signal of the first radio frame is strong, the T-node can detect six clusters of peak values ​​greater than or equal to the first threshold during peak detection. When the length of the first CP is 18 basic time units, the length of the third CP is twice the length of the first CP, which is 36 basic time units. When the length of the third CP is 36 basic time units, the length of the third CP is not equal to the length of the OFDM symbol that does not contain a CP. The FTS carries 2 OFDM symbols, therefore, during peak detection, two clusters of peak values ​​greater than or equal to the first threshold can be detected.

[0293] Steps 503A to 504A are optional. Steps 503A to 504A and steps 503B to 506B are two parallel options. The method flow in Figure 5 may include steps 503A to 504A or steps 503B to 506B.

[0294] When the FTS is the second sequence, nodes 503B and T determine the length of the first CP to be 39 basic time units or 64 basic time units.

[0295] 504B and T nodes are timed based on FTS, coarse frequency offset is estimated based on STS, and fine frequency offset is estimated based on FTS.

[0296] In one possible implementation, node T first performs timing based on FTS, and simultaneously uses multiple 32-point cyclic sequences in STS for coarse frequency offset estimation. Then, fine frequency offset estimation is performed based on FTS. Figure 8 is a comparative schematic diagram of partial contents in two synchronization information blocks provided in the embodiments of this application. As shown in Figure 8, 801 represents a partial content in synchronization information block #1, and 802 represents a partial content in synchronization information block #2. The length of the CP before STS in synchronization information block #1 (i.e., the first CP mentioned above) is 64 basic time units (not shown), the length of the CP before FTS in synchronization information block #1 (i.e., the third CP mentioned above) is 128 basic time units, the length of the CP before STS in synchronization information block #2 is 39 basic time units, and the length of the CP before FTS in synchronization information block #2 is 78 basic time units; when the synchronization information block is synchronization information block #1... If node T uses multiple 32-point cyclic sequences located before the first time point in synchronization information block #1 to perform coarse frequency offset estimation, then at least 7 32-point cyclic sequences can be used for coarse frequency offset estimation. The first time point is the basic time unit forward of the FTS synchronization point in the time domain by (128+x), where x is an integer and is an empirical value or a protection margin, for example, x is 8. When the synchronization information block is synchronization information block #2, if node T uses multiple 32-point cyclic sequences located before the first time point in synchronization information block #2 to perform coarse frequency offset estimation, then at least 6 32-point cyclic sequences can be used for coarse frequency offset estimation. It should be understood that when the length of the first CP is 39 or 64 basic time units, if node T uses multiple 32-point cyclic sequences located before the first time point in the synchronization information block (i.e., the first radio frame) to perform coarse frequency offset estimation, then at least 6 32-point cyclic sequences can be used for coarse frequency offset estimation. Therefore, when node T does not know whether the length of the first CP is 39 or 64 basic time units, it can use multiple 32-point cyclic sequences located before the first time point in the synchronization information block (i.e., the first radio frame) to perform coarse frequency offset estimation. Step 504B is optional.

[0297] The 505B and T nodes use 39 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0298] The T node uses 39 basic time units as the length of the first CP. Synchronization and decoding based on the first radio frame can be performed as follows: The T node uses 39 basic time units as the length of the first CP for time synchronization and frequency offset estimation, and then decodes the information carried in the first radio frame. If the decoding result obtained by the T node using 39 basic time units as the length of the first CP passes the cyclic redundancy check (CRC), then decoding is considered successful; otherwise, decoding is considered unsuccessful. In this application, successful decoding can be determined by the T node decoding the first radio frame and the decoding result passing the CRC, but it does not necessarily confirm that the decoding result is correct.

[0299] 506B. If decoding fails when using 39 basic time units as the length of the first CP, use 64 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0300] Step 505B can be replaced by: Node T uses 64 basic time units as the length of the first CP and performs synchronization and decoding based on the first radio frame. Correspondingly, step 506B can be replaced by: If decoding is unsuccessful when using 64 basic time units as the length of the first CP, use 39 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0301] Optionally, the first radio frame also includes first indication information, which indicates the length of the first CP. After successfully decoding the information carried in the first radio frame, the T node can verify the length of the first CP based on the first indication information to improve the reliability of decoding. Assume that the T node successfully decodes the first radio frame when it uses t basic time units as the length of the first CP, where t is an integer greater than 0. The T node can verify the length of the first CP based on the first indication information by: determining whether t basic time units is the length of the first CP indicated by the first indication information; if yes, the length of the first CP passes the verification; if not, the length of the first CP fails the verification, and the T node needs to try other CP lengths for synchronization and decoding based on the first radio frame. The first indication information can be one or more bits in the synchronization information of the first radio frame. For example, the first radio frame includes a synchronization information block, where one bit in the synchronization information block is the first indication information. As one example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 39 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 64 basic time units or 128 basic time units. As another example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 64 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 39 basic time units or 128 basic time units.

[0302] Optionally, after successfully decoding the information carried in the first radio frame, the T node can perform the following operations: Based on the synchronization results of the FTS and STS, determine the length of the first CP; then, determine whether the length of this first CP is the same as the length of the first CP used to successfully decode the first radio frame; if they are the same, the length of the first CP passes the verification; if they are different, the length of the first CP fails the verification, and the T node needs to try using other CP lengths to synchronize and decode based on the first radio frame. The synchronization result of the FTS can be the start time of the FTS in the time domain (or the position of the FTS synchronization point) determined by the T node, i.e., the specific start position of the FTS in the received signal (first radio frame). The synchronization result of the STS can be the start time of the STS in the time domain (or the position of the STS synchronization point) determined by the T node, i.e., the specific start position of the STS in the received signal. The methods by which the T node obtains the synchronization results of the FTS and the STS can be found in the above description of determining the specific start position of the FTS in the received signal (first radio frame), and will not be repeated here. As an example, referring to Figure 7A, the time offset between the start time of STS in the time domain and the start time of FTS in the time domain is the length of STS in the time domain plus twice the length of the first CP; the T node determines the length of the first CP based on the synchronization results of FTS and STS as: the time offset minus the length of STS, and then divided by 2.

[0303] In one possible implementation, the first CP also includes the CP preceding the STS in the first radio frame. The first radio frame can be a synchronization information block. Referring to Figure 7A, the OFDM symbols in the first radio frame are, in chronological order, the first CP-OFDM symbol, the second CP-OFDM symbol, the third CP-OFDM symbol, and the fourth CP-OFDM symbol. The first CP includes the CP of the first CP-OFDM symbol, the CP of the third CP-OFDM symbol, and the CP of the fourth CP-OFDM symbol. The third CP is the CP of the second CP-OFDM symbol. The STS is carried in the first CP-OFDM symbol, the FTS is carried in the second CP-OFDM symbol, synchronization information #1 is carried in the third CP-OFDM symbol, and synchronization information #2 is carried in the fourth CP-OFDM symbol. The length of the second CP-OFDM symbol in the time domain is greater than the length of the two OFDM symbols that do not contain a CP. Figure 7A is a schematic diagram of the frame structure of a first radio frame provided in an embodiment of this application.

[0304] In one possible implementation, the first radio frame includes a second CP, which precedes the STS in the first radio frame. The first radio frame can be a synchronization information block. Referring to Figure 7B, the OFDM symbols in the first radio frame are, in chronological order, a first CP-OFDM symbol, a second CP-OFDM symbol, a third CP-OFDM symbol, and a fourth CP-OFDM symbol. The first CP includes the CP of the third CP-OFDM symbol and the CP of the fourth CP-OFDM symbol. The second CP is the CP of the first CP-OFDM symbol, and the third CP is the CP of the second CP-OFDM symbol. The STS is carried in the first CP-OFDM symbol, the FTS is carried in the second CP-OFDM symbol, synchronization information #1 is carried in the third CP-OFDM symbol, and synchronization information #2 is carried in the fourth CP-OFDM symbol. The length of the second CP-OFDM symbol in the time domain is greater than the length of two OFDM symbols that do not contain a CP. Figure 7B is a schematic diagram of another frame structure of the first radio frame provided in an embodiment of this application.

