A time delay and frequency offset estimation method, device, apparatus and storage medium

Abstract

The application discloses a time delay and frequency offset estimation method, device, equipment and storage medium. The method comprises the following steps: acquiring a first preamble signal and a second preamble signal sent by a user equipment at a first random access occasion and a second random access occasion, the two occasions are adjacent in the time domain or the frequency domain, and the two signals are respectively generated based on a first root sequence and a second root sequence whose sum of indexes is equal to a preset ZC sequence length; performing time domain correlation detection on the two signals respectively to obtain first and second correlation peak positions; dividing the sum of the two correlation peak positions by a first calculation parameter to obtain a time delay; dividing the difference by a second calculation parameter to obtain an offset, and determining a frequency offset according to the offset. According to the scheme, the complementary root sequence double-occasion transmission and algebraic decoupling are adopted, the time delay and frequency offset estimation can be obtained simultaneously without prior frequency offset estimation or multiple hypothesis search, and the time delay estimation precision in the large frequency offset scene is improved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a delay and frequency offset estimation method, apparatus, device and storage medium. Background Technology

[0002] PRACH (Physical Random Access Channel) detection is a crucial step in establishing uplink synchronization between the UE (User Equipment) and the base station in 5G mobile communication systems. The PRACH preamble is generated based on the ZC (Zadoff-Chu) sequence, which possesses excellent constant envelope and zero autocorrelation characteristics, facilitating accurate delay estimation in multipath environments. PRACH receivers typically employ time-domain sliding correlation or frequency-domain matched filtering to detect the preamble. Under ideal, frequency-off-free conditions, the correlation result between the received signal and the local sequence will form a sharp peak at the correct delay. However, when CFO (Carrier Frequency Offset) exists, the correlation peak experiences positional shift and energy diffusion; the larger the frequency offset and the smaller the PRACH subcarrier spacing, the more pronounced the offset.

[0003] In high-speed mobile scenarios (such as high-speed rail and drones) and NTN (Non-Terrestrial Network) scenarios, the Doppler frequency shift can reach tens of kHz. Existing PRACH detection schemes have the following main problems when dealing with large frequency offsets: First, the frequency offset pre-compensation accuracy is insufficient. In NTN scenarios, there may be deviations between satellite ephemeris and actual satellite operating status, and GNSS (Global Navigation Satellite System) positioning on the terminal side may also be interrupted, resulting in large errors in frequency offset estimation based on ephemeris and terminal positioning, making it difficult to guarantee pre-compensation accuracy. Second, multi-hypothesis detection is highly complex. Within a large frequency offset range, the receiver needs to search for multiple frequency offset hypotheses and use parallel correlation operations with multiple different frequency offset compensation values, resulting in high computational resource consumption. Third, the three-peak detection algorithm has limitations. In addition to the main peak, correlation processing at high frequencies will generate two side peaks. Although the frequency offset can be derived from the position of the three peaks and the leading root sequence factor, this method requires a sufficiently high SNR (Signal-to-Noise Ratio) to detect the low-energy side peaks, and different root sequence factors require different derivation methods, resulting in high complexity. Therefore, in scenarios with large frequency offsets, such as high-speed mobile and non-terrestrial networks, how to obtain frequency offset estimates while suppressing the interference of frequency offset on time delay estimation without relying on prior frequency offset estimates and avoiding highly complex multi-hypothesis searches is a technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a delay and frequency offset estimation method, apparatus, device, and storage medium to address the technical problem in related technologies where frequency offset and delay are coupled in scenarios with large frequency offsets, such as high-speed mobile and non-terrestrial networks. This makes it impossible to suppress the interference of frequency offset on delay estimation and simultaneously obtain frequency offset estimation without relying on prior frequency offset estimation or avoiding highly complex multi-hypothesis searches. This application achieves algebraic decoupling of delay and frequency offset by transmitting preamble signals generated based on complementary root sequences at two random access times. Time-domain correlation detection is performed on the two preamble signals to obtain the positions of two correlation peaks. The summation and difference of the two correlation peak positions decouple delay and frequency offset, achieving algebraic decoupling. Accurate delay and frequency offset estimations can be obtained simultaneously without prior frequency offset estimation or multi-hypothesis searches, thus improving the accuracy of delay estimation in high-speed mobile and non-terrestrial network scenarios.

