Doppler frequency offset determination method and device, equipment and storage medium

Abstract

The present disclosure proposes a Doppler frequency offset determination method, apparatus and device, and a storage medium, the method comprising: a terminal sampling from an initial signal sequence sent by a space node in each time slot to obtain a plurality of first signal sequences, and determining a second signal sequence matched with the first signal sequences, the second signal sequence comprising: a synchronization code, and processing each first signal sequence and each second signal sequence to obtain a plurality of first complex sequences, determining a target complex sequence matched with the synchronous code from the plurality of first complex sequences, and determining Doppler frequency offset according to the target complex sequence corresponding to each time slot in a plurality of continuous time slots. According to the invention, the Doppler frequency can be accurately determined based on the target complex sequence matched with the synchronous code in the plurality of continuous time sequences, so that the requirement for determining the Doppler frequency offset in a low signal-to-noise ratio scene can be effectively met.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communication technology, and in particular to a method, device, equipment and storage medium for determining a Doppler frequency shift. Background Art

[0002] As a new type of communication system, the space network communication system has its own dedicated communication system. Especially for power-limited areas, it uses spread spectrum technology to reduce signal power. In addition, the large Doppler frequency deviation caused by the high-speed movement of low-orbit satellites will make it extremely difficult for user equipment to initially access the cell. Therefore, it is necessary to determine the Doppler frequency deviation before the user equipment initially accesses the cell, and then complete the frequency deviation compensation. Summary of the invention

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the purpose of the present disclosure is to propose a method, device, communication equipment and storage medium for determining Doppler frequency deviation, which can accurately determine the Doppler frequency based on a target complex sequence matching synchronization codes in multiple consecutive time sequences, thereby effectively meeting the determination requirements of Doppler frequency deviation in low signal-to-noise ratio scenarios.

[0005] The method for determining Doppler frequency shift proposed in the embodiment of the first aspect of the present disclosure includes:

[0006] Sampling an initial signal sequence sent by the spatial node in each time slot to obtain a plurality of first signal sequences;

[0007] The terminal determines a second signal sequence that matches the first signal sequence, wherein the second signal sequence includes: a synchronization code;

[0008] Processing each of the first signal sequence and the second signal sequence to obtain a plurality of first complex number sequences;

[0009] Determine a target complex sequence matching the synchronization code from a plurality of first complex sequences;

[0010] A Doppler frequency offset is determined according to a target complex sequence corresponding to each time slot in a plurality of consecutive time slots.

[0011] In some embodiments of the present disclosure, determining a target complex number sequence matching a synchronization code from a plurality of first complex number sequences includes:

[0012] Acquire position information of the synchronization code in the second signal sequence;

[0013] A target complex number sequence matching the synchronization code is determined from a plurality of first complex number sequences according to the position information.

[0014] In some embodiments of the present disclosure, determining a target complex number sequence matching a synchronization code from a plurality of first complex number sequences according to the position information includes:

[0015] sorting the first complex number sequences corresponding to each first signal sequence according to the sampling time of each first signal sequence;

[0016] Determine a second complex number sequence corresponding to the position information from the sorted plurality of first complex number sequences;

[0017] Determine a preset number of third complex number sequences adjacent to the second complex number sequence from the sorted plurality of first complex number sequences;

[0018] The second complex number sequence and a preset number of third complex number sequences are used together as a target complex number sequence.

[0019] In some embodiments of the present disclosure, determining the Doppler frequency shift according to a target complex sequence corresponding to each time slot in a plurality of consecutive time slots includes:

[0020] Acquire a frequency domain signal sequence corresponding to each target complex sequence;

[0021] Taking the modulus of each element in the frequency domain signal sequence to determine the amplitude value of the frequency domain signal sequence at different frequency components;

[0022] The Doppler frequency shift is determined according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in a plurality of consecutive time slots when the frequency domain signal sequence is in different frequency components.

[0023] In some embodiments of the present disclosure, obtaining a frequency domain signal sequence corresponding to each target complex sequence includes:

[0024] Perform fast Fourier transform on each target complex sequence to obtain a frequency domain signal sequence.

[0025] In some embodiments of the present disclosure, multiple frequency domain signal sequences in each time slot are arranged based on sampling time;

[0026] Wherein, determining the Doppler frequency shift according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in the continuous multiple time slots when in different frequency components includes:

[0027] Accumulating the amplitude values ​​of the frequency domain signal sequences at the same arrangement position in a plurality of consecutive time slots at the same frequency component to determine a plurality of amplitude sum values;

[0028] Based on the multiple amplitudes and values, a Doppler frequency shift is determined.

[0029] In some embodiments of the present disclosure, each first signal sequence and second signal sequence is processed to obtain a plurality of first complex number sequences, including:

[0030] Each of the first signal sequence and the second signal sequence is input into a correlator together to obtain a first complex sequence.

[0031] In some embodiments of the present disclosure, a plurality of first signal sequences are obtained by sampling an initial signal sequence sent by a spatial node in each time slot, including:

[0032] receiving an initial signal sequence respectively sent by the spatial node in each time slot;

[0033] The initial signal sequence in each time slot is sampled based on a preset clock cycle to obtain a plurality of first signal sequences.