[0305] Optionally, the method flow in Figure 5 may include the following steps: When the FTS is the first sequence, the T node determines the length of the second CP to be 34 basic time units or 128 basic time units; when the T node obtains three clusters of peaks by peak detection of the first radio frame based on the FTS, the T node determines the length of the second CP to be 128 basic time units; or, when the T node obtains two clusters of peaks by peak detection of the first radio frame based on the FTS, the T node determines the length of the second CP to be 34 basic time units. Alternatively, the method flow in Figure 5 may include the following steps: When the FTS is the second sequence, the T node determines the length of the second CP to be 59 basic time units or 64 basic time units; the T node performs timing based on the FTS, coarse frequency offset estimation based on the STS, and fine frequency offset estimation based on the FTS; the T node uses 59 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding fails when using 59 basic time units as the length of the second CP, the T node uses 64 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame.

[0306] Optionally, the method flow in Figure 9 may include the following steps: When the FTS is the first sequence, the T node determines the length of the second CP to be 20 basic time units, 22 basic time units, or 128 basic time units; when the T node obtains three clusters of peaks by peak detection of the first radio frame based on the FTS, the T node determines the length of the second CP to be 128 basic time units; or, when the T node obtains two clusters of peaks by peak detection of the first radio frame based on the FTS, the T node determines the length of the second CP to be 20 basic time units or 22 basic time units; the T node performs timing based on the FTS, performs coarse frequency offset estimation based on the STS, and performs fine frequency offset estimation based on the FTS; the T node uses 20 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding fails when using 20 basic time units as the length of the second CP, the T node uses 22 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame. Alternatively, the method flow in Figure 9 can include the following steps: When the FTS is the second sequence, the T node determines the length of the second CP to be 44 basic time units or 64 basic time units; the T node performs timing based on the FTS, coarse frequency offset estimation based on the STS, and fine frequency offset estimation based on the FTS; the T node uses 44 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding fails when using 44 basic time units as the length of the second CP, the T node uses 64 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame.

[0307] Optionally, the first radio frame further includes third indication information, which indicates the length of the first CP and the length of the second CP. After the T node decodes the third indication information, it verifies the detected length of the second CP based on the length of the second CP indicated by the third indication information. As an example, when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 20 or 44 basic time units; when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 22 or 64 basic time units. As another example, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 20 or 64 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 22 or 44 basic time units.

[0308] As an example, the first radio frame includes a first CP and a second CP. The first CP includes one or more CPs following the FTS in the first radio frame; for example, the first CP includes all CPs following the FTS in the first radio frame. The length of the first CP can be called the general cyclic prefix length. The second CP is the CP in the first radio frame before the STS. The length of the second CP can be called the boundary cyclic prefix length. CP-OFDM symbols can be divided into general CP-OFDM symbols and boundary CP-OFDM symbols. The length of the CPs contained in a general CP-OFDM symbol is the general cyclic prefix length. The length of a general CP-OFDM symbol can be simply referred to as the general CP-OFDM symbol length. The length of the CPs contained in a boundary CP-OFDM symbol is the boundary cyclic prefix length. The length of a boundary CP-OFDM symbol can be simply referred to as the boundary CP-OFDM symbol length. When the subcarrier spacing in the radio frame is 120 kHz, a possible design for the CP-OFDM symbols in the radio frame is shown in Table 1.

[0309] Table 1 120kHz Subcarrier CP-OFDM Symbol Design

[0310] Referring to Table 1, the general cyclic prefix length, general CP-OFDM symbol length, boundary cyclic prefix length, and boundary CP-OFDM symbol length can all be divided into four types: Type 1, Type 2, Type 3, and Type 4. A radio frame can contain any type of general cyclic prefix length (i.e., the length of the first CP) and any type of boundary cyclic prefix length (i.e., the length of the second CP) from Table 1. In Type 1, the general cyclic prefix length is 18 Ts, or 0.586 μs; the general CP-OFDM symbol length is 274 Ts, or 8.919 μs; the boundary cyclic prefix length is 34 Ts, or 1.107 μs; and the boundary CP-OFDM symbol length is 290 Ts, or 9.440 μs. In Type 2, the general cyclic prefix length is 39Ts, or 1.270us; the general CP-OFDM symbol length is 295Ts, or 9.603us; the boundary cyclic prefix length is 59Ts, or 1.921us; and the boundary CP-OFDM symbol length is 315Ts, or 10.254us. In Type 3, the general cyclic prefix length is 64Ts, or in other words, the general cyclic prefix length is 2.083us; the general CP-OFDM symbol length is 320Ts, or in other words, the general CP-OFDM symbol length is 10.417us; the boundary cyclic prefix length is 64Ts, or in other words, the boundary cyclic prefix length is 2.083us; the boundary CP-OFDM symbol length is 320Ts, or in other words, the boundary CP-OFDM symbol length is 10.417us. In Type 4, the general cyclic prefix length is 128 Ts, or 4.1667 μs; the general CP-OFDM symbol length is 384 Ts, or 12.500 μs; the boundary cyclic prefix length is 128 Ts, or 4.1667 μs; and the boundary CP-OFDM symbol length is 384 Ts, or 12.500 μs. It should be understood that Table 1 is only one example. The general and boundary cyclic prefix lengths may also be other lengths.

[0311] Another possible design for the CP-OFDM symbol in the radio frame is shown in Table 2.

[0312] Table 2

[0313] Referring to Table 2, the general cyclic prefix length, general CP-OFDM symbol length, boundary cyclic prefix length, and boundary CP-OFDM symbol length can all be classified into five types: Type 1A, Type 1B, Type 2, Type 3, and Type 4. A radio frame can contain any type of general cyclic prefix length (i.e., the length of the first CP) and any type of boundary cyclic prefix length (i.e., the length of the second CP) from Table 2. It should be understood that Table 2 is only one example. The general cyclic prefix length and boundary cyclic prefix length may also be other lengths. The radio frame designed through the embodiments of this application can achieve support for NR systems, simplify chip implementation, and reduce chip implementation complexity.

[0314] As an example, the first radio frame includes a synchronization information block, which comprises STS, FTS, and synchronization information. An example of a synchronization information format is as follows: the synchronization information contains 50 valid bits, 6 reserved bits, and 24 CRC bits (24 bits for CRC), totaling 80 bits. As an example, the 50 valid bits in the synchronization information, from least significant bit to most significant bit, specifically contain the following information:

[0315] 3 bits: Information format indicator. For synchronization information in the communication domain, or in other words, the value of this 3 bits is 0.

[0316] 24 bits: G node identifier, for example, the G node identifier is randomly generated after the G node is powered on.

[0317] 8 bits: Indicator of multi-domain synchronization capability of G node.

[0318] 2 bits: Synchronization block transmission period. A value of 0 indicates no period. A value of 1 indicates a synchronization block transmission period of 2 superframes. A value of 2 indicates a synchronization block transmission period of 4 superframes. A value of 3 indicates a synchronization block transmission period of 8 superframes.

[0319] 4 bits: (Including the current synchronization block period) Number of remaining synchronization block periods. A value of 15 indicates continuous mode, 14 indicates continuous mode with RACH at the end, and 0 indicates non-continuous mode with RACH at the end.

[0320] 8 bits: Indicates which T-node groups' GCIs are included in this 20MHz. A bitmap is used to indicate this, with each bit corresponding to one T-node group, where "0" indicates no inclusion and "1" indicates inclusion.

[0321] 1 bit: Symbol type indicator. For example, "0" represents type one or type two above, and "1" represents type three or type four above. Another example: "0" represents type 1A or type 2 above, and "1" represents type 1B or type 3 above. Yet another example: "0" represents type 1A or type 3 above, and "1" represents type 1B or type 2 above.

