Method and device for determining Doppler frequency offset

Abstract

The invention provides a Doppler frequency offset determination method and device, and the method comprises the steps: receiving a target data packet, and carrying out the frequency offset prediction of the target data packet through employing a target frequency offset prediction mode, so as to obtain the initial Doppler frequency offset of the target data packet; generating a frequency vector matched with the set time length according to the receiving sequence of the target data packet and the initial Doppler frequency offset of the target data packet; clustering the plurality of first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determining a target cluster from the at least one cluster according to the number of the first elements in the at least one cluster; and the target Doppler frequency offset of the target data packet is determined according to the first element in the target cluster, so that the accuracy of Doppler frequency offset prediction and the stability of Doppler frequency offset are improved, the packet error rate can be reduced, and the decoding accuracy can be improved.

Description

Technical Field

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

[0002] At present, in the process of wireless communication, Doppler frequency offset has a great impact on the performance of the physical layer. A small residual Doppler frequency offset will cause a large phase rotation at the end of the frame structure, which is likely to cause decoding errors. On the other hand, if the Doppler frequency offset fluctuates greatly, it will directly lead to an error in the phase relationship between the best sampling points, and the packet error rate will rise sharply. Therefore, in order to reduce the packet error rate and improve the accuracy of decoding, it is very important to accurately estimate the Doppler frequency offset and reduce the fluctuation of the Doppler frequency offset. 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 first object of the present disclosure is to propose a method for determining a Doppler frequency deviation, so as to achieve frequency deviation prediction of a target data packet by adopting a target frequency deviation prediction method, so as to obtain an initial Doppler frequency deviation of the target data packet, and generate a frequency vector matching a set time length according to a receiving order of the target data packet and the initial Doppler frequency deviation, cluster the frequency vector to obtain at least one cluster, and determine a target cluster from at least one cluster according to the number of first elements in at least one cluster, and determine a target Doppler frequency deviation of the target data packet according to the first element in the target cluster, thereby, after obtaining the initial Doppler frequency deviation, generating a frequency vector matching a set time length. The set time length is determined according to the set maximum allowable frequency error value and the set unit frequency error value of the target data packet, so that the Doppler frequency deviation does not exceed the maximum allowable frequency error value within the time period corresponding to the set time length, so as to improve the accuracy of subsequent decoding. According to the clustering algorithm, the frequency vector corresponding to the initial Doppler frequency deviation is clustered, and the target Doppler frequency deviation of the target data packet is determined according to the first element in the target cluster in at least one cluster obtained by clustering, so as to improve the accuracy of Doppler frequency deviation prediction and the stability of Doppler frequency deviation, thereby reducing the packet error rate and improving the accuracy of decoding.

[0005] A second objective of the present disclosure is to provide a device for determining Doppler frequency shift.

[0006] A third objective of the present disclosure is to provide an electronic device.

[0007] A fourth objective of the present disclosure is to provide a computer-readable storage medium.

[0008] A fifth object of the present disclosure is to provide a computer program product.

[0009] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present disclosure proposes a method for determining a Doppler frequency deviation, comprising: receiving a target data packet, and predicting the frequency deviation of the target data packet using a target frequency deviation prediction method to obtain an initial Doppler frequency deviation of the target data packet; generating a frequency vector matching a set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packet, wherein the set time length is determined according to a set maximum allowable frequency error value and a set unit frequency error value of the target data packet; clustering multiple first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determining a target cluster from the at least one cluster according to the number of first elements in the at least one cluster; and determining the target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0010] The method for determining the Doppler frequency deviation of the embodiment of the present disclosure receives a target data packet and predicts the frequency deviation of the target data packet using a target frequency deviation prediction method to obtain an initial Doppler frequency deviation of the target data packet; generates a frequency vector matching a set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packets, wherein the set time length is determined according to a set maximum allowable frequency error value and a set unit frequency error value of the target data packet; clusters a plurality of first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determines a target cluster from the at least one cluster according to the number of first elements in the at least one cluster; and determines a target cluster according to the first elements in the target cluster. The target Doppler frequency deviation of the target data packet is determined based on the initial Doppler frequency deviation, thereby generating a frequency vector matching the set time length after obtaining the initial Doppler frequency deviation, wherein the set time length is determined based on the set maximum allowable frequency error value and the set unit frequency error value of the target data packet, so that the Doppler frequency deviation does not exceed the maximum allowable frequency error value within the time period corresponding to the set time length, so as to improve the accuracy of subsequent decoding, and cluster the frequency vectors corresponding to the initial Doppler frequency deviation according to the clustering algorithm, and determine the target Doppler frequency deviation of the target data packet based on the first element in the target cluster in at least one cluster obtained by clustering, thereby improving the accuracy of Doppler frequency deviation prediction and the stability of Doppler frequency deviation, thereby reducing the packet error rate and improving the accuracy of decoding.

[0011] To achieve the above-mentioned purpose, the second aspect of the present disclosure proposes a device for determining Doppler frequency deviation, including: a first prediction module, used to receive a target data packet, and use a target frequency deviation prediction method to predict the frequency deviation of the target data packet to obtain the initial Doppler frequency deviation of the target data packet; a generation module, used to generate a frequency vector matching a set time length according to the reception order of the target data packets and the initial Doppler frequency deviation of the target data packet, wherein the set time length is determined according to the set maximum allowable frequency error value and the set unit frequency error value of the target data packet; a clustering module, used to cluster multiple first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determine a target cluster from the at least one cluster according to the number of first elements in the at least one cluster; a first determination module, used to determine the target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0012] To achieve the above-mentioned purpose, the third aspect embodiment of the present disclosure proposes an electronic device, including 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 as described in the first aspect embodiment of the present disclosure is implemented.

[0013] In order to achieve the above-mentioned purpose, the fourth aspect of the present disclosure proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for determining the Doppler frequency deviation as described in the first aspect of the present disclosure is implemented.

[0014] In order to achieve the above-mentioned purpose, the fifth aspect of the present disclosure proposes a computer program product. When the instruction processor in the computer program product executes, the method for determining the Doppler frequency offset as described in the first aspect of the present disclosure is implemented.