[0034] The Doppler frequency shift determination device provided in the second aspect of the present disclosure includes:

[0035] A sampling module, used for sampling from an initial signal sequence sent by a spatial node in each time slot to obtain a plurality of first signal sequences;

[0036] A first determination module is used for the terminal to determine a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code;

[0037] A processing module, configured to process each of the first signal sequence and the second signal sequence to obtain a plurality of first complex number sequences;

[0038] A second determination module, configured to determine a target complex number sequence matching the synchronization code from a plurality of first complex number sequences;

[0039] The third determination module is used to determine the Doppler frequency deviation according to the target complex sequence corresponding to each time slot in a plurality of consecutive time slots.

[0040] In some embodiments of the present disclosure, the second determining module is further configured to:

[0041] Acquire position information of the synchronization code in the second signal sequence;

[0042] A target complex number sequence matching the synchronization code is determined from a plurality of first complex number sequences according to the position information.

[0043] In some embodiments of the present disclosure, the second determining module is further configured to:

[0044] sorting the first complex number sequences corresponding to each first signal sequence according to the sampling time of each first signal sequence;

[0045] Determine a second complex number sequence associated with the position information from the sorted plurality of first complex number sequences;

[0046] Determine a preset number of third complex number sequences adjacent to the second complex number sequence from the sorted plurality of first complex number sequences;

[0047] The second complex number sequence and a preset number of third complex number sequences are used together as a target complex number sequence.

[0048] In some embodiments of the present disclosure, the third determining module is further configured to:

[0049] Acquire a frequency domain signal sequence corresponding to each target complex sequence;

[0050] Taking the modulus of each element in the frequency domain signal sequence to determine the amplitude value of the frequency domain signal sequence at different frequency components;

[0051] The Doppler frequency shift is determined according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in a plurality of consecutive time slots when the frequency domain signal sequence is in different frequency components.

[0052] In some embodiments of the present disclosure, the third determining module is further configured to:

[0053] Perform fast Fourier transform on each target complex sequence to obtain a frequency domain signal sequence.

[0054] In some embodiments of the present disclosure, multiple frequency domain signal sequences in each time slot are arranged based on sampling time;

[0055] Wherein, the third determination module is further used for:

[0056] Accumulating the amplitude values ​​of the frequency domain signal sequences at the same arrangement position in a plurality of consecutive time slots at the same frequency component to determine a plurality of amplitude sum values;

[0057] Based on the multiple amplitudes and values, a Doppler frequency shift is determined.

[0058] In some embodiments of the present disclosure, the third determining module is further configured to:

[0059] determining a maximum amplitude and value from among the plurality of amplitudes and values;

[0060] If the maximum amplitude sum value is greater than or equal to the amplitude threshold, the frequency component corresponding to the maximum amplitude sum value is determined as the Doppler frequency shift.

[0061] In some embodiments of the present disclosure, the processing module is specifically configured to:

[0062] Each of the first signal sequence and the second signal sequence is input into a correlator together to obtain a first complex sequence.

[0063] In some embodiments of the present disclosure, the sampling module is further used to:

[0064] receiving an initial signal sequence respectively sent by the spatial node in each time slot;

[0065] The initial signal sequence in each time slot is sampled based on a preset clock cycle to obtain a plurality of first signal sequences.

[0066] The communication device proposed in the third aspect embodiment of the present disclosure includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for determining the Doppler frequency deviation proposed in the first aspect embodiment of the present disclosure is implemented.

[0067] The fourth aspect embodiment of the present disclosure proposes a non-temporary computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the method for determining the Doppler frequency offset proposed in the first aspect embodiment of the present disclosure is implemented.

[0068] The fifth aspect of the present disclosure provides a computer program product. When the instructions in the computer program product are executed by a processor, the steps of the method for determining the Doppler frequency offset provided in the first aspect of the present disclosure are performed.

[0069] The present disclosure proposes a method, apparatus, communication device and storage medium for determining Doppler frequency deviation. The terminal obtains multiple first signal sequences by sampling from an initial signal sequence sent by a spatial node in each time slot, and determines a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code, and then processes each first signal sequence and the second signal sequence to obtain multiple first complex number sequences, and then determines a target complex number sequence matching the synchronization code from the multiple first complex number sequences, and determines the Doppler frequency deviation according to the target complex number sequence corresponding to each time slot in a plurality of consecutive time slots, thereby being able to accurately determine the Doppler frequency based on the target complex number sequence matching the synchronization code in a plurality of consecutive time sequences, thereby being able to effectively meet the determination requirements of the Doppler frequency deviation in low signal-to-noise ratio scenarios.

[0070] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0072] Figure 1 is a schematic diagram of the architecture of a communication system provided by an embodiment of the present disclosure;

[0073] Figure 2 is a flow chart of a method for determining a Doppler frequency shift provided by an embodiment of the present disclosure;

[0074] Figure 3 is a block diagram of the implementation principle of the correlator provided by the embodiment of the present disclosure;

[0075] Figure 4 is a flow chart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0076] Figure 5A is a data cache diagram of a target complex sequence provided according to an embodiment of the present disclosure;

[0077] Figure 5B is a schematic diagram of a data cache structure in RAM1 provided according to an embodiment of the present disclosure;

[0078] Figure 6 is a flow chart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0079] Fig. 7A is a schematic diagram of the processing flow corresponding to the FFT module provided in the embodiment of the present disclosure;

[0080] Figure 7B It is a schematic diagram of the modulus process of the frequency domain signal sequence provided by the embodiment of the present disclosure;

[0081] Figure 7C is a schematic diagram of the data cache structure in RAM2 provided in an embodiment of the present disclosure;

[0082] Figure 8 is a structural schematic diagram of a device for determining a Doppler frequency shift provided by an embodiment of the present disclosure;

[0083] Fig. 9 A block diagram of an exemplary communication device suitable for implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0084] Embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and are not to be construed as limitations of the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications, and equivalents that fall within the spirit and connotation of the appended claims.