[0322] In this embodiment, when the FTS is the first sequence, the T node determines the length of the first CP to be 18 basic time units or 128 basic time units; this narrows the range of possible values ​​for the first CP length, thereby reducing synchronization time. When the FTS is the second sequence, the T node determines the length of the first CP to be 39 basic time units or 64 basic time units; this narrows the range of possible values ​​for the first CP length, thereby reducing synchronization time. Furthermore, when the T node determines the length of the first CP to be 128 basic time units based on peak detection of the first radio frame using the FTS and obtains three clusters of peaks, the length of the first CP can be determined quickly; alternatively, when the T node determines the length of the first CP to be 18 basic time units based on peak detection of the first radio frame using the FTS and obtains two clusters of peaks, the length of the first CP can be determined quickly, thereby reducing synchronization time.

[0323] Figure 9 is a flowchart illustrating another communication method provided in an embodiment of this application. Based on the method in Figure 2, Figure 9 describes an implementation of determining the length of the first CP based on FTS. As shown in Figure 9, the method includes:

[0324] 901. G node generates the first wireless frame.

[0325] The first radio frame includes a first CP, an FTS, an STS, a third CP, and synchronization information. The FTS is used to determine the length of the first CP. The first radio frame can be a synchronization information block. For a description of the first radio frame, please refer to the description of the first radio frame in step 501, which will not be repeated here.

[0326] 902. G node sends the first wireless frame.

[0327] Accordingly, node T receives the first radio frame.

[0328] When FTS is the first sequence, nodes 903A and T determine the length of the first CP to be 39 basic time units or 128 basic time units.

[0329] If three clusters of peak values ​​are obtained by peak detection of the first radio frame based on FTS, the length of the first CP is determined to be 128 basic time units; or, if two clusters of peak values ​​are obtained by peak detection of the first radio frame based on FTS, the length of the first CP is determined to be 39 basic time units.

[0330] One possible implementation of step 904A is as follows: If the T node detects three clusters of peak values ​​greater than or equal to the first threshold during peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be 128 basic time units; or, if two clusters of peak values ​​greater than or equal to the first threshold are obtained during peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be 39 basic time units. The first threshold can be set according to actual requirements and is not limited here. The first threshold can be a standard specification supported by the T node and the G node or configured by the G node. When the length of the first CP is 128 basic time units, the length of the third CP is twice the length of the first CP, which is 256 basic time units. Referring to Figure 7A, when the length of the third CP is 256 basic time units, the length of the third CP is equal to the length of the OFDM symbol without the CP, which is equivalent to the FTS being carried by 3 OFDM symbols, or in other words, equivalent to the FTS being an FTS of 3 OFDM symbols. Therefore, during peak detection, three clusters of peak values ​​greater than or equal to the first threshold can be detected. When the length of the first CP is 39 basic time units, the length of the third CP is twice the length of the first CP, which is 78 basic time units. When the length of the third CP is 78 basic time units, the length of the third CP is not equal to the length of the OFDM symbol that does not contain the CP. The FTS is carried by 2 OFDM symbols, so when performing peak detection, two clusters of peaks greater than or equal to the first threshold can be detected.

[0331] The T node can quickly and accurately detect that the length of the first CP is 128 basic time units. Since the length of the first CP is 39 basic time units and is frequently used, when the FTS is the first sequence, the length of the first CP is determined to be either 39 basic time units or 128 basic time units. This allows for the rapid detection of the length of the first CP as 39 basic time units, thereby reducing synchronization time.

[0332] Steps 903A to 904A are optional. Steps 903A to 904A and steps 903B to 905B are two parallel options. The method flow in Figure 9 may include steps 903A to 904A or steps 903B to 905B.

[0333] When the FTS is the second sequence, nodes 903B and T determine the length of the first CP to be 18 basic time units or 64 basic time units.

[0334] The 904B and T nodes use 18 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0335] The T node uses 18 basic time units as the length of the first CP. Synchronization and decoding based on the first radio frame can be performed as follows: The T node uses 18 basic time units as the length of the first CP for time synchronization and frequency offset estimation, and then decodes the information carried in the first radio frame. If the decoding result obtained by the T node using 18 basic time units as the length of the first CP passes the CRC checksum, then decoding is considered successful; otherwise, decoding is considered unsuccessful.

[0336] 905B: If decoding fails when 18 basic time units are used as the length of the first CP, 64 basic time units are used as the length of the first CP, and synchronization and decoding are performed based on the first radio frame.

[0337] Step 904B can be replaced by: Node T uses 64 basic time units as the length of the first CP and performs synchronization and decoding based on the first radio frame. Correspondingly, step 905B can be replaced by: If decoding is unsuccessful when using 64 basic time units as the length of the first CP, use 18 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0338] Optionally, the first radio frame also includes first indication information, which indicates the length of the first CP. After successfully decoding the information carried in the first radio frame, the T node can verify the length of the first CP based on the first indication information to improve the reliability of decoding. Assume that the T node successfully decodes the first radio frame when it uses t basic time units as the length of the first CP, where t is an integer greater than 0. The T node can verify the length of the first CP based on the first indication information by: determining whether t basic time units is the length of the first CP indicated by the first indication information; if yes, the length of the first CP passes the verification; if no, the length of the first CP fails the verification, and the T node needs to try other CP lengths for synchronization and decoding based on the first radio frame. The first indication information can be one or more bits in the synchronization information of the first radio frame. For example, the first indication information can be one bit in the synchronization information of the first radio frame. As an example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 39 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 64 basic time units or 128 basic time units. As another example, when the value of the first indication information is 0, it is used to indicate that the length of the first CP is 18 basic time units or 128 basic time units; or, when the value of the first indication information is 1, it is used to indicate that the length of the first CP is 39 basic time units or 64 basic time units.

[0339] Optionally, after successfully decoding the information carried in the first radio frame, the T node can perform the following operations: determine the length of the first CP based on the synchronization results of the FTS and STS; then, determine whether the length of the first CP is the same as the length of the first CP used to successfully decode the first radio frame; if they are the same, the length of the first CP passes the verification; if they are different, the length of the first CP fails the verification, and the T node needs to try to use other CP lengths to synchronize and decode based on the first radio frame. As an example, referring to Figure 7A, the time offset between the start time of the STS in the time domain and the start time of the FTS in the time domain is the length of the STS in the time domain plus twice the length of the first CP; the T node determines the length of the first CP based on the synchronization results of the FTS and STS as: the time offset minus the length of the STS, and then divided by 2.

[0340] In one possible implementation, the first CP also includes the CP preceding the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7A.

[0341] In one possible implementation, the first radio frame includes a second CP, which precedes the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7B.

[0342] Optionally, the method flow in Figure 9 may include the following steps: When the FTS is the first sequence, the T node determines the length of the second CP to be 59 basic time units or 128 basic time units; when the T node obtains three clusters of peaks by peak detection of the first radio frame based on the FTS, the T node determines the length of the second CP to be 128 basic time units; or, when the T node obtains two clusters of peaks by peak detection of the first radio frame based on the FTS, the T node determines the length of the second CP to be 59 basic time units. Alternatively, the method flow in Figure 9 may include the following steps: When the FTS is the second sequence, the T node determines the length of the second CP to be 34 basic time units or 64 basic time units; the T node performs timing based on the FTS, coarse frequency offset estimation based on the STS, and fine frequency offset estimation based on the FTS; the T node uses 34 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding fails when using 34 basic time units as the length of the second CP, the T node uses 64 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame.

[0343] Optionally, the method flow in Figure 9 may include the following steps: when the FTS is the first sequence, the T node determines that the length of the second CP is 44 basic time units or 128 basic time units; when the T node obtains three clusters of peaks by peak detection of the first radio frame based on the FTS, the length of the second CP is determined to be 128 basic time units; or, when the T node obtains two clusters of peaks by peak detection of the first radio frame based on the FTS, the length of the second CP is determined to be 44 basic time units. Alternatively, the method flow in Figure 9 can include the following steps: When the FTS is the second sequence, the T node determines the length of the second CP to be 20 basic time units, 22 basic time units, or 64 basic time units; the T node performs timing based on the FTS, coarse frequency offset estimation based on the STS, and fine frequency offset estimation based on the FTS; the T node uses 20 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding with 20 basic time units as the length of the second CP fails, the T node uses 22 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding with 22 basic time units as the length of the second CP fails, the T node uses 64 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame.

