Shared repeater-based cell frequency offset estimation method and device, and medium

Abstract

The invention discloses a shared repeater-based cell frequency offset estimation method and device and a medium, and the method comprises the steps: obtaining preprocessed IQ signal data, and enabling the IQ signal data to be mutually closed with a sequence of a local main synchronization signal to obtain a corresponding peak value and a rough frequency offset of a cell; according to the position of the peak value and the corresponding relation between the auxiliary synchronization signal and the local main synchronization signal in the time domain and the frequency domain, the initial position of the time domain of the auxiliary synchronization signal is determined; analyzing the auxiliary synchronization signal, and determining the ID group number of the cell according to the intra-group ID of the cell; determining the ID number of the cell according to the ID group number of the cell and the ID in the group; analyzing the demodulation reference signal according to the cell ID number to obtain a synchronous broadcast block index; and determining the position of the synchronous broadcast block index according to the synchronous broadcast block index, and determining the accurate frequency offset of the cell. The invention belongs to the field of base station frequency offset estimation. According to the invention, accurate estimation of the frequency offset of the base station can be realized.

Description

Technical Field

[0001] This invention relates to the field of base station frequency offset estimation, and more particularly to a method, device, and medium for frequency offset estimation of shared repeater cells. Background Technology

[0002] Currently, shared repeaters are widely used for coordinated amplification of wireless signals from multiple operators to improve network coverage. However, due to the inherent frequency difference between the repeater and the base station, coupled with the difficulty in perfectly synchronizing the local crystal oscillator with the carrier frequency, frequency offset is inevitably introduced, severely affecting cell search and subsequent communication performance. As the first step in the access process, accurate frequency offset estimation is crucial for ensuring system stability. Nevertheless, frequency offset estimation technology for shared repeater architectures is still in the initial exploratory stage. Existing solutions have significant shortcomings in terms of applicability, accuracy, and efficiency, making it difficult to meet the actual deployment needs under multi-band and multi-standard coexistence.

[0003] Existing frequency offset estimation methods mainly fall into three categories: independent estimation methods (such as maximum likelihood and cyclic prefix correlation), centralized joint estimation methods (such as multidimensional Kalman filtering), and distributed cooperative methods (such as consensus algorithms and federated learning). These methods generally suffer from high resource consumption and limited computational accuracy. On the one hand, repetitive computation at each node wastes hardware resources; on the other hand, in real multipath channels, signal orthogonality is disrupted, leading to phase detection distortion. Furthermore, most schemes do not implement dynamic adjustment of frame timing, affecting subsequent demodulation performance. Therefore, a novel frequency offset estimation method with low complexity, high accuracy, and adaptability to different bandwidths across multiple operators is urgently needed. Summary of the Invention

[0004] This invention solves the technical problem of base station frequency offset accuracy in the prior art by providing a method, equipment and medium for estimating cell frequency offset based on shared repeaters, and achieves the technical effect of improving the accuracy of determining base station frequency offset.

[0005] In a first aspect, the present invention provides a method for estimating the frequency offset of a cell based on a shared repeater, comprising:

[0006] The preprocessed IQ signal data is acquired, and the IQ signal data is cross-correlated with the sequence of the local master synchronization signal to obtain the corresponding peak value and the coarse frequency offset of the cell. The peak value is used to determine the intra-group ID of the cell and the start position of the local master synchronization signal in the time domain. Based on the position of the peak and the correspondence between the auxiliary synchronization signal and the local primary synchronization signal in the time and frequency domains, the starting position of the auxiliary synchronization signal in the time domain is determined, where the starting position is used to convert the time domain data of the auxiliary synchronization signal into frequency domain data. Analyze the secondary synchronization signal and determine the cell's ID group number based on the cell's intra-group ID; The cell ID number is determined based on the cell ID group number and the IDs within the group; Based on the cell ID number, the demodulation reference signal is parsed to obtain the synchronization broadcast block index; Based on the synchronization broadcast block index, determine the location of the synchronization broadcast block index and the precise frequency offset of the cell.

