Time and frequency synchronization method and system of one-bit quantization cellular-free large-scale MIMO system

Abstract

The invention discloses a time and frequency synchronization method and system for a one-bit quantization cellular-free large-scale MIMO system based on positioning and speed measurement. The method comprises the following steps: step 1, estimating symbol timing offset (STO) and carrier frequency offset (CFO) by using a Schmidl-Cox synchronization algorithm; step 2, estimating the distance between the user UE and the access point AP and the movement speed of the user UE according to the estimated values of the STO and the CFO; and step 3, estimating the STO and the CFO again by using the distance and the movement speed in the step 2. According to the technical scheme, the method has good realizability, and a low system synchronization error can be obtained through tests.

Description

Technical Field

[0001] The present invention belongs to the field of wireless communication technology, and specifically proposes a time and frequency synchronization method and system based on positioning and speed measurement for a time and frequency synchronization technology in a non-cellular large-scale multiple-input multiple-output (MIMO) system in combination with one-bit quantization technology and radio frequency (RF) structure optimization. Background Art

[0002] With the rapid development of wireless communication technology, especially in 5G and future 6G networks, non-cellular massive MIMO technology has received widespread attention as one of the key technologies to improve system capacity and communication quality. Traditional synchronization methods mostly rely on relatively complex hardware equipment and high-precision clock systems, which significantly increases the cost and complexity of the system. In non-cellular massive MIMO systems, time synchronization and frequency synchronization become particularly important due to factors such as user movement, multipath propagation of signals, and frequency offset. In dynamic scenarios, the relative movement between the user (UE) and the access point (AP) will cause a large Doppler frequency shift, further increasing the difficulty of synchronization. Accurate time and frequency synchronization is the basis for ensuring stable system operation and communication performance. How to reduce hardware complexity and power consumption while ensuring system synchronization accuracy has become a key issue in current wireless communication technology. Summary of the invention

[0003] In order to solve the above technical problems, the present invention effectively solves the contradiction between synchronization accuracy and hardware complexity in the system and reduces synchronization error by using time and frequency synchronization technology based on positioning and speed measurement in a non-cellular large-scale MIMO system with one-bit quantization and radio frequency RF structure. The technical solution of the present invention provides an efficient and stable synchronization solution.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme:

[0005] Consider a non-cellular massive MIMO uplink system, which consists of U user UEs and B access points APs. Specifically, in the distributed MIMO architecture involved in the present invention, the UE sends a radio frequency RF signal to the AP, and the RF signal received by the single antenna port of each AP first passes through a bandpass filter (BPF), and then jitter noise is added in the signal processing. The signal is quantized by a zero threshold comparator to generate a binary waveform, which is then transmitted to the central processing unit (CPU) through an optical fiber. There are unknown symbol timing offsets (STO) and carrier frequency offsets (CFO) between each UE and each AP, which affect the quality and correct demodulation of the received signal, and reduce the reliability and performance of the system. At the CPU, STO and CFO are estimated to reduce the synchronization error, and after compensation, the signal is subjected to digital down-conversion, spatial processing, and subsequent demodulation and decoding operations.

[0006] In the distributed system involved in the present invention, STO and CFO between a single UE and B APs are considered, and the synchronization error caused by STO and CFO is accurately estimated and reduced through a time and frequency synchronization method based on positioning and speed measurement.

[0007] In this non-cellular massive MIMO system, a three-dimensional space coordinate system (x, y, z) is established, and the distances from a given UE to B APs are (d 1 , d 2 , ..., d B ), the position coordinates of the bth AP are p b =(x b ,y b , h), the UE’s location coordinate is p (u) =(x (u) ,y (u) , 0), the UE's moving speed is v = (v x , v y , 0).

[0008] Assume that the signal propagates in free space and the propagation time t b Through the distance d b and the speed of light c, we get:

[0009]

[0010] δ b is the STO between the UE and the bth AP normalized by the sampling period, δ b It can be given by the following formula:

[0011]

[0012] Among them, f s is the sampling frequency.