[0085] In order to better understand a method for determining a Doppler frequency shift disclosed in an embodiment of the present disclosure, a communication system to which the embodiment of the present disclosure is applicable is first described below.

[0086] See also Figure 1 , Figure 1 Schematic diagram of the architecture of a communication system provided by an embodiment of the present disclosure. The communication system may include but is not limited to a satellite and a terminal device. Figure 1 The number and form of the devices shown are for illustrative purposes only and do not constitute a limitation on the embodiments of the present disclosure. In actual applications, two or more spatial nodes and two or more terminal devices may be included. Figure 1 The communication system shown includes a space node 101 and a terminal device 102 as an example.

[0087] The space node 101 in the embodiment of the present disclosure is an entity for transmitting or receiving signals. The embodiment of the present disclosure does not limit the specific technology and specific device form adopted by the space node.

[0088] The terminal device 102 in the embodiment of the present disclosure is an entity on the user side for receiving or transmitting signals, such as a mobile phone. The terminal device may also be referred to as a terminal device (terminal), user equipment (UE), mobile station (MS), mobile terminal device (MT), etc. The terminal device may be a car with communication function, a smart car, a mobile phone, a wearable device, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control (industrial control), a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in smart grid (smart grid), a wireless terminal device in transportation safety (transportation safety), a wireless terminal device in smart city (smart city), a wireless terminal device in smart home (smart home), etc. The embodiment of the present disclosure does not limit the specific technology and specific device form adopted by the terminal device.

[0089] It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution provided by the embodiment of the present disclosure. A person skilled in the art can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution provided by the embodiment of the present disclosure is also applicable to similar technical problems.

[0090] The Doppler frequency deviation determination method and device provided by the present disclosure are described in detail below with reference to the accompanying drawings. Figure 2 It is a flow chart of a method for determining a Doppler frequency deviation provided by an embodiment of the present disclosure.

[0091] like Figure 2 As shown, the method may include but is not limited to the following steps:

[0092] S201: A plurality of first signal sequences are obtained by sampling an initial signal sequence sent by a spatial node in each time slot.

[0093] The space node may refer to a node in wireless communication or a node in satellite communication, for example. In a satellite communication system, a satellite may serve as a space node and play the role of a signal repeater, transmitting a signal from one earth station to another earth station. The space node in the embodiment of the present disclosure may refer to a low-orbit multi-beam satellite, for example, or may refer to any other type of space node device, without limitation.

[0094] The spatial node may send a signal sequence to the terminal device in each time slot, and the signal sequence is the initial signal sequence.

[0095] Among them, the multiple partial signal sequences sampled from the initial signal sequence can be called the first signal sequence.

[0096] That is to say, in some embodiments, the terminal device may intercept multiple partial signal sequences of a preset signal sequence length from the initial signal sequence sent by the space node in each time slot as the first signal sequence.

[0097] Optionally, in some other embodiments, multiple first signal sequences are sampled from the initial signal sequence sent by the space node in each time slot. The initial signal sequence sent by the receiving space node in each time slot can be respectively received, and the initial signal sequence in each time slot is sampled based on a preset clock period to obtain multiple first signal sequences.

[0098] That is to say, in the embodiment of the present disclosure, the terminal device may be a receiving space node that sends an initial signal sequence in each time slot, and samples the initial signal sequence in each time slot based on a preset clock cycle to obtain a plurality of first signal sequences of the same number and with the same sampling interval in each time slot, thereby providing convenient conditions for the execution of the subsequent Doppler frequency deviation determination method.

[0099] S202: The terminal determines a second signal sequence that matches the first signal sequence, where the second signal sequence includes: a synchronization code.

[0100] Among them, the signal sequence containing the synchronization code which matches the first signal in the local terminal device is the second signal sequence.

[0101] The synchronization code may also be called a unique word, a synchronization word, a keyword, (Unique Word, UW), etc., without limitation.

[0102] Among them, the synchronization code can be used to synchronize the data stream to ensure that the receiving end can correctly parse and process the transmitted data.

[0103] That is to say, in the embodiment of the present disclosure, after the terminal device samples multiple first signal sequences from the initial signal sequence sent by the spatial node in each time slot, it can determine the second signal sequence for data stream synchronization with the first signal sequence.

[0104] In some embodiments, determining the second signal sequence matching the first signal sequence may be by using a preset specific synchronization signal as the second signal sequence, or by using a local pseudo-random sequence of the receiving end as the second signal sequence, without limitation.

[0105] S203: Process each first signal sequence and second signal sequence to obtain a plurality of first complex number sequences.

[0106] In an embodiment of the present disclosure, after sampling multiple first signal sequences from an initial signal sequence sent by a spatial node in each time slot and determining a second signal sequence matching the first signal sequence, each first signal sequence and second signal sequence can be processed to obtain multiple results in complex form, and the multiple results in complex form constitute a first complex sequence.