[0007] Furthermore, the IQ signal data is cross-correlated with the local master synchronization signal sequence to obtain the corresponding peak value and the cell's coarse frequency offset, including: Constructing the theoretical cross-correlation modulus function includes:

[0008] in, For IQ signal data and the first The local master synchronization signal has a time index of The magnitude of the cross-correlation result, For IQ signal data road signal, For IQ signal data road signal, The length of the sequence of local master synchronization signals, where The value of is related to the downsampling factor. , Local master synchronization sequence The time-domain sequence of the road signal, This is the time-domain sequence of the Q-channel signal of the local master synchronization sequence, where the group ID is denoted as... , For time indexing; Further processing includes:

[0009] The maximum value among the amplitudes is taken as the peak value; Determining the approximate frequency offset of a cell includes:

[0010] in, The value of the independent variable that makes the function reach its maximum value, This is the group ID within the community.

[0011] Furthermore, based on the position of the peak value and the correspondence between the auxiliary synchronization signal and the local primary synchronization signal in the time and frequency domains, the starting position of the auxiliary synchronization signal in the time domain is determined, including: Based on the secondary synchronization signal and the pre-stored complex rotation factor, the frequency domain data of the secondary synchronization signal is obtained, including:

[0012]

[0013]

[0014] in, For time index Time-domain data of the auxiliary synchronization signal. For time index Frequency domain data of the auxiliary synchronization signal at that time. For the auxiliary synchronization signal, I-channel data, For the Q-channel data of the auxiliary synchronization signal, For the imaginary part expression, d is the rotation factor corresponding to the auxiliary synchronization signal I-channel data, and d is the rotation factor corresponding to the auxiliary synchronization signal Q-channel data. Rotation factor for auxiliary synchronization signal; Calculate the real and imaginary parts of the frequency domain data of the auxiliary synchronization signal, including:

[0015] in, To represent the conjugate of a signal, we need to perform a Fourier transform from the time domain to the frequency domain.

[0016] Furthermore, based on the location of the peak value, the secondary synchronization signal is analyzed, and the cell's ID group number is determined based on the cell's intra-group ID, including: The frequency domain data of the auxiliary synchronization signal is mapped to obtain the sequence. ,in, , The length of the frequency domain data is denoted as , where the cell ID group number is denoted as . ; will sequence and The corresponding frequency domain data sequence Perform cross-correlation calculations, including:

[0017] in, The result of the cross-correlation calculation, for The conjugate; The cell ID group number is determined based on the maximum likelihood decision. ,include:

[0018] in, .

[0019] Furthermore, based on the cell's ID group number and the IDs within that group, the cell ID number is determined, including:

[0020] in, This is the community ID number.

[0021] Furthermore, based on the cell ID number, the demodulation reference signal is parsed to obtain the synchronization broadcast block index, including: Based on the 3GPP protocol and according to the cell ID number, the start bit of the local master synchronization signal is determined; Decoding is aided by a demodulation reference signal; A synchronization broadcast block index is generated based on the decoded physical downlink shared channel and cell ID number, including:

[0022]

[0023]

[0024]

[0025] in, For sequence The demodulation reference signal, For time index Pseudo-random sequences at time, for The first one generated sequence, The fixed offset value is 1600. It is a modulo 2 function. for The second one generated sequence, Even-numbered subcarriers are numbered. Number the odd-numbered subcarriers;

[0026] in, The initial value of the pseudo-random sequence is... To synchronize the broadcast block index, .

[0027] Furthermore, based on the synchronization broadcast block index, the location of the synchronization broadcast block index is determined, and the precise frequency offset of the cell is determined, including: Record the location of the peak; Based on a 33-level dynamic threshold and under the synchronous broadcast block index, the air interface offset is determined and the precise frequency offset of the cell is obtained.