[0013] Since the UE is located in the xoy plane, its projection speed is also limited to this plane. By ignoring the z-axis component, calculate the projection d of the direction vector from the UE to the bth AP on the xoy plane b，proj , expressed as:

[0014] d b，proj =(x b -x (u) ,y b -y (u) ,0)

[0015] Its unit projection vector for:

[0016]

[0017] In three-dimensional space, the projection speed v of the UE's motion speed in the direction of the unit projection vector b，proj for:

[0018]

[0019] According to the Doppler frequency shift formula, the frequency shift f b It can be expressed as:

[0020]

[0021] Among them, f c is the carrier frequency.

[0022] ε b is the CFO between the UE and the bth AP normalized by the subcarrier spacing, ε b With frequency shift f b The relationship between them is:

[0023]

[0024] Where N is the length of the orthogonal frequency division multiplexing (OFDM) symbol, f s is the sampling frequency.

[0025] For a fixed symbol length N, consider the time interval T = N / f s The received signal passes through a one-bit analog-to-digital converter (ADC) at the CPU, that is, a one-bit quantization operation is performed on the signal. The sample of the i-th OFDM symbol of the output signal of the b-th one-bit ADC at the CPU is expressed as:

[0026]

[0027] in, represents the discrete-time RF signal of the i-th OFDM symbol received at the b-th AP, after BP filtering and sampling, and before one-bit quantization at the n-th sample. Assume that it is The function sgn(·) applies element-wise to the input vector.

[0028] Received signal It is expressed as:

[0029]

[0030] Baseband signal The time domain expression of is:

[0031]

[0032] Among them, h b is the channel gain from UE to the bth AP, is the signal transmitted by UE, where E s represents the average energy of each sample, is the noise, where N 0 Represents the power spectral density of the noise.

[0033] The signal s[n] transmitted to the b-th AP consists of continuous time-domain OFDM symbols and cyclic prefix (CP), which can be expressed as:

[0034]

[0035] Among them, G≥L-1 is the length of CP, and the relationship between i and n is -G≤ni(n+G)≤N-1.

[0036] s (i) [n] is the time domain representation of the i-th OFDM symbol, which can be expressed as:

[0037]

[0038] The one-bit quantization time and frequency synchronization method of the non-cellular large-scale MIMO system of the present invention comprises the following specific steps:

[0039] Step 1: Use the Schmidl-Cox synchronization algorithm to estimate the symbol timing offset STO and the carrier frequency offset CFO;

[0040] Step 2: Estimate the distance between the user UE and the access point AP and the movement speed of the user UE according to the estimated values ​​of STO and CFO;

[0041] Step 3: Use the distance and movement speed from step 2 to estimate STO and CFO again.

[0042] Preferably, step 1, Schmidl-Cox synchronization algorithm estimation;

[0043] The CPU uses time-frequency synchronization and uses the Schmidl-Cox synchronization algorithm to quantize the signal Synchronize time and carrier frequency, and estimate STO and CFO. The estimated values ​​of STO and CFO between UE and the bth AP are respectively recorded as

[0044] Step 1.1. STO estimation:

[0045] Compute the autocorrelation of the signal at different time offsets:

[0046]

[0047] Where N is the fixed OFDM symbol length, n is the index variable, δ is the time offset, and * represents the complex conjugate;

[0048] Calculate the energy distribution of the signal at different offsets:

[0049]

[0050] Calculate the ratio of the signal's correlation to the signal's energy:

[0051]

[0052] Where G is the length of the cyclic prefix;

[0053] Estimate the STO at the bth AP:

[0054]

[0055] Step 1.2, CFO estimation:

[0056] calculate Related metrics Use the function arg{·} to obtain the phase and estimate the frequency offset of the signal:

[0057]

[0058] Preferably, step 2, positioning and speed measurement;

[0059] The estimated values ​​of STO and CFO obtained by the Schmidl-Cox algorithm are used to further calculate the estimated value of the distance between the UE and the AP and the estimated value of the UE's projection speed on the xoy plane. The least squares (LS) algorithm is used to estimate the UE's location information coordinates and the UE's movement speed, and a more accurate estimate of the system's time and frequency synchronization is made.

