Symbol timing synchronization method, apparatus and communication device

Abstract

The application discloses a symbol timing synchronization method, device and communication equipment, and belongs to the technical field of communication. The symbol timing synchronization method of the application comprises the following steps: a communication equipment performs oversampling on a received signal to obtain a sampling signal; the communication equipment performs clustering processing on the sampling signal by using a clustering algorithm to obtain a received signal sampling point sequence; and the communication equipment determines the sampling points which are continuous and have the same value in the received signal sampling point sequence as one symbol, and completes symbol timing synchronization.

Description

Technical Field

[0001] This application belongs to the field of communication technology, specifically relating to a symbol timing synchronization method, apparatus, and communication equipment. Background Technology

[0002] In communication systems, to recover the data signal from the received signal, the receiver needs to periodically sample and decide on the demodulated output signal at the symbol rate. The receiver generates a clock signal synchronized with the symbol rate of the received digital baseband signal to obtain accurate sampling timing. In practical systems, there is also a frequency offset between the receiver and transmitter. The receiver's sampling clock must adjust its clock frequency and timing phase in real time to compensate for this frequency offset, ensuring the optimal sampling time for the output signal. Therefore, symbol timing synchronization is one of the key functions that the receiver must perform in a communication system.

[0003] In existing digital communication systems, symbol timing synchronization modules are all based on phase-locked loop (PLL) structures, employing different symbol synchronization algorithms to address variations in the modulation scheme at the transmitting end. For example, for Pulse Amplitude Modulation (PAM) or Quadrature Amplitude Modulation (QAM) systems, current symbol timing methods include PLL schemes based on early-late gates, maximum likelihood, zero-crossing, and Gardner timing detectors. Current symbol timing synchronization modules track signal frequency offsets in real time and adjust the optimal sampling time accordingly, but they also suffer from drawbacks such as slow loop entry into steady state and synchronization failures due to limited frequency offset ranges. Furthermore, existing symbol timing synchronization algorithms are incompatible with space-time coding. For instance, in wireless devices using multi-antenna space-time coding schemes, the received signal constellation diagram is a superposition of constellation diagrams from multiple antennas, resulting in unclear amplitude and phase relationships between constellation points. Moreover, in practical deployments, the constellation diagram is more susceptible to environmental influences, making it difficult to apply synchronization methods designed based on existing modulation schemes. Summary of the Invention

[0004] This application provides a symbol timing synchronization method, apparatus, and communication device, which can solve the problems of insufficient generalization ability and strong specialization of existing symbol timing synchronization algorithms.

[0005] Firstly, a symbol timing synchronization method is provided, including:

[0006] Communication equipment oversamples the received signal to obtain the sampled signal;

[0007] The communication device uses a clustering algorithm to cluster the sampled signal to obtain a sequence of received signal sampling points;

[0008] The communication device determines consecutive sampling points with the same value in the sequence of received signal sampling points as one symbol, and completes symbol timing synchronization.

[0009] Secondly, a symbol timing synchronization device is provided, comprising:

[0010] The sampling module is used to oversample the received signal to obtain the sampled signal;

[0011] The clustering module is used to perform clustering processing on the sampled signal using a clustering algorithm to obtain a sequence of received signal sampling points;

[0012] The determination module is used to determine consecutive sampling points with the same value in the received signal sampling point sequence as one symbol, thereby completing symbol timing synchronization.

[0013] Thirdly, a communication device is provided, the terminal including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect.

[0014] Fourthly, a communication device is provided, including a processor and a communication interface, wherein the processor is used to oversample the received signal to obtain a sampled signal; to cluster the sampled signal using a K-means clustering algorithm to obtain a sequence of received signal sampling points; and to determine consecutive sampling points with the same value in the sequence of received signal sampling points as one symbol to complete symbol timing synchronization.

[0015] Fifthly, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or implement the steps of the method described in the third aspect.

[0016] In a sixth aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being used to run programs or instructions to implement the method as described in the first aspect.

[0017] In a seventh aspect, a computer program / program product is provided, the computer program / program product being stored in a storage medium, the computer program / program product being executed by at least one processor to perform the steps of the method as described in the first aspect.

[0018] In this embodiment, the sampled signals of the received signal are judged and clustered. By continuously judging the sampled point sequence after clustering, symbols are output to achieve symbol timing synchronization. This method is simple to implement, highly versatile, and flexible, and can meet the requirements of wireless communication symbol timing synchronization. Attached Figure Description

[0019] Figure 1 A block diagram illustrating a wireless communication system to which embodiments of this application may be applied;

[0020] Figure 2 This is a flowchart illustrating the steps of the symbol timing synchronization method provided in the embodiments of this application;

[0021] Figure 3 This diagram illustrates an application system of the symbol timing synchronization method provided in the embodiments of this application.