[0028] Further, the preprocessed IQ signal data is acquired, including: Acquire the IQ signal data to be processed; Based on a low-pass filter, out-of-band signals and noise in the IQ signal data to be processed are removed; After passing through the low-pass filter, the IQ signal data to be processed is downsampled to obtain the preprocessed IQ signal data. The downsampling method includes using a counter to divide the frequency inside the FPGA to achieve a 16-fold downsampling.

[0029] In a second aspect, the present invention provides an electronic device, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to execute a shared repeater cell frequency offset estimation method as provided in the first aspect.

[0030] Thirdly, the present invention provides a non-transitory computer-readable storage medium, wherein when the instructions in the non-transitory computer-readable storage medium are executed by a processor of an electronic device, the electronic device is able to execute the frequency offset estimation method based on a shared repeater cell as provided in the first aspect.

[0031] One or more technical solutions provided in this invention have at least the following technical effects or advantages: This invention improves estimation accuracy step by step from coarse synchronization to fine synchronization through multi-stage collaborative processing: First, cross-correlation detection of the primary synchronization signal is used to obtain the peak position and coarse frequency offset, and the cell group ID and PSS time domain start point are determined accordingly; then, the fixed time-frequency relationship between PSS and secondary synchronization signal (SSS) in the 3GPP protocol is combined to accurately extract the SSS time domain segment and convert it to the frequency domain to complete the cell ID group number parsing, and finally synthesize the complete physical layer cell ID.

[0032] Based on this, the DMRS signal corresponding to the PBCH is demodulated according to the cell ID, and one DMRS is distributed for every four subcarriers; by splicing the received DMRS and cross-correlating it with eight local DMRS sequences determined by the SSB index, the SSB offset can be accurately identified, thereby determining the frame start position and performing fine compensation for the frequency.

[0033] This method supports bandwidth options of 20M / 100M, can adapt to different center frequencies, finds the SSB frequency point, and determines the compensation value for accurate frequency offset estimation based on the SSB index value.

[0034] This method employs blind detection and fine-tuning. Cross-correlation is performed starting from any given time to demodulate the DMRS (Digital Modulation Sequence), with each DMRS consisting of one subcarrier every four subcarriers. The DMRS position is determined by the cell ID. DMRS information is extracted based on the cell ID. The DMRS signal is determined by the SSB (Segment Subcarrier) offset, which has eight possibilities. After concatenating the DMRS information, the SSB offset is obtained by correlating the eight different DMRS sequences with the concatenated sequence, thus determining the frame start position. Frequency compensation is then performed based on the SSB offset.

[0035] This invention requires no prior synchronization information, has the capability of fully blind startup, and balances resource efficiency and algorithm accuracy. It is particularly suitable for fast and reliable cell search and frequency offset correction in complex deployment scenarios such as shared repeaters. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart illustrating the frequency offset estimation method for shared repeater cells provided by the present invention. Figure 2 This is a flowchart illustrating another method for estimating cell frequency offset based on a shared repeater provided by the present invention. Detailed Implementation

[0038] This invention provides a method for estimating cell frequency offset based on shared repeaters, which solves the technical problem of base station frequency offset accuracy in the prior art.

[0039] The technical solution of this invention is to solve the above-mentioned technical problems, and the overall idea is as follows: The cell frequency offset estimation method based on shared repeaters includes: acquiring preprocessed IQ signal data and cross-correlating the IQ signal data with the sequence of the local primary synchronization signal to obtain the corresponding peak value and the coarse frequency offset of the cell, wherein the peak value is used to determine the cell's intra-group ID and the start position of the local primary synchronization signal in the time domain; determining the start position of the secondary synchronization signal in the time domain based on the position of the peak value and the correspondence between the secondary synchronization signal and the local primary synchronization signal in the time and frequency domains, wherein the start position is used to convert the time domain data of the secondary synchronization signal into frequency domain data; parsing the secondary synchronization signal and determining the cell's ID group number based on the cell's intra-group ID; determining the cell ID number based on the cell's ID group number and intra-group ID; parsing the demodulation reference signal based on the cell ID number to obtain the synchronization broadcast block index; and determining the position of the synchronization broadcast block index and the precise frequency offset of the cell based on the synchronization broadcast block index.

