Direct current offset determination method and apparatus, electronic device, and storage medium

Abstract

The application relates to the technical field of communication, and provides a direct current offset determination method and device, electronic equipment and a storage medium. The method constructs a local time domain reference signal according to a reference sequence corresponding to a target time domain symbol, and obtains a time domain receiving signal corresponding to the reference sequence; the target time domain sampling position is determined according to the time domain receiving signal and the time domain reference signal; the time domain receiving signal is intercepted at the target time domain sampling position through a pre-set intercepting window, a target time domain receiving signal is obtained, and a target time domain signal model is constructed according to the target time domain receiving signal and the time domain reference signal; and the direct current offset corresponding to the target time domain symbol is determined according to the target time domain signal model, so that a more accurate and stable direct current offset determination effect is realized.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a method, apparatus, electronic device and storage medium for determining DC offset. Background Technology

[0002] With the development of mobile communication technology, Long Term Evolution (LTE) systems have been widely used in mobile broadband communication. In the LTE uplink, the terminal equipment (UE) uses single-carrier frequency division multiple access (SC-FDMA) technology for signal transmission. This technology essentially uses a combination of Discrete Fourier Transform (DFT) and Inverse Fast Fourier Transform (IFFT) at the transmitting end to generate time-domain signals through multi-carrier modulation. The receiving end needs to convert the time-domain signal into a frequency-domain signal for demodulation.

[0003] In practical systems, due to hardware non-ideal factors such as RF link imbalance, analog-to-digital converter bias, power supply noise, and local oscillator leakage, a DC offset is usually introduced into the received signal. This DC offset manifests as a fixed or slowly varying DC component superimposed on the time-domain signal. After FFT transformation, the DC component not only generates an energy peak at zero frequency but also leaks on several nearby subcarriers, thus affecting the spectral characteristics of the received signal.

[0004] If the DC offset cannot be accurately estimated and compensated, the following problems will occur: amplitude and phase distortion of the frequency domain signal at zero frequency and adjacent subcarriers will occur, affecting the accuracy of channel estimation and data demodulation; in the uplink, the synchronization detection, channel estimation and signal-to-noise ratio calculation during base station demodulation may be affected by the DC component, resulting in a decrease in system performance.

[0005] In existing technologies, DC offset is usually estimated by calculating a simple average value of the received signal in the time domain. However, this method is easily affected by factors such as subcarrier leakage, resulting in limited estimation accuracy. Summary of the Invention

[0006] In view of this, embodiments of this application provide a method, apparatus, electronic device, and storage medium for determining DC offset, in order to solve the problem that the DC offset cannot be accurately obtained in the prior art.

[0007] A first aspect of this application provides a DC offset determination method, the method comprising: constructing a local time-domain reference signal based on a reference sequence corresponding to a target time-domain symbol, and obtaining a time-domain received signal corresponding to the reference sequence; determining a target time-domain sampling position based on the time-domain received signal and the time-domain reference signal; truncating the time-domain received signal at the target time-domain sampling position through a pre-set truncation window to obtain a target time-domain received signal, and constructing a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and determining the DC offset corresponding to the target time-domain symbol based on the target time-domain signal model.

[0008] A second aspect of this application provides a DC offset determination apparatus, comprising: an acquisition module, configured to construct a local time-domain reference signal based on a reference sequence corresponding to a target time-domain symbol, and acquire a time-domain received signal corresponding to the reference sequence; a determination module, configured to determine a target time-domain sampling position based on the time-domain received signal and the time-domain reference signal; a model module, configured to truncate the time-domain received signal at the target time-domain sampling position through a pre-set truncation window to obtain a target time-domain received signal, and construct a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and an estimation module, configured to determine the DC offset corresponding to the target time-domain symbol based on the target time-domain signal model.