[0060] Step 2.1: Estimate the distance from UE to AP and the projection speed of UE:

[0061] Using the estimated value of STO Make a distance estimate and compute an estimate of the travel time:

[0062]

[0063] Among them, f b is the frequency shift;

[0064] Calculate the estimated distance from UE to AP:

[0065]

[0066] Where c is the speed of light;

[0067] Using the CFO's Estimates Perform a projection velocity estimate and calculate an estimate of the frequency shift:

[0068]

[0069] According to the Doppler frequency shift formula, the projection estimate of the UE's motion speed is calculated:

[0070]

[0071] Step 2.2: Estimate the location coordinates of the UE and the movement speed of the UE:

[0072] Use the estimated distance between the UE and each AP obtained in step 2.1 The UE's position is estimated using the LS algorithm.

[0073] Construct the matrix:

[0074]

[0075]

[0076] Among them, (x b ,y b ) is the position coordinate of the bth AP in the horizontal plane;

[0077] Solve using LS algorithm:

[0078]

[0079] is the matrix of the estimated coordinates of the UE, then the estimated value of the UE's position coordinates can be expressed as in, and are the estimated values ​​of the x-coordinate and y-coordinate of the UE on the horizontal plane, respectively.

[0080] Based on the estimated value of UE location coordinates and the projected estimate of the motion velocity Etc. information to solve the estimated value of UE's movement speed in, and They represent the estimated speed of the UE in the x-axis and y-axis directions in the horizontal plane respectively.

[0081] For the unit projection vector direction between the UE and the bth AP, calculate the velocity projection estimate:

[0082]

[0083] Construct the matrix:

[0084]

[0085]

[0086] Among them, B contains the unit projection vector in the direction of each AP, and c contains the velocity projection estimate to each AP.

[0087] Solve using LS algorithm:

[0088]

[0089] The estimated value of the UE's movement speed is then expressed as

[0090] Preferably, step 3, using distance and speed to estimate system synchronization;

[0091] Based on the estimated value of UE coordinates And the location coordinates of each AP, calculate the distance between UE and the bth AP:

[0092]

[0093] Where, h represents the vertical height of AP;

[0094] Using distance estimates Compute a propagation time estimate:

[0095]

[0096] Calculate the estimated time synchronization offset between the UE and the bth AP:

[0097]

[0098] According to the estimated value of UE's moving speed Calculate the unit projection vector Projected velocity estimates in the direction:

[0099]

[0100] Compute the frequency shift estimate:

[0101]

[0102] Calculate the estimated value of the frequency synchronization offset between the UE and the bth AP:

[0103]

[0104] Where N is the length of OFDM symbol, f s is the sampling frequency.

[0105] The present invention also discloses a one-bit quantized time and frequency synchronization system for a non-cellular massive MIMO system, which is used to execute the above method and includes the following modules:

[0106] SC algorithm estimation STO / CFO module: uses the Schmidl-Cox synchronization algorithm to estimate the symbol timing offset STO and carrier frequency offset CFO;

[0107] Positioning and speed measurement module: estimates the distance between the user UE and the access point AP and the movement speed of the user UE based on the estimated values ​​of STO and CFO;

[0108] STO / CFO estimation module based on positioning and speed measurement: STO and CFO are estimated again using the distance and movement speed.

[0109] Compared with the prior art, the present invention estimates STO and CFO based on the time and frequency synchronization method of positioning and speed measurement, which can obtain more accurate time and frequency synchronization, help reduce estimation errors, and improve the receiving performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Figure 1 It is a structural diagram of a non-cellular massive MIMO system involved in a preferred embodiment of the present invention.

[0111] Figure 2 It is a simulation experiment diagram of the user transmission power and the root mean square error of STO estimation in the preferred embodiment of the present invention.

[0112] Figure 3 It is a simulation experiment diagram of the user transmission power and the CFO estimation root mean square error of the preferred embodiment of the present invention.