[0040] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0041] First, it should be clarified that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0042] This invention provides, for example Figure 1 The frequency offset estimation method for shared repeater cells shown includes steps S11-S16. In addition, the process of this invention can also be referred to. Figure 2 : Step S11: Obtain the preprocessed IQ signal data and cross-correlate the IQ signal data with the sequence of the local master synchronization signal to obtain the corresponding peak value and the coarse frequency offset of the cell. The peak value is used to determine the intra-group ID of the cell and the start position of the local master synchronization signal in the time domain.

[0043] The process of acquiring preprocessed IQ signal data includes: acquiring IQ signal data to be processed; processing out-of-band signals and noise in the IQ signal data to be processed based on a low-pass filter; and downsampling the IQ signal data to be processed after passing through the low-pass filter to obtain preprocessed IQ signal data. The downsampling method includes: using a counter to divide the frequency inside the FPGA to achieve 16-fold downsampling.

[0044] Specifically: IQ signal data is a digital baseband signal that represents a real-frequency band signal in complex form, where I represents the in-phase component, corresponding to the real part of the signal; and Q represents the quadrature component, corresponding to the imaginary part of the signal. By down-converting the radio frequency signal and mixing it with the sine and cosine reference signals of the local oscillator, followed by low-pass filtering and sampling, the two orthogonal baseband signals I and Q can be obtained. In this article, "cell" can refer to a base station.

[0045] During the signal preprocessing stage of 5G base station reception, two 16-bit precision IQ baseband signals are received, each wireless frame has a duration of 10 milliseconds, the subcarrier spacing is set to 30kHz, and two bandwidth configurations of 20MHz or 100MHz are supported.

[0046] To ensure signal quality, the input signal can first be filtered: a dynamically configurable low-pass filter can be used, whose cutoff frequency can be flexibly adjusted according to the current operating bandwidth (20M or 100M), effectively suppressing out-of-band interference and noise; Taking China Mobile's 2.6GHz band as an example, when the center frequency is set to 2565MHz and a bandwidth of 100MHz is selected, it can fully cover the SSB frequency point of 2524.95MHz.

[0047] Subsequently, data downsampling is performed. Traditional solutions often rely on direct digital frequency synthesis (DDS) to achieve this, but this consumes a lot of FPGA resources.

[0048] This invention uses a counter-based frequency division method to achieve 16x downsampling within the FPGA, significantly reducing computational complexity and saving hardware resources.

[0049] By cross-correlating the IQ signal data with the local master synchronization signal sequence, the corresponding peak value and the cell's coarse frequency offset are obtained, including: Constructing the theoretical cross-correlation modulus function includes:

[0050] in, For IQ signal data and the first The local master synchronization signal has a time index of The magnitude of the cross-correlation result, For IQ signal data road signal, For IQ signal data road signal, The length of the sequence of local master synchronization signals, where The value of is related to the downsampling factor. , Local master synchronization sequence The time-domain sequence of the road signal, This is the time-domain sequence of the Q-channel signal of the local master synchronization sequence, where the group ID is denoted as... , For time indexing; Further processing includes:

[0051] The maximum value among the amplitudes is taken as the peak value; Determining the approximate frequency offset of a cell includes:

[0052] in, The value of the independent variable that makes the function reach its maximum value, This is the group ID within the community.

[0053] This invention achieves frame timing synchronization and initial cell ID search by using the cross-correlation value between IQ signal data and locally pre-stored synchronization signals (local master synchronization signals).

[0054] Specifically, multiple cross-correlators are deployed in parallel in the FPGA, each corresponding to a possible PSS sequence (master synchronization signal sequence). The IQ data stream is multiplied and added point by point with the template of each master synchronization signal sequence, and the cross-correlation result within the sliding window is accumulated. When the energy of a certain cross-correlation output is significantly higher than the threshold (33-level dynamic threshold), it can be determined that a synchronization signal has been detected, and the arrival time of the signal (used for frame synchronization) and the index of the corresponding main synchronization signal sequence can be obtained.