[0022] Figure 4 This diagram illustrates the sampling signal in the symbol timing synchronization method provided in the embodiments of this application.

[0023] Figure 5 A flowchart illustrating Example 1 provided in the embodiments of this application;

[0024] Figure 6 This is a schematic diagram of the symbol timing synchronization device provided in the embodiments of this application;

[0025] Figure 7 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application;

[0026] Figure 8 This is a schematic diagram of the structure of the terminal provided in the embodiments of this application;

[0027] Figure 9 This is a schematic diagram illustrating the structure of the network-side device provided in the embodiments of this application. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0029] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0030] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency Division Multiple Access (SC-FDMA), and other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and NR terminology is used in most of the following description; however, these technologies can also be applied to applications beyond NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0031] Figure 1This diagram illustrates a block diagram of a wireless communication system applicable to embodiments of this application. The wireless communication system includes a terminal 11 and a network-side device 12. Terminal 11 can be a mobile phone, tablet computer, laptop computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, vehicle-mounted device (VUE), pedestrian terminal (PUE), smart home (home devices with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game console, personal computer (PC), ATM, or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. It should be noted that the specific type of terminal 11 is not limited in this embodiment. Network-side equipment 12 may include access network equipment or core network equipment. Access network equipment 12 may also be referred to as radio access network equipment, radio access network (RAN), radio access network function, or radio access network unit. Access network equipment 12 may include base stations, WLAN access points, or WiFi nodes, etc. Base stations may be referred to as Node B, evolved Node B (eNB), access point, base transceiver station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), home B node, home evolved B node, Transmitting Receiving Point (TRP), or any other suitable term in the field, as long as the same technical effect is achieved. The base station is not limited to specific technical terms. It should be noted that this application embodiment only uses a base station in an NR system as an example for description and does not limit the specific type of base station.

[0032] The symbol timing synchronization method, apparatus, and communication equipment provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0033] like Figure 2 As shown, this application provides a symbol timing synchronization method, including:

[0034] Step 201: The communication device oversamples the received signal to obtain the sampled signal;

[0035] Step 202: The communication device uses a clustering algorithm to cluster the sampled signal to obtain a sequence of received signal sampling points;

[0036] In this step, the clustering algorithm includes any one of the following: 1. K-Means clustering; 2. Mean-shift clustering; 3. Density-based clustering method (DBSCAN); 4. Expectation-Maximum (EM) clustering using Gaussian Mixture Model (GMM); 5. Agglomerated hierarchical clustering; 6. Graph Community Detection.

[0037] Step 203: The communication device determines consecutive sampling points with the same value in the sequence of received signal sampling points as one symbol, and completes symbol timing synchronization.

[0038] In at least one optional embodiment of this application, the communication device is a receiving device. For example... Figure 3 The diagram illustrates an application system for the symbol timing synchronization method provided in this application. For example, the application system includes a transmitter and a receiver. The transmitter generates a data signal with a specific center frequency; the receiver receives the data signal from the transmitter and performs symbol timing synchronization. Alternatively, the application system includes a transmitter, a transmitter, and a receiver. The transmitter generates a carrier signal with a specific center frequency; the reflector transmits the data signal using backscatter modulation; and the receiver receives the data signal from the reflector and performs symbol timing synchronization.

[0039] As an optional embodiment, the sampling signal in step 201 is as follows: Figure 4 As shown, the sampled signal includes a preamble field y. P [n] and data field y D [n], where the preamble field y P [n] contains K symbols, namely symbol 1 to symbol K. Based on the assumption of good synchronization of the preamble field, this embodiment uses the preamble field to determine the initial value (K) for the clustering algorithm.

[0040] This application addresses the shortcomings of existing symbol timing synchronization algorithms, such as insufficient generalization ability and strong specialization. It proposes a symbol timing synchronization method to achieve symbol timing synchronization of received signals under different modulation and coding schemes. Based on a clustering algorithm, it defines multiple data similarity measures to extract common features of symbol timing synchronization under different modulation and coding schemes, transforming the symbol timing synchronization problem into a problem of classifying and jointly deciding similar sampled data points, thereby enhancing the generalization ability of symbol timing synchronization algorithms in wireless communication systems.

[0041] In at least one embodiment of this application, step 202 includes:

[0042] Obtain the K central constellation points corresponding to the K symbols in the sampled signal;

[0043] Clustering is performed based on the central constellation points. The clustering operation includes: clustering the sampled points into a symbol cluster corresponding to the central constellation point with the smallest distance based on the distance between the sampled points and the K central constellation points, and calculating the new mean point of the cluster corresponding to each symbol.

[0044] If the new mean point is different from the center constellation point, the new mean point is determined as the center constellation point of the corresponding cluster, and the process jumps to the step of performing clustering operation based on the center constellation point until the new mean point is the same as the center constellation point or until the preset iteration counter overflows.