[0015] 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

[0016] 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:

[0017] Figure 1 It is a flow chart of a Doppler frequency deviation estimation method based on a characteristic code in the related art;

[0018] Figure 2 A flowchart of a Doppler frequency deviation estimation method based on a service in the related art;

[0019] Figure 3 A flow chart of a method for determining a Doppler frequency shift provided by an embodiment of the present disclosure;

[0020] Figure 4 A schematic flow chart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0021] Figure 5 A schematic flow chart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0022] Figure 6 A schematic flow chart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0023] Figure 7 A schematic flow chart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0024] Figure 8 A schematic diagram of a process of clustering a plurality of first elements in a frequency vector provided by an embodiment of the present disclosure;

[0025] Fig. 9 A schematic diagram of a frame format of a channel corresponding to a target data packet provided in an embodiment of the present disclosure;

[0026] Fig.10 A schematic diagram of spectral line characteristics of a frequency deviation estimation method based on a characteristic code provided in an embodiment of the present disclosure;

[0027] Fig.11 A schematic diagram of spectral line characteristics of a frequency deviation estimation method based on service data provided in an embodiment of the present disclosure;

[0028] Fig.12 A schematic diagram of a frequency deviation estimation result based on a feature code provided in an embodiment of the present disclosure;

[0029] Fig.13 A schematic diagram of a frequency offset estimation result based on service data provided by an embodiment of the present disclosure;

[0030] Fig.14 A schematic diagram of frequency deviation estimation results using the method for determining Doppler frequency deviation provided by an embodiment of the present disclosure;

[0031] Fig.15 A structural schematic diagram of a device for determining a Doppler frequency shift provided by an embodiment of the present disclosure;

[0032] Fig.16 It is a block diagram of an electronic device for determining Doppler frequency shift according to an exemplary embodiment. DETAILED DESCRIPTION

[0033] Embodiments of the present disclosure are described in detail below, examples of which 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 intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0034] In the physical layer technology of wireless communication, the methods of Doppler frequency deviation (frequency) estimation are mainly divided into two categories: Doppler frequency deviation estimation method based on signature code (first frequency deviation prediction method) and Doppler frequency deviation estimation method based on service data (second frequency deviation prediction method).

[0035] Among them, Figure 1 As shown, the Doppler frequency deviation estimation method based on the signature code usually maps the continuous or scattered signature code sequence to the constellation according to the modulation specified by the protocol, and sets the data at the non-signature code position to 0 for the scattered signature code sequence. After the receiver captures the signal, it intercepts the data at the signature code position from the restored optimal sampling point data according to the signature code start and end positions specified by the protocol, and sets the corresponding service data to 0. By performing conjugate multiplication processing on the received signature code constellation and the theoretical signature code constellation diagram data, and then performing fast Fourier transform (Fast Fourier Transform, referred to as FFT) on the conjugate processing result, the position of the largest spectrum line is found, and the signal frequency is estimated by combining parameters such as sampling rate and FFT point number. In order to improve the accuracy of Doppler frequency deviation estimation, the parabolic interpolation method can also be used. Taking the peak spectrum line, the left side of the peak spectrum line, and the right side of the peak spectrum line as the reference, a parabolic model is established to perform parameter estimation, and then obtain super-resolution frequency estimation, which can further improve the estimation accuracy of Doppler frequency deviation.

[0036] Doppler frequency deviation estimation method based on business data, such as Figure 2 As shown, according to the modulation type of the data, the optimal sampling point data corresponding to the business data is extracted from the data packet, and the data at the location of the original feature code data is replaced with 0, and the array is subjected to high-order spectrum analysis to find the spectrum peak, and the frequency deviation value is estimated by combining the aforementioned parabolic interpolation algorithm.

[0037] The Doppler frequency deviation estimation method based on characteristic code and the Doppler frequency deviation estimation method based on business data both rely on characteristic spectral lines. When the signal-to-noise ratio is low, high-intensity noise will seriously interfere with the characteristic spectral lines, resulting in false spectral lines, which will cause large fluctuations in the estimated frequency values ​​and seriously affect the subsequent processing process.

[0038] In the process of wireless communication, Doppler frequency deviation has a great impact on the performance of the physical layer. A small residual frequency deviation will cause a large phase rotation at the end of the frame structure, which is likely to cause decoding errors. On the other hand, if the residual frequency deviation fluctuates greatly, it will directly lead to the phase relationship error between the best sampling points, and the packet error rate will rise sharply. In the actual communication process, the Doppler frequency deviation estimation method based on the signature code is often sensitive to noise due to the short length of the signature code or the scattered distribution. Especially under low signal-to-noise ratio conditions, the spectral line characteristics appear and disappear from time to time from the time dimension. When the spectrum line is submerged by noise, the residual frequency deviation is usually large, and the packet error rate rises sharply. The Doppler frequency deviation estimation method based on business data has the advantage that the data length is longer than the signature code length, but because the modulation order of the data is usually higher than that of the signature code, high-order spectra are often used when seeking the statistics of the spectral line characteristics. The nonlinear effect causes the noise to be amplified, which will also cause the spectral line characteristics to appear and disappear from time to time, resulting in large fluctuations in the Doppler frequency deviation estimation error and an increase in the packet error rate.

[0039] In view of the above problems, the present disclosure proposes a method and device for determining Doppler frequency offset. It should be noted that the method for determining Doppler frequency offset of the embodiment of the present disclosure can be applied to the device for determining Doppler frequency offset of the embodiment of the present disclosure, and the device can be configured in an electronic device, which can be a satellite receiving device.

[0040] The following describes a method and apparatus for determining a Doppler frequency offset according to an embodiment of the present disclosure with reference to the accompanying drawings.

[0041] Figure 3 A flowchart of a method for determining a Doppler frequency offset provided in an embodiment of the present disclosure is provided.

[0042] like Figure 3 As shown, the method for determining the Doppler frequency shift may include the following steps:

[0043] Step 301: Receive a target data packet, and use a target frequency deviation prediction method to perform frequency deviation prediction on the target data packet to obtain an initial Doppler frequency deviation of the target data packet.

[0044] In order to improve the accuracy of Doppler frequency deviation, in the embodiment of the present disclosure, a Doppler frequency deviation estimation method is preferably selected from a feature code Doppler frequency deviation estimation method or a service data based Doppler frequency deviation estimation method, that is, a target frequency deviation prediction method is determined from a first frequency deviation prediction method and a second frequency deviation prediction method, thereby using the target frequency deviation prediction method to perform frequency deviation prediction on a target data packet to obtain an initial Doppler frequency deviation of the target data packet.

[0045] Step 302: Generate a frequency vector matching the set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packets.

[0046] The set time length is determined according to a set maximum allowable frequency error value and a set unit frequency error value of the target data packet.

[0047] It should be understood that the principle of setting the time length (memory time length) is that the frequency change does not exceed the maximum frequency error within the time period corresponding to the time length. The maximum frequency error refers to the maximum frequency value at which subsequent decoding can be performed correctly when the frequency offset reaches this frequency value in an ideal environment without noise.

[0048] In the embodiment of the present disclosure, the set time length can be determined based on the set maximum allowable frequency error value and the set unit frequency error value in the protocol, and then, based on the reception order of the target data packets (for example, whether the target data packet is the first) and the initial Doppler frequency deviation of the target data packet, a frequency vector matching the set time length is generated.

[0049] Step 303: clustering the first elements in the frequency vector based on the set frequency threshold to obtain at least one cluster, and determining a target cluster from the at least one cluster according to the number of the first elements in the at least one cluster.

[0050] In order to improve the stability of the Doppler frequency deviation, further, multiple first elements in the frequency vector can be clustered based on a set frequency threshold (threshold value), and a target cluster can be determined from at least one cluster according to the number of first elements in at least one cluster, for example, the cluster with the most first elements in the cluster is taken as the target cluster.

