Synchronization signal transmission method, device and system

Abstract

The embodiment of the invention provides a method, a device and a system for transmitting a synchronization signal, which are used for improving the transmission quality of the synchronization signal. The method comprises the following steps of: pre-coding a plurality of subsequences included in a synchronization sequence according to a corresponding relationship between a precoder and subsequence groups; wherein; a first sub-sequence in the plurality of sub-sequences is pre-coded by adopting a pre-coder corresponding to the sub-sequence group where the first sub-sequence is located; and sending a synchronization signal, wherein the synchronization signal comprises the plurality of pre-coded subsequences.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method, device and system for transmitting a synchronization signal. Background Art

[0002] Precoding technology is usually applied in multiple input multiple output (MIMO) systems. At the transmitting end of a signal, a precoder can be used to optimize the spatial characteristics of the transmitted signal, thereby eliminating interference between users.

[0003] In the existing transmission scheme, the base station uses a precoder to send a signal only after sending a synchronization signal to a user equipment (UE), which results in that the transmission quality of the synchronization signal cannot be guaranteed. Summary of the invention

[0004] The embodiments of the present application provide a method, device and system for transmitting a synchronization signal, which are used to improve the transmission quality of the synchronization signal.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, a method for transmitting a synchronization signal is provided, and a device for executing the method for transmitting the synchronization signal may be a network device, or may be a module applied to the network device, such as a chip or a chip system. The method for transmitting the synchronization signal comprises: precoding a plurality of subsequences included in a synchronization sequence according to a correspondence between a precoder and a subsequence group; wherein: a first subsequence among the plurality of subsequences is precoded using a precoder corresponding to a subsequence group to which the first subsequence belongs; and sending a synchronization signal, wherein the synchronization signal comprises the plurality of precoded subsequences.

[0007] In the synchronization signal transmission method provided in the embodiment of the present application, the network device can precode the subsequences according to the subsequence groups, thereby introducing a precoder to improve the transmission quality of the synchronization signal, thereby enabling the terminal device to achieve downlink synchronization faster and more accurately. In addition, the broadband terminal device can receive a complete synchronization signal including multiple precoded subsequences, and the narrowband terminal device can receive a partial synchronization signal including one or more precoded subsequences. For broadband terminal devices and narrowband terminal devices, the embodiment of the present application can adopt the same synchronization signal sending structure, thereby reducing the complexity of the cellular network system design and achieving the technical effect of saving time and frequency resources.

[0008] In combination with the first aspect above, in a possible implementation, the total length of the subsequences contained in the subsequence group is an integer multiple of a first preset value. The first preset value in this solution can be the number of subcarriers contained in the minimum PRG, so that the solution can be compatible with parameter settings in existing precoding technologies.

[0009] In combination with the first aspect, in a possible implementation, the total length of the subsequences included in the subsequence group is an integer multiple of a second preset value, wherein the total length of the subsequences included in the subsequence group is obtained by padding extension. The second preset value in the scheme may be less than or equal to the first preset value, that is, the scheme may break through the limitation of the minimum PRG in the existing precoding technology.

[0010] In combination with the above-mentioned first aspect, in a possible implementation method, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to each M subsequence groupings constitute the same precoder set, and the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer. In this scheme, the network device adopts multiple precoders, and can select a precoder with better reception performance for subsequent network devices to transmit signals to terminal devices. The embodiment of the present application does not impose any limitation on the order of the precoders corresponding to each M subsequence groupings. The order of the precoders corresponding to each M subsequence groupings can be the same or different.

[0011] In combination with the first aspect above, in a possible implementation, the precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the precoders corresponding to each M subsequence groupings are the same. In this solution, the order of the precoders corresponding to each M subsequence groupings can be the same.

[0012] In combination with the first aspect above, in a possible implementation, the precoders corresponding to every M subsequence groups constitute the same precoder set, including: the index value of the precoder is the remainder obtained by dividing the index value of the subsequence group by M.

[0013] In combination with the first aspect above, in a possible implementation manner, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to each subsequence grouping are different from each other.

[0014] In combination with the above first aspect, in a possible implementation manner, the precoder corresponding to any subsequence group corresponds to a codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and K is a positive integer.

[0015] In combination with the first aspect above, in a possible implementation, K is less than or equal to N, N represents the number of antennas, N is a positive integer, and the K codewords are mutually orthogonal. This solution can obtain diversity gain through the design of multiple antennas.

[0016] In combination with the above first aspect, in a possible implementation manner, K is greater than N, N represents the number of antennas, and N is a positive integer. The K codewords include N mutually orthogonal codewords, and the cross-correlation between the K codewords is minimal.

[0017] In combination with the first aspect above, in a possible implementation, the method further includes: receiving first information, the first information carrying an index of a first precoder and / or an index of a first subsequence group; the first subsequence group corresponds to the first precoder, and the first precoder is used for signal precoding. In this solution, the terminal device can select a first precoder with better reception performance to feed back to the network device, so that the network device can subsequently use the first precoder to improve the transmission quality when transmitting a signal to the terminal device.

[0018] In combination with the first aspect, in a possible implementation, the number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence. In this solution, the subsequence has a good ambiguity function performance, specifically, the correlation value of the sequence has a lower side lobe at the corresponding error delay and / or Doppler frequency offset.

[0019] In combination with the above first aspect, in a possible implementation manner, the subsequence included in the synchronization sequence is a longest linear shift register sequence or a multi-phase sequence.

[0020] In combination with the first aspect above, in a possible implementation manner, the first subsequence included in the synchronization sequence is a multi-phase sequence; and the general term of the first subsequence satisfies the following formula:

[0021]

[0022] Among them, a, b, c, d, p, q are constants; n=1, 2, ..., N, N represents the length of the first subsequence, and N is a positive integer; k=1, 2, ..., K, K represents the number of subsequences included in the synchronization sequence, and K is a positive integer.

[0023] In combination with the first aspect above, in a possible implementation, each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources. When each subsequence included in the synchronization sequence occupies the same frequency domain resources, for a terminal device, especially a second type of terminal device, the synchronization sequence may not be limited by bandwidth, so that the synchronization sequence may include more subsequences, or the synchronization sequence may carry more information.

[0024] In a second aspect, a method for transmitting a synchronization signal is provided. The device for executing the method for transmitting the synchronization signal may be a terminal device, or may be a module applied to the terminal device, such as a chip or a chip system. The method for transmitting the synchronization signal includes: when the terminal device is a terminal device of the first type, receiving a synchronization signal, the synchronization signal including a plurality of precoded subsequences; performing downlink synchronization according to the synchronization signal; or, when the terminal device is a terminal device of the second type, receiving one or more precoded subsequences in the synchronization signal; performing downlink synchronization according to one or more precoded subsequences in the synchronization signal; wherein the bandwidth of the signal received by the terminal device of the first type is wider than the bandwidth of the signal received by the terminal device of the second type.

[0025] In combination with the above second aspect, in a possible implementation manner, the total length of the subsequences included in the subsequence group is an integer multiple of a first preset value.

[0026] In combination with the above second aspect, in a possible implementation manner, the total length of the subsequences included in the subsequence group is an integer multiple of a second preset value, wherein the total length of the subsequences included in the subsequence group is obtained by padding extension.

[0027] In combination with the above-mentioned second aspect, in a possible implementation method, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to every M subsequence groups constitute the same precoder set, and the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer.