[0107] In some embodiments, processing each first signal sequence and second signal sequence may be performed by calculating an autocorrelation function of the first signal sequence, where the autocorrelation function describes the degree of similarity between the signal and itself at different time delays, and calculating a cross-correlation function of the second signal sequence, where the cross-correlation function describes the degree of similarity between the two signals at different time delays. The autocorrelation and cross-correlation function values ​​obtained by calculation constitute correlated complex results, and multiple correlated complex results constitute a first complex sequence.

[0108] Optionally, in some embodiments, each first signal sequence and second signal sequence is processed to obtain a plurality of first complex sequences, and each first signal sequence and second signal sequence may be input into a correlator together to obtain a first complex sequence.

[0109] In the embodiments of the present disclosure, see Figure 3 , Figure 3This is a block diagram of the implementation principle of the correlator provided in the embodiment of the present disclosure, with the signal sequence length being 2 N As an example, the correlator mainly includes a cache unit, a correlation unit and a summing unit, wherein the cache unit includes 2 N registers for storing raw data streams. The relevant units include 2 N multipliers (which can be degenerated into a pass-through or an inverter when the local sequence is ±1); the summing unit is a 4-input adder add4 (the number of input channels can be adjusted according to the comprehensive layout and routing capabilities of the FPGA or chip), which outputs a group of multi-channel complex results (for example, out[1], out[2]...out

[32] , without limitation) through multi-stage summing processing, and the group of multi-channel complex results is the first complex sequence.

[0110] That is to say, in the embodiment of the present disclosure, each first signal sequence and second signal sequence may be input into the correlator together to obtain a set of multi-path complex results output by the correlator as the first complex sequence. The first complex sequence may include multiple complex elements, and each complex element is a path of complex results.

[0111] S204: Determine a target complex number sequence matching the synchronization code from the plurality of first complex number sequences.

[0112] Among them, the first complex number sequence matching the synchronization code among the multiple first complex number sequences is the target complex number sequence.

[0113] After processing each first signal sequence and the second signal sequence to obtain a plurality of first complex number sequences, the embodiment of the present disclosure can determine a target complex number sequence matching the synchronization code from the plurality of first complex number sequences.

[0114] In some embodiments, determining a target complex sequence that matches a synchronization code from a plurality of first complex sequences may be performed by respectively inputting the plurality of first complex sequences into a matching filter to determine whether the first complex sequence contains synchronization code information, and when it is determined that the first complex sequence contains synchronization code information, using the first complex sequence containing the synchronization code information as the target complex sequence.

[0115] In some other embodiments, a target complex sequence matching the synchronization code may be determined from a plurality of first complex sequences, or a correlation analysis may be performed on the first complex sequence and the synchronization code to determine the degree of similarity between the first complex sequence and the synchronization code, and when the degree of similarity is greater than a degree threshold, the first complex sequence may be determined as the target complex sequence, without limitation.

[0116] S205: Determine the Doppler frequency offset according to the target complex sequence corresponding to each time slot in the plurality of consecutive time slots.

[0117] In an embodiment of the present disclosure, after sampling and obtaining multiple first signal sequences from an initial signal sequence sent by a spatial node in each time slot, and processing the first signal sequence and the second signal sequence in each time slot to obtain multiple first complex sequences in the time slot, it is possible to determine the Doppler frequency deviation from the multiple first complex sequences in the time slot, after processing the first signal sequence and the second signal sequence to obtain multiple first complex sequences, based on a target complex sequence corresponding to each time slot in a plurality of consecutive time slots.

[0118] It can be understood that due to the limited length of the synchronization code and the low signal-to-noise ratio in a single time slot, the frequency deviation estimation of the synchronization code faces two difficulties: first, the synchronization code position obtained by the capture algorithm in the initial access phase of the user equipment is not completely accurate, and there is usually an error of several code bits; second, the synchronization code information is too short, and the single time slot synchronization code information often cannot provide sufficient energy to determine the Doppler frequency deviation. Therefore, in the embodiment of the present disclosure, the Doppler frequency deviation can be determined based on the target complex sequence that matches the synchronization code in each time slot in a plurality of consecutive time slots, so that the Doppler frequency can be accurately determined based on the target complex sequence that matches the synchronization code in a plurality of consecutive time sequences.

[0119] In the disclosed embodiment, the terminal obtains multiple first signal sequences by sampling from the initial signal sequence sent by the space node in each time slot, and determines a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code, and then processes each first signal sequence and the second signal sequence to obtain multiple first complex sequences, and then determines a target complex sequence matching the synchronization code from the multiple first complex sequences, and determines the Doppler frequency deviation according to the target complex sequence corresponding to each time slot in a plurality of consecutive time slots, thereby being able to accurately determine the Doppler frequency based on the target complex sequence matching the synchronization code in a plurality of consecutive time sequences, thereby being able to effectively meet the determination requirements of the Doppler frequency deviation in low signal-to-noise ratio scenarios.

[0120] Figure 4 It is a flowchart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure.

[0121] like Figure 4 As shown, the method may include but is not limited to the following steps:

[0122] S401: A plurality of first signal sequences are obtained by sampling an initial signal sequence sent by a spatial node in each time slot.

[0123] S402: Determine a second signal sequence that matches the first signal sequence, wherein the second signal sequence includes: a synchronization code.

[0124] S403: Process each first signal sequence and second signal sequence to obtain a plurality of first complex number sequences.

[0125] The specific description of S401 - S403 can be found in the above embodiment, which will not be repeated here.