[0051] Step 304: Determine a target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0052] As an example, according to the first element in the target cluster, the average value of the first element of the target cluster is determined, and the average value is used as the target Doppler frequency deviation of the target data packet.

[0053] As another example, the frequency deviation value corresponding to the center of the target cluster is used as the target Doppler frequency deviation of the target data packet.

[0054] In summary, a target data packet is received and a frequency deviation prediction method is used to predict the frequency deviation of the target data packet to obtain an initial Doppler frequency deviation of the target data packet; a frequency vector matching a set time length is generated according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packet; based on a set frequency threshold, multiple first elements in the frequency vector are clustered to obtain at least one cluster, and a target cluster is determined from at least one cluster according to the number of first elements in at least one cluster; a target Doppler frequency deviation of the target data packet is determined according to the first element in the target cluster, and thus, after obtaining the initial Doppler frequency deviation, a frequency vector matching a set time length is generated. A frequency vector matching a set time length, wherein the set time length is determined based on a set maximum allowable frequency error value and a set unit frequency error value of a target data packet, so that within a time period corresponding to the set time length, the Doppler frequency deviation does not exceed the maximum allowable frequency error value, so as to improve the accuracy of subsequent decoding. According to a clustering algorithm, the frequency vector corresponding to the initial Doppler frequency deviation is clustered, and based on the first element in a target cluster in at least one cluster obtained by clustering, the target Doppler frequency deviation of the target data packet is determined, thereby improving the accuracy of Doppler frequency deviation prediction and the stability of Doppler frequency deviation, thereby reducing the packet error rate and improving the accuracy of decoding.

[0055] In order to clearly illustrate how the above embodiment clusters multiple first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, the present disclosure proposes another method for determining a Doppler frequency shift.

[0056] Figure 4 A flowchart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure is provided.

[0057] like Figure 4 As shown, the method for determining the Doppler frequency shift may include the following steps:

[0058] Step 401: Receive a target data packet, and use a target frequency deviation prediction method to predict the frequency deviation of the target data packet to obtain an initial Doppler frequency deviation of the target data packet.

[0059] Step 402: Generate a frequency vector matching the set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packets.

[0060] Step 403: Obtain the arrangement order of multiple first elements in the frequency vector.

[0061] In the embodiment of the present disclosure, the frequency vector matches the set time length (frequency memory time length). For example, if the set time length is Len, the frequency vector f_vector = [f_1, f_2, ..., f_Len]. The frequency vector may include multiple first elements, so that the arrangement order of the multiple first elements can be obtained.

[0062] Step 404: traverse the multiple first elements in the frequency vector in sequence according to the arrangement order and the frequency threshold to cluster the multiple first elements in the frequency vector to obtain at least one cluster.

[0063] As a possible implementation manner of the embodiment of the present disclosure, at least one round of clustering process is performed on the multiple first elements according to the arrangement order and the frequency threshold to obtain at least one cluster.

[0064] Among them, the first round of clustering process includes: taking the first first element among multiple first elements in the frequency vector as the clustering center of the first round of clustering process, traversing the non-first first element among the multiple elements in turn according to the arrangement order, and judging whether the distance between the currently traversed first element and the clustering center of the first round of clustering process is less than the set frequency threshold, if so, clustering the currently traversed first element and the first first element into the same cluster, if not, taking the currently traversed first element as the clustering center of the next round of clustering process.

[0065] The non-first-round clustering process includes: determining, from multiple first elements, a second element in a cluster obtained by clustering in any round of clustering process before the non-first-round clustering process; traversing each second element in turn according to the arrangement order, and judging whether the distance between the currently traversed second element and the cluster center of any round of clustering process is less than the set frequency threshold; when the distance between the currently traversed second element and the cluster center of any round of clustering process is less than the set frequency threshold, clustering the currently traversed second element to the cluster obtained by clustering in any round of clustering process; when the distance between the currently traversed second element and the cluster center of any round of clustering process is greater than or equal to the set frequency threshold, using the currently traversed second element as the cluster center of the next round of clustering process.

[0066] As a possible implementation, the number of clusters (classes) f_cluster_num can be initialized to 1, the center of the cluster f_cluster_center[1] is f_1, the frequency accumulation value of the current cluster f_cluster_accu[1] is f_1, and the number of elements of the current cluster f_cluster_count=1. In the order of f_2, ..., f_Len, for each i, currently process f_i, if the distance difference between f_i and each cluster center is greater than the frequency threshold, a new cluster is generated, the number of clusters f_cluster_num is increased by 1, the center of the current cluster cluster_center[f_cluster_num] = f_i, the frequency accumulation value of the current cluster f_cluster_accu[f_cluster_num] = f_i, the number of clusters f_cluster_count = f_cluster_count+1, otherwise, there is k such that the distance between f_i and the center of cluster k f_cluster_center[k] is lower than the frequency threshold, then f_i is merged into the kth cluster, and the frequency accumulation value of the kth cluster f_cluster_accu[k] = f_cluster_accu[k]+f_i. The number of elements in the kth cluster f_cluster_count[k] = f_cluster_count[k]+1. The loop is continued until all elements (the first elements) of the frequency vector are processed.

[0067] Step 405: Determine a target cluster from at least one cluster according to the number of first elements in at least one cluster.

[0068] Step 406: Determine the target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0069] It should be noted that the execution process of steps 401 to 402 and steps 405 to 406 can be implemented in any way in the embodiments of the present disclosure, and the embodiments of the present disclosure do not limit this and will not be described in detail.

[0070] In summary, by obtaining the arrangement order of multiple first elements in the frequency vector; according to the arrangement order and the frequency threshold, traversing the multiple first elements in the frequency vector in turn to cluster the multiple first elements in the frequency vector to obtain at least one cluster, thereby, the multiple first elements in the frequency vector can be effectively clustered, so that according to the first element in the target cluster in at least one cluster obtained by clustering, the target Doppler frequency deviation of the target data packet can be determined, which improves the accuracy of Doppler frequency deviation prediction and the stability of Doppler frequency deviation, thereby reducing the packet error rate and improving the decoding accuracy.

[0071] In order to improve the accuracy of Doppler frequency offset, in the embodiment of the present disclosure, a target frequency offset prediction method is determined from the first frequency offset prediction method and the second frequency offset prediction method, so that the target frequency offset prediction method is used to predict the frequency offset of the target data packet to obtain the initial Doppler frequency offset of the target data packet. Figure 5 Provide detailed explanation.

[0072] like Figure 5 As shown, the method for determining the Doppler frequency shift may include the following steps:

[0073] Step 501: Receive a target data packet, and use a first frequency offset prediction method to predict the frequency offset of the target data packet under a set minimum signal-to-noise ratio to obtain a first Doppler frequency offset of the target data packet.