[0028] In combination with the above second aspect, in a possible implementation manner, the precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the precoders corresponding to each M subsequence groupings are the same.

[0029] In combination with the above second aspect, in a possible implementation manner, the precoders corresponding to each M subsequence groups constitute the same precoder set, including: the index value of the precoder is the remainder obtained by dividing the index value of the subsequence group by M.

[0030] In combination with the second aspect above, in a possible implementation manner, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to each subsequence grouping are different from each other.

[0031] In combination with the above second aspect, in a possible implementation manner, the precoder corresponding to any subsequence group corresponds to one codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and K is a positive integer.

[0032] In combination with the above second aspect, in a possible implementation manner, K is less than or equal to N, N represents the number of antennas, N is a positive integer, and the K codewords are mutually orthogonal.

[0033] In combination with the above second aspect, in a possible implementation manner, K is greater than N, N represents the number of antennas, N is a positive integer, the K codewords include N mutually orthogonal codewords, and the mutual correlation between the K codewords is minimal.

[0034] In combination with the above-mentioned second aspect, in a possible implementation manner, the method also includes: sending first information, the first information carrying an index of a first precoder and / or an index of a first subsequence group; the first subsequence group corresponds to the first precoder, and the first precoder is used for signal precoding.

[0035] In combination with the second aspect above, in a possible implementation manner, the number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence.

[0036] In combination with the above second aspect, in a possible implementation manner, the first subsequence included in the synchronization sequence is a multi-phase sequence; and the general term of the first subsequence satisfies the following formula:

[0037]

[0038] Among them, a, b, c, d, p, q are constants; n=1, 2, ..., N, N represents the length of the first subsequence, and N is a positive integer; k=1, 2, ..., K, K represents the number of subsequences included in the synchronization sequence, and K is a positive integer.

[0039] In combination with the above second aspect, in a possible implementation manner, each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources.

[0040] In a third aspect, a communication device is provided for implementing the above method. The communication device includes a module, unit, or means corresponding to the above method, and the module, unit, or means can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0041] In combination with the third aspect above, in a possible implementation, the communication device includes: a precoding module and a transceiver module. The precoding module is used to precode multiple subsequences included in the synchronization sequence according to the corresponding relationship between the precoder and the subsequence grouping; wherein: the first subsequence among the multiple subsequences is precoded using the precoder corresponding to the subsequence grouping to which the first subsequence belongs; the transceiver module is used to send a synchronization signal, and the synchronization signal includes the multiple subsequences after precoding.

[0042] In combination with the third aspect above, in a possible implementation manner, the total length of the subsequences included in the subsequence group is an integer multiple of a first preset value.

[0043] In combination with the third aspect above, in a possible implementation manner, the total length of the subsequences included in the subsequence group is an integer multiple of a second preset value, wherein the total length of the subsequences included in the subsequence group is obtained by padding extension.

[0044] In combination with the above-mentioned third aspect, in a possible implementation method, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to every M subsequence groups constitute the same precoder set, and the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer.

[0045] In combination with the third aspect above, in a possible implementation manner, the precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the precoders corresponding to each M subsequence groupings are the same.

[0046] In combination with the third aspect above, in a possible implementation, the precoders corresponding to every M subsequence groups constitute the same precoder set, including: the index value of the precoder is the remainder obtained by dividing the index value of the subsequence group by M.

[0047] In combination with the third aspect above, in a possible implementation manner, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to each subsequence grouping are different from each other.

[0048] In combination with the third aspect above, in a possible implementation manner, the precoder corresponding to any subsequence group corresponds to one codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and K is a positive integer.

[0049] In combination with the third aspect above, in a possible implementation manner, K is less than or equal to N, where N represents the number of antennas, and N is a positive integer, and the K codewords are mutually orthogonal.

[0050] In combination with the third aspect above, in a possible implementation, K is greater than N, N represents the number of antennas, and N is a positive integer. The K codewords include N mutually orthogonal codewords, and the cross-correlation between the K codewords is minimal.

[0051] In combination with the above-mentioned third aspect, in a possible implementation method, the transceiver module is also used to receive first information, which carries the index of the first precoder and / or the index of the first subsequence group; the first subsequence group corresponds to the first precoder, and the first precoder is used for signal precoding.

[0052] In combination with the third aspect above, in a possible implementation manner, the number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence.

[0053] In combination with the third aspect, in a possible implementation manner, the first subsequence included in the synchronization sequence is a multi-phase sequence; and the general term of the first subsequence satisfies the following formula:

[0054]

[0055] Among them, a, b, c, d, p, q are constants; n=1, 2, ..., N, N represents the length of the first subsequence, and N is a positive integer; k=1, 2, ..., K, K represents the number of subsequences included in the synchronization sequence, and K is a positive integer.

[0056] In combination with the third aspect above, in a possible implementation manner, each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources.

[0057] In a fourth aspect, a communication device is provided for implementing the above method. The communication device includes a module, unit, or means corresponding to the above method, and the module, unit, or means can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0058] In combination with the fourth aspect above, in a possible implementation, the communication device includes: a transceiver module and a synchronization module. In the case where the communication device is a first type of communication device, the transceiver module is used to receive a synchronization signal, and the synchronization signal includes multiple precoded subsequences; the synchronization module is used to perform downlink synchronization according to the synchronization signal; or, in the case where the communication device is a second type of communication device, the transceiver module is used to receive one or more precoded subsequences in the synchronization signal; the synchronization module is used to perform downlink synchronization according to one or more precoded subsequences in the synchronization signal; wherein the bandwidth of the signal received by the first type of communication device is wider than the bandwidth of the signal received by the second type of communication device.

[0059] In combination with the fourth aspect above, in a possible implementation manner, the total length of the subsequences included in the subsequence group is an integer multiple of a first preset value.

[0060] In combination with the fourth aspect above, in a possible implementation manner, the total length of the subsequences included in the subsequence group is an integer multiple of a second preset value, wherein the total length of the subsequences included in the subsequence group is obtained by padding extension.

[0061] In combination with the fourth aspect above, in a possible implementation method, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to every M subsequence groups constitute the same precoder set, and the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer.

[0062] In combination with the fourth aspect above, in a possible implementation manner, the precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the precoders corresponding to each M subsequence groupings are the same.

[0063] In combination with the fourth aspect, in a possible implementation, the precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the index value of the precoder is the remainder obtained by dividing the index value of the subsequence grouping by M.

[0064] In combination with the fourth aspect above, in a possible implementation manner, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to each subsequence grouping are different from each other.

[0065] In combination with the fourth aspect above, in a possible implementation manner, the precoder corresponding to any subsequence group corresponds to one codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and K is a positive integer.

[0066] In combination with the fourth aspect above, in a possible implementation manner, K is less than or equal to N, where N represents the number of antennas, and N is a positive integer, and the K codewords are mutually orthogonal.

[0067] In combination with the fourth aspect above, in a possible implementation, K is greater than N, N represents the number of antennas, N is a positive integer, the K codewords include N mutually orthogonal codewords, and the cross-correlation between the K codewords is minimal.

[0068] In combination with the above-mentioned fourth aspect, in a possible implementation method, the transceiver module is also used to send first information, which carries the index of the first precoder and / or the index of the first subsequence group; the first subsequence group corresponds to the first precoder, and the first precoder is used for signal precoding.