[0045] If the new mean point is the same as the center constellation point, or if the preset iteration counter overflows, the value of the sample point is replaced with the value of the center constellation point of the cluster corresponding to the sample point, and the received signal sample point sequence is obtained.

[0046] In this embodiment of the application, the conditions for determining whether clustering is complete include:

[0047] 1. Is the new mean point the same as the central constellation point?

[0048] 2. Check if the preset iteration counter overflows.

[0049] In order to avoid the new mean point still being different from the central constellation point after multiple rounds of clustering, resulting in an infinite number of rounds of clustering, this application embodiment uses whether the preset iteration counter overflows as a criterion for judging whether the clustering is complete, thereby saving computing resources.

[0050] In at least one embodiment of this application, before performing clustering operations based on the central constellation points, the method further includes:

[0051] Calculate the absolute value of the difference in magnitude between any two central constellation points;

[0052] Based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and the first threshold, the indicator variable for the distance calculation formula is determined;

[0053] The distance between the sampling point and the central constellation point is calculated based on the distance calculation formula indicating the variable.

[0054] Among them, based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and the first threshold, the indicator variables for the distance calculation formula are determined, including:

[0055] If the minimum absolute value of the difference between the magnitudes of the central constellation points is less than the first threshold, the indicator variable of the distance calculation formula is determined to be the first value; for example, the first value is 1.

[0056] or,

[0057] If the minimum absolute value of the difference between the magnitudes of the central constellation points is greater than or equal to the first threshold, the indicator variable of the distance calculation formula is determined to be a second value; for example, the second value is 0.

[0058] Accordingly, based on the distance calculation formula indicating the variable, the distance between the sampling point and the central constellation point is calculated, including:

[0059] When the indicator variable in the distance calculation formula is a first value, the distance between the sampling point and the central constellation point is calculated using the first formula;

[0060] or,

[0061] When the indicator variable in the distance calculation formula is the second value, the distance between the sampling point and the central constellation point is calculated using the second formula; wherein,

[0062] The first formula is: d n,k =||y D [n]-m k ||2; The second formula is: d n,k =||y D [n]|-|m k ||;d n,k y is the distance between the sampling point and the central constellation point; D [n] represents the data field of the sampled signal; n represents the number of sampling points; m k Let be the central constellation point of the k-th cluster; ||·||2 is the 2-norm operator.

[0063] The sampling signal in this application includes a preamble field, wherein the preamble field includes K symbols;

[0064] Obtaining the central constellation points of the clusters corresponding to K symbols from the sampled signal includes:

[0065] Using the third formula, the central constellation points of the clusters corresponding to K symbols are obtained from the sampled signal; wherein, the third formula is:

[0066]

[0067] Where, m k Let k be the central constellation point of the k-th cluster, where k is the index of the cluster central constellation point, K is the number of symbol types, and N is the index of the cluster central constellation point. k The number of sampling points for calculating the mean of the k-th symbol, y P [n] represents the preamble of the sampled signal. Let n be the starting sampling point corresponding to the kth symbol, and n be the sampling point.

[0068] In summary, in this embodiment, the sampled signals of the received signal are judged and clustered, and symbols are output by continuously judging the sampled point sequence after clustering, thereby achieving the purpose of symbol timing synchronization. It is simple to implement, highly versatile, and highly flexible, and can meet the needs of wireless communication symbol timing synchronization.

[0069] To more clearly describe the symbol timing synchronization method provided in the embodiments of this application, two examples are given below.

[0070] Example 1, such as Figure 5 As shown:

[0071] S101: Obtain the central constellation points of the clusters corresponding to K types of symbols from the sampled signal, and initialize the set of K symbol sampling points and the iteration counter;

[0072] S102: Calculate the absolute value of the difference between the modulus values ​​of any two central constellation points;

[0073] S103: Based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and a given threshold, calculate the indicator variable for the distance calculation formula;

[0074] S104: Based on the distance calculation formula indicator variable, calculate the distance between the sampling point and the K cluster center constellation points, and cluster the sampling point to the center constellation point with the smallest distance to it;

[0075] S105: Calculate the new mean points within the K clusters and update the iteration counter;

[0076] S106: Determine if the iteration counter has overflowed. If yes, go to S108; otherwise, go to S107.

[0077] S107: Determine whether the new mean point is the same as the center constellation point. If yes, go to S108. Otherwise, update the new mean point to the center constellation point and repeat steps S104 to S106.

[0078] S108: Replace the value of the sampled point with the value of the central constellation point of its corresponding cluster;

[0079] S109: Traverse the sequence of received signal sampling points after clustering, and output multiple consecutive identical constellation points in the signal sampling point sequence as 1 symbol to complete symbol timing synchronization.