[0005] In a first aspect, embodiments of this application provide a delay and frequency offset estimation method, comprising: The first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time are respectively acquired. The first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain. The first preamble signal and the second preamble signal are generated based on the preset first root sequence and the second root sequence, respectively. The sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence. Time-domain correlation detection is performed on the first preamble signal and the second preamble signal respectively to obtain the first correlation peak position and the second correlation peak position. The first correlation peak position is used to represent the sum of the time delay to be estimated and the offset caused by the frequency offset to be estimated, and the second correlation peak position is used to represent the difference between the time delay to be estimated and the offset. The positions of the first and second correlation peaks are summed to obtain a first value. The first value is then divided by a preset first calculation parameter to obtain the time delay. Subtract the position of the second correlation peak from the position of the first correlation peak to obtain the second value. Divide the second value by the preset second calculation parameter to obtain the offset. Determine the frequency offset based on the offset.

[0006] Optionally, time-domain correlation detection is performed on the first preamble signal and the second preamble signal respectively to obtain the positions of the first correlation peak and the second correlation peak, including: The first preamble signal is subjected to time-domain correlation detection using the first local sequence corresponding to the first root sequence to obtain the position of the first correlation peak. The second preamble signal is subjected to temporal correlation detection using the second local sequence corresponding to the second root sequence to obtain the position of the second correlation peak. Among them, the first local sequence and the second local sequence are complex conjugates of each other.

[0007] Optionally, before acquiring the first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time, the method further includes: Send a first signaling message to the user equipment, the first signaling message being used to indicate the multiplexing method used for the first random access opportunity and the second random access opportunity, wherein the multiplexing method includes time division multiplexing or frequency division multiplexing; A second signaling message is sent to the user equipment, which instructs the user equipment to use the random access resources to send the first preamble signal and the second preamble signal.

[0008] Optionally, the generation process of the first preamble signal and the second preamble signal includes: Generate a first preamble sequence based on the first root sequence, and generate a second preamble sequence based on the second root sequence; The first preamble sequence is mapped to the first subcarrier set to obtain the first frequency domain signal, and the second preamble sequence is mapped to the second subcarrier set to obtain the second frequency domain signal. Perform an inverse Fourier transform on the first frequency domain signal to obtain a first time domain signal, and perform an inverse Fourier transform on the second frequency domain signal to obtain a second time domain signal; A cyclic prefix is ​​added to the first time-domain signal to obtain the first preamble signal, and a cyclic prefix is ​​added to the second time-domain signal to obtain the second preamble signal.

[0009] Optionally, the frequency offset can be determined based on the offset, including: The conversion factor is determined based on the ratio of the index of the first sequence to the length of the ZC sequence; Multiply the offset by the conversion factor to obtain the third value; Multiply the third value by the preset subcarrier interval to obtain the frequency offset.

[0010] Optionally, the positions of the first and second correlation peaks are summed to obtain a first value, including: Obtain the preset symmetry constraints; When the positions of the first and second correlation peaks satisfy the symmetry constraint, the positions of the first and second correlation peaks are summed to obtain the first value.

[0011] Optionally, the second value is obtained by subtracting the position of the second correlation peak from the position of the first correlation peak, including: When the positions of the first and second correlation peaks satisfy the symmetry constraint, the second correlation peak position is subtracted from the first correlation peak position to obtain the second value.