[0069] In combination with the fourth aspect above, in a possible implementation manner, the number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence.

[0070] In combination with the fourth aspect, in a possible implementation manner, the first subsequence included in the synchronization sequence is a multi-phase sequence; and the general term of the first subsequence satisfies the following formula:

[0071]

[0072] Among them, a, b, c, d, p, q are constants; n=1, 2, ..., N, N represents the length of the first subsequence, and N is a positive integer; k=1, 2, ..., K, K represents the number of subsequences included in the synchronization sequence, and K is a positive integer.

[0073] In combination with the fourth aspect above, in a possible implementation manner, each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources.

[0074] In a fifth aspect, a communication device is provided, comprising: a processor; the processor is used to couple with a memory, and after reading a computer instruction stored in the memory, execute the method as described in the first aspect or the second aspect according to the instruction.

[0075] In combination with the fifth aspect above, in a possible implementation, the communication device also includes a memory; the memory is used to store computer instructions.

[0076] In conjunction with the fifth aspect, in a possible implementation, the communication device further includes a communication interface; the communication interface is used for the communication device to communicate with other devices. Exemplarily, the communication interface can be a transceiver, an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit, etc.

[0077] In conjunction with the fifth aspect, in a possible implementation, the communication device may be a chip or a chip system. When the communication device is a chip system, the communication device may be composed of a chip, or may include a chip and other discrete devices.

[0078] In conjunction with the fifth aspect, in a possible implementation, when the communication device is a chip or a chip system, the communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip or the chip system. The processor may also be embodied as a processing circuit or a logic circuit.

[0079] In a sixth aspect, a communication system is provided, comprising: a network device executing the method described in the first aspect above, and a terminal device executing the method described in the second aspect above.

[0080] In a seventh aspect, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium, and when the computer-readable storage medium is run on a computer, the computer can execute the method described in the first aspect or the second aspect above.

[0081] In an eighth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the method described in any one of the first or second aspects above.

[0082] Among them, the technical effects brought about by any possible implementation method of the second to eighth aspects can refer to the technical effects brought about by the above-mentioned first aspect or different implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 A schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0084] Figure 2 A schematic diagram of the structure of the communication device provided in the embodiment of the present application Figure 1 ;

[0085] Figure 3 A flowchart of a synchronization signal transmission method provided in an embodiment of the present application;

[0086] Figure 4 A schematic diagram of the correspondence between a precoder and a subsequence grouping provided in an embodiment of the present application;

[0087] Figure 5A A schematic diagram of the correspondence between another precoder and subsequence grouping provided in an embodiment of the present application;

[0088] Figure 5B A schematic diagram of a correspondence relationship between another precoder and subsequence grouping provided in an embodiment of the present application;

[0089] Figure 6 A schematic diagram of the structure of the communication device provided in the embodiment of the present application Figure 2 ;

[0090] Figure 7 A schematic diagram of the structure of the communication device provided in the embodiment of the present application Figure 3 . DETAILED DESCRIPTION

[0091] In order to facilitate understanding of the technical solutions of the embodiments of the present application, a brief introduction to the relevant technologies or terms of the present application is first given as follows.

[0092] First, the application scenarios of sequences.

[0093] A sequence can be a set of numbers or a set of elements arranged in order. In different scenarios, a specific sequence can use its own structure and properties to achieve specific functions. The following will explain the application scenarios and functions of sequences.

[0094] In a communication system, a terminal device needs to access a network after being powered on. However, the terminal device does not know the prior information of the network, and thus cannot normally receive information from the network device. Therefore, the terminal device first needs to search the network and determine information such as timing information and frequency resources used by the network. In order for the terminal device to obtain this information, the network device can periodically send a synchronization signal carried on a synchronization channel to the terminal device. Among them, the synchronization signal can be generated according to a predefined sequence or one of multiple sequences, and the sequence included in the synchronization signal can be referred to as a synchronization sequence. Accordingly, the terminal device can search for a synchronization signal at multiple preset frequency points according to a predefined synchronization sequence, or a synchronization sequence that may be received. Once the terminal device searches for the synchronization signal, it means that the network has been successfully searched. Afterwards, the terminal device can perform time synchronization, as well as frequency offset estimation and compensation, so as to subsequently receive signal system broadcast information and other signals. It can be seen that the sequence plays an important role in the initial synchronization process. Furthermore, the detection performance of the sequence, as well as the ability to resist frequency deviation, interference and noise, determine whether the terminal device can successfully access the network and the speed of successful access to the network. The detection performance of the sequence can be characterized by sequence correlation.

[0095] Since the above synchronization signal is sent by the network device to the terminal device, the above synchronization signal can also be called a downlink synchronization signal, and the above synchronization process can also be called an uplink synchronization. In addition to downlink synchronization, the sequence can also be applied to uplink synchronization. Specifically, after obtaining the information required for accessing the network, the terminal device can attempt to communicate with the network device to notify the network device of its existence and cooperate with the network device to complete the subsequent access process. Similar to downlink synchronization, the terminal device can send an uplink synchronization signal on a reserved random access resource. Among them, the uplink synchronization signal may include an uplink synchronization sequence. Accordingly, the network device will detect the uplink synchronization signal on each reserved random access resource to know whether there is a terminal device requesting to access the network. While detecting the uplink synchronization signal, the network device will also estimate the uplink timing advance parameter and send the estimation result to the terminal device. The terminal device can adjust the timing of its own uplink transmission according to the estimation result, so that the uplink transmission of multiple terminal devices can achieve frame, subframe, time slot or symbol level synchronization. It can be seen that the detection performance of the sequence, as well as the ability to resist frequency offset, interference and noise also determine the detection performance of the uplink random access request and the performance of the uplink timing advance parameter estimation.

[0096] In addition to synchronization scenarios, sequences can also be used in multiple access systems. For example, code division multiple access can use sequences as spreading codes, and different terminal devices use different spreading codes. Since the spreading codes can be orthogonal, when a network device uses the spreading code of a certain terminal device during reception, it can eliminate the influence of information from other terminal devices, thereby completing the reception of information from a specific terminal device. Similarly, in resource reuse and information transmission scenarios, such as pilot multiplexing scenarios, sequences can be used as a means of code division. It can be seen that sequence correlation affects the performance of multiple access systems.

[0097] Sequences can also be used in the design of low peak to average power ratio (PAPR) signals. For communication systems that use orthogonal frequency division multiplexing (OFDM) or similar frequency domain modulation as waveforms, one of the important factors to be considered may be the PAPR of the signal, especially the uplink signal, including the PAPR of the uplink random access signal and / or the uplink pilot signal. In the above communication system, the characteristics of a specific sequence can be used to design a low PAPR signal.

[0098] In future communication systems, such as the sixth generation (6G) mobile communication system, the combination of communication and perception will be a new main feature. In the study of perception and communication perception integration, the sequence can affect the realization and performance of the perception function. Specifically, during the wireless transmission of the signal, a time delay will be generated due to the transmission distance, and a frequency offset, namely, Doppler frequency deviation, will be generated due to the relative movement between the transceiver and the receiver. The target to be detected can send a specific sequence known to both the transceiver and the receiver. Accordingly, the receiving end can detect the time delay and Doppler frequency deviation of the received specific sequence transmitted through the channel relative to the specific sequence, thereby calculating the distance and speed information of the target to be detected. In order to achieve better perception performance, the specific sequence needs to have better fuzzy function performance. Specifically, the correlation value of the specific sequence has a peak value at the corresponding correct time delay and / or Doppler frequency deviation, and has a lower side lobe at the corresponding incorrect time delay and / or Doppler frequency deviation.