[0080] Example 2: Assume a modulation or coding scheme with K = 4 symbol types.

[0081] In S101, the central constellation points of the clusters corresponding to the K-class symbols are obtained from the sampled signal, and the relevant formula is shown in (1):

[0082]

[0083] Where, m k Let k be the central constellation point of the k-th cluster, where k is the index of the cluster central constellation point, K is the number of symbol types, and N is the index of the cluster central constellation point. k The number of sampling points for calculating the mean of the k-th symbol, where yP[n] is the preamble of the sampled signal. Let n be the starting sampling point corresponding to the k-th symbol, and n be the sampling point.

[0084] Assuming that three consecutive sampling points are selected from each of the symbol intervals 1, 2, 3, and 4 in the preamble field of the sampled signal, the cluster center constellation points corresponding to the four types of symbols obtained by calculating the mean using formula (1) are m1 = 0.1571 + 0.2129j, m2 = 0.1714 + 0.1633j, m3 = 0.1381 + 0.1491j, and m4 = 0.0916 + 0.1802j. Initialize the set of sampling points for the four symbols. and the iteration counter value t = 0, where j 2 =-1 is the imaginary unit;

[0085] In S102, the absolute value of the difference between the magnitudes of the two central constellation points is calculated using formulas as shown in (2) and (3):

[0086]

[0087] in, It is the absolute value of the difference between the moduli of the two central constellation points. and Let k1 and k2 be the central constellation points of the k1th and k2th clusters, respectively, where k1 and k2 are the indices of the central constellation points. |·| is the modulo operator for complex numbers and the absolute value operator for real numbers. K is the number of symbol types. The absolute value of the difference between the moduli of each constellation point is placed in a set and expressed by formula (3):

[0088]

[0089] Where D is the set of absolute values ​​of the difference in magnitude between constellation points. K represents the absolute value of the difference between the moduli of the two central constellation points, k1 and k2 are the indices of the cluster central constellation points, and K is the number of symbol types.

[0090] From formulas (2) and (3), it can be seen that the set of absolute values ​​of the difference in magnitude of the central constellation points is: D = {0.0279, 0.0614, 0.0624, 0.0335, 0.0346, 0.0011};

[0091] In S103, the distance calculation formula indicates the variable, and the relevant formula is shown in (4):

[0092]

[0093] Where α is the indicator variable for the distance calculation formula, D is the set of absolute values ​​of the difference between constellation point moduli, min{·} is the minimum value operator of the set, and δ is a given judgment threshold, calculated by formula (5):

[0094]

[0095] Where ∈ represents a given decision threshold control factor, and C(K,2) is the combination number operator, representing the number of combinations formed by selecting two elements without repetition from K distinct elements. k1 and k2 are the absolute values ​​of the difference between the moduli of the two central constellation points, and the indices of the cluster center constellation points.

[0096] In S104, the distance between the sampling point and the K cluster center constellation points is calculated, involving the formula shown in (6):

[0097]

[0098] Where, d n,k For data sampling point y D [n] and the k-th cluster center constellation point m k The distance between them, ‖·‖2 is the 2-norm operator, y D [n] represents the data field of the sampled signal, m k Let α be the central constellation point of the k-th cluster, and let α be the indicator variable.

[0099] Clustering the sampling points to the central constellation point with the smallest distance to them includes: determining the cluster label of the data sampling points based on the distance, involving the formula shown in (7):

[0100] λ n =argmin k {d n,k} (7),

[0101] Where, λn For data sampling point y D Clustering label for [n], argmin k {·} is the index k operator for finding the minimum value of the objective function, d n,k For data sampling point y D [n] and the k-th cluster center constellation point m k The distance between them; the data sampling points are assigned to the corresponding clusters according to the clustering labels, and the formulas involved are shown in (8):

[0102]

[0103] in, Cluster label λ n The corresponding set of symbolic sampling points, ∪ is the union operator, {·} represents a set consisting of specific elements, y D [n] represents the data field of the sampled signal.

[0104] In S104, firstly, assuming a given decision threshold control factor ε = 0.1, the decision threshold δ = 0.0037 is calculated according to formula (5); then, based on the condition min{D} = 0.0011 < δ = 0.0037 in formula (4), the distance calculation formula indicator variable α = 1 is obtained; secondly, assuming there is a data sampling point y D [1]=0.1569+0.2011j, the distance between the sampling point yD[1] and the four cluster center constellation points is calculated by α=1 and formula (6), d 1,1 =0.0118, d 1,2 =0.0405, d 1,3 =0.0553 and d 1,4 =0.0686; Secondly, the cluster label of the data sampling points is calculated by formula (7): λ1 = 1, and then the sampling points are clustered to the central constellation point 1 by formula (8): C1 = {y D [1]};

[0105] In S105, the new mean points within K clusters are calculated, involving the formula shown in (9):

[0106]

[0107] Where, m′ k Let card(·) be the new mean point within the k-th cluster, and card(·) is the operator for counting the elements in the set. k Let y be the set of sampling points for the k-th symbol class. D [n] represents the data field of the sampled signal, K represents the number of symbol types, and the update iteration counter value is t = t + 1.