[0009] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0010] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0011] The beneficial effects of this application embodiment compared with the prior art are as follows: The method in this application embodiment constructs a local time-domain reference signal based on the reference sequence corresponding to the target time-domain symbol, and obtains the time-domain received signal corresponding to the reference sequence; determines the target time-domain sampling position based on the time-domain received signal and the time-domain reference signal; intercepts the time-domain received signal at the target time-domain sampling position through a pre-set interception window to obtain the target time-domain received signal, and constructs a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and determines the DC offset corresponding to the target time-domain symbol based on the target time-domain signal model. Through the above process, this application first accurately determines the target time-domain sampling position based on the time-domain received signal and the time-domain reference signal, and obtains the target time-domain received signal by intercepting the time-domain received signal based on the target time-domain sampling position, thereby ensuring the accuracy of the signal used to construct the model in the time domain; furthermore, by constructing a target time-domain signal model describing the relationship between the target time-domain received signal and the time-domain reference signal, and performing calculations based on the model, a more accurate and stable DC offset determination effect is achieved, avoiding the problem of inaccurate DC offset acquisition in the prior art. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart illustrating a DC offset determination method provided in an embodiment of this application;

[0014] Figure 2 This is a schematic diagram of a typical structure of an LTE uplink time-frequency signal provided in an embodiment of this application;

[0015] Figure 3 This is a schematic diagram of a time-domain received signal provided in an embodiment of this application;

[0016] Figure 4 This is a schematic diagram illustrating the construction of a time-domain reference signal according to an embodiment of this application;

[0017] Figure 5 This is a schematic diagram illustrating the calculation of a sliding correlation function provided in an embodiment of this application;

[0018] Figure 6 This is a schematic diagram of the modulus of a sliding correlation function provided in an embodiment of this application;

[0019] Figure 7This is a schematic diagram of the structure of a DC offset determination device provided in an embodiment of this application;

[0020] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0021] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0022] A DC offset determination method and apparatus according to an embodiment of this application will now be described in detail with reference to the accompanying drawings.

[0023] Figure 1 This is a flowchart illustrating a DC offset determination method provided in an embodiment of this application, as shown below. Figure 1 As shown, the method includes:

[0024] S101. Construct a local time-domain reference signal based on the reference sequence corresponding to the target time-domain symbol, and obtain the time-domain received signal corresponding to the reference sequence;

[0025] S102. Determine the target time-domain sampling position based on the received time-domain signal and the time-domain reference signal;

[0026] S103. By using a pre-set interception window, the time-domain received signal is intercepted at the target time-domain sampling position to obtain the target time-domain received signal, and a target time-domain signal model is constructed based on the target time-domain received signal and the time-domain reference signal.

[0027] S104. Based on the target time-domain signal model, determine the DC offset corresponding to the target time-domain symbol.

[0028] like Figure 2 As shown, Figure 2 A typical structure for LTE uplink time-frequency signals is as follows: each user is allocated several resource blocks that are contiguous in the frequency domain. Along the time domain direction, each resource block contains 7 consecutive time-domain symbols; along the frequency domain direction, each resource block contains 12 consecutive subcarriers. Figure 2 A complete resource block is outlined in bold. Within each resource block, the target time-domain symbol located in the middle of the time slot carries a Demodulation Reference Signal (DM-RS) subcarrier. The DM-RS subcarrier carries a reference sequence known to the receiver, used for system synchronization and channel estimation.

[0029] like Figure 3 As shown, a complete OFDM time-domain symbol in an LTE / OFDM system consists of two parts in terms of time structure: the cyclic prefix (CP): located at the very beginning of the symbol, with a length denoted as . As shown in the white area between the "start of time domain symbol" and the "start of effective data portion" in the figure. The CP (Constant Proportion) is mainly used to combat multipath delay spread and protect subsequent effective data from interference by the previous symbol. Effective data portion: immediately following the CP, its length is denoted as... As shown in the shaded area in the figure, this data is the core region for subsequent demodulation (FFT transformation) or parameter estimation (such as DC offset estimation in this case).