[0099] In addition to the above application scenarios, sequences are also widely used in scenarios including scrambling, encryption, and codebook generation in precoding of communication systems. In short, the future research trend for sequences is to achieve better performance in solving classic problems on the one hand, and to propose new sequence designs and expand new application scenarios on the other hand. Since the definitions of sequences in existing systems are numerous and complex, and lack a systematic definition method, it is urgent to study systematic sequence generation methods that are applicable to a variety of scenarios and have multiple functions in future communication systems.

[0100] Second, the existing synchronization signal transmission method.

[0101] In one possible implementation, the synchronization signal including the PSS and the SSS may be sent in a synchronization signal and physical broadcast channel block (synchronization signal and PBCH block, SSB).

[0102] In an LTE network, the transmission period of PSS or SSS may be 5 milliseconds (ms), and the transmission period of PBCH may be 10 ms. The length of the synchronization sequence included in PSS may be 63, and SSS may include two synchronization sequences of length 31. PBCH may occupy 6 resource blocks (RBs).

[0103] In the NR network, the period of SSB transmission for initial access may be 20 ms. The synchronization sequence included in the PSS may be a maximum linear shift register sequence of length 127, and the synchronization sequence included in the SSS may be a Gold sequence of length 127. The maximum linear shift register sequence (maximal length linear shift register sequence) may also be referred to as an m sequence.

[0104] PSS and SSS can occupy 12 RBs each, and PBCH can occupy 20 RBs. In NR networks, SSBs can include PSS, SSS, and PBCH.

[0105] The PSS or SSS sent by the base station to the UE includes a synchronization sequence, and as described in the background technology, the base station uses a precoder to send a signal only after sending a synchronization signal including the PSS and / or SSS to the UE. This will result in the transmission quality of the synchronization signal being unable to be guaranteed.

[0106] In order to ensure the transmission quality of the synchronization signal, in an embodiment of the present application, the network device may precode multiple subsequences according to the subsequence grouping, thereby improving the transmission quality of the synchronization signal by introducing precoding in advance.

[0107] The technical solution in the embodiment of the present application will be described below in conjunction with the drawings in the embodiment of the present application. Among them, in the description of the present application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; "and / or" in the present application is only a description of the associated relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. And, in the description of the present application, unless otherwise specified, "multiple" refers to two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second" and the like are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not necessarily limit the differences. At the same time, in the embodiments of the present application, the words "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design solutions. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0108] Figure 1 The schematic diagram of the architecture of the mobile communication system shown is a schematic diagram of the architecture of the communication system 1000 applied in the embodiment of the present application. Figure 1 As shown, the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include the Internet 300. The wireless access network 100 may include at least one wireless access network device (such as Figure 1 110a and 110b), and may also include at least one terminal device (such as Figure 1120a-120j in the figure). The terminal device is connected to the wireless access network device by wireless means, and the wireless access network device is connected to the core network by wireless or wired means. The core network device and the wireless access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device can be integrated on the same physical device, or part of the functions of the core network device and part of the functions of the wireless access network device can be integrated on one physical device. Terminal devices and terminal devices, as well as wireless access network devices and wireless access network devices can be connected to each other by wired or wireless means. Figure 1 The figure is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices. Figure 1 Not drawn in.

[0109] The radio access network device is an access device that the terminal device accesses to the communication system by wireless means. The radio access network device may be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in the fifth generation (5G) mobile communication system, a next generation base station in the 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc.; in another possible scenario, multiple radio access network (RAN) nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, a RAN node may be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and DU may be set separately, or may be included in the same network element, such as a baseband unit (BBU). The RU may be included in a radio frequency device or a radio frequency unit, for example, in a remote radio unit (RRU), an active antenna unit (AAU) or a remote radio head (RRH).

[0110] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open RAN (open RAN, ORAN) system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application takes CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. The embodiments of the present application may be implemented by DU or RU.

[0111] The wireless access network device can be a macro base station (such as Figure 1 110a), or a micro base station or an indoor station (such as Figure 1 110b), may also be a relay node or a donor node, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the wireless access network device. For ease of description, the following description takes a base station as an example of a wireless access network device.

[0112] The terminal device is a device with wireless transceiver function, which can send signals to the base station or receive signals from the base station. The terminal device can also be called a terminal, user equipment (UE), mobile station, mobile terminal device, etc. The terminal device can be widely used in various scenarios, for example, device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, automatic driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0113] Base stations and terminal devices can be fixed or mobile. Base stations and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on airplanes, balloons, and artificial satellites. The embodiments of this application do not limit the application scenarios of base stations and terminal devices.

[0114] The roles of base stations and terminal devices can be relative, for example, Figure 1 The helicopter or drone 120i in the figure can be configured as a mobile base station. For the terminal devices 120j that access the wireless access network 100 through 120i, the terminal device 120i is a base station; but for the base station 110a, 120i is a terminal device, that is, 110a and 120i communicate through the wireless air interface protocol. Of course, 110a and 120i can also communicate through the interface protocol between base stations. In this case, relative to 110a, 120i is also a base station. Therefore, base stations and terminal devices can be collectively referred to as communication devices. Figure 1 110a and 110b in the figure may be referred to as communication devices having base station functions. Figure 1 120a-120j in the figure can be called communication devices with terminal equipment functions.

[0115] Base stations and terminal devices, base stations and base stations, and terminal devices and terminal devices can communicate through authorized spectrum, unauthorized spectrum, or both; they can communicate through spectrum below 6 gigahertz (GHz), spectrum above 6 GHz, or spectrum below 6 GHz and spectrum above 6 GHz. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0116] Functions such as synchronization, channel estimation, and perception can be achieved between the base station and the terminal device through a sequence. In the embodiment of the present application, the synchronization signal sent by the base station to the terminal device may include a synchronization sequence. Accordingly, the terminal device can achieve downlink synchronization based on the partial or complete synchronization signal received from the base station. Among them, synchronization can be understood as the process of establishing time synchronization and / or frequency synchronization between the base station and the terminal device. Specifically, the transmitting end can send a specific sequence, namely the synchronization sequence. The receiving end can detect this specific sequence. Afterwards, the receiving end can adjust its own timing according to the time of the detected specific sequence, and / or the receiving end can adjust its own carrier frequency according to the frequency of the detected specific sequence. Alternatively, afterwards, the receiving end can notify the transmitting end to adjust the timing and / or carrier frequency. For the downlink, the transmitting end can be a base station, and the receiving end can be a terminal device. For the uplink, the transmitting end can be a terminal device, and the receiving end can be a base station.

[0117] In the embodiments of the present application, the functions of the base station may also be performed by a module (such as a chip) in the base station, or by a control subsystem including the base station functions. The control subsystem including the base station functions here may be a control center in the above-mentioned application scenarios such as smart grid, industrial control, smart transportation, smart city, etc. The functions of the terminal device may also be performed by a module (such as a chip or a modem) in the terminal device, or by a device including the terminal device functions.