[0113] Figure 4 It is a block diagram of a time and frequency synchronization system of a one-bit quantized cellular-free massive MIMO system based on positioning and speed measurement in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0114] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments.

[0115] like Figure 1 As shown, in the non-cellular massive MIMO uplink system involved in the preferred embodiment of the present invention, the system is composed of U UEs and B APs. Specifically, in the distributed MIMO architecture involved in the preferred embodiment of the present invention, the UE sends an RF signal to the AP, and the RF signal received by the single antenna port of each AP first passes through the BPF, and then jitter noise is added in the signal processing. The signal is quantized by a zero threshold comparator to generate a binary waveform, which is then transmitted to the CPU through an optical fiber. There are unknown STO and CFO between each UE and each AP, which affects the quality and correct demodulation of the received signal and reduces the reliability and performance of the system. At the CPU, the STO and CFO are estimated to reduce the synchronization error, and after compensation, the signal is subjected to digital down-conversion, spatial processing, and subsequent demodulation and decoding operations.

[0116] In the distributed system involved in the preferred embodiment of the present invention, STO and CFO between a single UE and B APs are considered, and the synchronization error caused by STO and CFO is accurately estimated and reduced through a time and frequency synchronization method based on positioning and speed measurement.

[0117] In this non-cellular massive MIMO system, a three-dimensional space coordinate system (x, y, z) is established, and the distances from a given UE to B APs are (d 1 ,d 2 ,…,d B ), the position coordinates of the bth AP are p b =(x b ,y b ,h), the UE’s location coordinate is p (u) =(x (u) ,y (u),0), the UE's moving speed is v=(v x ,v y ,0).

[0118] Assume that the signal propagates in free space and the propagation time t b Through the distance d b and the speed of light c, we get:

[0119]

[0120] δ b is the STO between the UE and the bth AP normalized by the sampling period, δ b It can be given by the following formula:

[0121]

[0122] Among them, f s is the sampling frequency.

[0123] Since the UE is located in the xoy plane, its projection speed is also limited to this plane. By ignoring the z-axis component, calculate the projection d of the direction vector from the UE to the bth AP on the xoy plane b,proj , expressed as:

[0124] d b,proj =(x b -x (u) ,y b -y (u) ,0)

[0125] Its unit projection vector for:

[0126]

[0127] In three-dimensional space, the projection speed v of the UE's motion speed in the direction of the unit projection vector b,proj for:

[0128]

[0129] According to the Doppler frequency shift formula, the frequency shift f b It can be expressed as:

[0130]

[0131] Among them, f c is the carrier frequency.

[0132] ε b is the CFO between the UE and the bth AP normalized by the subcarrier spacing, ε b With frequency shift f bThe relationship between them is:

[0133]

[0134] Where N is the length of OFDM symbol, f s is the sampling frequency.

[0135] For a fixed symbol length N, consider the time interval T = N / f s The sample of the i-th OFDM symbol of the output signal of the b-th ADC at the CPU is expressed as:

[0136]

[0137] in, represents the discrete-time RF signal of the i-th OFDM symbol received at the b-th AP, after BP filtering and sampling, and before one-bit quantization at the n-th sample. Assume that it is The function sgn(·) applies element-wise to the input vector.

[0138] Received signal It is expressed as:

[0139]

[0140] Baseband signal The time domain expression of is:

[0141]

[0142] Among them, h b is the channel gain from UE to the bth AP, is the signal transmitted by UE, where E s represents the average energy of each sample, is the noise, where N 0 Represents the power spectral density of the noise.

[0143] The signal s[n] transmitted to the b-th AP consists of continuous time-domain OFDM symbols and CP, which can be expressed as:

[0144]

[0145] Among them, G≥L-1 is the length of CP, and the relationship between i and n is -G≤ni(n+G)≤N-1.

[0146] s (i) [n] is the time domain representation of the i-th OFDM symbol, which can be expressed as:

[0147]

[0148] In this embodiment, it is defined that the number of UEs U=1, the number of APs B=4, the number of sampling points N=4050, the number of occupied subcarriers S=1201, and the carrier frequency f c =2.4GHz, signal bandwidth is 24MHz, number of channel taps L=1, and the application scenario is a non-cellular massive MIMO uplink system.