[0108] Assuming that the new mean points within the four clusters calculated by formula (9) are m′1=0.1571+0.2129j, m′2=0.1714+0.1633j, m′3=0.1381+0.1491j and m′4=0.0916+0.1802j respectively, update the iteration counter value t=1;

[0109] In S106, assuming a given upper limit T for the overflow of the iteration counter. max =100, and it is determined that t=1 <T max =100, the iteration counter has not overflowed;

[0110] In S107, it was determined that the new mean point is the same as the central constellation point, that is, m1=m′1, m2=m′2, m3=m′3 and m4=m′4;

[0111] In S108, the sampling point y D The value of [1] is replaced with the value of m1, i.e., y D [1] = 0.1571 + 0.2129j;

[0112] In S109, the sequence of received signal sampling points after clustering is traversed, and multiple consecutive identical constellation points in the sequence of received signal sampling points are output as 1 symbol to complete symbol timing synchronization; assuming that 3 consecutive identical constellation points (also called sampling points) appear in the sequence of received signal sampling points, then the 3 constellation points correspond to 1 symbol.

[0113] The symbol timing synchronization method provided in this application can be executed by a symbol timing synchronization device. This application uses the execution of the symbol timing synchronization method by a symbol timing synchronization device as an example to illustrate the symbol timing synchronization device provided in this application.

[0114] like Figure 6 As shown in the figure, this application embodiment also provides a symbol timing synchronization device 600, including:

[0115] The sampling module 601 is used to oversample the received signal to obtain the sampled signal;

[0116] Clustering module 602 is used to perform clustering processing on the sampled signal using a clustering algorithm to obtain a sequence of received signal sampling points;

[0117] The determination module 603 is used to determine consecutive sampling points with the same value in the received signal sampling point sequence as one symbol, and complete symbol timing synchronization.

[0118] As an optional embodiment, the clustering module includes:

[0119] The first acquisition submodule is used to acquire the K central constellation points corresponding to the K symbols in the sampled signal;

[0120] The first clustering submodule is used to perform clustering operations based on the central constellation points. The clustering operations include: clustering the sampled points into a symbol cluster corresponding to the central constellation point with the smallest distance based on the distance between the sampled points and the K central constellation points, and calculating the new mean point of the cluster corresponding to each symbol.

[0121] The first determining submodule is used to determine the new mean point as the center constellation point of the corresponding cluster when the new mean point is different from the center constellation point, and jump to the step of performing clustering operation based on the center constellation point until the new mean point is the same as the center constellation point or until the preset iteration counter overflows.

[0122] The second clustering submodule is used to replace the value of the sampling point with the value of the center constellation point of the cluster corresponding to the sampling point when the new mean point is the same as the center constellation point, or when the preset iteration counter overflows, to obtain the received signal sampling point sequence.

[0123] As an optional embodiment, the apparatus further includes:

[0124] The first calculation module is used to calculate the absolute value of the difference between the modulus values ​​of any two central constellation points;

[0125] The variable determination module is used to determine the indicator variable for the distance calculation formula based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and the first threshold.

[0126] The second calculation module is used to calculate the distance between the sampling point and the central constellation point according to the distance calculation formula indicator variable.

[0127] As an optional embodiment, the variable determination module includes:

[0128] The first variable determination submodule is used to determine the distance calculation formula indicator variable as the first value when the minimum absolute value of the difference between the modulus values ​​of the central constellation points is less than the first threshold.

[0129] And / or,

[0130] The second variable determination submodule is used to determine the distance calculation formula indicator variable as the second value when the minimum absolute value of the difference between the modulus values ​​of the central constellation points is greater than or equal to the first threshold.

[0131] As an optional embodiment, the second computing module includes:

[0132] The calculation submodule is used to calculate the distance between the sampling point and the central constellation point using the first formula when the distance calculation formula indicator variable is a first value;

[0133] Alternatively, when the indicator variable in the distance calculation formula is a second value, the second formula can be used to calculate the distance between the sampling point and the central constellation point; wherein,

[0134] The first formula is: d n,k =||y D [n]-m k ||2; The second formula is: d n,k =||y D [n]|-|m k ||;d n,k y is the distance between the sampling point and the central constellation point; D [n] represents the data field of the sampled signal; n represents the number of sampling points; m k Let be the central constellation point of the k-th cluster; ||·||2 is the 2-norm operator.