[0118] In this application, the base station sends a downlink signal or downlink information to the terminal device, and the downlink information is carried on the downlink channel; the terminal device sends an uplink signal or uplink information to the base station, and the uplink information is carried on the uplink channel. In order to communicate with the base station, the terminal device needs to establish a wireless connection with the cell controlled by the base station. The cell with which the terminal device has established a wireless connection is called the service cell of the terminal device. When the terminal device communicates with the service cell, it will also be interfered by signals from neighboring cells.

[0119] For example, the network device 110 provided in the embodiment of the present application may be Figure 1 110a or 110b in the embodiment of the present application, the terminal device 120 provided in the embodiment of the present application may be Figure 1 Any one of 120a-120j.

[0120] Optionally, the relevant functions of the terminal device or network device in the embodiment of the present application can be implemented by one device, or by multiple devices together, or by one or more functional modules in one device, and the embodiment of the present application does not specifically limit this. It is understandable that the above functions can be network elements in hardware devices, or software functions running on dedicated hardware, or a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0121] For example, the relevant functions of the terminal device or network device in the embodiment of the present application can be Figure 2 It is implemented by the communication device 20 in.

[0122] Figure 2 FIG. 2 is a schematic diagram of the structure of a communication device 20 provided in an embodiment of the present application. The communication device 20 includes one or more processors 201, a communication line 202, and at least one communication interface ( Figure 2 The example in which the communication interface 204 and a processor 201 are included is merely exemplary), and a memory 203 may also be included optionally.

[0123] The processor 201 may be a CPU, a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0124] The communication line 202 may include pathways for connecting different components.

[0125] The communication interface 204 may be a transceiver module for communicating with other devices or communication networks, such as Ethernet, RAN, WLAN, etc. For example, the transceiver module may be a device such as a transceiver or a transceiver. Optionally, the communication interface 204 may also be a transceiver circuit located in the processor 201 to implement signal input and signal output of the processor.

[0126] The memory 203 may be a device with a storage function. For example, it may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be connected to the processor via a communication line 202. The memory may also be integrated with the processor.

[0127] The memory 203 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 201. The processor 201 is used to execute the computer-executable instructions stored in the memory 203, thereby realizing the synchronization signal transmission method provided in the embodiment of the present application.

[0128] Alternatively, in an embodiment of the present application, the processor 201 may also perform processing-related functions in the synchronization signal transmission method provided in the following embodiments of the present application, and the communication interface 204 is responsible for communicating with other devices or communication networks, which is not specifically limited in the embodiments of the present application.

[0129] The computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which is not specifically limited in the embodiments of the present application.

[0130] In a specific implementation, as an embodiment, the processor 201 may include one or more CPUs, such as Figure 2 CPU0 and CPU1 in.

[0131] In a specific implementation, as an embodiment, the communication device 20 may include multiple processors, such as Figure 2 201 and processor 207 in the embodiment of the present invention. Each of these processors may be a single-CPU processor or a multi-CPU processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0132] In a specific implementation, as an embodiment, the communication device 20 may further include an output device 205 and an input device 206. The output device 205 communicates with the processor 201 and may display information in a variety of ways.

[0133] The communication device 20 may be a general purpose device or a dedicated device. For example, the communication device 20 may be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a vehicle-mounted terminal device, an embedded device, or a computer having Figure 2 The embodiment of the present application does not limit the type of the communication device 20.

[0134] The following will be combined Figure 1 and Figure 2 The synchronization signal transmission method provided in the embodiment of the present application is specifically described.

[0135] like Figure 3 As shown, a synchronization signal transmission method provided in an embodiment of the present application includes the following steps:

[0136] Step S301: The network device precodes a plurality of subsequences included in a synchronization sequence according to a correspondence between precoders and subsequence groups.

[0137] The first subsequence among the multiple subsequences is precoded using a precoder corresponding to the subsequence group to which the first subsequence belongs.

[0138] Exemplarily, the synchronization sequence in the embodiment of the present application may be a PSS sequence or an SSS sequence. The subsequence grouping in the embodiment of the present application may be a part of a synchronization sequence included in the PSS or SSS.

[0139] The multiple subsequences in the embodiment of the present application may constitute the synchronization sequence included in the synchronization signal in the existing synchronization signal transmission method. In the embodiment of the present application, each subsequence may be mapped to multiple subcarriers of OFDM in the frequency domain.

[0140] Optionally, the number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence. In this scheme, the synchronization sequence can be equally divided into K subsequences, that is, the number of subsequences included in the synchronization signal can be expressed as K. The length of the subsequence can be expressed as N. Exemplarily, K=N=11. Simulation results show that in this scheme, the subsequence has a better ambiguity function performance, specifically, the correlation value of the sequence has a lower sidelobe at the corresponding error delay and / or Doppler frequency offset.

[0141] In the embodiment of the present application, the values ​​of K and N may also be different. In addition, the lengths of the multiple subsequences included in the synchronization signal may also be different, that is, the synchronization sequence may be divided into K subsequences, and the lengths of at least two subsequences in the K subsequences are different. The embodiment of the present application does not impose any limitation on this.

[0142] Optionally, the subsequence included in the synchronization signal is a longest linear shift register sequence or a multi-phase sequence.

[0143] Optionally, the first subsequence included in the synchronization signal is a multi-phase sequence; the general term of the first subsequence satisfies the following formula (1):

[0144]

[0145] Wherein, a, b, c, d, p, q are constants; n = 1, 2, ..., N, N represents the length of the first subsequence, N is a positive integer; k = 1, 2, ..., K, K represents the number of subsequences included in the synchronization signal, K is a positive integer. In particular, p = 3, q ​​= 2, then the above formula (1) can be expressed as formula (2):

[0146]

[0147] Optionally, each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources. In this scheme, the multiple subsequences included in the synchronization sequence can be mapped to multiple consecutive subcarriers of OFDM. Alternatively, the multiple subsequences included in the synchronization sequence can be mapped to multiple consecutive OFDM symbols, and each subsequence can be mapped to multiple consecutive subcarriers of OFDM. The embodiments of the present application do not impose any restrictions on this. When each subsequence included in the synchronization sequence occupies the same frequency domain resources, for terminal devices, especially the second type of terminal devices, the synchronization sequence may not be limited by bandwidth, so that the synchronization sequence can include more subsequences, or the synchronization sequence can carry more information.

[0148] Optionally, the total length of the subsequences contained in the subsequence group is an integer multiple of the first preset value. The first preset value in the embodiment of the present application can be the number of subcarriers contained in the minimum precoding resource block group (PRG), so that the scheme can be compatible with the parameter setting in the existing precoding technology. Assuming that the minimum PRG is two RBs, since each RB contains 12 subcarriers in the frequency domain, the first preset value can be 24.

[0149] Assuming that the synchronization sequence includes 12 subsequences of 12 bits in length, the 12 subsequences can be divided into 2 subsequence groups, each of which includes 6 subsequences of 12 bits in length, that is, the length of each subsequence group is 72 bits, which is 3 times of 24. Alternatively, the 12 subsequences can be divided into 3 subsequence groups, each of which includes 4 subsequences of 12 bits in length, that is, the length of each subsequence group is 48 bits, which is 2 times of 24. Alternatively, the 12 subsequences can be divided into 6 subsequence groups, each of which includes 2 subsequences of 12 bits in length, that is, the length of each subsequence group is 24 bits, which is 1 times of 24.