[0055] Step S12: Based on the position of the peak value and the correspondence between the auxiliary synchronization signal and the local main synchronization signal in the time and frequency domains, determine the starting position of the auxiliary synchronization signal in the time domain, where the starting position is used to convert the time domain data of the auxiliary synchronization signal into frequency domain data.

[0056] Specifically, it includes: Based on the secondary synchronization signal and the pre-stored complex rotation factor, the frequency domain data of the secondary synchronization signal is obtained, including:

[0057]

[0058]

[0059] in, For time index Time-domain data of the auxiliary synchronization signal. For time index Frequency domain data of the auxiliary synchronization signal at that time. For the auxiliary synchronization signal, I-channel data, For the Q-channel data of the auxiliary synchronization signal, For the imaginary part expression, d is the rotation factor corresponding to the auxiliary synchronization signal I-channel data, and d is the rotation factor corresponding to the auxiliary synchronization signal Q-channel data. Rotation factor for auxiliary synchronization signal; Calculate the real and imaginary parts of the frequency domain data of the auxiliary synchronization signal, including:

[0060] in, To represent the conjugate of a signal, we need to perform a Fourier transform from the time domain to the frequency domain.

[0061] After completing the detection of the local primary synchronization signal (PSS) and determining its peak position, the starting position of the SSS in the time domain can be accurately calculated based on the fixed timing relationship between the PSS (local primary synchronization signal) and the SSS (secondary synchronization signal) defined in the 3GPP protocol. Then, the time-domain IQ data segment of SSS (length is...) was extracted. The frequency domain transformation is performed on the IQ signal data by multiplying it with a pre-stored twitch factor (i.e., DFT basis function) using complex conjugate multiplication.

[0062] The structure based on table lookup and fixed-point multiplication and addition avoids complex FFT operations and can be implemented efficiently in parallel in FPGA. This saves resources and meets the requirements of 5G systems for fast frequency domain extraction of SSS, providing key input for subsequent accurate cell ID positioning and PBCH demodulation.

[0063] Step S13: Analyze the secondary synchronization signal and determine the ID group number of the cell based on the cell's intra-group ID.

[0064] Specifically, it includes: The frequency domain data of the auxiliary synchronization signal is mapped to obtain the sequence. ,in, , The length of the frequency domain data is denoted as , where the cell ID group number is denoted as . ; will sequence and The corresponding frequency domain data sequence Perform cross-correlation calculations, including:

[0065] in, The result of the cross-correlation calculation, for . conjugate.

[0066] The cell ID group number is determined based on the maximum likelihood decision. ,include:

[0067] in, .

[0068] Step S14: Determine the cell ID number based on the cell ID group number and the ID within the group.

[0069] Specifically, it includes:

[0070] in, This is the community ID number.

[0071] Steps S13 and S14 will be explained together: In 5G NR (New Radio, a globally unified radio access standard for fifth-generation mobile communication technology), the SSS is 127 bits long and is used to indicate the cell ID group number, with a value range of 0 to 335.

[0072] First, the frequency domain SSS signal obtained in the previous stage is demapped to obtain a received frequency domain sequence of length 127. Then, based on the signal detected by the local master synchronization signal (PSS)... This generates 336 corresponding local frequency domain SSS reference sequences, and performs cross-correlation calculations on each sequence with the received sequence. .

[0073] By using the maximum likelihood criterion, select the option that makes the maximum likelihood decision possible. The largest index is used as an estimate. .

[0074] Combined with known and According to the formula The complete physical layer cell ID number (ranging from 0 to 1007) is calculated to uniquely identify the 5G cell, providing key parameters for subsequent access and communication establishment.