[0344] Optionally, the first radio frame further includes third indication information, which indicates the length of the first CP and the length of the second CP. After the T node decodes the third indication information, it verifies the detected length of the second CP based on the length of the second CP indicated by the third indication information. As an example, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 20 or 44 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 22 or 64 basic time units. As another example, when the value of the third indication information is 0, it indicates that the length of the first CP is 18 or 64 basic time units, and the length of the second CP is 20 or 64 basic time units; when the value of the third indication information is 1, it indicates that the length of the first CP is 18 or 39 basic time units, and the length of the second CP is 22 or 44 basic time units.

[0345] In this embodiment, when the FTS is the first sequence, the T node determines the length of the first CP to be 39 basic time units or 128 basic time units; this narrows the range of possible values ​​for the first CP length, thereby reducing synchronization time. When the FTS is the second sequence, the T node determines the length of the first CP to be 18 basic time units or 64 basic time units; this narrows the range of possible values ​​for the first CP length, thereby reducing synchronization time. Furthermore, when the T node performs peak detection on the first radio frame based on the FTS and obtains three clusters of peaks, it determines the length of the first CP to be 128 basic time units, allowing for rapid determination of the first CP length and thus reducing synchronization time; alternatively, when the T node performs peak detection on the first radio frame based on the FTS and obtains two clusters of peaks, it determines the length of the first CP to be 39 basic time units, allowing for rapid determination of the first CP length and thus reducing synchronization time.

[0346] Figure 10 is a flowchart illustrating another communication method provided in an embodiment of this application. Based on the method in Figure 2, Figure 10 describes an implementation of determining the length of the first CP based on FTS. As shown in Figure 10, the method includes:

[0347] 1001, G node generates the first wireless frame.

[0348] The first radio frame includes a first CP, an FTS, an STS, a third CP, and synchronization information. The FTS is used to determine the length of the first CP. The first radio frame can be a synchronization information block. For a description of the first radio frame, please refer to the description of the first radio frame in step 501, which will not be repeated here.

[0349] 1002. Node G sends the first wireless frame.

[0350] Accordingly, node T receives the first radio frame.

[0351] When FTS is the first sequence, nodes 1003A and T determine the length of the first CP to be 64 basic time units or 128 basic time units.

[0352] If three clusters of peak values ​​are obtained by peak detection of the first radio frame based on FTS, nodes 1004A and T determine that the length of the first CP is 128 basic time units; or, if two clusters of peak values ​​are obtained by peak detection of the first radio frame based on FTS, the length of the first CP is determined to be 64 basic time units.

[0353] One possible implementation of step 1004A is as follows: If the T node detects three clusters of peak values ​​greater than or equal to the first threshold during peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be 128 basic time units; or, if two clusters of peak values ​​greater than or equal to the first threshold are obtained during peak detection of the first radio frame based on the FTS, the length of the first CP is determined to be 64 basic time units. The first threshold can be set according to actual requirements and is not limited here. The first threshold can be a standard specification supported by the T node and the G node or configured by the G node. When the length of the first CP is 128 basic time units, the length of the third CP is twice the length of the first CP, which is 256 basic time units. Referring to Figure 7A, when the length of the third CP is 256 basic time units, the length of the third CP is equal to the length of the OFDM symbol without the CP, which is equivalent to the FTS being carried by 3 OFDM symbols, or in other words, equivalent to the FTS being an FTS of 3 OFDM symbols. Therefore, during peak detection, three clusters of peak values ​​greater than or equal to the first threshold can be detected. When the length of the first CP is 64 basic time units, the length of the third CP is twice the length of the first CP, which is 128 basic time units. When the length of the third CP is 128 basic time units, the length of the third CP is not equal to the length of the OFDM symbol that does not contain the CP. The FTS is carried by 2 OFDM symbols, so when performing peak detection, two clusters of peaks greater than or equal to the first threshold can be detected.

[0354] Steps 1003A to 1004A are optional. Steps 1003A to 1004A and steps 1003B to 1005B are two parallel options. The method flow in Figure 10 may include steps 1003A to 1004A or steps 1003B to 1005B.

[0355] When the FTS is the second sequence, nodes 1003B and T determine the length of the first CP to be 18 basic time units or 39 basic time units.

[0356] Nodes 1004B and T use 18 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0357] The T node uses 18 basic time units as the length of the first CP. Synchronization and decoding based on the first radio frame can be performed as follows: The T node uses 18 basic time units as the length of the first CP for time synchronization and frequency offset estimation, and then decodes the information carried in the first radio frame. If the decoding result obtained by the T node using 18 basic time units as the length of the first CP passes the CRC checksum, then decoding is considered successful; otherwise, decoding is considered unsuccessful.

[0358] 1005B. If decoding fails when 18 basic time units are used as the length of the first CP, 39 basic time units are used as the length of the first CP, and synchronization and decoding are performed based on the first radio frame.

[0359] Step 1004B can be replaced by: Node T uses 39 basic time units as the length of the first CP and performs synchronization and decoding based on the first radio frame. Correspondingly, step 1005B can be replaced by: If decoding is unsuccessful when using 39 basic time units as the length of the first CP, use 18 basic time units as the length of the first CP and perform synchronization and decoding based on the first radio frame.

[0360] Optionally, the first radio frame also includes first indication information, which indicates the length of the first CP. After successfully decoding the information carried in the first radio frame, the T node can verify the length of the first CP based on the first indication information to improve the reliability of decoding. Assume that the T node successfully decodes the first radio frame when it uses t basic time units as the length of the first CP, where t is an integer greater than 0. The T node can verify the length of the first CP based on the first indication information by: determining whether t basic time units is the length of the first CP indicated by the first indication information; if yes, the length of the first CP passes the verification; if no, the length of the first CP fails the verification, and the T node needs to try other CP lengths for synchronization and decoding based on the first radio frame. The first indication information can be one or more bits in the synchronization information of the first radio frame. For example, the first indication information can be one bit in the synchronization information of the first radio frame. As an example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 64 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 39 basic time units or 128 basic time units. As another example, when the value of the first indication information is 0, it is used to indicate that the length of the first CP is 18 basic time units or 128 basic time units; or, when the value of the first indication information is 1, it is used to indicate that the length of the first CP is 39 basic time units or 64 basic time units.

[0361] Optionally, after successfully decoding the information carried in the first radio frame, the T node can perform the following operations: determine the length of the first CP based on the synchronization results of the FTS and STS; then, determine whether the length of the first CP is the same as the length of the first CP used to successfully decode the first radio frame; if they are the same, the length of the first CP passes the verification; if they are different, the length of the first CP fails the verification, and the T node needs to try to use other CP lengths to synchronize and decode based on the first radio frame. As an example, referring to Figure 7A, the time offset between the start time of the STS in the time domain and the start time of the FTS in the time domain is the length of the STS in the time domain plus twice the length of the first CP; the T node determines the length of the first CP based on the synchronization results of the FTS and STS as: the time offset minus the length of the STS, and then divided by 2.

[0362] In one possible implementation, the first CP also includes the CP preceding the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7A.

[0363] In one possible implementation, the first radio frame includes a second CP, which precedes the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7B. In this possible implementation, the method flow in Figure 10 can include the following steps: when the FTS is the first sequence, the T node determines that the length of the second CP is 64 basic time units or 128 basic time units; when the T node obtains three clusters of peaks by peak detection of the first radio frame based on the FTS, the length of the second CP is determined to be 128 basic time units; or, when the T node obtains two clusters of peaks by peak detection of the first radio frame based on the FTS, the length of the second CP is determined to be 64 basic time units. Alternatively, the method flow in Figure 10 can include the following steps: When the FTS is the second sequence, the T node determines the length of the second CP to be 34 basic time units or 59 basic time units; the T node performs timing based on the FTS, coarse frequency offset estimation based on the STS, and fine frequency offset estimation based on the FTS; the T node uses 34 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame; if decoding fails when using 34 basic time units as the length of the second CP, the T node uses 59 basic time units as the length of the second CP and performs synchronization and decoding based on the first radio frame.