[0126] S404: Acquire position information of the synchronization code in the second signal sequence.

[0127] Among them, the position information of the synchronization code in the second signal sequence can be, for example, the position number of the synchronization code in the second signal sequence. For example, the second signal sequence contains 8 elements, and the 6th element is the synchronization code, then the position number 6 can be determined as the position information of the synchronization code in the second signal sequence, and there is no limitation on this.

[0128] In the disclosed embodiment, the position information of the synchronization code in the second signal sequence is obtained by predetermining the position number of the synchronization code in the second signal sequence by a corresponding capture algorithm as the position information. Then, based on the position information of the synchronization code in the second signal sequence, a target complex sequence matching the synchronization code can be determined from multiple first complex sequences. For details, please refer to the subsequent embodiments and will not be repeated here.

[0129] S405: Determine a target complex number sequence matching the synchronization code from a plurality of first complex number sequences according to the position information.

[0130] After acquiring the position information of the synchronization code in the second signal sequence, the embodiment of the present disclosure can determine a target complex number sequence matching the synchronization code from a plurality of first complex number sequences according to the position information.

[0131] Optionally, in some embodiments, a target complex sequence matching the synchronization code is determined from multiple first complex sequences based on the position information. The first complex sequences corresponding to each first signal sequence may be sorted according to the sampling time of each first signal sequence, and a second complex sequence related to the position information is determined from the sorted multiple first complex sequences, and a preset number of third complex sequences adjacent to the second complex sequence are determined from the sorted multiple first complex sequences, and the second complex sequence and the preset number of third complex sequences are taken together as the target complex sequence. As a result, frequency offset estimation can be performed on multiple first complex sequences before and after the position information of the synchronization code is extracted from the multiple first complex sequences, thereby overcoming the influence of the synchronization code error on the frequency offset estimation to a certain extent.

[0132] For example, the first complex number sequences corresponding to each first signal sequence may be sorted according to the sampling time of each first signal sequence, and then a second complex number sequence ( Where slot refers to the accumulated time slot count value, index refers to the count value of the first complex sequence in the current time slot), and sequentially intercepts the count value of the second complex sequence Each of the five adjacent first complex sequences (a total of A total of 11 groups) as the target complex sequence, such as Figure 5A As shown, Figure 5A is a schematic diagram of data cache of a target complex sequence provided according to an embodiment of the present disclosure, Figure 5A Each vertical column in represents a set of target complex sequences, and the elements in each set of target complex sequences are a set of 32-way complex results output by the correlator.

[0133] In the embodiment of the present disclosure, after determining the target complex sequence matching the synchronization code from the plurality of first complex sequences according to the position information, the determined target complex sequence may be stored in a random access memory (RAM) 1 (e.g., Figure 5B As shown, Figure 5B is a schematic diagram of the data cache structure in RAM1 provided according to an embodiment of the present disclosure), thereby enabling regular storage of a larger-scale target complex number sequence, so that in the subsequent process of processing the target complex number sequence, the corresponding target complex number sequence can be conveniently read sequentially from RAM1.

[0134] S406: Determine the Doppler frequency offset according to the target complex sequence corresponding to each time slot in the plurality of consecutive time slots.

[0135] The specific description of S406 can be found in the above embodiment, which will not be repeated here.

[0136] In the disclosed embodiment, multiple first signal sequences are obtained by sampling from an initial signal sequence sent by a spatial node in each time slot, and a second signal sequence matching the first signal sequence is determined, wherein the second signal sequence includes: a synchronization code, and then each first signal sequence and the second signal sequence are processed to obtain multiple first complex number sequences, and the position information of the synchronization code in the second signal sequence is obtained, and then according to the position information, a target complex number sequence matching the synchronization code is accurately determined from the multiple first complex number sequences, and then the Doppler frequency deviation is determined according to the target complex number sequence corresponding to each time slot in a plurality of consecutive time slots, thereby being able to accurately determine the Doppler frequency based on the target complex number sequence matching the synchronization code in a plurality of consecutive time sequences, thereby being able to effectively meet the determination requirements of the Doppler frequency deviation in low signal-to-noise ratio scenarios.

[0137] Figure 6 It is a flowchart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure.

[0138] like Figure 6 As shown, the method may include but is not limited to the following steps:

[0139] S601: A plurality of first signal sequences are obtained by sampling an initial signal sequence sent by a spatial node in each time slot.

[0140] S602: Determine a second signal sequence that matches the first signal sequence, where the second signal sequence includes: a synchronization code.

[0141] S603: Process each first signal sequence and second signal sequence to obtain a plurality of first complex number sequences.

[0142] S604: Determine a target complex number sequence matching the synchronization code from the plurality of first complex number sequences.

[0143] The description of S601 - S604 can be specifically referred to the above embodiment, which will not be repeated here.

[0144] S605: Acquire a frequency domain signal sequence corresponding to each target complex sequence.

[0145] In some embodiments, obtaining the frequency domain signal sequence corresponding to each target complex sequence may be performing discrete Fourier transform on each target complex sequence to obtain the frequency domain signal sequence corresponding to each target complex sequence, and there is no limitation to this.

[0146] Optionally, in some embodiments, obtaining the frequency domain signal sequence corresponding to each target complex number sequence may be performing a fast Fourier transform on each target complex number sequence to obtain the frequency domain signal sequence.