[0075] Step S15: Based on the cell ID number, parse the demodulation reference signal to obtain the synchronization broadcast block index.

[0076] Specifically, it includes: Based on the 3GPP protocol and according to the cell ID number, the start bit of the local master synchronization signal is determined; Decoding is aided by a demodulation reference signal; A synchronization broadcast block index is generated based on the decoded physical downlink shared channel and cell ID number, including:

[0077]

[0078]

[0079]

[0080] in, For sequence The demodulation reference signal, For time index Pseudo-random sequences at time, for The first one generated sequence, The fixed offset value is 1600. It is a modulo 2 function. for The second one generated sequence, Even-numbered subcarriers are numbered. Number the odd-numbered subcarriers;

[0081] in, The initial value of the pseudo-random sequence is... To synchronize the broadcast block index, .

[0082] According to the 3GPP protocol, an SSB may appear in the time domain in the time slot numbered 0, 1, 2 or 3 in the radio frame, and its specific location is determined by the SSB index (the value ranges from 0 to 7).

[0083] 5G NR no longer relies on the Cell Reference Signal (CRS) in 4G LTE, but instead uses the Demodulation Reference Signal (DMRS) dedicated to the Physical Broadcast Channel (PBCH) and Physical Downlink Shared Channel (PDSCH) for channel estimation and decoding.

[0084] PBCH DMRS is generated from a Gold sequence, which consists of two m sequences. , as well as Add to form.

[0085] Therefore, in the known Under the premise that we can try all possibilities Each DMRS sequence is generated and its correlation is matched with the received PBCH DMRS. The one with the highest related peak This is the index of the actual transmitted synchronization signal block.

[0086] This process not only determined the exact location of the SSB in the time domain, but also provided parameters for the subsequent correct decoding of the PBCH payload.

[0087] Step S16: Determine the location of the synchronization broadcast block index and the precise frequency offset of the cell based on the synchronization broadcast block index.

[0088] Specifically, this includes: recording the location of peak values; determining the air interface offset and obtaining the precise frequency offset of the cell based on a 33-level dynamic threshold and under the synchronous broadcast block index.

[0089] It can dynamically record the position of cross-correlation peaks, providing a reliable basis for accurate timing of wireless frames. Secondly, it adopts a 33-level adjustable dynamic threshold, covering a wide range of received signal strength from -99dB to 0dB, significantly improving detection robustness in low signal-to-noise ratio or deep fading environments. The noise immunity is improved by about 3dB compared to a fixed threshold, effectively avoiding missed detection of synchronization signals due to excessively high thresholds. Finally, after completing the SSB (Synchronization Signal Block) index identification, it dynamically selects the corresponding air interface propagation delay compensation formula based on the index, and combines it with an 8-level moving average filter to smooth and suppress clock jitter, thereby calculating the accurate frequency offset matching the current SSB position and achieving high-precision carrier frequency synchronization.

[0090] In summary, this invention improves estimation accuracy step by step from coarse synchronization to fine synchronization through multi-stage collaborative processing: First, the peak position and coarse frequency offset are obtained by cross-correlation detection of the primary synchronization signal, and the cell group ID and PSS time domain start point are determined accordingly; then, the fixed time-frequency relationship between PSS and secondary synchronization signal (SSS) in the 3GPP protocol is combined to accurately extract the SSS time domain segment and convert it to the frequency domain to complete the cell ID group number parsing, and finally synthesize the complete physical layer cell ID.

[0091] Based on this, the DMRS signal corresponding to the PBCH is demodulated according to the cell ID, and one DMRS is distributed for every four subcarriers; by splicing the received DMRS and cross-correlating it with eight local DMRS sequences determined by the SSB index, the SSB offset can be accurately identified, thereby determining the frame start position and performing fine compensation for the frequency.

[0092] This method supports bandwidth options of 20M / 100M, can adapt to different center frequencies, finds the SSB frequency point, and determines the compensation value for accurate frequency offset estimation based on the SSB index value.