[0150] Optionally, the total length of the subsequences contained in the subsequence group is an integer multiple of the second preset value, wherein the total length of the subsequences contained in the subsequence group is obtained by padding extension. The embodiment of the present application does not impose any limitation on the padding method. The second preset value in the embodiment of the present application may be less than or equal to the first preset value, that is, the scheme can break through the limitation of the minimum PRG in the existing precoding technology. The second preset value may be, for example, 12 or 24. The following is described by taking the second preset value of 12 as an example.

[0151] Optionally, the total length of the subsequences contained in the subsequence group may not be an integer multiple of the second preset value. Assuming that the synchronization sequence includes 11 subsequences with a length of 11 bits, then the 11 subsequences can be divided into 11 subsequence groups, each of which can include 1 subsequence with a length of 11 bits, that is, the length of each subsequence group is 11 bits, which is not an integer multiple of 12. Alternatively, the 11 subsequences can be divided into 11 subsequence groups, and each subsequence group can be extended to 12 in length by padding, such as padding 0 or cycling padding.

[0152] Exemplarily, the synchronization sequence may include 6 subsequences, and each subsequence may be 6 bits long. The first subsequence group may include 1 subsequence with a length of 6; the second subsequence group may include 2 subsequences with a length of 12; and the third subsequence group may include 3 subsequences with a length of 18. Since the lengths of the first and third groups are 6 and 18, respectively, which are not integer multiples of 12, the lengths of the first and third groups may be extended to 12 and 24, respectively. Alternatively, the subsequences may be grouped according to integer multiples of 12, for example, every two subsequences may be grouped together, and the length of each subsequence group is 12.

[0153] In the embodiment of the present application, one subsequence group may correspond to one encoder.

[0154] Optionally, the correspondence between the precoder and the subsequence grouping includes: the precoders corresponding to each M subsequence groupings constitute the same precoder set, the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer. In this scheme, the network device uses multiple precoders, and can select a precoder with better reception performance for subsequent network devices to transmit signals to terminal devices. The embodiment of the present application does not impose any limitation on the order of the precoders corresponding to each M subsequence groupings. The order of the precoders corresponding to each M subsequence groupings can be the same or different.

[0155] Exemplarily, assuming that the subsequence is divided into 11 subsequence groups, the precoder set consisting of the precoders corresponding to every 3 subsequence groups can be {precoder 1, precoder 2, precoder 3}. Among them, different precoder indexes indicate different precoders. The precoders corresponding to the remaining 2 subsequence groups can be any two of precoder 1, precoder 2 or precoder 3.

[0156] Optionally, the precoders corresponding to each M subsequence groups constitute the same precoder set, including: the precoders corresponding to each M subsequence groups are the same. In this scheme, the order of the precoders corresponding to each M subsequence group can be the same. Exemplarily, assuming that the subsequence is divided into 9 subsequence groups, K=9, M=3, then the 1st, 2nd, and 3rd subsequence groups can correspond to precoder 2, precoder 3, and precoder 1, respectively; the 4th, 5th, and 6th subsequence groups can also correspond to precoder 2, precoder 3, and precoder 1, respectively; the 7th, 8th, and 9th subsequence groups can also correspond to precoder 2, precoder 3, and precoder 1, respectively.

[0157] Optionally, the precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the index value of the precoder is the remainder obtained by dividing the index value of the subsequence grouping by M. Exemplarily, assuming that the subsequence is divided into 11 subsequence groups, K=11, M=3, then the 1st, 4th, 7th and 10th subsequence groups can correspond to precoder 1; the 2nd, 5th, 8th and 11th subsequence groups can correspond to precoder 2; the 3rd, 6th and 9th subsequence groups can correspond to precoder 3.

[0158] For example, Figure 4It is a schematic diagram of the correspondence between a precoder and a subsequence grouping. Among them, the synchronization sequence may include 11 subsequences with a length of 11 bits. The 11 subsequences can be divided into 11 subsequence groups, and each subsequence grouping may include 1 subsequence with a length of 11 bits. Each subsequence or each subsequence grouping may be carried on 11 consecutive subcarriers, and each subsequence or each subsequence grouping corresponds to a precoder. Specifically, the 1st, 4th, 7th and 10th subsequences may correspond to precoder 1; the 2nd, 5th, 8th and 11th subsequences may correspond to precoder 2; the 3rd, 6th and 9th subsequences may correspond to precoder 3. Figure 4 The subsequence in can be a PSS subsequence or an SSS subsequence.

[0159] Optionally, the correspondence between the precoders and the subsequence groups includes: the precoders corresponding to each subsequence group are different.

[0160] Combination Figure 4 , Figure 5A Schematic diagram of another correspondence between a precoder and a subsequence group. The synchronization sequence may include 11 subsequences of 11 bits in length. The 11 subsequences may be divided into 11 subsequence groups, each of which may include 1 subsequence of 11 bits in length. Each subsequence or each subsequence group may be carried on 11 consecutive subcarriers, and each subsequence or each subsequence group corresponds to a precoder. Figure 4 The difference is that in Figure 5A , the i-th subsequence may correspond to precoder i, where i=1, 2, ..., 11. Figure 5A The subsequence in can be a PSS subsequence or an SSS subsequence.

[0161] Combination Figure 5A , Figure 5B FIG. 1 is a schematic diagram showing the corresponding relationship between another precoder and subsequence grouping. Figure 5A Similarly, the precoders corresponding to each subsequence group are different. Figure 5B In , the i-th subsequence can correspond to precoder i, i = 1, 2, ..., 5. Figure 5A The difference is, Figure 5B The subsequences are grouped differently. Specifically, the first subsequence group may include subsequence 1 and subsequence 2; the second subsequence group may include subsequence 3 and subsequence 4; the third subsequence group may include subsequence 5 and subsequence 6; the fourth subsequence group may include subsequence 7 and subsequence 8; the fifth subsequence group may include subsequence 9 and subsequence 10; and the sixth subsequence group may include subsequence 11. Figure 5BThe subsequence in can be a PSS subsequence or an SSS subsequence.

[0162] It should be noted that Figure 5B Only one example of grouping 11 subsequences is shown. In fact, other grouping methods may be used, and the present application embodiment does not limit this. For example, the fifth subsequence group may include subsequence 9, subsequence 10, and subsequence 11, and the sixth subsequence group does not exist. In addition, Figure 5B The correspondence between the precoder and the subsequence grouping can also be expressed as Figure 4 The correspondence between the precoder and the subsequence grouping. That is, the first and fourth subsequence groups may correspond to precoder 1; the second and fifth subsequence groups may correspond to precoder 2; the third and sixth subsequence groups may correspond to precoder 3; the embodiment of the present application does not impose any limitation on this.

[0163] Optionally, the precoder corresponding to any subsequence group corresponds to one codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and K is a positive integer.

[0164] In the embodiment of the present application, one precoder may correspond to one codeword, or the precoder and the codeword may correspond one to one, or one precoder may be associated with one codeword. This is explained uniformly here and will not be repeated below.

[0165] Optionally, K is less than or equal to N, N represents the number of antennas, N is a positive integer, and the K codewords are mutually orthogonal. This solution can obtain diversity gain through the design of multiple antennas.

[0166] Exemplarily, when K=3 and N=4, precoder 6, precoder 8, and precoder 9 may be selected.