[0030] It is understandable that the "time-domain received signal corresponding to the reference sequence" obtained by the receiving end in step S101 refers to a sampled data stream containing the complete structure described above (i.e., including the CP and valid data portion) or a portion of its time range. Due to limitations in wireless transmission delay and coarse synchronization accuracy, the actual "time-domain symbol start point" in the data stream obtained by the receiving end may not be at the 0th position of the sampled data stream, but rather has a certain time offset.

[0031] The reference sequence refers to the pilot sequence specified by the communication protocol and known to both the transmitter and receiver. In LTE systems, this sequence is typically a Zadoff-Chu (ZC) sequence or a pseudo-random sequence extended from a ZC sequence. The specific form of this sequence is usually determined by parameters such as the cell ID, slot number, and the bandwidth resources allocated to the user.

[0032] This application also constructs a local time-domain reference signal based on the reference sequence. To accurately reproduce a standard signal with no channel fading and no noise at the receiver as a comparison template, such as... Figure 4 As shown, the construction process specifically includes the following steps: Subcarrier Mapping: First, the generated frequency domain reference sequence is mapped to the subcarrier positions allocated to the target user. The reference sequence is placed on the corresponding subcarrier within the allocated bandwidth (i.e., the subcarrier contained in the time-domain symbol in the middle of each resource block), while zeros are padded at unallocated subcarrier positions. IFFT Transformation: The mapped frequency domain data is then subjected to... The Inverse Fast Fourier Transform (IFFT) transforms a signal from the frequency domain to the time domain. Half-Subcarrier Frequency Shift: In LTE uplinks, to reduce the impact of DC components on the signal, a frequency shift of half a subcarrier interval is typically applied. This is achieved by multiplying the IFFT-transformed time-domain data by a phase rotation factor. After the above processing, the final length is obtained as follows: The local time-domain reference signal. This time-domain reference signal will serve as a standard "template" for the sliding correlation operation in the subsequent step S102, used to accurately determine the starting position of the effective data portion of the target time-domain symbol in the received data stream containing timing bias.

[0033] This application determines the target time-domain sampling position based on the received time-domain signal and the time-domain reference signal. Specifically, this application calculates a sliding correlation function based on the received time-domain signal and the time-domain reference signal; determines the sliding offset corresponding to the maximum value of the square of the modulus of the sliding correlation function, and determines the time-domain position corresponding to the sliding offset as the target time-domain sampling position; such as Figure 5 As shown, the sliding correlation function is:

[0034] ;

[0035] in, The length of the valid data portion in a single OFDM time-domain symbol, i.e., the length of the pre-set truncation window. For the time-domain received signal in the first... The value of each sampling point The length of the cyclic prefix. This is the sliding offset. The time-domain reference signal is represented at the 1st... The complex conjugate of each sampling point For the sliding offset The relevant values ​​were calculated below.

[0036] Different calculations yielded different results. Value Then, determine the sliding offset corresponding to the maximum value of the square root (or magnitude) of the sliding correlation function. The time-domain position corresponding to the sliding offset of this maximum value is determined as the target time-domain sampling position (i.e., the precise starting point of the effective data portion).

[0037] Since the system has typically completed coarse synchronization processes such as CP synchronization or preamble synchronization before this step, the residual time synchronization error is usually small. Therefore, the sliding range of the sliding window (i.e., The range of values ​​should not be set too large to reduce computational complexity and avoid misjudgments. As a specific implementation method, a preset number of sampling points can be slid forward and backward from the starting point of the effective data portion determined by coarse synchronization. For example, The range of values ​​can be set as follows: That is, slide 4 sampling points forward and backward, searching a total of 9 positions.

[0038] like Figure 6 As shown, Figure 6 The sliding correlation function is given. The model The diagram is provided by The location of the peak value can determine the starting point of a more precise portion of the effective data, i.e., the target time-domain sampling location.

[0039] After determining the target time-domain sampling location, this application will further extract the time-domain received signal at the target time-domain sampling location through a pre-set interception window to obtain the target time-domain received signal, and construct the target time-domain signal model based on the target time-domain received signal and the time-domain reference signal.