[0364] In this embodiment, when the FTS is the first sequence, the T node determines the length of the first CP to be 64 basic time units or 128 basic time units; this narrows the range of possible values ​​for the first CP length, thereby reducing synchronization time. When the FTS is the second sequence, the T node determines the length of the first CP to be 18 basic time units or 39 basic time units; this narrows the range of possible values ​​for the first CP length, thereby reducing synchronization time. Furthermore, when the T node performs peak detection on the first radio frame based on the FTS and obtains three clusters of peaks, it determines the length of the first CP to be 128 basic time units, allowing for rapid determination of the first CP length and thus reducing synchronization time; alternatively, when the T node performs peak detection on the first radio frame based on the FTS and obtains two clusters of peaks, it determines the length of the first CP to be 64 basic time units, allowing for rapid determination of the first CP length and thus reducing synchronization time.

[0365] Figure 11 is a flowchart illustrating another communication method provided in an embodiment of this application. Based on the method in Figure 2, Figure 11 describes an implementation of determining the length of the first CP based on FTS. As shown in Figure 11, the method includes:

[0366] 1101. Node G generates the first wireless frame.

[0367] The first radio frame includes a first CP, an FTS, an STS, a third CP, and synchronization information. The FTS is used to determine the length of the first CP. The first radio frame can be a synchronization information block. For a description of the first radio frame, please refer to the description of the first radio frame in step 501, which will not be repeated here.

[0368] 1102. Node G sends the first wireless frame.

[0369] Accordingly, node T receives the first radio frame.

[0370] When nodes 1103A and T are in the first sequence of FTS, the length of the first CP is determined to be one of the CP lengths in the first CP length set.

[0371] The first set of CP lengths includes one or more CP lengths.

[0372] Nodes 1104A and T use each CP length in the first CP length set to perform synchronization and decoding based on the first radio frame.

[0373] For example, the first CP length set includes CP length #10, CP length #11, CP length #12, ..., CP length #p, where p is an integer. Node T uses CP length #10 as the length of the first CP for time synchronization and frequency offset estimation, and decodes the information carried in the first radio frame. If decoding is successful, the process in Figure 11 ends. If decoding is unsuccessful, CP length #11 is used as the length of the first CP for time synchronization and frequency offset estimation, and the information carried in the first radio frame is decoded. This process continues until successful decoding is achieved.

[0374] Steps 1103A to 1104A are optional. Steps 1103A to 1104A and steps 1103B to 1104B are two parallel options. The method flow in Figure 11 may include steps 1103A to 1104A or steps 1103B to 1104B.

[0375] When the FTS is the second sequence, nodes 1103B and T determine the length of the first CP to be one of the CP lengths in the second CP length set.

[0376] The second set of CP lengths includes one or more CP lengths. The intersection of the second set of CP lengths and the first set of CP lengths is an empty set.

[0377] The union of the first CP length set and the second CP length set contains all possible lengths of the first CP. For example, the first CP length set includes 18 basic time units and 128 basic time units, and the second CP length set includes 39 basic time units and 64 basic time units. Another example: the first CP length set includes 39 basic time units and 128 basic time units, and the second CP length set includes 18 basic time units and 64 basic time units. Yet another example: the first CP length set includes 64 basic time units and 128 basic time units, and the second CP length set includes 18 basic time units and 39 basic time units. The number of CP lengths in the first CP length set and the number of CP lengths in the second CP length set can be the same or different.

[0378] Nodes 1104B and T use each CP length in the second CP length set to synchronize and decode based on the first radio frame.

[0379] For example, the second CP length set includes CP length #20, CP length #21, CP length #22, ..., CP length #q, where q is an integer. Node T uses CP length #20 as the length of the first CP for time synchronization and frequency offset estimation, and decodes the information carried in the first radio frame. If decoding is successful, the process in Figure 11 ends. If decoding is unsuccessful, CP length #21 is used as the length of the first CP for time synchronization and frequency offset estimation, and the information carried in the first radio frame is decoded. This process continues until successful decoding is achieved.

[0380] Optionally, the first radio frame also includes first indication information, which indicates the length of the first CP. After successfully decoding the information carried in the first radio frame, the T node can verify the length of the first CP based on the first indication information to improve the reliability of decoding. Assume that the T node successfully decodes the first radio frame when it uses t basic time units as the length of the first CP, where t is an integer greater than 0. The T node can verify the length of the first CP based on the first indication information by: determining whether t basic time units is the length of the first CP indicated by the first indication information; if yes, the length of the first CP passes the verification; if no, the length of the first CP fails the verification, and the T node needs to try other CP lengths for synchronization and decoding based on the first radio frame. The first indication information can be one or more bits in the synchronization information of the first radio frame. For example, the first indication information can be one bit in the synchronization information of the first radio frame. As an example, when the value of the first indication information is 0, it indicates that the length of the first CP is 18 basic time units or 64 basic time units; or, when the value of the first indication information is 1, it indicates that the length of the first CP is 39 basic time units or 128 basic time units. As another example, when the value of the first indication information is 0, it is used to indicate that the length of the first CP is 18 basic time units or 128 basic time units; or, when the value of the first indication information is 1, it is used to indicate that the length of the first CP is 39 basic time units or 64 basic time units.

[0381] Optionally, after successfully decoding the information carried in the first radio frame, the T node can perform the following operations: determine the length of the first CP based on the synchronization results of the FTS and STS; then, determine whether the length of the first CP is the same as the length of the first CP used to successfully decode the first radio frame; if they are the same, the length of the first CP passes the verification; if they are different, the length of the first CP fails the verification, and the T node needs to try to use other CP lengths to synchronize and decode based on the first radio frame. As an example, referring to Figure 7A, the time offset between the start time of the STS in the time domain and the start time of the FTS in the time domain is the length of the STS in the time domain plus twice the length of the first CP; the T node determines the length of the first CP based on the synchronization results of the FTS and STS as: the time offset minus the length of the STS, and then divided by 2.

[0382] In one possible implementation, the first CP also includes the CP preceding the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7A.

[0383] In one possible implementation, the first radio frame includes a second CP, which precedes the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7B. In this possible implementation, the method flow in Figure 11 can include the following steps: when the FTS is the first sequence, the T node determines that the length of the second CP is one of the CP lengths in a third CP length set, which includes one or more CP lengths; the T node uses each CP length in the first CP length set to perform synchronization and decoding based on the first radio frame. Alternatively, the method flow in Figure 11 can include the following steps: when the FTS is the second sequence, the T node determines that the length of the second CP is one of the CP lengths in a fourth CP length set, which includes one or more CP lengths; the T node uses each CP length in the fourth CP length set to perform synchronization and decoding based on the first radio frame. For example, the third CP length set includes 34 basic time units and 128 basic time units, and the fourth CP length set includes 59 basic time units and 64 basic time units. For example, the third CP length set includes 59 basic time units and 128 basic time units, and the fourth CP length set includes 34 basic time units and 64 basic time units.

[0384] In this embodiment, when the FTS is a first sequence, the T node determines the length of the first CP to be one of the CP lengths in the first CP length set; this reduces the range of values ​​for the first CP length, thereby reducing the time required to determine the length of the first CP. When the FTS is a second sequence, the T node determines the length of the first CP to be one of the CP lengths in the second CP length set; this also reduces the range of values ​​for the first CP length, thereby reducing the time required to determine the length of the first CP.

[0385] Figure 12 is a flowchart illustrating another communication method provided in an embodiment of this application. Based on the method in Figure 2, Figure 12 describes an implementation of determining the length of the first CP based on FTS. As shown in Figure 12, the method includes:

[0386] 1201. Node G generates the first wireless frame.

[0387] The first radio frame includes a first CP, an FTS, an STS, a third CP, and synchronization information. The FTS is used to determine the length of the first CP. The length of the third CP is twice the length of the first CP. The first radio frame can be a synchronization information block. For a description of the first radio frame, please refer to the description of the first radio frame in step 501, which will not be repeated here.

[0388] 1202. Node G sends the first wireless frame.

[0389] Accordingly, node T receives the first radio frame.

[0390] When FTS is the first sequence, nodes 1203A and T determine the length of the first CP as the first CP length.

[0391] When the FTS is the second sequence, nodes 1203B and T determine the length of the first CP as the length of the second CP.