[0074] In order to improve the accuracy of Doppler frequency deviation, the target frequency deviation prediction method can be determined from the first frequency deviation prediction method and the second frequency deviation prediction method, that is, under the set minimum signal-to-noise ratio, the first frequency deviation prediction method and the second frequency deviation prediction method are respectively used to predict the frequency deviation of the target data packet to obtain the first Doppler frequency deviation and the second Doppler frequency deviation, and the target frequency deviation prediction method is determined based on the first difference between the first Doppler frequency deviation and the set Doppler frequency deviation, and the second difference between the second Doppler frequency deviation and the set Doppler frequency deviation.

[0075] In the embodiment of the present disclosure, under the setting of the minimum signal-to-noise ratio, the first frequency offset prediction method can be used to predict the frequency offset of the target data packet to obtain the first Doppler frequency offset of the target data packet.

[0076] As a possible implementation method, a first auxiliary vector of a target data packet is obtained, wherein each element of the first auxiliary vector is used to indicate whether the third element corresponding to the target data packet is a feature code; a set feature code vector of the target data packet is obtained, and a conjugate operation is performed on the set feature code vector to obtain a conjugate feature code vector; the product of the conjugate feature code vector and the first auxiliary vector is used as a second auxiliary vector of the target data packet; a K-point FFT transform is performed on the second auxiliary vector to obtain a first amplitude spectrum, wherein the K point is determined based on a set adoption rate of the target data packet and a set maximum allowable frequency error value; and a first Doppler frequency deviation of the target data packet is determined based on the first amplitude spectrum.

[0077] For example, taking the target data packet containing M third elements as an example, for each third element r_i in the target data packet, if its attribute is a feature code, the corresponding flag flag_vector(i) = 1, otherwise flag_vector(i) = 0, the first auxiliary vector rx = r.*flag_vector, ".*" indicates the corresponding multiplication, that is, rx(i) = r(i)*flag_vector(i). According to the set communication protocol, the feature code binary sequence is obtained, and the feature code vector is generated in combination with the modulation method specified in the communication protocol. According to the set position of the feature code vector and the service data vector contained in a frame of data vector feature in the communication protocol, the feature code vector and the service data vector are respectively filled into the feature, and the position element of the service data vector is set to 0. The second auxiliary vector ry=rx.*conj(feature), conj(*) represents the conjugate operation, and a K-point FFT is performed on the second auxiliary vector ry to obtain the first amplitude spectrum rz. The subscript s corresponding to the maximum value of rz is found, and the first Doppler frequency deviation is calculated as (sK / 2-1)*Rs / K, where Rs represents the symbol rate (set sampling rate). The principle for determining the K value is that the Rs / K value is less than or equal to the set maximum allowable frequency error value.

[0078] Step 502: Under the condition of setting the minimum signal-to-noise ratio, a second frequency offset prediction method is used to predict the frequency offset of the target data packet to obtain a second Doppler frequency offset of the target data packet.

[0079] As a possible implementation method of an embodiment of the present disclosure, a third auxiliary vector of the target data packet is obtained, wherein each element of the third auxiliary vector is used to indicate whether the third element corresponding to the target data packet is business data; the third auxiliary vector is modulated with a set modulation order to obtain a fourth auxiliary vector of the target data packet; a K-point FFT transform is performed on the fourth auxiliary vector to obtain a second amplitude spectrum; and a second Doppler frequency deviation of the target data packet is determined based on the second amplitude spectrum.

[0080] For example, taking the target data packet containing M third elements as an example, for each third element r_i, if its attribute is business data, the corresponding flag flag_vector(i) = 1, otherwise flag_vector(i) = 0. The third auxiliary vector rx = r.*flag_vector; ".*" indicates corresponding multiplication, that is, rx(i) = r(i)*flag_vector(i). Assuming that the set modulation order of the target data packet is P, a high-order spectrum operation is performed on the third auxiliary vector rx to obtain the fourth auxiliary vector ry, and a K-point FFT operation is performed on ry to obtain the second amplitude spectrum rz, and the subscript s corresponding to the maximum value of rz is determined. The second Doppler frequency deviation is calculated as (sK / 2-1)*Rs / K / P, where Rs represents the symbol rate (set sampling rate), and the principle for determining the K value is that the Rs / P / K value is less than or equal to the set maximum allowable frequency error value.

[0081] Step 503: Obtain a first difference between the first Doppler frequency offset and the set Doppler frequency offset, and a second difference between the second Doppler frequency offset and the set Doppler frequency offset.

[0082] Furthermore, the first Doppler frequency offset is compared with the set Doppler frequency offset to obtain a first difference between the first Doppler frequency offset and the set Doppler frequency offset, and the second Doppler frequency offset is compared with the set Doppler frequency offset to obtain a second difference between the second Doppler frequency offset and the set Doppler frequency offset.

[0083] Step 504: Determine a target frequency offset prediction method from the first frequency offset prediction method and the second frequency offset prediction method according to the first difference and the second difference.

[0084] Furthermore, the first difference is compared with the second difference. When the first difference is smaller than the second difference, that is, the first Doppler frequency deviation is slightly different from the set Doppler frequency deviation, the first frequency deviation prediction method can be used as the target frequency deviation prediction method. Similarly, when the first difference is larger than the second difference, that is, the second Doppler frequency deviation is slightly different from the set Doppler frequency deviation, the second frequency deviation prediction method can be used as the target frequency deviation prediction method. When the first difference is equal to the second difference, the first frequency deviation prediction method or the second frequency deviation prediction method can be used as the target frequency deviation prediction method.

[0085] Step 505: Use a target frequency deviation prediction method to predict the frequency deviation of the target data packet to obtain an initial Doppler frequency deviation of the target data packet.

[0086] Step 506: Generate a frequency vector matching the set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packets.

[0087] Step 507: clustering the multiple first elements in the frequency vector based on the set frequency threshold to obtain at least one cluster, and determining a target cluster from the at least one cluster according to the number of the first elements in the at least one cluster.

[0088] Step 508: Determine the target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0089] It should be noted that the execution process of steps 505 to 508 can be implemented in any manner in the embodiments of the present disclosure, and the embodiments of the present disclosure do not limit this and will not be described in detail.

[0090] In summary, by using the first frequency deviation prediction method to predict the frequency deviation of the target data packet under the setting of the minimum signal-to-noise ratio, the first Doppler frequency deviation of the target data packet is obtained; by using the second frequency deviation prediction method to predict the frequency deviation of the target data packet under the setting of the minimum signal-to-noise ratio, the second Doppler frequency deviation of the target data packet is obtained; according to the first difference and the second difference, the target frequency deviation prediction method is determined from the first frequency deviation prediction method and the second frequency deviation prediction method, thereby, the frequency deviation prediction method is selected from the first frequency deviation prediction method and the second frequency deviation prediction method, that is, the target frequency deviation prediction method, and the target frequency deviation prediction method is used to predict the frequency deviation of the target data packet to obtain the initial Doppler frequency deviation of the target data packet, thereby improving the accuracy of the initial Doppler frequency deviation.