[0040] Specifically, after determining the precise starting point of the effective data portion (i.e., the target time-domain sampling position) in step S102, the receiving end utilizes a pre-set length of... The capture window, starting from this point, captures a continuous sequence. Each sampling point. This process is physically equivalent to removing the cyclic prefix (CP) and retaining the valid data portion of the OFDM time-domain symbol. This extracted data set is defined as the "target time-domain received signal," denoted as [missing information]. ,in .

[0041] Next, this application will construct a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal, including: establishing an original time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and constructing the target time-domain signal model based on the original time-domain signal model.

[0042] The original time-domain signal model is a signal model at the level of a single sampling point, which can be represented as:

[0043] ;

[0044] in, The first time domain received signal of the target Values ​​of each sampling point The first time-domain reference signal Values ​​of each sampling point For the unknown time-domain channel response, For the DC offset to be determined, For the first The noise term corresponding to each sampling point.

[0045] In order to solve the problem using linear algebra methods, this application further... The scalar equations are assembled into a vector-matrix form target time-domain signal model (linear regression model), which is expressed as:

[0046] ;

[0047] in, For the reason The column vector formed, i.e. , For the reason The column vector formed For designing a matrix, it is a The matrix whose first column consists of Composition (corresponding to) The coefficients), the second column consists of the constant 1 (corresponding to the coefficients), and the second column consists of the constant 1 (corresponding to the coefficients). The coefficient, because ), specifically in the form of: .

[0048] According to the classic linear regression theory, and The least squares method can be used for fitting: ; This represents the conjugate transpose operator.

[0049] To reduce computational complexity, this application expands the aforementioned matrix operations. First, the relevant matrices are calculated. and vector ;

[0050] Next, calculate the inverse of the correlation matrix: ;

[0051] Finally, by substituting the values ​​into the solution, the estimated channel response is obtained. Closed-form solution for DC offset:

[0052] ;

[0053] ;

[0054] Using the above formula, the receiver can quickly and accurately calculate the DC offset corresponding to the target time domain symbol. .

[0055] According to the technical solution provided in this application, a local time-domain reference signal is constructed based on the reference sequence corresponding to the target time-domain symbol, and the time-domain received signal corresponding to the reference sequence is obtained; the target time-domain sampling position is determined based on the time-domain received signal and the time-domain reference signal; the time-domain received signal is truncated at the target time-domain sampling position through a pre-set truncation window to obtain the target time-domain received signal, and a target time-domain signal model is constructed based on the target time-domain received signal and the time-domain reference signal; the DC offset corresponding to the target time-domain symbol is determined based on the target time-domain signal model. Through the above process, this application first accurately determines the target time-domain sampling position based on the time-domain received signal and the time-domain reference signal, and then truncates the time-domain received signal based on this target time-domain sampling position to obtain the target time-domain received signal, thereby ensuring the accuracy of the signal used to construct the model in the time domain; furthermore, by constructing a target time-domain signal model describing the relationship between the target time-domain received signal and the time-domain reference signal, and performing calculations based on this model, a more accurate and stable DC offset determination effect is achieved, avoiding the problem of inaccurate DC offset acquisition in the prior art.

[0056] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0057] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0058] This embodiment also provides a DC offset determination device, such as... Figure 7 As shown, the DC offset determination device includes:

[0059] The acquisition module 701 is used to construct a local time-domain reference signal based on the reference sequence corresponding to the target time-domain symbol, and to acquire the time-domain received signal corresponding to the reference sequence.

[0060] The determining module 702 is used to determine the target time-domain sampling position based on the time-domain received signal and the time-domain reference signal;

[0061] Model module 703 is used to capture the time-domain received signal at the target time-domain sampling position through a pre-set capture window to obtain the target time-domain received signal, and to construct a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal.

[0062] The estimation module 704 is used to determine the DC offset corresponding to the target time domain symbol based on the target time domain signal model.