[0392] When the FTS is the third sequence, nodes 1203C and T determine the length of the first CP as the length of the third CP.

[0393] When the FTS is the fourth sequence, nodes 1203D and T determine the length of the first CP to be the length of the fourth CP.

[0394] Steps 1203A, 1203B, 1203C, and 1203D are four parallel steps. The method flow in Figure 12 may include any one of steps 1203A, 1203B, 1203C, and 1203D.

[0395] The first sequence, the second sequence, the third sequence, and the fourth sequence are four different sequences. The first CP length, the second CP length, the third CP length, and the fourth CP length are four different lengths. In this application, embodiments are described using examples of a first CP length of 18 basic time units, a second CP length of 39 basic time units, a third CP length of 64 basic time units, and a third CP length of 128 basic time units.

[0396] In one possible implementation, the first, second, third, and fourth sequences are rooted in different ZC sequences; this ensures consistent timing synchronization performance of the FTS even when the FTS sequences are different. Optionally, the first and second sequences are conjugate sequences, and the third and fourth sequences are conjugate sequences, thereby reducing the workload of sequence detection. For example, the first sequence is a ZC sequence rooted in 1, the second sequence is a ZC sequence rooted in 160, the first sequence is a ZC sequence rooted in 2, and the second sequence is a ZC sequence rooted in 159.

[0397] In another possible implementation, the first sequence, second sequence, third sequence, and fourth sequence are four different types of sequences, and the length of the first CP is determined according to which type of sequence it is. For example, the first sequence is a ZC sequence rooted at 1, the second sequence is an m sequence, the third sequence is a Golden sequence, and the fourth sequence is a Golay sequence.

[0398] In another possible implementation, the first and second sequences are of type 1, and the third and fourth sequences are of type 2. Since the first and second types are different, the length of the first CP is determined based on which type of sequence it is. For example, the first sequence is a ZC sequence rooted at 1, the second sequence is a ZC sequence rooted at 160, and the third and fourth sequences are different Golden sequences.

[0399] The T node can detect which sequence the FTS is, and thus determine the length of the first CP. As an example, the T node first checks if the FTS is the first sequence; if the FTS is not the first sequence, it checks if the FTS is the second sequence; if the FTS is not the second sequence, it checks if the FTS is the third sequence; if the FTS is not the third sequence, it checks if the FTS is the fourth sequence or determines that the FTS is the fourth sequence. As another example, the T node can simultaneously perform the following operations: check if the FTS is the first sequence; check if the FTS is the second sequence; check if the FTS is the third sequence; check if the FTS is the fourth sequence.

[0400] Optionally, after determining the length of the first CP, the T node performs synchronization based on the determined length of the first CP and decodes the information in the first radio frame.

[0401] The inventive concept of the method flow in Figure 12 is as follows: each possible length of the first CP corresponds to a sequence. After the T node detects a certain sequence, it determines the length of the first CP to be the length corresponding to that sequence. The method flow in Figure 12 illustrates an example where the length of the first CP has four possibilities. It should be understood that when the length of the first CP has more than four possibilities, the T node can use a method similar to that in Figure 12 to determine the length of the first CP.

[0402] In one possible implementation, the first CP also includes the CP preceding the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7A.

[0403] In one possible implementation, the first radio frame includes a second CP, which precedes the STS in the first radio frame. The first radio frame can be a synchronization information block. An example of the first radio frame is shown in Figure 7B. In this possible implementation, the method flow in Figure 10 can include the following steps: when the FTS is the first sequence, the T node determines the length of the second CP to be the length of the fifth CP; or, when the FTS is the second sequence, the T node determines the length of the second CP to be the length of the sixth CP; when the FTS is the third sequence, the T node determines the length of the second CP to be the length of the seventh CP; when the FTS is the fourth sequence, the T node determines the length of the second CP to be the length of the eighth CP. The lengths of the fifth CP, sixth CP, seventh CP, and eighth CP are four different lengths. This application embodiment describes examples with a fifth CP length of 34 basic time units, a sixth CP length of 59 basic time units, a seventh CP length of 64 basic time units, and an eighth CP length of 128 basic time units.

[0404] In this embodiment, when the FTS is the first sequence, the T node determines the length of the first CP to be the first CP length. Since detecting which sequence the FTS is requires less time than trying different CP lengths for synchronization and decoding, the synchronization time can be reduced.

[0405] The following describes the communication device provided in the embodiments of this application.

[0406] This application divides the communication device into functional modules according to the above method embodiments. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application is illustrative and only represents one logical functional division; other division methods may be used in actual implementation. The communication device of the embodiments of this application will be described in detail below with reference to Figures 13 to 15.

[0407] Figure 13 is a schematic diagram of a communication device 130 provided in an embodiment of this application. As shown in Figure 13, the communication device includes a processing module 1301 and a transceiver module 1302. The transceiver module 1302 can implement corresponding communication functions, and the processing module 1301 is used to implement corresponding processing functions. For example, the transceiver module 1302 can also be called an interface, a communication interface, or a communication module, etc.

[0408] In some embodiments of this application, the communication device can be used to perform the actions performed by the T node in the above method embodiments. In this case, the T node can be the T node itself or a chip or functional module configurable in the T node. The transceiver module 1302 is used to perform the transceiver-related operations of the T node in the above method embodiments, and the processing module 1301 is used to perform the processing-related operations of the T node in the above method embodiments.

[0409] In some embodiments, the transceiver module 1302 is configured to receive a first radio frame, the first radio frame including a first CP and an FTS; the processing module 1301 is configured to determine the length of the first CP based on the FTS.

[0410] In one possible implementation, the processing module 1301 is specifically used to determine the length of the first CP based on the sequence attributes of the FTS.

[0411] In one possible implementation, the processing module 1301 is specifically used to determine the length of the first CP to be 18 basic time units or 128 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, to determine the length of the first CP to be 39 basic time units or 64 basic time units.

[0412] In one possible implementation, the processing module 1301 is specifically used to determine the length of the first CP to be 39 basic time units or 128 basic time units when the FTS is a first sequence; or, when the FTS is a second sequence, to determine the length of the first CP to be 18 basic time units or 64 basic time units.

[0413] In one possible implementation, the processing module 1301 is specifically used to determine the length of the first CP as a CP length from the first CP length set when the FTS is a first sequence, or to determine the length of the first CP as a CP length from the second CP length set when the FTS is a second sequence.

[0414] In one possible implementation, the first radio frame further includes an STS and a third CP, the length of the third CP being twice the length of the first CP; in the first radio frame, the first CP is after the FTS, and the third CP is after the STS and before the FTS; the processing module 1301 is further configured to: determine the length of the first CP as 128 basic time units when three clusters of peaks are obtained by peak detection of the first radio frame based on the FTS; or, determine the length of the first CP as 18 basic time units when two clusters of peaks are obtained by peak detection of the first radio frame based on the FTS.

[0415] In one possible implementation, the first radio frame further includes an STS and a third CP, the length of which is twice the length of the first CP; in the first radio frame, the first CP is after the FTS, and the third CP is after the STS and before the FTS; the processing module 1301 is further configured to: determine the length of the first CP as 128 basic time units when three clusters of peaks are obtained by peak detection of the first radio frame based on the FTS; or, determine the length of the first CP as 39 basic time units when two clusters of peaks are obtained by peak detection of the first radio frame based on the FTS.

[0416] Reusing Figure 13, in some other embodiments of this application, the communication device can be used to perform the actions performed by the G node in the above method embodiments. In this case, the communication device can be the G node itself or a chip or functional module configurable in the G node. The transceiver module 1302 is used to perform the transceiver-related operations of the G node in the above method embodiments, and the processing module 1301 is used to perform the processing-related operations of the G node in the above method embodiments.

[0417] In some embodiments, the processing module 1301 is used to generate a first radio frame, the first radio frame including a first CP and an FTS; the transceiver module 1302 is used to transmit the first radio frame, the FTS being used to determine the length of the first CP.

[0418] Optionally, in the above embodiments, the communication device may further include a storage module, which can be used to store instructions and / or data. The processing module 1301 can read the instructions and / or data in the storage module so that the communication device can implement the aforementioned method embodiments.