[0091] In order to clearly explain how the frequency vector matching the set time length is generated according to the receiving order of the target data packets and the initial Doppler frequency offset in the above embodiment, the present disclosure proposes another method for determining the Doppler frequency offset.

[0092] Figure 6 A flowchart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure is provided.

[0093] like Figure 6 As shown, the method for determining the Doppler frequency shift may include the following steps:

[0094] Step 601: Receive a target data packet, and use a target frequency deviation prediction method to predict the frequency deviation of the target data packet to obtain an initial Doppler frequency deviation of the target data packet.

[0095] Step 602, obtaining a set maximum allowable frequency error value and a set unit frequency error value of a target data packet.

[0096] The unit frequency error value is used to indicate the maximum frequency change value within a unit time.

[0097] In the embodiment of the present disclosure, the communication protocol used for the transmission of the target data packet has specified the set maximum allowable frequency error value and the set unit frequency error value of the target data packet, so the set maximum allowable frequency error value and the set unit frequency error value of the target data packet can be obtained according to the communication protocol used for the transmission of the target data packet. The maximum allowable frequency error value refers to the maximum frequency value at which subsequent decoding can be performed correctly when the frequency deviation reaches this frequency value in an ideal environment without noise.

[0098] Step 603, determining a set time length according to a ratio between a set maximum allowable frequency error value and a set unit frequency error value.

[0099] Furthermore, the set time length is determined based on the ratio between the set maximum allowable frequency error value and the set unit frequency error value. For example, the ratio between the set maximum allowable frequency error value and the set unit frequency error value is used as the set time length so that the frequency deviation does not exceed the maximum allowable frequency error value within the time period corresponding to the set time length, thereby improving the accuracy of subsequent decoding.

[0100] Step 604: When the receiving order of the target data packet is the first time, a frequency vector matching the set time length is generated.

[0101] Among them, the multiple first elements in the frequency vector are all initial Doppler frequency offsets.

[0102] For example, when the receiving order of the target data packet is the first time, the initial Doppler frequency deviation of the target data packet is f, and the value of each element in the frequency vector f_vector=[f_1, f_2,…, f_Len] is f.

[0103] Step 605: When the receiving order of the target data packet is not the first time, a frequency vector matching the set time length is generated.

[0104] The last element of the multiple first elements in the frequency vector is the initial Doppler frequency deviation, and the other elements of the multiple first elements in the frequency vector except the last element are determined according to the initial Doppler frequency deviation of the data packets received historically.

[0105] For example, when the receiving order of the target data packet is not the first time, the value of the last element in the frequency vector f_vector=[f_1, f_2,…, f_Len] is the initial Doppler frequency deviation of the target data packet, and the other elements except the last element are determined according to the initial Doppler frequency deviation of the data packets received historically.

[0106] Step 606: cluster the multiple first elements in the frequency vector based on the set frequency threshold to obtain at least one cluster, and determine a target cluster from the at least one cluster according to the number of the first elements in the at least one cluster.

[0107] Step 607: Determine the target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0108] It should be noted that the execution process of step 601 and steps 606 to 607 can be implemented in any manner in the embodiments of the present disclosure, and the embodiments of the present disclosure do not limit this and will not be described in detail.

[0109] In summary, by obtaining the set maximum allowable frequency error value and the set unit frequency error value of the target data packet, wherein the unit frequency error value is used to indicate the maximum frequency change value within a unit time; the set time length is determined according to the ratio between the set maximum allowable frequency error value and the set unit frequency error value; when the receiving order of the target data packet is the first time, a frequency vector matching the set time length is generated, wherein multiple first elements in the frequency vector are all initial Doppler frequency deviations; when the receiving order of the target data packet is not the first time, a frequency vector matching the set time length is generated, wherein the last element of multiple first elements in the frequency vector is the initial Doppler frequency deviation , the other elements except the last element in the multiple first elements in the frequency vector are determined according to the initial Doppler frequency deviation of the data packet received historically, thereby, according to the set maximum allowable frequency error value and the set unit frequency error value, the set time length is determined so that the frequency deviation does not exceed the maximum allowable frequency error value within the time period corresponding to the set time length, so as to improve the correctness of subsequent decoding, and according to the receiving order of the target data packet and the initial Doppler frequency deviation of the target data packet, a frequency vector matching the set time length is generated, thereby, the multiple first elements in the frequency vector are clustered to determine the target Doppler frequency deviation of the target data packet, which can improve the accuracy and stability of the Doppler frequency deviation.

[0110] In order to clearly explain how the target Doppler frequency deviation of the target data packet is determined according to the first element in the target cluster in the above embodiment, the present disclosure proposes another method for determining the Doppler frequency deviation.

[0111] Figure 7 A flowchart of another method for determining Doppler frequency deviation provided by an embodiment of the present disclosure is provided.

[0112] like Figure 7 As shown, the method for determining the Doppler frequency shift may include the following steps:

[0113] Step 701: Receive a target data packet, and use a target frequency deviation prediction method to perform frequency deviation prediction on the target data packet to obtain an initial Doppler frequency deviation of the target data packet.

[0114] Step 702: Generate a frequency vector matching the set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packets.

[0115] Step 703: cluster multiple first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determine a target cluster from the at least one cluster according to the number of first elements in the at least one cluster.

[0116] Step 704: add the first elements in the target cluster to obtain the sum of the first elements in the target cluster.

[0117] In the embodiment of the present disclosure, the first elements in the target cluster may be added to obtain the sum value of the first elements in the target cluster.

[0118] Step 705: Determine the target Doppler frequency deviation of the target data packet according to the ratio of the sum value to the number of first elements in the target cluster.

[0119] Furthermore, the mean of the target cluster can be determined based on the sum of the first elements in the target cluster and the number of first elements in the target cluster. For example, by comparing the sum with the number of first elements in the target cluster, the mean of the target cluster can be obtained, and the mean can be used as the target Doppler frequency deviation of the target data packet.

[0120] like Figure 8As shown, the flag FLAG is initialized, the register length (set time length) is N, if the first frequency value f is obtained, the frequency vector f_vector = [f_1, f_2, ..., f_N] is updated to f_vector = [f, f, ..., f], otherwise, f_vector = [f_1, f_2, ..., f_N] is updated to f_vector = [f_2, ..., f_N-1, f]. Secondly, clustering (clustering) processing is performed. The number of clusters (classes) is initialized to f_cluster_num = 1, the center of the cluster f_cluster_center[1] is f_1, the frequency accumulation value of the current class f_cluster_accu[1] is f_1, and the number of elements of the current class f_cluster_count = 1. In the order of f_2, ..., f_N, for each i, currently process f_i, if the distance difference between f_i and each cluster center is greater than the threshold value (frequency threshold), a new cluster is generated, and the number of clusters f_cluster_num is increased by 1, cluster_center[f_cluster_num] = f_i, f_cluster_accu[f_cluster_num] = f_i, f_cluster_count = f_cluster_count+1 Otherwise, there is k such that the distance between f_i and f_cluster_center[k] is less than thold, then f_i is merged into the kth cluster, f_cluster_accu[k] = f_cluster_accu[k] + f_i. f_cluster_count[k] = f_cluster_count[k] + 1. The loop is performed until all elements of the frequency vector are processed.