[0012] In a second aspect, embodiments of this application provide a delay and frequency offset estimation apparatus, comprising: The acquisition module is used to acquire the first preamble signal and the second preamble signal sent by the user equipment at a preset first random access time and a preset second random access time, wherein the first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain, and the first preamble signal and the second preamble signal are generated based on a preset first root sequence and a preset second root sequence, respectively, and the sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence. The detection module is used to perform time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the first correlation peak position and the second correlation peak position. The first correlation peak position is used to represent the sum of the time delay to be estimated and the offset caused by the frequency offset to be estimated, and the second correlation peak position is used to represent the difference between the time delay to be estimated and the offset. The calculation module is used to sum the positions of the first and second correlation peaks to obtain a first value; The calculation module is also used to divide the first value by a preset first calculation parameter to obtain the time delay; The calculation module is also used to subtract the position of the second correlation peak from the position of the first correlation peak to obtain the second value; The calculation module is also used to divide the second value by a preset second calculation parameter to obtain the offset; The determination module is used to determine the frequency offset based on the offset.

[0013] In a third aspect, embodiments of this application provide an electronic device, including: a memory and one or more processors; Memory, used to store one or more programs; When one or more programs are executed by one or more processors, the one or more processors implement the delay and frequency offset estimation method as described in the first aspect.

[0014] In a fourth aspect, embodiments of this application provide a storage medium for storing computer-executable instructions, which, when executed by a computer processor, are used to perform the delay and frequency offset estimation method as described in the first aspect.

[0015] In this embodiment, by transmitting a first preamble signal and a second preamble signal generated based on complementary root sequences at the first random access time and the second random access time, respectively, and performing time-domain correlation detection on the two preamble signals to obtain the positions of the first correlation peak and the second correlation peak, and summing and subtracting the two correlation peak positions, algebraic decoupling of time delay and frequency offset is achieved. This solves the problem in the prior art where frequency offset and time delay are coupled in high-frequency offset scenarios such as high-speed mobile and non-terrestrial networks, and it is difficult to obtain time delay estimation and frequency offset estimation simultaneously without relying on prior frequency offset estimation and avoiding high-complexity multi-hypothesis search. It can suppress the interference of frequency offset on time delay estimation and obtain accurate time delay estimation and frequency offset estimation at the same time, thereby improving the time delay estimation accuracy in high-speed mobile and non-terrestrial network scenarios. Attached Figure Description

[0016] Figure 1 This is a flowchart of a time delay and frequency offset estimation method provided in an embodiment of this application; Figure 2 This is a flowchart illustrating the generation process of a first preamble signal and a second preamble signal, as provided in an embodiment of this application. Figure 3 This is a flowchart illustrating a method for determining frequency offset based on offset provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a time delay and frequency offset estimation device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but additional steps not included in the drawings may also be present. The above processes can correspond to methods, functions, procedures, subroutines, subroutines, etc.

[0018] Figure 1 This is a flowchart of a time delay and frequency offset estimation method provided in an embodiment of this application, referred to... Figure 1The time delay and frequency offset estimation method includes: Step S101: Obtain the first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time, respectively. The first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain. The first preamble signal and the second preamble signal are generated based on the preset first root sequence and the second root sequence, respectively. The sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence.

[0019] The user equipment (UE) can be a terminal device that accesses a wireless communication network and communicates wirelessly with a base station, including handheld terminals, IoT terminals, vehicle-mounted terminals, UAV communication modules, and other communication devices capable of transmitting physical random access channels (PRAMs). The random access timing can be a time-frequency resource location defined in the PRAM resource configuration for transmitting a PRAM preamble. The preamble signal can be a time-domain signal transmitted by the UE at the random access timing after mapping a preamble sequence generated based on a ZC sequence to a subcarrier, performing an inverse Fourier transform, and adding a cyclic prefix. The root sequence can be a reference sequence identified by a root sequence index used to generate the ZC sequence. The first preamble signal and the second preamble signal are generated based on preset first and second root sequences, respectively. The sum of the indices of the first and second root sequences equals the length of the preset ZC sequence. The first and second root sequences are complementary root sequences, and the two ZC sequences generated from the complementary root sequences are complex conjugates.