[0167] Optionally, K is greater than N, N represents the number of antennas, N is a positive integer, the K codewords include N mutually orthogonal codewords, and the mutual correlation between the K codewords is minimal.

[0168] Exemplarily, when K=6 and N=4, encoder 0, precoder 1, precoder 2, precoder 3, precoder 20, and precoder 22 may be selected.

[0169] Step S302: The network device sends a synchronization signal to the terminal device, wherein the synchronization signal includes a plurality of precoded subsequences.

[0170] Optionally, the synchronization signal transmission method provided in the embodiment of the present application also includes: the terminal device sends first information to the network device. The first information carries the index of the first precoder and / or the index of the first subsequence grouping; the first subsequence grouping corresponds to the first precoder, and the first precoder is used for signal precoding. Accordingly, the network device receives the first information from the terminal device. In this scheme, the terminal device can select the first precoder with better receiving performance to feed back to the network device, so that the network device can use the first precoder to improve the transmission quality when transmitting the signal to the terminal device later.

[0171] Specifically, the first precoder is used by the network device to precode the signal sent to the terminal device.

[0172] Exemplarily, the first precoder may be used by the network device to precode a random access response (RAR) and / or a message (MSG) 4 sent to the terminal device.

[0173] When the terminal device is a terminal device of the first type, the following step S303 is performed:

[0174] Step S303: The terminal device receives a synchronization signal from the network device and performs downlink synchronization according to the synchronization signal.

[0175] Alternatively, when the terminal device is a terminal device of the second type, the following step S304 is performed:

[0176] Step S304: The terminal device receives one or more precoded subsequences in a synchronization signal from the network device, and performs downlink synchronization according to the one or more precoded subsequences in the synchronization signal.

[0177] The bandwidth of the signal received by the first type of terminal device is wider than the bandwidth of the signal received by the second type of terminal device.

[0178] Exemplarily, the first type of terminal device in the embodiment of the present application may be a broadband terminal device, and the second type of terminal device in the embodiment of the present application may be a narrowband terminal device, such as a narrowband Internet of Things (NB-IoT) terminal device.

[0179] In the synchronization signal transmission method provided in the embodiment of the present application, the network device can precode the subsequences according to the subsequence groups, thereby introducing a precoder to improve the transmission quality of the synchronization signal, thereby enabling the terminal device to achieve downlink synchronization faster and more accurately. In addition, the broadband terminal device can receive a complete synchronization signal including multiple precoded subsequences, and the narrowband terminal device can receive a partial synchronization signal including one or more precoded subsequences. For broadband terminal devices and narrowband terminal devices, the embodiment of the present application can adopt the same synchronization signal sending structure, thereby reducing the complexity of the cellular network system design and achieving the technical effect of saving time and frequency resources.

[0180] It can be understood that in the above embodiments, the methods and / or steps implemented by the network device can also be implemented by components (such as chips or circuits) that can be used for the network device or by an apparatus including the network device; the methods and / or steps implemented by the terminal device can also be implemented by components (such as chips or circuits) that can be used for the terminal device or by an apparatus including the terminal device.

[0181] It is understandable that, in order to realize the above functions, the network device or terminal device includes a hardware structure and / or software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0182] The embodiment of the present application can divide the functional modules of the network device or terminal device according to the above method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0183] For example, the network device in the embodiment of the present application can adopt Figure 6 The communication device 600 shown in the figure is implemented. The communication device 600 may include a precoding module 601 and a transceiver module 602. The communication device 600 is used to implement the above Figures 3 to 5B The functions of the network device in the method embodiment are shown.

[0184] For example, when the communication device 600 is used to implement Figure 3 The functions of the network device in the method embodiment shown are: a precoding module 601, used to precode multiple subsequences included in the synchronization sequence according to the corresponding relationship between the precoder and the subsequence grouping; a transceiver module 602, sending a synchronization signal.

[0185] For a more detailed description of the above precoding module 601 and the transceiver module 602, please refer to Figures 3 to 5B The method embodiment shown is described in detail.

[0186] For another example, the terminal device in the embodiment of the present application may adopt Figure 7 The communication device 700 shown in the figure is implemented. The communication device 700 may include a transceiver module 701 and a synchronization module 702. The communication device 700 is used to implement the above Figures 3 to 5B The functions of the terminal device in the method embodiment are shown.

[0187] For example, when the communication device 700 is used to implement Figure 3 The functions of the terminal device in the method embodiment shown are: when the terminal device is a first type of terminal device, the transceiver module 701 is used to receive a synchronization signal; the synchronization module 702 is used to perform downlink synchronization according to the synchronization signal; or, when the terminal device is a second type of terminal device, the transceiver module 701 is used to receive one or more precoded subsequences in the synchronization signal; the synchronization module 702 is used to perform downlink synchronization according to one or more precoded subsequences in the synchronization signal.

[0188] For more detailed description of the above-mentioned transceiver module 701 and synchronization module 702, please refer to Figures 3 to 5B The method embodiment shown is described in detail.

[0189] In this embodiment, the communication device 600 or the communication device 700 may be presented in the form of dividing various functional modules in an integrated manner. The "module" here may refer to a specific ASIC, a circuit, a processor and a memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions.

[0190] In a simple embodiment, those skilled in the art will appreciate that the communication device 600 may be configured as follows: Figure 2 The form of the communication device 20 is shown.

[0191] for example, Figure 2 The processor 201 and / or the processor 207 in the communication device 20 shown can call the computer-executable instructions stored in the memory 203, so that the communication device 20 executes the synchronization signal transmission method in the above method embodiment. Specifically, Figure 6 Part of the functions / implementation process of the precoding module 601 in Figure 2 The processor 201 and / or the processor 207 in the communication device 20 shown calls the computer execution instructions stored in the memory 203 to implement; Figure 6 Part of the functions / implementation process of the transceiver module 602 in the embodiment can be achieved by Figure 2 This is achieved by using a communication module connected to the communication interface 204 in the embodiment.

[0192] In a simple embodiment, those skilled in the art will appreciate that the communication device 700 may be configured as follows: Figure 2 The form of the communication device 20 is shown.

[0193] for example, Figure 2 The processor 201 and / or the processor 207 in the communication device 20 shown can call the computer-executable instructions stored in the memory 203, so that the communication device 20 executes the synchronization signal transmission method in the above method embodiment. Specifically, Figure 7 Part of the functions / implementation process of the transceiver module 701 in the embodiment can be achieved by Figure 2 This is achieved by using a communication module connected to the communication interface 204 in the embodiment. Figure 7 Part of the functions / implementation process of the synchronization module 702 in can be achieved by Figure 2 The processor 201 and / or the processor 207 in the communication device 20 shown call the computer execution instructions stored in the memory 203 to implement.

[0194] Since the communication device 600 and the communication device 700 provided in this embodiment can execute the above-mentioned method for transmitting the synchronization signal, the technical effects that can be obtained can refer to the above-mentioned method embodiments and will not be repeated here.

[0195] It should be noted that one or more of the above modules or units can be implemented by software, hardware or a combination of the two. When any of the above modules or units is implemented by software, the software exists in the form of computer program instructions and is stored in a memory, and a processor can be used to execute the program instructions and implement the above method flow. The processor can be built into an SoC (system on chip) or an ASIC, or it can be an independent semiconductor chip. In addition to the core used to execute software instructions for calculation or processing in the processor, it can also further include necessary hardware accelerators, such as field programmable gate arrays (FPGA), PLDs (programmable logic devices), or logic circuits that implement dedicated logic operations.