[0063] In some examples, the determining module 702 is further configured to calculate a sliding correlation function based on the time-domain received signal and the time-domain reference signal; determine the sliding offset corresponding to the maximum value of the square of the sliding correlation function, and determine the time-domain position corresponding to the sliding offset as the target time-domain sampling position; the sliding correlation function is:

[0064] ;

[0065] in, The length of the valid data portion in a single OFDM time-domain symbol, i.e., the length of the pre-set truncation window. For the time-domain received signal in the first... The value of each sampling point The length of the cyclic prefix. This is the sliding offset. The time-domain reference signal is represented at the 1st... The complex conjugate of each sampling point For the sliding offset The relevant values ​​were calculated below.

[0066] In some examples, model module 703 is also used to establish an original time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and to construct the target time-domain signal model based on the original time-domain signal model. The original time-domain signal model is represented as follows:

[0067] ;

[0068] in, The first time domain received signal of the target Values ​​of each sampling point The first time-domain reference signal Values ​​of each sampling point For the unknown time-domain channel response, For the DC offset to be determined, For the first The noise term corresponding to each sampling point.

[0069] The target time-domain signal model is represented as:

[0070] ;

[0071] in, For the reason The column vector formed For the reason The column vector formed To design the matrix, its first column is composed of... The second column consists of all 1s.

[0072] In some examples, the estimation module 704 also uses the least squares method to solve the target time-domain signal model to obtain the DC offset; the formula for calculating the DC offset is:

[0073] ;

[0074] in, DC offset, The first time domain received signal of the target Values ​​of each sampling point The first time-domain reference signal Values ​​of each sampling point The length of the valid data portion in a single OFDM time-domain symbol.

[0075] According to the technical solution provided in this application, a local time-domain reference signal is constructed based on the reference sequence corresponding to the target time-domain symbol, and the time-domain received signal corresponding to the reference sequence is obtained; the target time-domain sampling position is determined based on the time-domain received signal and the time-domain reference signal; the time-domain received signal is truncated at the target time-domain sampling position through a pre-set truncation window to obtain the target time-domain received signal, and a target time-domain signal model is constructed based on the target time-domain received signal and the time-domain reference signal; the DC offset corresponding to the target time-domain symbol is determined based on the target time-domain signal model. Through the above process, this application first accurately determines the target time-domain sampling position based on the time-domain received signal and the time-domain reference signal, and then truncates the time-domain received signal based on this target time-domain sampling position to obtain the target time-domain received signal, thereby ensuring the accuracy of the signal used to construct the model in the time domain; furthermore, by constructing a target time-domain signal model describing the relationship between the target time-domain received signal and the time-domain reference signal, and performing calculations based on this model, a more accurate and stable DC offset determination effect is achieved, avoiding the problem of inaccurate DC offset acquisition in the prior art.

[0076] Figure 8 This is a schematic diagram of the electronic device 8 provided in an embodiment of this application. For example... Figure 8 As shown, the electronic device 8 of this embodiment includes a processor 801, a memory 802, and a computer program 803 stored in the memory 802 and executable on the processor 801. When the processor 801 executes the computer program 803, it implements the steps in the various method embodiments described above. Alternatively, when the processor 801 executes the computer program 803, it implements the functions of each module / unit in the various device embodiments described above.

[0077] Electronic device 8 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 8 may include, but is not limited to, processor 801 and memory 802. Those skilled in the art will understand that... Figure 8This is merely an example of electronic device 8 and does not constitute a limitation on electronic device 8. It may include more or fewer components than shown, or different components.

[0078] The processor 801 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0079] The memory 802 can be an internal storage unit of the electronic device 8, such as a hard disk or RAM of the electronic device 8. The memory 802 can also be an external storage device of the electronic device 8, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc., equipped on the electronic device 8. The memory 802 can also include both internal and external storage units of the electronic device 8. The memory 802 is used to store computer programs and other programs and data required by the electronic device.