[0121] Then, after obtaining multiple clusters corresponding to the frequency vector, select the cluster with the most elements (target cluster) and output its mean. Among all cluster types, select the cluster with the largest number of cluster elements as the target cluster. The number of elements in the target cluster is set as index, then the target Doppler frequency deviation = the accumulated value of the first element of the target cluster / index.

[0122] It should be noted that the calculation method of the above formula is only exemplary, and those skilled in the art can also set other calculation formulas according to actual conditions. For example, those skilled in the art can also add some correction coefficients, weight coefficients, etc. to the above calculation formula. Such changes in specific calculation methods do not deviate from the basic principles of the present invention and belong to the protection scope of the present invention.

[0123] In summary, the first elements in the target cluster are added to obtain the sum of the first elements in the target cluster; the target Doppler frequency deviation of the target data packet is determined according to the ratio of the sum to the number of first elements in the target cluster, thereby improving the accuracy of Doppler frequency deviation prediction and the stability of Doppler frequency deviation, thereby reducing the packet error rate and improving the decoding accuracy.

[0124] In order to explain the above embodiment more clearly, examples are given below.

[0125] like Fig. 9 As shown, the frame format of the channel (target data packet) consists of a signature code + service data, where the signature code is BPSK (Binary Phase Shift Keying) modulated with a length of 30, and the service data is QPSK (Quadrature Phase Shift Keying) modulated with a length of 200. When Es / N0=5dB, where Es represents the energy of the modulation symbol, N0 represents the bilateral power spectral density, the symbol rate is 10ksps, and the frequency deviation is 1kHz, the Doppler frequency deviation (frequency) estimation method based on the signature code has the spectral line characteristics as shown in FIG. Fig.10 As shown in the figure, the Doppler frequency deviation (frequency) estimation method based on business data, spectral line characteristics Fig.11 As shown in the figure, two methods were used to perform 10,000 simulation tests, and the frequency estimation results were as follows: Fig.12 and Fig.13 As shown in the figure, after statistical analysis, it is found that the Doppler frequency deviation estimation method based on the signature code has a deviation of more than 5Hz from the theoretical value more than 7500 times in 10000 simulations, while the Doppler frequency deviation estimation method based on business data has a deviation of only 260 times. The accuracy of the Doppler frequency deviation estimation method based on business data is significantly higher than that of the Doppler frequency deviation estimation method based on the signature code, so the Doppler frequency deviation estimation method based on business data is selected for Doppler frequency deviation estimation.

[0126] Assuming that the maximum allowable frequency error value that the decoder can tolerate is 5Hz, and the frequency change of the signal within a subframe (unit) time range does not exceed 1Hz, the set time length (time memory length) is selected as 5, and the set frequency threshold is 15Hz. Under this condition, further processing of Doppler frequency deviation is carried out, and the results are as follows Fig.14 As shown. Therefore, the frequency estimation performed by determining the Doppler frequency offset described in the embodiment of the present disclosure reduces the error fluctuation of up to the kHz level generated by the Doppler frequency offset estimation method based on business data to the error of the Hz level, so that the residual frequency error is within the range allowed by the decoder, that is, the Doppler frequency offset is more stable.

[0127] In order to implement the above embodiment, the present disclosure also proposes a device for determining Doppler frequency shift.

[0128] Fig.15 A schematic diagram of the structure of a device for determining a Doppler frequency shift provided in an embodiment of the present disclosure.

[0129] like Fig.15 As shown, the Doppler frequency shift determination device 1500 includes: a first prediction module 1510 , a generation module 1520 , a clustering module 1530 and a first determination module 1540 .

[0130] Among them, the first prediction module 1510 is used to receive a target data packet and use a target frequency deviation prediction method to predict the frequency deviation of the target data packet to obtain the initial Doppler frequency deviation of the target data packet; the generation module 1520 is used to generate a frequency vector matching a set time length according to the reception order of the target data packets and the initial Doppler frequency deviation of the target data packets; the clustering module 1530 is used to cluster multiple first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determine a target cluster from at least one cluster according to the number of first elements in at least one cluster; the first determination module 1540 is used to determine the target Doppler frequency deviation of the target data packet according to the first element in the target cluster.

[0131] As a possible implementation method of the embodiment of the present disclosure, the clustering module 1530 is specifically used to: obtain the arrangement order of multiple first elements in the frequency vector; traverse the multiple first elements in the frequency vector in turn according to the arrangement order and the frequency threshold to cluster the multiple first elements in the frequency vector to obtain at least one cluster.

[0132] As a possible implementation method of the embodiment of the present disclosure, the clustering module 1530 is also used to: perform at least one round of clustering process on multiple first elements according to the arrangement order and frequency threshold to obtain at least one cluster; wherein the first round of clustering process includes: taking the first first element among the multiple first elements in the frequency vector as the cluster center of the first round of clustering process, traversing the non-first first elements among the multiple elements in turn according to the arrangement order, and judging whether the distance between the currently traversed first element and the cluster center of the first round of clustering process is less than the set frequency threshold; if so, clustering the currently traversed first element and the first first element into the same cluster; if not, taking the currently traversed first element as the cluster center of the next round of clustering process.

[0133] As a possible implementation method of an embodiment of the present disclosure, a non-first-round clustering process includes: determining, from multiple first elements, a second element in a cluster obtained by clustering in any round of clustering process before the non-first-round clustering process; traversing each of the second elements in turn according to the arrangement order, and judging whether the distance between the currently traversed second element and the cluster center of any round of clustering process is less than a set frequency threshold; when the distance between the currently traversed second element and the cluster center of any round of clustering process is less than the set frequency threshold, clustering the currently traversed second element to the cluster obtained by clustering in any round of clustering process; when the distance between the currently traversed second element and the cluster center of any round of clustering process is greater than or equal to the set frequency threshold, using the currently traversed second element as the cluster center of the next round of clustering process.

[0134] As a possible implementation manner of the embodiment of the present disclosure, the Doppler frequency shift determination device 1500 further includes: a second prediction module, a third prediction module, an acquisition module and a second determination module.

[0135] Among them, the second prediction module is specifically used to predict the frequency deviation of the target data packet using the first frequency deviation prediction method under the set minimum signal-to-noise ratio, so as to obtain the first Doppler frequency deviation of the target data packet; the third prediction module is specifically used to predict the frequency deviation of the target data packet using the second frequency deviation prediction method under the set minimum signal-to-noise ratio, so as to obtain the second Doppler frequency deviation of the target data packet; the acquisition module is specifically used to obtain the first difference between the first Doppler frequency deviation and the set Doppler frequency deviation, and the second difference between the second Doppler frequency deviation and the set Doppler frequency deviation; the second determination module is specifically used to determine the target frequency deviation prediction method from the first frequency deviation prediction method and the second frequency deviation prediction method according to the first difference and the second difference.