[0196] When the above modules or units are implemented in hardware, the hardware can be any one or any combination of a CPU, a microprocessor, a digital signal processing (DSP) chip, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, a SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator or a non-integrated discrete device, which can run the necessary software or not rely on the software to execute the above method flow.

[0197] Optionally, an embodiment of the present application further provides a chip system, including: at least one processor and an interface, the at least one processor is coupled to a memory through the interface, and when the at least one processor executes a computer program or instruction in the memory, the method in any of the above method embodiments is executed. In one possible implementation, the communication device also includes a memory. Optionally, the chip system can be composed of chips, or can include chips and other discrete devices, which is not specifically limited in the embodiments of the present application.

[0198] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or may contain one or more servers, data centers and other data storage devices that can be integrated with the medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0199] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0200] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for transmitting a synchronization signal, characterized in that: The method comprises: Precoding a plurality of subsequences included in a synchronization sequence according to a correspondence between a precoder and a subsequence group; wherein a first subsequence among the plurality of subsequences is precoded using a precoder corresponding to a subsequence group in which the first subsequence is located; A synchronization signal is sent, where the synchronization signal includes the multiple precoded subsequences.

2. The method according to claim 1, characterized in that The total length of the subsequences contained in the subsequence group is an integer multiple of a first preset value.

3. The method according to claim 1, characterized in that The total length of the subsequences contained in the subsequence group is an integer multiple of a second preset value, wherein the total length of the subsequences contained in the subsequence group is obtained by padding extension.

4. The method according to any one of claims 1 to 3, characterized in that: The correspondence between the precoders and the subsequence groups includes: the precoders corresponding to every M subsequence groups constitute the same precoder set, and the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer.

5. The method according to claim 4, characterized in that The precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the precoders corresponding to each M subsequence groupings are the same.

6. The method according to any one of claims 1 to 3, characterized in that: The correspondence between the precoders and the subsequence groups includes: the precoders corresponding to each subsequence group are different from each other.

7. The method according to claim 6, characterized in that The precoder corresponding to any subsequence group corresponds to one codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and is a positive integer.

8. The method according to claim 7, characterized in that K is less than or equal to N, where N represents the number of antennas and is a positive integer, and the K codewords are orthogonal to each other.

9. The method according to claim 7, characterized in that: K is greater than N, where N represents the number of antennas and is a positive integer. The K codewords include N mutually orthogonal codewords, and the mutual correlation between the K codewords is minimal.

10. The method according to any one of claims 1 to 9, characterized in that: The method further comprises: First information is received, where the first information carries an index of a first precoder and / or an index of a first subsequence grouping; the first subsequence grouping corresponds to the first precoder, and the first precoder is used for signal precoding.

11. The method according to any one of claims 1 to 10, characterized in that: The number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence.

12. The method according to claim 11, characterized in that The first subsequence included in the synchronization sequence is a multi-phase sequence; the general term of the first subsequence satisfies the following formula: Among them, a, b, c, d, p, q are constants; n=1, 2, ..., N, N represents the length of the first subsequence, and N is a positive integer; k=1, 2, ..., K, K represents the number of subsequences included in the synchronization sequence, and K is a positive integer.

13. The method according to claim 11 or 12, characterized in that: Each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources.

14. A method for transmitting a synchronization signal, characterized in that: Applied to terminal equipment, including: In the case where the terminal device is a terminal device of the first type, receiving a synchronization signal, the synchronization signal including a plurality of precoded subsequences; performing downlink synchronization according to the synchronization signal; or, In the case where the terminal device is a terminal device of the second type, receiving one or more precoded subsequences in the synchronization signal; performing downlink synchronization according to the one or more precoded subsequences in the synchronization signal; The bandwidth of the signal received by the first type of terminal device is wider than the bandwidth of the signal received by the second type of terminal device.

15. The method according to claim 14, characterized in that The total length of the subsequences contained in the subsequence group is an integer multiple of a first preset value.

16. The method according to claim 14, characterized in that The total length of the subsequences contained in the subsequence group is an integer multiple of a second preset value, wherein the total length of the subsequences contained in the subsequence group is obtained by padding extension.

17. The method according to any one of claims 14 to 16, characterized in that: The correspondence between the precoders and the subsequence groups includes: the precoders corresponding to every M subsequence groups constitute the same precoder set, and the precoder set includes M different precoders, M is a positive integer, 1<M<K, K represents the number of subsequence groups, and K is a positive integer.

18. The method according to claim 17, characterized in that The precoders corresponding to each M subsequence groupings constitute the same precoder set, including: the precoders corresponding to each M subsequence groupings are the same.

19. The method according to any one of claims 14 to 16, characterized in that: The correspondence between the precoders and the subsequence groups includes: the precoders corresponding to each subsequence group are different from each other.

20. The method according to claim 19, characterized in that The precoder corresponding to any subsequence group corresponds to one codeword among K codewords selected from the precoding matrix, where K represents the number of subsequence groups and is a positive integer.

21. The method according to claim 20, characterized in that K is less than or equal to N, where N represents the number of antennas and is a positive integer, and the K codewords are orthogonal to each other.

22. The method according to claim 20, characterized in that K is greater than N, where N represents the number of antennas and is a positive integer. The K codewords include N mutually orthogonal codewords, and the mutual correlation between the K codewords is minimal.

23. The method according to any one of claims 14 to 22, characterized in that: The method further comprises: Sending first information, where the first information carries an index of a first precoder and / or an index of a first subsequence group; the first subsequence group corresponds to the first precoder, and the first precoder is used for signal precoding.

24. The method according to any one of claims 14 to 23, characterized in that: The number of subsequences included in the synchronization sequence is the same as the length of each subsequence included in the synchronization sequence.

25. The method according to claim 24, characterized in that The first subsequence included in the synchronization sequence is a multi-phase sequence; the general term of the first subsequence satisfies the following formula: Among them, a, b, c, d, p, q are constants; n=1, 2, ..., N, N represents the length of the first subsequence, and N is a positive integer; k=1, 2, ..., K, K represents the number of subsequences included in the synchronization sequence, and K is a positive integer.

26. The method according to claim 24 or 25, characterized in that Each subsequence included in the synchronization sequence occupies the same time domain resources, or each subsequence included in the synchronization sequence occupies the same frequency domain resources.

27. A communication device, characterized in that: The communication device includes: a module or unit for implementing the method according to any one of claims 1 to 13; or a module or unit for implementing the method according to any one of claims 14 to 26.

28. A communication device, characterized in that: include: A memory and a processor coupled to the memory, the memory being used to store a program, and the processor being used to execute the program stored in the memory; when the communication device is running, the processor runs the program, so that the communication device executes the method described in any one of claims 1 to 13; or, the communication device executes the method described in any one of claims 14 to 26.

29. A communication system, characterized in that: The communication system includes a network device and a terminal device; wherein the network device is used to execute the method according to any one of claims 1-13, and the terminal device is used to execute the method according to any one of claims 14-26.

30. A computer-readable storage medium, characterized in that: A computer program is stored thereon, which, when executed by a computer, enables the computer to execute the method described in any one of claims 1 to 13; or, when executed by a computer, enables the computer to execute the method described in any one of claims 14 to 26.

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