[0135] As an optional embodiment, the sampling signal includes: a preamble field, the preamble field including K symbols;

[0136] The first acquisition submodule includes:

[0137] The acquisition unit is used to obtain the center constellation points of the clusters corresponding to K symbols from the sampled signal using a third formula; wherein the third formula is:

[0138]

[0139] Where, m k Let k be the central constellation point of the k-th cluster, where k is the index of the cluster central constellation point, K is the number of symbol types, and N is the index of the cluster central constellation point. k The number of sampling points for calculating the mean of the k-th symbol, y P [n] represents the preamble of the sampled signal. Let n be the starting sampling point corresponding to the kth symbol, and n be the sampling point.

[0140] In this embodiment, the sampled signals of the received signal are judged and clustered. By continuously judging the sampled point sequence after clustering, symbols are output to achieve symbol timing synchronization. This method is simple to implement, highly versatile, and flexible, and can meet the requirements of wireless communication symbol timing synchronization.

[0141] It should be noted that the symbol timing synchronization device provided in this application embodiment is a device capable of executing the above symbol timing synchronization method. Therefore, all embodiments of the above symbol timing synchronization method are applicable to this device and can achieve the same or similar beneficial effects.

[0142] The symbol timing synchronization device in this application embodiment can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal, or other devices besides a terminal. For example, the terminal can include, but is not limited to, the type of terminal 11 listed above; other devices can be servers, network attached storage (NAS), etc., and this application embodiment does not specifically limit the type.

[0143] The symbol timing synchronization device provided in this application embodiment can achieve... Figures 1 to 5 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0144] Optional, such as Figure 7 As shown, this application embodiment also provides a communication device 700, including a processor 701 and a memory 702. The memory 702 stores a program or instructions that can run on the processor 701. When the program or instructions are executed by the processor 701, they implement the various steps of the above-described symbol timing synchronization method embodiment and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0145] In the embodiments of this application, the aforementioned communication device can be a terminal or a network-side device; no specific limitation is made here.

[0146] In the case where the communication device is a terminal, this application embodiment also provides a terminal, including a processor and a communication interface. The processor is used to oversample the received signal to obtain a sampled signal; to perform clustering processing on the sampled signal using a clustering algorithm to obtain a sequence of received signal sampling points; and to determine consecutive sampling points with the same value in the sequence of received signal sampling points as one symbol, thereby completing symbol timing synchronization. This terminal embodiment corresponds to the above-described terminal-side method embodiment. All implementation processes and methods of the above-described method embodiments can be applied to this terminal embodiment and achieve the same technical effect. Specifically, Figure 8 A schematic diagram of the hardware structure of a terminal to implement an embodiment of this application.

[0147] The terminal 800 includes, but is not limited to, at least some of the following components: radio frequency unit 801, network module 802, audio output unit 803, input unit 804, sensor 805, display unit 806, user input unit 807, interface unit 808, memory 809, and processor 810.

[0148] Those skilled in the art will understand that the terminal 800 may also include a power supply (such as a battery) for supplying power to various components. The power supply may be logically connected to the processor 810 through a power management system, thereby enabling functions such as managing charging, discharging, and power consumption through the power management system. Figure 8 The terminal structure shown does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0149] It should be understood that, in this embodiment, the input unit 804 may include a graphics processing unit (GPU) 8041 and a microphone 8042. The GPU 8041 processes image data of still images or videos obtained by an image capture device (such as a camera) in video capture mode or image capture mode. The display unit 806 may include a display panel 8061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like. The user input unit 807 includes at least one of a touch panel 8071 and other input devices 8072. The touch panel 8071 is also called a touch screen. The touch panel 8071 may include a touch detection device and a touch controller. Other input devices 8072 may include, but are not limited to, physical keyboards, function keys (such as volume control buttons, power buttons, etc.), trackballs, mice, and joysticks, which will not be described in detail here.

[0150] In this embodiment, after receiving downlink data from the network-side device, the radio frequency unit 801 can transmit it to the processor 810 for processing; in addition, the radio frequency unit 801 can send uplink data to the network-side device. Typically, the radio frequency unit 801 includes, but is not limited to, antennas, amplifiers, transceivers, couplers, low-noise amplifiers, duplexers, etc.

[0151] The memory 809 can be used to store software programs or instructions, as well as various data. The memory 809 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, the memory 809 may include volatile memory or non-volatile memory, or both. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory 809 in the embodiments of this application includes, but is not limited to, these and any other suitable types of memory.

[0152] Processor 810 may include one or more processing units; optionally, processor 810 integrates an application processor and a modem processor, wherein the application processor mainly handles operations involving the operating system, user interface, and applications, and the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into processor 810.