[0149] Specifically, the time and frequency synchronization method of the one-bit quantization non-cellular massive MIMO system in this embodiment has the following specific steps:

[0150] Step 1: Use the Schmidl-Cox synchronization algorithm to estimate the symbol timing offset STO and the carrier frequency offset CFO;

[0151] The CPU uses time-frequency synchronization and uses the Schmidl-Cox synchronization algorithm to quantize the signal Synchronize time and carrier frequency, and estimate STO and CFO. The estimated values ​​of STO and CFO between UE and the bth AP are respectively recorded as The details are as follows:

[0152] Step 1.1. STO estimation:

[0153] Compute the autocorrelation of the signal at different time offsets:

[0154]

[0155] Calculate the energy distribution of the signal at different offsets:

[0156]

[0157] Calculate the ratio of the signal's correlation to the signal's energy:

[0158]

[0159] Estimate the STO at the bth AP:

[0160]

[0161] Step 1.2, CFO estimation:

[0162] calculate Related metrics Use the function arg{·} to obtain the phase and estimate the frequency offset of the signal:

[0163]

[0164] Step 2: Positioning and speed measurement;

[0165] The estimated values ​​of STO and CFO obtained initially by the Schmidl-Cox algorithm are used to further calculate the estimated value of the distance between the UE and the AP and the estimated value of the UE's projection speed on the xoy plane. The least squares (LS) algorithm is used to estimate the UE's location information coordinates and the UE's movement speed, and a more accurate estimate of the system's time and frequency synchronization is made. The details are as follows:

[0166] Step 2.1: Estimate the distance from UE to AP and the projection speed of UE:

[0167] Using the estimated value of STO Make a distance estimate and compute an estimate of the travel time:

[0168]

[0169] Calculate the estimated distance from UE to AP:

[0170]

[0171] Using the CFO's Estimates Perform a projection velocity estimate and calculate an estimate of the frequency shift:

[0172]

[0173] According to the Doppler frequency shift formula, the projection estimate of the UE's motion speed is calculated:

[0174]

[0175] Step 2.2: Estimate the location coordinates of the UE and the movement speed of the UE:

[0176] Use the estimated distance between the UE and each AP obtained in step 2.1 The UE's position is estimated using the LS algorithm.

[0177] Construct the matrix:

[0178]

[0179] Solve using LS algorithm:

[0180]

[0181] is the matrix of the estimated coordinates of the UE, then the estimated value of the UE's position coordinates can be expressed as

[0182] Based on the estimated value of UE location coordinates and the projected estimate of the motion velocity Etc. information to solve the estimated value of UE's movement speed

[0183] For the unit projection vector direction between the UE and the bth AP, calculate the velocity projection estimate:

[0184]

[0185] Construct the matrix:

[0186]

[0187]

[0188] Among them, B contains the unit projection vector in the direction of each AP, and c contains the velocity projection estimate to each AP.

[0189] Solve using LS algorithm:

[0190]

[0191] The estimated value of the UE's movement speed is then expressed as

[0192] Step 3: Use distance and speed to estimate STO and CFO again;

[0193] Based on the estimated value of UE coordinates And the location coordinates of each AP, calculate the distance between UE and the bth AP:

[0194]

[0195] Using distance estimates Compute a propagation time estimate:

[0196]

[0197] Calculate the estimated time synchronization offset between the UE and the bth AP:

[0198]

[0199] According to the estimated value of UE's moving speed Calculate the unit projection vector Projected velocity estimates in the direction:

[0200]

[0201] Compute the frequency shift estimate:

[0202]

[0203] Calculate the estimated value of the frequency synchronization offset between the UE and the bth AP:

[0204]