[0093] This method employs blind detection and fine-tuning. Cross-correlation is performed starting from any given time to demodulate the DMRS (Digital Modulation Sequence), with each DMRS consisting of one subcarrier every four subcarriers. The DMRS position is determined by the cell ID. DMRS information is extracted based on the cell ID. The DMRS signal is determined by the SSB (Segment Subcarrier) offset, which has eight possibilities. After concatenating the DMRS information, the SSB offset is obtained by correlating the eight different DMRS sequences with the concatenated sequence, thus determining the frame start position. Frequency compensation is then performed based on the SSB offset.

[0094] This invention requires no prior synchronization information, has the capability of fully blind startup, and balances resource efficiency and algorithm accuracy. It is particularly suitable for fast and reliable cell search and frequency offset correction in complex deployment scenarios such as shared repeaters.

[0095] Based on the same inventive concept, the present invention also provides an electronic device, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to execute the frequency offset estimation method for shared repeater cells as described above.

[0096] Based on the same inventive concept, the present invention also provides a non-transitory computer-readable storage medium, which, when the instructions in the storage medium are executed by the processor of an electronic device, enables the electronic device to implement the frequency offset estimation method for shared repeater cell as described above.

[0097] Since the electronic device described in this embodiment is an electronic device used to implement the information processing method in the embodiments of the present invention, those skilled in the art can understand the specific implementation methods and various variations of the electronic device in this embodiment based on the information processing method described in the embodiments of the present invention. Therefore, how the electronic device implements the method in the embodiments of the present invention will not be described in detail here. Any electronic device used by those skilled in the art to implement the information processing method in the embodiments of the present invention falls within the scope of protection of the present invention.

[0098] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0099] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0100] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0101] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0102] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0103] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for estimating frequency offset based on a shared repeater cell, characterized in that, The method comprises the following steps: acquiring pre-processed IQ signal data, and correlating the IQ signal data with a sequence of a local primary synchronization signal to obtain corresponding peak values and a coarse frequency offset of a cell, wherein the peak values are used to determine an intra-group ID of the cell and a starting position of a time domain of the local primary synchronization signal; determining a starting position of a time domain of the secondary synchronization signal according to the position of the peak values and a corresponding relationship between the secondary synchronization signal and the local primary synchronization signal in the time domain and the frequency domain, wherein the starting position is used to convert time domain data of the secondary synchronization signal into frequency domain data; parsing the secondary synchronization signal and determining an ID group number of the cell according to the intra-group ID of the cell; determining a cell ID number according to the ID group number of the cell and the intra-group ID; parsing a demodulation reference signal to obtain a synchronization broadcast block index according to the cell ID number; determining a position of the synchronization broadcast block index and an accurate frequency offset of the cell according to the synchronization broadcast block index.

2. The method for estimating frequency offset of a shared repeater cell based on claim 1, characterized in that, The method of correlating the IQ signal data with the sequence of the local primary synchronization signal to obtain the corresponding peak values and the coarse frequency offset of the cell comprises the following steps: constructing a theoretical cross-correlation modulo function, comprising the following steps: wherein, is the amplitude of the cross-correlation result of the IQ signal data and the first local primary synchronization signal at the time index , is the I signal in the IQ signal data, is the Q signal in the IQ signal data, is the length of the sequence of the local primary synchronization signal, wherein the value of is related to the multiple of the down-sampling, , is the time-domain sequence of the local primary synchronization sequence I signal, is the time-domain sequence of the local primary synchronization sequence Q signal, wherein the group ID is denoted as is the time index;​​​ further processing, comprising the following steps: taking the maximum value in the amplitude as the peak value; determining the coarse frequency offset of the cell, comprising the following steps: wherein, is the value of the argument of the function for which the function attains a maximum value, is the intra-group ID of the cell.