[0080] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0081] If an integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium may include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in a computer-readable medium can be appropriately added to or subtracted according to the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0082] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for determining DC offset, characterized in that, The method includes: A local time-domain reference signal is constructed based on the reference sequence corresponding to the target time-domain symbol, and the time-domain received signal corresponding to the reference sequence is obtained; The target time-domain sampling position is determined based on the received time-domain signal and the time-domain reference signal; The time-domain received signal is intercepted at the target time-domain sampling position through a pre-set interception window to obtain the target time-domain received signal, and a target time-domain signal model is constructed based on the target time-domain received signal and the time-domain reference signal. Based on the target time-domain signal model, determine the DC offset corresponding to the target time-domain symbol; Constructing a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal includes: establishing an original time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and constructing the target time-domain signal model based on the original time-domain signal model. The original time-domain signal model is represented as follows: ; in, The first time domain received signal of the target Values ​​of each sampling point, The first time-domain reference signal Values ​​of each sampling point, The time-domain channel response is unknown, and DC is the DC offset to be determined. For the first Noise term corresponding to each sampling point; The target time-domain signal model is represented as follows: ; in, For the reason The column vector formed For the reason The column vector formed To design the matrix, its first column is composed of... The second column consists of all 1s. Based on the target time-domain signal model, the DC offset corresponding to the target time-domain symbol is determined, including: solving the target time-domain signal model using the least squares method to obtain the DC offset; the formula for calculating the DC offset is: ; in, The calculated DC offset, The length of the pre-set capture window, The time-domain reference signal is in the first... The complex conjugate of each sampling point.

2. The method according to claim 1, characterized in that, Determining the target time-domain sampling location based on the received time-domain signal and the time-domain reference signal includes: Calculate the sliding correlation function based on the received time-domain signal and the time-domain reference signal; Determine the sliding offset corresponding to the maximum value of the square of the sliding correlation function, and determine the time-domain position corresponding to the sliding offset as the target time-domain sampling position; the sliding correlation function is: ; in, The length of the pre-set capture window, For the time-domain received signal in the first... The value of each sampling point The length of the cyclic prefix. This is the sliding offset. For the sliding offset The relevant values ​​were calculated below.

3. A DC offset determining device, characterized in that, The device includes: The acquisition module is used to construct a local time-domain reference signal based on the reference sequence corresponding to the target time-domain symbol, and to acquire the time-domain received signal corresponding to the reference sequence; The determining module is used to determine the target time-domain sampling position based on the time-domain received signal and the time-domain reference signal; The model module is used to capture the time-domain received signal at the target time-domain sampling position through a pre-set capture window to obtain the target time-domain received signal, and to construct a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal. The estimation module is used to determine the DC offset corresponding to the target time-domain symbol based on the target time-domain signal model; Constructing a target time-domain signal model based on the target time-domain received signal and the time-domain reference signal includes: establishing an original time-domain signal model based on the target time-domain received signal and the time-domain reference signal; and constructing the target time-domain signal model based on the original time-domain signal model. The original time-domain signal model is represented as follows: ; in, The first time domain received signal of the target Values ​​of each sampling point The first time-domain reference signal Values ​​of each sampling point The time-domain channel response is unknown, and DC is the DC offset to be determined. For the first Noise term corresponding to each sampling point; The target time-domain signal model is represented as follows: ; in, For the reason The column vector formed For the reason The column vector consists of A, the design matrix, whose first column is composed of The second column consists of all 1s. Based on the target time-domain signal model, the DC offset corresponding to the target time-domain symbol is determined, including: solving the target time-domain signal model using the least squares method to obtain the DC offset; the formula for calculating the DC offset is: ; in, The calculated DC offset, The length of the pre-set capture window, The time-domain reference signal is in the first... The complex conjugate of each sampling point.

4. The apparatus according to claim 3, characterized in that, The determining module is also configured to calculate a sliding correlation function based on the time-domain received signal and the time-domain reference signal; Determine the sliding offset corresponding to the maximum value of the square of the sliding correlation function, and determine the time-domain position corresponding to the sliding offset as the target time-domain sampling position; the sliding correlation function is: ; in, The length of the pre-set capture window, For the time-domain received signal in the first... The value of each sampling point The length of the cyclic prefix. This is the sliding offset. For the sliding offset The relevant values ​​were calculated below.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 2.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 2.

Images