[0153] The processor 810 is used to oversample the received signal to obtain a sampled signal; to use the K-means clustering algorithm to cluster the sampled signal to obtain a sequence of received signal sampling points; and to determine a symbol as a sequence of consecutive sampling points with the same value in the sequence of received signal sampling points to complete symbol timing synchronization.

[0154] In this embodiment, the sampled signals of the received signal are judged and clustered. By continuously judging the sampled point sequence after clustering, symbols are output to achieve symbol timing synchronization. This method is simple to implement, highly versatile, and flexible, and can meet the requirements of wireless communication symbol timing synchronization.

[0155] It should be noted that the terminal provided in this application embodiment is a terminal capable of executing the above symbol timing synchronization method. Therefore, all embodiments of the above symbol timing synchronization method are applicable to this terminal and can achieve the same or similar beneficial effects.

[0156] In the case where the communication device is a network-side device, this application embodiment also provides a network-side device, including a processor and a communication interface. The processor is used to oversample the received signal to obtain a sampled signal; to cluster the sampled signal using a K-means clustering algorithm to obtain a sequence of received signal sampling points; and to determine the sampling point corresponding to each symbol based on the sequence of received signal sampling points to complete symbol timing synchronization. Wherein, multiple consecutive sampling points with the same value in the sequence of received signal sampling points correspond to one symbol. This network-side device embodiment corresponds to the above-described network-side device method embodiment. All implementation processes and methods of the above method embodiments can be applied to this network-side device embodiment and achieve the same technical effects.

[0157] Specifically, embodiments of this application also provide a network-side device. For example... Figure 9 As shown, the network-side device 900 includes: an antenna 91, a radio frequency (RF) device 92, a baseband device 93, a processor 94, and a memory 95. The antenna 91 is connected to the RF device 92. In the uplink direction, the RF device 92 receives information through the antenna 91 and transmits the received information to the baseband device 93 for processing. In the downlink direction, the baseband device 93 processes the information to be transmitted and sends it to the RF device 92. The RF device 92 processes the received information and transmits it through the antenna 91.

[0158] The method executed by the network-side device in the above embodiments can be implemented in the baseband device 93, which includes a baseband processor.

[0159] Baseband device 93 may include, for example, at least one baseband board on which multiple chips are disposed, such as Figure 9 As shown, one of the chips is, for example, a baseband processor, which is connected to the memory 95 via a bus interface to call the program in the memory 95 and execute the network device operations shown in the above method embodiment.

[0160] The network-side device may also include a network interface 96, such as a common public radio interface (CPRI).

[0161] Specifically, the network-side device 900 of this embodiment further includes: instructions or programs stored in a memory 95 and executable on a processor 94, wherein the processor 94 calls the instructions or programs in the memory 95 to execute. Figure 6 The methods executed by each module shown achieve the same technical effect, and to avoid repetition, they will not be described in detail here.

[0162] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described symbol timing synchronization method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0163] The processor is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0164] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described symbol timing synchronization method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0165] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0166] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described symbol timing synchronization method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0167] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0168] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0169] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A symbol timing synchronization method, characterized in that, include: Communication equipment oversamples the received signal to obtain the sampled signal; The communication device uses a clustering algorithm to cluster the sampled signal to obtain a sequence of received signal sampling points; The communication device determines consecutive sampling points with the same value in the sequence of received signal sampling points as one symbol, and completes symbol timing synchronization; The communication device uses a clustering algorithm to cluster the sampled signals to obtain a sequence of received signal sampling points, including: Obtain the K central constellation points corresponding to the K symbols in the sampled signal; Clustering is performed based on the central constellation points. The clustering operation includes: clustering the sampled points into a single symbol cluster corresponding to the central constellation point with the smallest distance based on the distance between the sampled points and the K central constellation points, and calculating the new mean point of the cluster corresponding to each symbol. If the new mean point is different from the center constellation point, the new mean point is determined as the center constellation point of the corresponding cluster, and the process jumps to the step of performing clustering operation based on the center constellation point until the new mean point is the same as the center constellation point or until the preset iteration counter overflows. If the new mean point is the same as the center constellation point, or if the preset iteration counter overflows, the value of the sample point is replaced with the value of the center constellation point of the cluster corresponding to the sample point, and the received signal sample point sequence is obtained.

2. The method according to claim 1, characterized in that, Before performing clustering operations based on the central constellation points, the method further includes: Calculate the absolute value of the difference in modulus between any two central constellation points; Based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and the first threshold, the indicator variable for the distance calculation formula is determined; The distance between the sampling point and the central constellation point is calculated based on the distance calculation formula indicating the variable.

3. The method according to claim 2, characterized in that, Based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and the first threshold, the indicator variables for the distance calculation formula are determined, including: If the minimum absolute value of the difference between the modulus values ​​of the central constellation points is less than the first threshold, the indicator variable of the distance calculation formula is determined to be the first value; or, If the minimum absolute value of the difference between the magnitudes of the central constellation points is greater than or equal to the first threshold, the indicator variable of the distance calculation formula is determined to be the second value.