[0020] In one embodiment, the method for obtaining the first preamble signal and the second preamble signal transmitted by the user equipment at a preset first random access time and a preset second random access time can be as follows: the base station receives the first radio signal and the second radio signal transmitted by the user equipment at the preset first random access time and the preset second random access time, respectively, and extracts the first preamble signal and the second preamble signal from the received first radio signal and the preset second radio signal, respectively. Wherein, when time-division multiplexing is used between the first random access time and the second random access time, the first random access time and the second random access time are adjacent in the time domain, and the time interval between them is controlled within the channel correlation time range; when frequency-division multiplexing is used between the first random access time and the second random access time, they are adjacent in the frequency domain. After receiving the signals, the base station can perform time-frequency synchronization and cyclic prefix removal processing on the two received signals respectively to obtain two received signals for subsequent time-domain correlation detection.

[0021] For example, the preset ZC sequence length is 139, the index of the first root sequence is 10, and the index of the second root sequence is 129. Their sum equals 139, satisfying the complementary root sequence relationship. The user equipment generates a first preamble signal based on the root sequence corresponding to index 10 and a second preamble signal based on the root sequence corresponding to index 129, and transmits them at adjacent time-domain random access times, respectively. The base station receives a first radio signal and a second radio signal carrying the first and second preamble signals respectively through a receiver, and extracts the first and second preamble signals from them. After reception, the base station performs time-frequency synchronization and cyclic prefix removal processing on the two received signals to obtain two received signals for subsequent time-domain correlation detection.

[0022] Therefore, by transmitting the first preamble signal and the second preamble signal, generated based on the first root sequence and the second root sequence respectively, at the first and second random access times, and with the first and second root sequences being complementary root sequences, the ZC sequences corresponding to the two preamble signals are complex conjugates, having opposite instantaneous frequency change directions. In the presence of carrier frequency offset, the receiver subsequently performs time-domain correlation detection on these two preamble signals. The frequency offset introduces offsets in opposite directions and equal in magnitude to the positions of the first and second correlation peaks, thus forming a correlation peak offset characteristic symmetrical about the true time delay. Based on this symmetry, the frequency offset component and the time delay component can be eliminated respectively by summing and subtracting the positions of the two correlation peaks, achieving algebraic decoupling of time delay and frequency offset. Therefore, the above-mentioned dual-timing complementary preamble signal transmission method provides a signal foundation for obtaining time delay and frequency offset estimates simultaneously without prior frequency offset estimation or multiple hypothesis searches.

[0023] Step S102: Perform time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the positions of the first correlation peak and the second correlation peak.

[0024] The correlation peak position can be the time-domain position in the correlation output sequence where the receiver obtains the maximum value or meets the peak detection condition after performing a time-domain correlation operation between the received preamble signal and the local sequence. It is usually represented by a sampling point number or a time offset. The receiver is the receiving and processing unit in the base station used to receive and process the PRACH preamble signal.

[0025] In one embodiment, the time-domain correlation detection method can be as follows: The received first and second preamble signals are respectively subjected to sliding correlation operations in the time domain with their corresponding local sequences, and the time-domain position corresponding to the maximum value of the correlation output is determined as the corresponding correlation peak position. The local sequence can be a reference sequence pre-stored locally by the receiver, corresponding to the root sequence at the transmitter. The first correlation peak position represents the sum of the estimated time delay and the offset caused by the estimated frequency offset, and the second correlation peak position represents the difference between the estimated time delay and the offset.

[0026] In one embodiment, the process of obtaining the positions of the first and second correlation peaks can be as follows: the receiver performs time-domain sliding correlation on the first preamble signal using a first local sequence corresponding to the first root sequence to obtain the position of the first correlation peak; and performs time-domain sliding correlation on the second preamble signal using a second local sequence corresponding to the second root sequence to obtain the position of the second correlation peak. Since the first and second root sequences are complementary root sequences, and the preamble sequences generated by them are complex conjugates, and their instantaneous frequency signs are opposite, when a frequency offset exists, the offset introduced by the frequency offset to the two correlation peaks is opposite in direction and equal in magnitude. The position of the first correlation peak is equal to the time delay to be estimated plus the offset caused by the frequency offset, and the position of the second correlation peak is equal to the time delay to be estimated minus the offset caused by the frequency offset.