3. The method for estimating frequency offset of a shared repeater cell based cell according to claim 2, wherein, determining the starting position of the time domain of the secondary synchronization signal according to the position of the peak values and the corresponding relationship between the secondary synchronization signal and the local primary synchronization signal in the time domain and the frequency domain, comprising the following steps: obtaining the frequency domain data of the secondary synchronization signal according to the secondary synchronization signal and a pre-stored complex rotation factor, comprising the following steps: wherein, is time-domain data of a secondary synchronization signal with time index , is frequency-domain data of a secondary synchronization signal with time index , is I-channel data of a secondary synchronization signal, is Q-channel data of a secondary synchronization signal, is an imaginary part expression, is a rotation factor corresponding to the I-channel data of the secondary synchronization signal, and d is a rotation factor corresponding to the Q-channel data of the secondary synchronization signal, is a secondary synchronization signal rotation factor; calculating the real part and the imaginary part of the frequency domain data of the secondary synchronization signal, comprising the following steps: wherein is the conjugate of the signal, i.e. the Fourier transform of the time domain to the frequency domain.

4. The method for estimating frequency offset of a shared repeater cell based cell according to claim 3, wherein, parsing the secondary synchronization signal according to the position of the peak values and determining the ID group number of the cell according to the intra-group ID of the cell, comprising the following steps: Mapping the frequency domain data of the secondary synchronization signal to obtain a sequence wherein, , is the length of the frequency domain data, wherein the ID group number of the cell is denoted as ; The sequence of sequences corresponding to the sequence of sequences of frequency domain data performing cross-correlation calculations, including: wherein is the result of the mutual correlation calculation, is the conjugate of determining an ID group number of the cell based on a maximum likelihood decision comprising: wherein .

5. The method for estimating frequency offset of a shared repeater cell based cell according to claim 4, wherein, determining the cell ID number according to the ID group number of the cell and the intra-group ID, comprising the following steps: wherein, is a cell ID number.

6. The method for estimating frequency offset of a shared repeater cell based cell according to claim 5, wherein, parsing the demodulation reference signal to obtain the synchronization broadcast block index according to the cell ID number, comprising the following steps: determining the starting bit of the local primary synchronization signal based on the 3GPP protocol and the cell ID number; assisting decoding based on the demodulation reference signal; generating the synchronization broadcast block index based on the decoded physical downlink shared channel and the cell ID number, comprising the following steps: in, For sequence The demodulation reference signal, For time index Pseudo-random sequences at time, for The first one generated sequence, The fixed offset value is 1600. It is a modulo 2 function. for The second one generated sequence, Even-numbered subcarriers are numbered. Number the odd-numbered subcarriers; wherein is an initial value of a pseudo-random sequence, is a synchronization broadcast block index, .

7. The method for estimating frequency offset of a shared repeater cell based cell according to claim 6, wherein, determining the position of the synchronization broadcast block index and the accurate frequency offset of the cell according to the synchronization broadcast block index, comprising the following steps: recording the position of the peak value; determining the air interface offset and obtaining the accurate frequency offset of the cell based on a 33-level dynamic threshold and under the synchronization broadcast block index.

8. The method for estimating frequency offset of a shared repeater cell based cell according to claim 1, wherein, The method of acquiring the pre-processed IQ signal data comprises the following steps: acquiring IQ signal data to be processed; processing out-of-band signals and noise in the IQ signal data to be processed based on a low-pass filter; after passing through the low-pass filter, performing downsampling on the IQ signal data to be processed to obtain the pre-processed IQ signal data, wherein the downsampling manner comprises using a counter frequency division inside an FPGA to achieve 16 times downsampling.

9. An electronic device, comprising: The method comprises the following steps: a processor; a memory for storing instructions executable by the processor; wherein the processor is configured to execute to implement the shared repeater cell frequency offset estimation method according to any one of claims 1 to 8.

10. A non-transitory computer-readable storage medium, comprising: When the instructions in the non-transitory computer-readable storage medium are executed by the processor of the electronic device, the electronic device is enabled to perform the shared repeater cell frequency offset estimation method as claimed in any one of claims 1 to 8.

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