[0205] Figure 2 This is a simulation experiment diagram of the system user transmission power and the root mean square error of STO estimation in the present invention. The horizontal axis represents the user's transmission power (dBm), and the vertical axis represents the root mean square error of STO estimation. In this figure, there are two curves, of which "based on positioning and speed measurement estimation" is the root mean square error simulation curve of synchronous estimation STO of the method of the present invention, and "SC algorithm estimation" is the root mean square error simulation curve of synchronous estimation STO using only Schmidl-Cox algorithm. Figure 2 It can be seen that under different user transmission powers, the root mean square error of STO estimation of the synchronous estimation method based on positioning and speed measurement is significantly lower than that of the synchronous estimation method using only the SC algorithm. The method of the present invention can obtain a lower STO estimation error result through software testing, and its performance is significantly better than that of the estimation using only the Schmidl-Cox algorithm.

[0206] Figure 3 This is a simulation experiment diagram of the system user transmission power and the CFO estimation root mean square error in the present invention. The horizontal axis represents the user's transmission power (dBm), and the vertical axis represents the CFO estimation root mean square error. There are two curves in this figure, among which "based on positioning and speed measurement estimation" is the simulation curve of the root mean square error of the synchronous estimation CFO of the method of the present invention, and "SC algorithm estimation" is the simulation curve of the root mean square error of the synchronous estimation CFO using only the Schmidl-Cox algorithm. Figure 3 It can be seen that under different user transmission powers, the CFO estimation root mean square error of the synchronous estimation method based on positioning and speed measurement is significantly lower than the CFO estimation root mean square error of the synchronous estimation method using only the SC algorithm. The method of the present invention can obtain a lower CFO estimation error result through software testing, and its performance is significantly better than that of the Schmidl-Cox algorithm estimation alone.

[0207] like Figure 4 As shown, this embodiment discloses a time and frequency synchronization system of a one-bit quantization non-cellular massive MIMO system based on positioning and speed measurement, including the following modules:

[0208] SC algorithm estimation STO / CFO module: uses the Schmidl-Cox synchronization algorithm to estimate the symbol timing offset STO and carrier frequency offset CFO;

[0209] Positioning and speed measurement module: estimates the distance between the user UE and the access point AP and the movement speed of the user UE based on the estimated values ​​of STO and CFO;

[0210] STO / CFO estimation module based on positioning and speed measurement: STO and CFO are accurately estimated again using distance and speed to reduce synchronization errors.

[0211] In summary, the present invention proposes a time and frequency synchronization method and system based on positioning and speed measurement, combined with one-bit quantization and RF structure optimization technology, aiming to achieve high-precision synchronization estimation in non-cellular large-scale MIMO systems. The present invention can significantly reduce the hardware complexity and power consumption of the system by adopting a one-bit quantization method, while simplifying the signal processing process. The present invention, combined with the radio frequency signal structure, can further enhance the flexibility and reliability of the system, and maintain efficient signal transmission and synchronization performance in a dynamic environment. The present invention can significantly improve the synchronization accuracy while reducing the system cost, and effectively improve the overall communication performance of the system, and has important technical advantages and broad application prospects.

[0212] For those skilled in the art, various changes, modifications, substitutions and variations can be made to the above-mentioned embodiments without departing from the principle and spirit of the method of the present invention. The scope of the present invention is defined by the attached claims and their equivalents, and still falls within the scope of the method described in the present invention and is still regarded as the scope of protection of the present invention.

Claims

1. A one-bit quantized time and frequency synchronization method for a non-cellular massive MIMO system, characterized in that: The specific steps are as follows: Step 1: Use the Schmidl-Cox synchronization algorithm to estimate the symbol timing offset STO and the carrier frequency offset CFO; Step 2: Estimate the distance between the user UE and the access point AP and the movement speed of the user UE according to the estimated values ​​of STO and CFO; Step 3: Use the distance and movement speed from step 2 to estimate STO and CFO again.

2. The time and frequency synchronization method of a one-bit quantization non-cellular massive MIMO system as claimed in claim 1, characterized in that: In step 1, the CPU uses time-frequency synchronization and uses the Schmidl-Cox synchronization algorithm to synchronize the quantized signal. Synchronize time and carrier frequency, and estimate symbol timing offset STO and carrier frequency offset CFO.