[0419] For details regarding the specific explanations of each term, noun, or step in the above embodiments, please refer to the descriptions in the above method embodiments; they will not be detailed here.

[0420] The specific descriptions of the transceiver module and processing module shown in the above embodiments are merely examples. For the specific functions or execution steps of the transceiver module and processing module, please refer to the above method embodiments, which will not be described in detail here.

[0421] The communication device of the present application embodiments has been described above. The following describes possible product forms of the communication device. Any product possessing the functions of the communication device shown in FIG13 above falls within the protection scope of the present application embodiments. The following description is merely illustrative and does not limit the product form of the communication device of the present application embodiments to this.

[0422] It should be understood that the communication device 130 here is embodied in the form of a functional module. The term "module" here may refer to application-specific integrated circuits (ASICs), electronic circuits, processors (e.g., shared processors, proprietary processors, or group processors) and memories for executing one or more software or firmware programs, combined logic circuits, and / or other suitable components that support the described functions.

[0423] The communication device 130 of each of the above schemes has the function of implementing the corresponding steps performed by the communication device (such as a T node or a G node) in the above methods. This function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the transceiver module can be replaced by a transceiver (for example, the sending unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as processing modules, can be replaced by processors, which respectively execute the transmission and reception operations and related processing operations in each method embodiment.

[0424] In addition, the transceiver module 1302 can also be a transceiver circuit (for example, it may include a receiving circuit and a transmitting circuit), and the processing module 1301 can be a processing circuit.

[0425] Figure 14 is a schematic diagram of another communication device provided in an embodiment of this application. As shown in Figure 14, the communication device includes one or more processors 1420 and transceivers 1410.

[0426] In some embodiments of this application, the communication device is used to execute the steps, methods, or functions performed by the T node described above. For example, the processor 1420 can be used to execute the functions or steps implemented by the processing module 1301 shown in FIG. 13, and the transceiver 1410 can be used to execute the functions or steps implemented by the transceiver module 1302 shown in FIG. 13. Detailed descriptions of the processor 1420 and the transceiver 1410 can be found in FIG. 13 or the method embodiments shown above, and will not be elaborated further here.

[0427] In other embodiments of this application, the communication device can be used to execute the steps, methods, or functions performed by the G node described above. For example, the processor 1420 can be used to execute the functions or steps implemented by the processing module 1301 shown in FIG. 13, and the transceiver 1410 can be used to execute the functions or steps implemented by the transceiver module 1302 shown in FIG. 13. Detailed descriptions of the processor 1420 and the transceiver 1410 can be found in FIG. 13 or the method embodiments shown above, and will not be elaborated further here.

[0428] In various implementations of the communication device shown in Figure 14, the transceiver may include a receiver for performing a receiving function (or operation) and a transmitter for performing a transmitting function (or operation). The transceiver is also used to communicate with other devices / appliances via a transmission medium.

[0429] Optionally, the communication device may further include one or more memories 1430 for storing program instructions and / or data. The memory 1430 is coupled to the processor 1420. The coupling in this embodiment is an indirect coupling or communication connection between communication devices, units, or modules, and can be electrical, mechanical, or other forms, used for information exchange between the communication devices, units, or modules. The processor 1420 may operate in conjunction with the memory 1430. The processor 1420 may execute program instructions stored in the memory 1430. Optionally, at least one of the above-mentioned memories may be included in the processor.

[0430] This application embodiment does not limit the specific connection medium between the transceiver 1410, processor 1420, and memory 1430. In Figure 14, the memory 1430, processor 1420, and transceiver 1410 are connected via a bus 1440, which is represented by a thick line in Figure 14. The connection methods between other components are only illustrative and are not intended to be limiting. Buses can be divided into address buses, data buses, control buses, etc. For ease of illustration, only one thick line is used in Figure 14, but this does not mean that there is only one bus or one type of bus.

[0431] In the embodiments of this application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., and can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or being executed by a combination of hardware and software modules within the processor.

[0432] In this application embodiment, the memory may include, but is not limited to, non-volatile memory such as hard disk drive (HDD) or solid-state drive (SSD), random access memory (RAM), erasable programmable read-only memory (EPROM), read-only memory (ROM), or compact disc read-only memory (CD-ROM), etc. Memory is any storage medium capable of carrying or storing program code in the form of instructions or data structures, and capable of being read and / or written by a computer (such as the communication device shown in this application), but is not limited to this. The memory in this application embodiment may also be a circuit or any other device capable of implementing storage functions, used to store program instructions and / or data.

[0433] The processor 1420 is primarily used for processing communication protocols and data, controlling the entire communication device, executing software programs, and processing software program data. The memory 1430 is primarily used for storing software programs and data. The transceiver 1410 may include control circuitry and an antenna. The control circuitry is primarily used for converting baseband signals to radio frequency signals and processing radio frequency signals. The antenna is primarily used for transmitting and receiving radio frequency signals in the form of electromagnetic waves. Input / output devices, such as touchscreens, displays, and keyboards, are primarily used for receiving user input data and outputting data to the user.

[0434] When the communication device is powered on, the processor 1420 can read the software program in the memory 1430, 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 1420 performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit processes the baseband signal and transmits the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor 1420. The processor 1420 converts the baseband signal into data and processes the data.

[0435] In another implementation, the aforementioned radio frequency circuits and antennas can be set up independently of the processor that performs baseband processing. For example, in a distributed scenario, the radio frequency circuits and antennas can be arranged in a remote manner, independent of the communication device.

[0436] The communication device shown in this application embodiment may also have more components than those in Figure 14, and this application embodiment does not limit this. The methods executed by the processor and transceiver shown above are only examples, and the specific steps executed by the processor and transceiver can be referred to the methods described above.

[0437] In another possible implementation, in the communication device shown in FIG13, the processing module 1301 can be one or more logic circuits, and the transceiver module 1302 can be an input / output interface, or a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiver module 1302 can also be a sending module and a receiving module. The sending module can be an output interface, and the receiving module can be an input interface. The sending module and the receiving module are integrated into one module, such as an input / output interface. As shown in FIG15, the communication device shown in FIG15 includes a logic circuit 1501 and an interface 1502. FIG15 is another structural schematic diagram of the communication device provided in the embodiment of this application. The above-mentioned processing module 1301 can be implemented by the logic circuit 1501, and the transceiver module 1302 can be implemented by the interface 1502. Among them, the logic circuit 1501 can be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, etc., and the interface 1502 can be a communication interface, an input / output interface, a pin, etc. For example, Figure 15 uses the above-mentioned communication device as an example of a chip, which includes logic circuit 1501 and interface 1502.

[0438] In this embodiment, the logic circuit and the interface can also be coupled to each other. The specific connection method of the logic circuit and the interface is not limited in this embodiment. For example, the logic circuit 1501 can be used to execute the functions or steps implemented by the processing module 1301 shown in FIG. 13, and the interface 1502 can be used to execute the functions or steps implemented by the transceiver module 1302 shown in FIG. 13. For a detailed description of the logic circuit 1501 and the interface 1502, please refer to FIG. 13 or the method embodiment shown above, which will not be detailed here.

[0439] The communication device shown in the embodiments of this application can implement the method provided in the embodiments of this application in hardware form, or it can implement the method provided in the embodiments of this application in software form, etc., and the embodiments of this application do not limit it in this way.

[0440] Furthermore, embodiments of this application also provide a communication system including T nodes and G nodes, which can be used to execute the methods in any of the foregoing embodiments. Optionally, the communication system may also include other T nodes.

[0441] This application also provides a computer-readable storage medium storing a computer program or instructions that, when run on a computer, cause the computer to perform the methods of the above embodiments.

[0442] This application also provides a computer program product, which includes instructions or a computer program that, when run on a computer, causes the methods in the above embodiments to be executed.

[0443] This application also provides a chip, which includes: a communication interface and a processor; the communication interface is used for signal transmission and reception of the chip; the processor is used to execute computer program instructions, causing a communication device including the chip to perform the methods as described in the above embodiments.