[0136] As a possible implementation method of the embodiment of the present disclosure, the second prediction module is specifically used to obtain a first auxiliary vector of the target data packet, wherein each element of the first auxiliary vector is used to indicate whether the third element corresponding to the target data packet is a feature code; obtain a set feature code vector of the target data packet, and perform a conjugate operation on the set feature code vector to obtain a conjugate feature code vector; use the product of the conjugate feature code vector and the first auxiliary vector as the second auxiliary vector of the target data packet; perform a K-point FFT transform on the second auxiliary vector to obtain a first amplitude spectrum, wherein the K point is determined based on a set adoption rate and a set maximum allowable frequency error value of the target data packet; and determine a first Doppler frequency deviation of the target data packet based on the first amplitude spectrum.

[0137] As a possible implementation method of an embodiment of the present disclosure, the third prediction module is specifically used to obtain a third auxiliary vector of the target data packet, wherein each element of the third auxiliary vector is used to indicate whether the third element corresponding to the target data packet is business data; the third auxiliary vector is modulated with a set modulation order to obtain a fourth auxiliary vector of the target data packet; the fourth auxiliary vector is subjected to a K-point FFT transform to obtain a second amplitude spectrum; and a second Doppler frequency deviation of the target data packet is determined based on the second amplitude spectrum.

[0138] As a possible implementation method of the embodiment of the present disclosure, the generation module 1520 is specifically used to: obtain a set maximum allowable frequency error value and a set unit frequency error value of the target data packet, wherein the unit frequency error value is used to indicate the maximum frequency change value within a unit time; determine the set time length according to the ratio between the set maximum allowable frequency error value and the set unit frequency error value; when the receiving order of the target data packet is the first time, generate a frequency vector matching the set time length, wherein multiple first elements in the frequency vector are all initial Doppler frequency deviations; when the receiving order of the target data packet is not the first time, generate a frequency vector matching the set time length, wherein the last element of the multiple first elements in the frequency vector is the initial Doppler frequency deviation, and the other elements of the multiple first elements in the frequency vector except the last element are determined according to the initial Doppler frequency deviation of the data packet received historically.

[0139] As a possible implementation method of the embodiment of the present disclosure, the first determination module 1540 is specifically used to: add the first elements in the target cluster to obtain the sum of the first elements in the target cluster; and determine the target Doppler frequency deviation of the target data packet based on the ratio of the sum to the number of first elements in the target cluster.

[0140] In summary, a target data packet is received and a frequency deviation prediction method is used to predict the frequency deviation of the target data packet to obtain an initial Doppler frequency deviation of the target data packet; a frequency vector matching a set time length is generated according to the receiving order of the target data packets and the initial Doppler frequency deviation of the target data packet; based on a set frequency threshold, multiple first elements in the frequency vector are clustered to obtain at least one cluster, and a target cluster is determined from at least one cluster according to the number of first elements in at least one cluster; a target Doppler frequency deviation of the target data packet is determined according to the first element in the target cluster, and thus, after obtaining the initial Doppler frequency deviation, a frequency vector matching a set time length is generated. A frequency vector matching a set time length, wherein the set time length is determined based on a set maximum allowable frequency error value and a set unit frequency error value of a target data packet, so that within a time period corresponding to the set time length, the Doppler frequency deviation does not exceed the maximum allowable frequency error value, so as to improve the accuracy of subsequent decoding. According to a clustering algorithm, the frequency vector corresponding to the initial Doppler frequency deviation is clustered, and based on the first element in a target cluster in at least one cluster obtained by clustering, the target Doppler frequency deviation of the target data packet is determined, thereby improving the accuracy of Doppler frequency deviation prediction and the stability of Doppler frequency deviation, thereby reducing the packet error rate and improving the accuracy of decoding.

[0141] It should be noted that the above explanation of the embodiment 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.

[0142] In order to implement the above embodiments, the present application also proposes an electronic device, such as Fig.16 As shown, Fig.16 It is a block diagram of an electronic device for determining Doppler frequency shift according to an exemplary embodiment.

[0143] like Fig.16 As shown, the electronic device 1600 includes:

[0144] The memory 1610 and the processor 1620, a bus 1630 connecting different components (including the memory 1610 and the processor 1620), the memory 1610 stores a computer program, and when the processor 1620 executes the program, the method for determining the Doppler frequency shift described in the embodiment of the present disclosure is implemented.

[0145] Bus 1630 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. 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 Interconnect (PCI) bus.

[0146] The electronic device 1600 typically includes a variety of electronic device readable media. These media can be any available media that can be accessed by the electronic device 1600, including volatile and non-volatile media, removable and non-removable media.

[0147] The memory 1610 may also include computer system readable media in the form of volatile memory, such as random access memory (RAM) 1640 and / or cache memory 1650. The electronic device 1600 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 1660 may be used to read and write non-removable, non-volatile magnetic media ( Fig.16 not shown, usually called a "hard drive"). Although Fig.16 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 1630 via one or more data medium interfaces. Memory 1610 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.

[0148] A program / utility 1680 having a set (at least one) of program modules 1670 may be stored, for example, in the memory 1610, such program modules 1670 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 1670 generally perform the functions and / or methods of the embodiments described in the present disclosure.

[0149] The electronic device 1600 may also communicate with one or more external devices 1690 (e.g., keyboards, pointing devices, displays, etc.), may communicate with one or more devices that enable a user to interact with the electronic device 1600, and / or may communicate with any device that enables the electronic device 1600 to communicate with one or more other computing devices (e.g., network cards, modems, etc.). Such communication may be performed through an input / output (I / O) interface 1692. Furthermore, the electronic device 1600 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 1693. Fig.16 As shown, the network adapter 1693 communicates with other modules of the electronic device 1600 via the bus 1630. It should be understood that although Fig.16 Not shown, other hardware and / or software modules may be used in conjunction with electronic device 1600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0150] The processor 1620 executes various functional applications and data processing by running the programs stored in the memory 1610 .

[0151] It should be noted that the implementation process and technical principles of the electronic device of this embodiment refer to the aforementioned explanation of the determination of the Doppler frequency shift in the embodiment of the present disclosure, which will not be repeated here.

[0152] In order to implement the above embodiments, the present application further proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for determining the Doppler frequency shift described in the above embodiments is implemented.

[0153] In order to implement the above embodiments, the present disclosure further provides a computer program product. When an instruction processor in the computer program product is executed, the method for determining the Doppler frequency shift described in the above embodiments is executed.