[0147] For example, performing a Fast Fourier Transform (FFT) on each target complex sequence may be performed by sequentially inputting each target complex sequence into an FFT module (see Fig. 7A , Fig. 7A , which is a processing flow diagram corresponding to the FFT module provided in the embodiment of the present disclosure) performs fast Fourier transform processing, and the FFT module mainly completes zero padding and fast Fourier transform of relevant data. In order to improve the frequency domain resolution, it is necessary to perform zero padding on the basis of each group of 32-point cached data. The number of zero padding can be determined according to the number of FFT points. For example, for a 1024-point FFT, 992 zero values ​​can be added after the cached data and then input into the FFT core for Fourier transform to obtain a frequency domain signal sequence corresponding to each target complex sequence.

[0148] S606: Taking the modulus of each element in the frequency domain signal sequence to determine the amplitude value of the frequency domain signal sequence when it is in different frequency components.

[0149] After obtaining the frequency domain signal sequence corresponding to each target complex number sequence, the embodiment of the present disclosure may modulo each element in the frequency domain signal sequence to determine the amplitude value of the frequency domain signal sequence when it is in different frequency components.

[0150] For example, to facilitate engineering implementation, see Figure 7B , Figure 7B is a schematic diagram of the modulus flow of the frequency domain signal sequence provided by the embodiment of the present disclosure, that is, it can be used Figure 7B The modulo process shown takes the modulo of each element in the frequency domain signal sequence, and calculates the absolute values ​​of the real part real and the imaginary part imag of each element in the frequency domain signal sequence to obtain |real| and |imag| respectively. If |real|≥|imag|, the output approximate modulo result is 2*|real|+|imag|. If |real|<|imag|, the output approximate modulo result is 2*|imag|+|real|. The modulo result is the amplitude value of the frequency domain signal sequence when it is at different frequency components.

[0151] S607: Determine the Doppler frequency offset according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in the plurality of consecutive time slots when the frequency domain signal sequence is in different frequency components.

[0152] In the disclosed embodiment, multiple frequency domain signal sequences in each time slot are arranged based on sampling time.

[0153] For example, in the embodiment of the present disclosure, each time slot may have 11 sets of frequency domain signal sequences (in RAM2), and the 11 sets of frequency domain signal sequences may be arranged based on the sampling time, that is, the amplitude values ​​of the 11 sets of frequency domain signals at different frequency components may be arranged based on the sampling time and stored in RAM2, see Figure 7C , Figure 7C It is a schematic diagram of the data cache structure in RAM2 provided in an embodiment of the present disclosure.

[0154] Optionally, in some embodiments, the Doppler frequency deviation is determined based on the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in a plurality of consecutive time slots when they are in different frequency components. The amplitude values ​​of the frequency domain signal sequence in the same arrangement position in a plurality of consecutive time slots at the same frequency component may be accumulated to determine multiple amplitude sum values, and then the Doppler frequency deviation is determined based on the multiple amplitude sum values.

[0155] That is to say, in the embodiment of the present disclosure, when the frequency domain signal sequence of the next continuous time slot arrives, the frequency domain signal sequence of the time slot may be arranged based on the sampling time, that is, the amplitude values ​​of the 11 groups of frequency domain signals of the time slot at different frequency components may be stored in the same arrangement in RAM2 based on the sampling time, see the above Figure 7CThe arrangement position corresponding to AMP[1] of the first group of data will accumulate and store the amplitude values ​​at the same frequency component in multiple consecutive time slots, and add the amplitude values ​​of the frequency domain signal sequence at the same arrangement position at the same frequency component to determine multiple amplitude and values.

[0156] Optionally, in some embodiments, the Doppler frequency deviation is determined based on multiple amplitudes and values, and the maximum amplitude and value can be determined from the multiple amplitudes and values, and then when the maximum amplitude and value is greater than or equal to an amplitude threshold, the frequency component corresponding to the maximum amplitude and value is determined as the Doppler frequency deviation.

[0157] In the embodiment of the present disclosure, the cumulative N slot After the accumulation of time slot data, the peak detection stage is entered. The maximum amplitude and value can be determined from the multiple amplitude and values ​​determined above, and the maximum amplitude and value is compared with the amplitude threshold. When the maximum amplitude and value is greater than or equal to the amplitude threshold, the frequency component corresponding to the maximum amplitude and value is determined as the Doppler frequency deviation.

[0158] In the disclosed embodiment, by performing time slot accumulation processing on the frequency domain amplitude values ​​of the frequency domain signal sequence corresponding to the first complex sequence matching the synchronization code in multiple consecutive time slots, the technical problem that the synchronization code information is too short and the single time slot synchronization code information often cannot provide sufficient energy for frequency offset estimation can be solved, thereby effectively improving the accuracy of Doppler frequency offset determination.

[0159] In the disclosed embodiment, multiple first signal sequences are obtained by sampling from an initial signal sequence sent by a spatial node in each time slot, and a second signal sequence matching the first signal sequence is determined, wherein the second signal sequence includes: a synchronization code, and then each first signal sequence and the second signal sequence are processed to obtain multiple first complex number sequences, and then a target complex number sequence matching the synchronization code is determined from the multiple first complex number sequences, and a frequency domain signal sequence corresponding to each target complex number sequence is obtained, and then each element in the frequency domain signal sequence is modulo-measured to determine the amplitude value of the frequency domain signal sequence when it is in different frequency components, and then the Doppler frequency deviation is determined according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in multiple consecutive time slots when they are in different frequency components, thereby solving the technical problem that the synchronization code information is too short and the single time slot synchronization code information often cannot provide sufficient energy for frequency deviation estimation, and effectively improving the accuracy of Doppler frequency deviation determination.