4. The method according to claim 3, characterized in that, Based on the distance calculation formula indicating the variable, the distance between the sampling point and the central constellation point is calculated, including: When the indicator variable in the distance calculation formula is a first value, the distance between the sampling point and the central constellation point is calculated using the first formula; or, When the indicator variable in the distance calculation formula is the second value, the distance between the sampling point and the central constellation point is calculated using the second formula; wherein, The first formula is: The second formula is: ; The distance between the sampling point and the central constellation point; This represents the data field of the sampled signal; n represents the number of sampling points. Let the center constellation point of the k-th cluster be ; This is a 2-norm operator.

5. The method according to claim 1, characterized in that, The sampled signal includes a preamble field, which includes K symbols; Obtain the K central constellation points corresponding to the K symbols in the sampled signal, including: Using the third formula, K central constellation points corresponding to K symbols in the sampled signal are obtained; wherein, the third formula is: ， in, For the first The central constellation point of each cluster, For the index of the cluster center constellation points, For the number of symbol types, For the first The number of sampling points for class symbolic mean calculation. The preamble of the sampled signal. No. The starting sampling point corresponding to each symbol These are the sampling points.

6. A symbol timing synchronization device, characterized in that, include: The sampling module is used to oversample the received signal to obtain the sampled signal; The clustering module is used to perform clustering processing on the sampled signal using a clustering algorithm to obtain a sequence of received signal sampling points; The determination module is used to determine consecutive sampling points with the same value in the received signal sampling point sequence as one symbol, thereby completing symbol timing synchronization; The clustering module includes: The first acquisition submodule is used to acquire the K central constellation points corresponding to the K symbols in the sampled signal; The first clustering submodule is used to perform clustering operations based on the central constellation points. The clustering operations include: clustering the sampled points into a symbol cluster corresponding to the central constellation point with the smallest distance based on the distance between the sampled points and the K central constellation points, and calculating the new mean point of the cluster corresponding to each symbol. The first determining submodule is used to determine the new mean point as the center constellation point of the corresponding cluster when the new mean point is different from the center constellation point, and jump to the step of performing clustering operation based on the center constellation point until the new mean point is the same as the center constellation point or until the preset iteration counter overflows. The second clustering submodule is used to replace the value of the sampling point with the value of the center constellation point of the cluster corresponding to the sampling point when the new mean point is the same as the center constellation point, or when the preset iteration counter overflows, to obtain the received signal sampling point sequence.

7. The apparatus according to claim 6, characterized in that, The device further includes: The first calculation module is used to calculate the absolute value of the difference between the modulus values ​​of any two central constellation points; The variable determination module is used to determine the indicator variable for the distance calculation formula based on the relationship between the minimum absolute value of the difference between the modulus values ​​of the central constellation points and the first threshold. The second calculation module is used to calculate the distance between the sampling point and the central constellation point according to the distance calculation formula indicator variable.

8. The apparatus according to claim 7, characterized in that, The variable determination module includes: The first variable determination submodule is used to determine the distance calculation formula indicator variable as the first value when the minimum absolute value of the difference between the modulus values ​​of the central constellation points is less than the first threshold. And / or, The second variable determination submodule is used to determine the distance calculation formula indicator variable as the second value when the minimum absolute value of the difference between the modulus values ​​of the central constellation points is greater than or equal to the first threshold.

9. The apparatus according to claim 8, characterized in that, The second calculation module includes: The calculation submodule is used to calculate the distance between the sampling point and the central constellation point using the first formula when the distance calculation formula indicator variable is a first value; Alternatively, when the indicator variable in the distance calculation formula is a second value, the second formula can be used to calculate the distance between the sampling point and the central constellation point; wherein, The first formula is: The second formula is: ; The distance between the sampling point and the central constellation point; This represents the data field of the sampled signal; n represents the number of sampling points. Let the center constellation point of the k-th cluster be ; This is a 2-norm operator.

10. The apparatus according to claim 6, characterized in that, The sampled signal includes a preamble field, which includes K symbols; The first acquisition submodule includes: The acquisition unit is used to obtain the center constellation points of the clusters corresponding to K symbols from the sampled signal using a third formula; wherein the third formula is: ， in, For the first The central constellation point of each cluster, For the index of the cluster center constellation point, For the number of symbol types, For the first The number of sampling points for class symbolic mean calculation. The preamble of the sampled signal. No. The starting sampling point corresponding to each symbol These are the sampling points.

11. A communication device, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the symbol timing synchronization method as described in any one of claims 1 to 5.

12. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the symbol timing synchronization method as described in any one of claims 1-5.

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