[0154] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0155] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 application. In this specification, the schematic representations of the above terms do 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0156] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for determining Doppler frequency shift, characterized in that: include: receiving a target data packet, and performing frequency deviation prediction on the target data packet using a target frequency deviation prediction method to obtain an initial Doppler frequency deviation of the target data packet; Generate a frequency vector matching a set time length according to a receiving order of the target data packets and an initial Doppler frequency deviation of the target data packets, wherein the set time length is determined according to a set maximum allowable frequency error value and a set unit frequency error value of the target data packets; Based on a set frequency threshold, clustering multiple first elements in the frequency vector to obtain at least one cluster, and determining a target cluster from the at least one cluster according to the number of first elements in the at least one cluster; A target Doppler frequency deviation of the target data packet is determined according to a first element in the target cluster.

2. The method according to claim 1, characterized in that The clustering of the plurality of first elements in the frequency vector based on the set frequency threshold to obtain at least one cluster includes: Obtaining an arrangement order of a plurality of first elements in the frequency vector; According to the arrangement order and the frequency threshold, the multiple first elements in the frequency vector are traversed in sequence to cluster the multiple first elements in the frequency vector to obtain at least one cluster.

3. The method according to claim 2, characterized in that The step of sequentially traversing the plurality of first elements in the frequency vector according to the arrangement order and the frequency threshold to cluster the plurality of first elements in the frequency vector to obtain at least one cluster includes: According to the arrangement order and the frequency threshold, performing at least one round of clustering process on the plurality of first elements to obtain at least one cluster; Among them, the first round of clustering process includes: taking the first first element among the multiple first elements in the frequency vector as the clustering center of the first round of clustering process, traversing the non-first first elements among the multiple elements in turn according to the arrangement order, and judging whether the distance between the currently traversed first element and the clustering center of the first round of clustering process is less than the set frequency threshold; if so, clustering the currently traversed first element and the first first element into the same cluster; if not, taking the currently traversed first element as the clustering center of the next round of clustering process.

4. The method according to claim 3, characterized in that The non-first round clustering process includes: Determine, from the plurality of first elements, a second element in a cluster that is not clustered in any round of clustering process before the non-first round of clustering process; Traversing each of the second elements in sequence according to the arrangement order, and determining whether the distance between the currently traversed second element and the cluster center of any round of clustering process is less than a set frequency threshold; When the distance between the second element currently traversed and the cluster center of any round of clustering process is less than the set frequency threshold, the second element currently traversed is clustered into the cluster obtained by clustering in any round of clustering process; When the distance between the currently traversed second element and the cluster center of any round of clustering process is greater than or equal to the set frequency threshold, the currently traversed second element is used as the cluster center of the next round of clustering process.

5. The method according to claim 1, characterized in that Before the frequency deviation prediction of the target data packet is performed in a target frequency prediction manner to obtain an initial Doppler frequency deviation of the target data packet, the method further includes: Under a set minimum signal-to-noise ratio, a first frequency deviation prediction method is used to perform frequency deviation prediction on the target data packet to obtain a first Doppler frequency deviation of the target data packet; Under the set minimum signal-to-noise ratio, using a second frequency offset prediction method to perform frequency offset prediction on the target data packet to obtain a second Doppler frequency offset of the target data packet; Acquire a first difference between the first Doppler frequency offset and a set Doppler frequency offset, and a second difference between the second Doppler frequency offset and the set Doppler frequency offset; The target frequency offset prediction method is determined from the first frequency offset prediction method and the second frequency offset prediction method according to the first difference and the second difference.

6. The method according to claim 5, characterized in that The target data packet includes a plurality of third elements, and under a set minimum signal-to-noise ratio, a first frequency offset prediction method is used to perform frequency offset prediction on the target data packet to obtain a first Doppler frequency offset of the target data packet, including: Acquire a first auxiliary vector of the target data packet, wherein each element of the first auxiliary vector is used to indicate whether a third element corresponding to the target data packet is a feature code; Acquire a set feature code vector of the target data packet, and perform a conjugate operation on the set feature code vector to obtain a conjugate feature code vector; The product of the conjugate feature code vector and the first auxiliary vector is used as the second auxiliary vector of the target data packet; Performing a K-point FFT transformation on the second auxiliary vector to obtain a first amplitude spectrum, wherein the K points are determined according to a set adoption rate of the target data packet and a set maximum allowable frequency error value; A first Doppler frequency deviation of the target data packet is determined according to the first amplitude spectrum.

7. The method according to claim 6, characterized in that The step of predicting the frequency offset of the target data packet using the second frequency offset prediction method under the set minimum signal-to-noise ratio to obtain a second Doppler frequency offset of the target data packet includes: Acquire a third auxiliary vector of the target data packet, wherein each element of the third auxiliary vector is used to indicate whether a third element corresponding to the target data packet is service data; modulating the third auxiliary vector with a set modulation order to obtain a fourth auxiliary vector of the target data packet; Performing a K-point FFT transform on the fourth auxiliary vector to obtain a second amplitude spectrum; A second Doppler frequency deviation of the target data packet is determined according to the second amplitude spectrum.

8. The method according to any one of claims 1 to 7, characterized in that The step of generating a frequency vector matching a set time length according to the receiving order of the target data packets and the initial Doppler frequency deviation comprises: Acquire a set maximum allowable frequency error value and a set unit frequency error value of the target data packet, wherein the unit frequency error value is used to indicate a maximum frequency change value within a unit time; Determining the set time length according to the ratio between the set maximum allowable frequency error value and the set unit frequency error value; In the case where the target data packet is received in the first order, a frequency vector matching the set time length is generated, wherein a plurality of first elements in the frequency vector are all the initial Doppler frequency deviations; In the case where the receiving order of the target data packet is not the first time, a frequency vector matching the set time length is generated, wherein the last element of the multiple first elements in the frequency vector is the initial Doppler frequency deviation, and the other elements of the multiple first elements in the frequency vector except the last element are determined according to the initial Doppler frequency deviation of the data packets received historically.

9. The method according to any one of claims 1 to 7, characterized in that: The step of determining a target Doppler frequency deviation of the target data packet according to the first element in the target cluster includes: Adding the first elements in the target cluster to obtain a sum of the first elements in the target cluster; The target Doppler frequency deviation of the target data packet is determined according to the ratio of the sum value to the number of first elements in the target cluster.

10. A device for determining Doppler frequency deviation, characterized in that: include: A first prediction module is used to receive a target data packet and perform frequency deviation prediction on the target data packet using a target frequency deviation prediction method to obtain an initial Doppler frequency deviation of the target data packet; A generating module, configured to generate a frequency vector matching a set time length according to a receiving order of the target data packets and an initial Doppler frequency deviation of the target data packets, wherein the set time length is determined according to a set maximum allowable frequency error value and a set unit frequency error value of the target data packets; a clustering module, configured to cluster the plurality of first elements in the frequency vector based on a set frequency threshold to obtain at least one cluster, and determine a target cluster from the at least one cluster according to the number of the first elements in the at least one cluster; The first determination module is used to determine a target Doppler frequency deviation of the target data packet according to a first element in the target cluster.

11. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the Doppler frequency offset determination method according to any one of claims 1 to 9 is implemented.

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