[0160] Figure 8 It is a structural schematic diagram of a device for determining Doppler frequency deviation provided in an embodiment of the present disclosure.

[0161] like Figure 8 As shown, the Doppler frequency shift determination device 80 includes:

[0162] The sampling module 801 is used to obtain multiple first signal sequences by sampling from the initial signal sequence sent by the spatial node in each time slot;

[0163] The first determination module 802 is used for the terminal to determine a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code;

[0164] A processing module 803 is used to process each first signal sequence and each second signal sequence to obtain a plurality of first complex number sequences;

[0165] A second determination module 804 is used to determine a target complex sequence matching the synchronization code from a plurality of first complex sequences;

[0166] The third determination module 805 is configured to determine the Doppler frequency offset according to a target complex sequence corresponding to each time slot in a plurality of consecutive time slots.

[0167] In some embodiments of the present disclosure, the second determining module 804 is further configured to:

[0168] Acquire position information of the synchronization code in the second signal sequence;

[0169] A target complex number sequence matching the synchronization code is determined from a plurality of first complex number sequences according to the position information.

[0170] In some embodiments of the present disclosure, the second determining module 804 is further configured to:

[0171] sorting the first complex number sequences corresponding to each first signal sequence according to the sampling time of each first signal sequence;

[0172] Determine a second complex number sequence associated with the position information from the sorted plurality of first complex number sequences;

[0173] Determine a preset number of third complex number sequences adjacent to the second complex number sequence from the sorted plurality of first complex number sequences;

[0174] The second complex number sequence and a preset number of third complex number sequences are used together as a target complex number sequence.

[0175] In some embodiments of the present disclosure, the third determining module 805 is further configured to:

[0176] Acquire a frequency domain signal sequence corresponding to each target complex sequence;

[0177] Taking the modulus of each element in the frequency domain signal sequence to determine the amplitude value of the frequency domain signal sequence at different frequency components;

[0178] The Doppler frequency shift is determined according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in a plurality of consecutive time slots when the frequency domain signal sequence is in different frequency components.

[0179] In some embodiments of the present disclosure, the third determining module 805 is further configured to:

[0180] Perform fast Fourier transform on each target complex sequence to obtain a frequency domain signal sequence.

[0181] In some embodiments of the present disclosure, multiple frequency domain signal sequences in each time slot are arranged based on sampling time;

[0182] The third determining module 805 is further used for:

[0183] Accumulating the amplitude values ​​of the frequency domain signal sequences at the same arrangement position in a plurality of consecutive time slots at the same frequency component to determine a plurality of amplitude sum values;

[0184] Based on the multiple amplitudes and values, a Doppler frequency shift is determined.

[0185] In some embodiments of the present disclosure, the third determining module 805 is further configured to:

[0186] determining a maximum amplitude and value from among the plurality of amplitudes and values;

[0187] If the maximum amplitude sum value is greater than or equal to the amplitude threshold, the frequency component corresponding to the maximum amplitude sum value is determined as the Doppler frequency shift.

[0188] In some embodiments of the present disclosure, the processing module 803 is specifically configured to:

[0189] Each of the first signal sequence and the second signal sequence is input into a correlator together to obtain a first complex sequence.

[0190] In some embodiments of the present disclosure, the sampling module 801 is further configured to:

[0191] receiving an initial signal sequence respectively sent by the spatial node in each time slot;

[0192] The initial signal sequence in each time slot is sampled based on a preset clock cycle to obtain a plurality of first signal sequences.

[0193] It should be noted that the above explanation of the method for determining the Doppler frequency offset is also applicable to the device for determining the Doppler frequency offset of this embodiment, and will not be described in detail here.

[0194] In this embodiment, the terminal obtains multiple first signal sequences by sampling from the initial signal sequence sent by the spatial node in each time slot, and determines a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code, and then processes each first signal sequence and the second signal sequence to obtain multiple first complex sequences, and then determines a target complex sequence matching the synchronization code from the multiple first complex sequences, and determines the Doppler frequency deviation according to the target complex sequence corresponding to each time slot in a plurality of consecutive time slots. Thus, the Doppler frequency can be accurately determined based on the target complex sequence matching the synchronization code in a plurality of consecutive time sequences, thereby effectively meeting the determination requirement of the Doppler frequency deviation in low signal-to-noise ratio scenarios.

[0195] Fig. 9 A block diagram of an exemplary communication device suitable for implementing embodiments of the present disclosure is shown. Fig. 9 The communication device shown is only an example and should not limit the functions and scope of use of the embodiments of the present disclosure. Fig. 9 As shown, the communication device is in the form of a general purpose computing device. The components of the communication device may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 connecting various system components (including the system memory 28 and the processing unit 16).

[0196] The bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus and Peripheral Component Interconnection (PCI) bus.

[0197] The communication device typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the communication device, including volatile and non-volatile media, removable and non-removable media.

[0198] The memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The communication device may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Fig. 9 Not shown, often called a "hard drive").

[0199] although Fig. 9 Not shown in the figure, a disk drive for reading and writing a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing a removable non-volatile optical disk (e.g., a compact disc read only memory (hereinafter referred to as: CD-ROM), a digital versatile disc read only memory (hereinafter referred to as: DVD-ROM) or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present disclosure.