[0444] In the several embodiments provided in this application, it should be understood that the disclosed systems, communication devices, and methods can be implemented in other ways. For example, the communication device embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, communication devices, or modules, or it may be an electrical, mechanical, or other form of connection. Modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of this application.

[0445] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0446] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0447] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) containing computer-usable program code.

[0448] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0449] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0450] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0451] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A communication method, characterized in that, include: Receive a first radio frame, the first radio frame including a first cyclic prefix (CP) and a first training sequence (FTS); Based on the FTS, the length of the first CP is determined.

2. The method according to claim 1, characterized in that, Based on the FTS, determining the length of the first CP includes: The length of the first CP is determined based on the sequence properties of the FTS.

3. The method according to claim 2, characterized in that, Based on the sequence properties of the FTS, the length of the first CP is determined, including: When the FTS is the first sequence, the length of the first CP is determined to be 18 basic time units or 128 basic time units; or, In the case that the FTS is the second sequence, the length of the first CP is determined to be 39 basic time units or 64 basic time units.

4. The method according to claim 2, characterized in that, Based on the sequence properties of the FTS, the length of the first CP is determined, including: When the FTS is the first sequence, the length of the first CP is determined to be 39 basic time units or 128 basic time units; or, In the case that the FTS is the second sequence, the length of the first CP is determined to be 18 basic time units or 64 basic time units.

5. The method according to any one of claims 1 to 4, characterized in that, In the first radio frame, the first CP follows the FTS.

6. The method according to claim 5, characterized in that, The first wireless frame further includes a second CP and a second training sequence STS, wherein the second CP precedes the STS, and the method further includes: Based on the FTS, the length of the second CP is determined.

7. The method according to claim 6, characterized in that, Based on the FTS, determining the length of the second CP includes: The length of the second CP is determined based on the sequence properties of the FTS.

8. The method according to claim 7, characterized in that, Based on the sequence properties of the FTS, the length of the second CP is determined, including: When the FTS is the first sequence, the length of the second CP is determined to be 34 basic time units or 128 basic time units; or, In the case that the FTS is the second sequence, the length of the second CP is determined to be 59 basic time units or 64 basic time units.

9. The method according to claim 7, characterized in that, Based on the sequence properties of the FTS, the length of the second CP is determined, including: When the FTS is the first sequence, the length of the second CP is determined to be 59 basic time units or 128 basic time units; or, In the case that the FTS is the second sequence, the length of the second CP is determined to be 34 basic time units or 64 basic time units.

10. The method according to claim 7, characterized in that, Based on the sequence properties of the FTS, the length of the second CP is determined, including: When the FTS is the first sequence, the length of the second CP is determined to be 20 basic time units, 22 basic time units, or 128 basic time units; or, In the case that the FTS is the second sequence, the length of the second CP is determined to be 44 basic time units or 64 basic time units.

11. The method according to claim 7, characterized in that, Based on the sequence properties of the FTS, the length of the second CP is determined, including: When the FTS is the first sequence, the length of the second CP is determined to be 44 basic time units or 128 basic time units; or, When the FTS is the second sequence, the length of the second CP is determined to be 20 basic time units, 22 basic time units, or 64 basic time units.

12. The method according to any one of claims 6 to 11, characterized in that, The first radio frame also includes third indication information, which is used to indicate the length of the first CP and the length of the second CP.

13. The method according to claim 12, characterized in that, The first wireless frame includes a synchronization information block, and one bit in the synchronization information of the synchronization information block is the third indication information.

14. The method according to any one of claims 1 to 5, characterized in that, The first radio frame also includes first indication information, which is used to indicate the length of the first CP.

15. The method according to claim 14, characterized in that, The first wireless frame includes a synchronization information block, and one bit in the synchronization information of the synchronization information block is the first indication information.

16. The method according to claim 3, 4, 8, 9, 10, or 11, characterized in that, The first sequence is a ZC sequence rooted at a first value, and the second sequence is a ZC sequence rooted at a second value, wherein the second value is different from the first value.

17. The method according to claim 3, 4, 8, 9, 10, 11, or 16, characterized in that, The first sequence and the second sequence are conjugate sequences.

18. The method according to any one of claims 1 to 17, characterized in that, The first radio frame also includes a third CP, the length of which is twice the length of the first CP; the first CP is after the FTS and the third CP is before the FTS.

19. A communication method, characterized in that, include: Generate a first radio frame, the first radio frame including a first cyclic prefix (CP) and a first training sequence (FTS); The first radio frame is transmitted, and the FTS is used by the receiver of the first radio frame to determine the length of the first CP.

20. The method according to claim 19, characterized in that, The sequence attribute of the FTS is used to determine the length of the first CP.

21. The method according to claim 20, characterized in that, The FTS is a first sequence, and the length of the first CP is 18 basic time units or 128 basic time units; or... The FTS is the second sequence, and the length of the first CP is 39 basic time units or 64 basic time units.

22. The method according to claim 20, characterized in that, The FTS is a first sequence, and the length of the first CP is 39 basic time units or 128 basic time units; or... The FTS is the second sequence, and the length of the first CP is 18 basic time units or 64 basic time units.

23. The method according to any one of claims 19 to 22, characterized in that, In the first radio frame, the first CP follows the FTS.

24. The method according to claim 23, characterized in that, The first radio frame also includes a second CP and a second training sequence STS, the second CP preceding the STS, and the FTS is also used to determine the length of the second CP.

25. The method according to claim 24, characterized in that, The sequence attributes of the FTS are used to determine the length of the second CP.

26. The method according to claim 25, characterized in that, The FTS is a first sequence, and the second CP has a length of 34 basic time units or 128 basic time units; or... The FTS is a second sequence, and the length of the second CP is 59 basic time units or 64 basic time units.

27. The method according to claim 25, characterized in that, The FTS is a first sequence, and the second CP has a length of 59 basic time units or 128 basic time units; or... The FTS is a second sequence, and the length of the second CP is 34 basic time units or 64 basic time units.

28. The method according to claim 25, characterized in that, The FTS is a first sequence, and the length of the second CP is 20 basic time units, 22 basic time units, or 128 basic time units; or... The FTS is a second sequence, and the length of the second CP is 44 basic time units or 64 basic time units.

29. The method according to claim 25, characterized in that, The FTS is a first sequence, and the second CP has a length of 44 basic time units or 128 basic time units; or... The FTS is a second sequence, and the length of the second CP is 20 basic time units, 22 basic time units, or 64 basic time units.

30. The method according to any one of claims 24 to 29, characterized in that, The first radio frame also includes third indication information, which is used to indicate the length of the first CP and the length of the second CP.

31. The method according to claim 30, characterized in that, The first wireless frame includes a synchronization information block, and one bit in the synchronization information of the synchronization information block is the third indication information.

32. The method according to any one of claims 19 to 23, characterized in that, The first radio frame also includes first indication information, which is used to indicate the length of the first CP.

33. The method according to claim 32, characterized in that, The first wireless frame includes a synchronization information block, and one bit in the synchronization information of the synchronization information block is the first indication information.

34. The method according to claim 21, 22, 26, 27, 28, or 29, characterized in that, The first sequence is a ZC sequence rooted at a first value, and the second sequence is a ZC sequence rooted at a second value, wherein the second value is different from the first value.

35. The method according to claim 21, 22, 26, 27, 28, 29, or 34, characterized in that, The first sequence and the second sequence are conjugate sequences.

36. The method according to any one of claims 19 to 35, characterized in that, The first radio frame also includes an STS and a third CP, the length of which is twice the length of the first CP; in the first radio frame, the first CP is after the FTS and the third CP is before the FTS.

37. A communication device, characterized in that, It includes a module for performing the method as described in any one of claims 1-18, or includes a module for performing the method as described in any one of claims 19-36.

38. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 36.

39. A chip, characterized in that, include: A communication interface and a processor; the communication interface is used for signal transmission and reception of the chip; the processor is used to execute a computer program or instructions, causing the communication device including the chip to perform the method as described in any one of claims 1 to 36.

40. A computer program product, characterized in that, When the computer program product is run on a computer, it causes the computer to perform the method as described in any one of claims 1 to 36.

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