3. The time and frequency synchronization method of a one-bit quantization non-cellular massive MIMO system as claimed in claim 2, characterized in that: The estimated values ​​of STO and CFO between the user UE and the bth access point AP are recorded as Step 1 is as follows: Step 1.

1. STO estimation: Compute the autocorrelation of the signal at different time offsets: Where N is the fixed OFDM symbol length, n is the index variable, δ is the time offset, and * represents the complex conjugate; Calculate the energy distribution of the signal at different offsets: Calculate the ratio of the signal's correlation to the signal's energy: Where G is the length of the cyclic prefix; Estimate the STO at the bth AP: Step 1.2, CFO estimation: calculate Related metrics Use the function arg{·} to obtain the phase and estimate the frequency offset of the signal:

4. The time and frequency synchronization method of a one-bit quantization non-cellular massive MIMO system as claimed in claim 3, characterized in that: In step 2, based on the estimated values ​​of STO and CFO, the distance from the UE to the AP and the movement speed of the UE are estimated using a least squares algorithm.

5. The time and frequency synchronization method of a one-bit quantization non-cellular massive MIMO system as claimed in claim 4, characterized in that: Step 2 is as follows: Step 2.1: Estimate the distance from UE to AP and the projection speed of UE: Using the estimated value of STO Make a distance estimate and compute an estimate of the travel time: Among them, f b is the frequency shift; Calculate the estimated distance from UE to AP: Where c is the speed of light; Using the CFO's estimate Perform a projection velocity estimate and calculate an estimate of the frequency shift: According to the Doppler frequency shift formula, the projection estimate of the UE's motion speed is calculated: Step 2.2: Estimate the location coordinates of the UE and the movement speed of the UE: Use the estimated distance between the UE and each AP obtained in step 2.1 Estimate the UE's position using the LS algorithm; Construct the matrix: Among them, (x b ,y b ) is the position coordinate of the bth AP in the horizontal plane; Solve using LS algorithm: is the matrix of the UE's coordinate estimate, then the UE's position coordinate estimate is expressed as in, and are the estimated x- and y-coordinates of the UE on the horizontal plane, respectively; Estimated value based on UE's location coordinates and the projected estimate of the motion velocity Solve the estimated value of UE's motion speed in, and Respectively represent the estimated speed of the UE in the x-axis and y-axis directions in the horizontal plane; For the unit projection vector direction between the UE and the bth AP, calculate the velocity projection estimate: Construct the matrix: Among them, B contains the unit projection vector in the direction of each AP, and c contains the velocity projection estimate to each AP; Solve using LS algorithm: Contains the estimated value of the UE's motion speed, then the estimated value of the UE's motion speed is expressed as 6. The time and frequency synchronization method of a one-bit quantization non-cellular massive MIMO system as claimed in claim 5, characterized in that: Step 3 is as follows: Based on the estimated value of UE coordinates And the location coordinates of each AP, calculate the distance between UE and the bth AP: Where, h represents the vertical height of AP; Using distance estimates Compute a propagation time estimate: Calculate the estimated time synchronization offset between the UE and the bth AP: According to the estimated value of UE's moving speed Calculate the unit projection vector Projected velocity estimates in the direction: Compute the frequency shift estimate: Calculate the estimated value of the frequency synchronization offset between the UE and the bth AP: Where N is the length of OFDM symbol, f s is the sampling frequency.

7. A time and frequency synchronization system for a one-bit quantization non-cellular massive MIMO system, configured to execute the method according to any one of claims 1 to 6, characterized in that: Includes the following modules: SC algorithm estimation STO / CFO module: uses the Schmidl-Cox synchronization algorithm to estimate the symbol timing offset STO and carrier frequency offset CFO; Positioning and speed measurement module: estimates the distance between the user UE and the access point AP and the movement speed of the user UE based on the estimated values ​​of STO and CFO; STO / CFO estimation module based on positioning and speed measurement: STO and CFO are estimated again using the distance and movement speed.

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