[0200] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described in the present disclosure.

[0201] The communication device may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), may also communicate with one or more devices that enable the human body to interact with the communication device, and / or communicate with any device that enables the communication device to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed through an input / output (I / O) interface 22. In addition, the communication device may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 20. As shown, the network adapter 20 communicates with other modules of the communication device through a bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the communication device, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0202] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28, such as implementing the determination method of the Doppler frequency shift mentioned in the above embodiment.

[0203] In order to implement the above embodiments, the present disclosure further proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for determining the Doppler frequency offset proposed in the above embodiments of the present disclosure is implemented.

[0204] In order to implement the above embodiments, the present disclosure further proposes a computer program product. When an instruction processor in the computer program product executes, the method for determining the Doppler frequency offset proposed in the above embodiments of the present disclosure is executed.

[0205] It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" is two or more.

[0206] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0207] It should be understood that the various parts of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0208] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by hardware matched with program instructions, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0209] In addition, each functional unit in each embodiment of the present disclosure may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0210] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0211] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0212] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A method for determining Doppler frequency shift, characterized in that: The method comprises: Sampling an initial signal sequence sent by the spatial node in each time slot to obtain a plurality of first signal sequences; The terminal determines a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code; Processing each of the first signal sequence and the second signal sequence to obtain a plurality of first complex number sequences; Determine a target complex sequence matching the synchronization code from a plurality of the first complex sequences; The Doppler frequency offset is determined according to the target complex number sequence corresponding to each time slot in a plurality of consecutive time slots.

2. The method according to claim 1, characterized in that The step of determining a target complex sequence matching the synchronization code from the plurality of first complex sequences comprises: Acquire position information of the synchronization code in the second signal sequence; The target complex number sequence matching the synchronization code is determined from a plurality of the first complex number sequences according to the position information.

3. The method according to claim 2, characterized in that The step of determining the target complex sequence matching the synchronization code from a plurality of the first complex sequences according to the position information comprises: sorting the first complex number sequences corresponding to each of the first signal sequences according to a sampling time of each of the first signal sequences; Determine a second complex number sequence corresponding to the position information from the plurality of first complex number sequences obtained by sorting; Determine a preset number of third complex number sequences adjacent to the second complex number sequence from the sorted plurality of first complex number sequences; The second complex number sequence and the preset number of third complex number sequences are used together as the target complex number sequence.

4. The method according to claim 1, characterized in that The determining of the Doppler frequency shift according to the target complex sequence corresponding to each time slot in the plurality of consecutive time slots comprises: Acquire a frequency domain signal sequence corresponding to each of the target complex number sequences; Taking the modulus of each element in the frequency domain signal sequence to determine the amplitude value of the frequency domain signal sequence when it is at different frequency components; The Doppler frequency offset is determined according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in the plurality of consecutive time slots when the frequency domain signal sequence is in different frequency components.

5. The method according to claim 4, characterized in that The acquiring of a frequency domain signal sequence corresponding to each of the target complex number sequences comprises: Perform fast Fourier transform on each of the target complex number sequences to obtain the frequency domain signal sequence.

6. The method according to claim 5, characterized in that The plurality of frequency domain signal sequences in each time slot are arranged based on sampling time; The determining of the Doppler frequency shift according to the amplitude values ​​of the frequency domain signal sequence corresponding to each time slot in the plurality of consecutive time slots when the frequency domain signal sequence is in different frequency components includes: Accumulating the amplitude values ​​of the frequency domain signal sequences at the same arrangement position in a plurality of consecutive time slots at the same frequency component to determine a plurality of amplitude sum values; The Doppler frequency shift is determined based on a plurality of the amplitudes and values.

7. The method according to claim 6, characterized in that Determining the Doppler frequency shift according to the multiple amplitudes and values ​​includes: determining a maximum amplitude and value from a plurality of said amplitudes and values; If the maximum amplitude sum value is greater than or equal to the amplitude threshold, a frequency component corresponding to the maximum amplitude sum value is determined as the Doppler frequency shift.

8. The method according to any one of claims 1 to 7, characterized in that: The processing of each of the first signal sequence and the second signal sequence to obtain a plurality of first complex number sequences includes: Each of the first signal sequence and the second signal sequence is input into a correlator together to obtain the first complex sequence.

9. The method according to any one of claims 1 to 7, characterized in that: The method of sampling an initial signal sequence sent by a slave space node in each time slot to obtain a plurality of first signal sequences includes: Receiving an initial signal sequence respectively sent by the spatial node in each time slot; The initial signal sequence in each of the time slots is sampled based on a preset clock cycle to obtain a plurality of the first signal sequences.

10. A device for determining Doppler frequency deviation, characterized in that: The device comprises: A sampling module, used for sampling an initial signal sequence sent by a spatial node in each time slot to obtain a plurality of first signal sequences; A first determining module is configured to determine a second signal sequence matching the first signal sequence, wherein the second signal sequence includes: a synchronization code; A processing module, configured to process each of the first signal sequence and the second signal sequence to obtain a plurality of first complex number sequences; A second determination module, configured to determine a target complex sequence matching the synchronization code from a plurality of the first complex sequences; The third determination module is used to determine the Doppler frequency offset according to the target complex sequence corresponding to each time slot in a plurality of consecutive time slots.

11. A communication device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 9.

12. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: in, The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 9.

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