[0027] For example, suppose the true time delay to be estimated is such that the correlation output reaches its maximum value at the 40th sampling point, and the offset caused by the frequency offset corresponds to 5 sampling points. Then the position of the first correlation peak obtained by the first local sequence detection is the 45th sampling point, and the position of the second correlation peak obtained by the second local sequence detection is the 35th sampling point. The two are symmetrical about the true time delay position.

[0028] Therefore, the receiver performs time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the positions of the first and second correlation peaks. Since the first preamble signal is generated based on the first root sequence, and the second preamble signal is generated based on the second root sequence, which is complementary to the first root sequence, in the presence of carrier frequency offset, the offset introduced by the frequency offset to the two correlation detections has opposite directions and equal magnitudes. Therefore, the first correlation peak position carries information about the sum of the estimated delay and the offset caused by the frequency offset, while the second correlation peak position carries information about the difference between the estimated delay and the offset caused by the frequency offset. The two correlation peak positions together constitute a binary linear relationship about the estimated delay and the frequency offset. Subsequently, by performing summation and difference operations on the first and second correlation peak positions respectively, the estimated delay and the frequency offset can be separated, thus providing a data basis for the algebraic decoupling of delay and frequency offset.

[0029] Step S103: Sum the positions of the first and second correlation peaks to obtain a first value, and divide the first value by a preset first calculation parameter to obtain the time delay.

[0030] The first calculation parameter can be a preset parameter used to normalize the summation result.

[0031] In one embodiment, the time delay is obtained by summing the positions of the first and second correlation peaks to obtain a first value, and then dividing the first value by a preset first calculation parameter. This can be achieved by: the receiver adding the positions of the first and second correlation peaks to obtain the first value; and then dividing the first value by the first calculation parameter, where the first calculation parameter can be preset to 2. Since the first correlation peak position equals the sum of the time delay and the offset, and the second correlation peak position equals the difference between the time delay and the offset, adding the first and second correlation peak positions causes the offset components to cancel each other out. Therefore, the first value equals twice the time delay, and dividing the first value by 2 yields the time delay.

[0032] For example, the first correlation peak is located at the 45th sampling point, and the second correlation peak is located at the 35th sampling point. The sum of the two is 80. Dividing 80 by the first calculation parameter 2, the time delay is obtained at the 40th sampling point, which is consistent with the actual time delay.

[0033] Therefore, by summing the operations, the offset component introduced by frequency offset is completely eliminated, and the true time delay that is not affected by frequency offset is obtained, thus improving the time delay estimation accuracy in frequency offset scenarios.

[0034] Step S104: Subtract the position of the second correlation peak from the position of the first correlation peak to obtain the second value. Divide the second value by the preset second calculation parameter to obtain the offset. Determine the frequency offset based on the offset.

[0035] The second calculation parameter can be a preset parameter used to normalize the difference result; the offset can be the position offset of the time-domain correlation peak caused by the frequency offset; the frequency offset can be the carrier frequency offset, that is, the frequency deviation between the received signal carrier and the receiver local oscillation. In high-speed mobile and non-terrestrial network scenarios, the frequency offset is mainly composed of Doppler frequency shift.

[0036] In one embodiment, the method of subtracting the second correlation peak position from the first correlation peak position to obtain a second value, and then dividing the second value by a preset second calculation parameter to obtain the offset, can be as follows: the receiver subtracts the second correlation peak position from the first correlation peak position to obtain a second value; the receiver divides the second value by the second calculation parameter to obtain the offset, wherein the second calculation parameter can be preset to 2. Since the first correlation peak position is equal to the sum of the delay and the offset, and the second correlation peak position is equal to the difference between the delay and the offset, after subtracting the second correlation peak position from the first correlation peak position, the delay components cancel each other out, and the second value is equal to twice the offset. Therefore, dividing the second value by 2 yields the offset.

[0037] For example, the first correlation peak is located at the 45th sampling point, and the second correlation peak is located at the 35th sampling point. The difference between the two is 10. Dividing 10 by the second calculation parameter 2, we get an offset of 5 sampling points. Then, based on the correspondence between the offset and the frequency offset, the frequency offset is calculated from the offset of 5 sampling points.

[0038] In this embodiment, since the position of the first correlation peak is the sum of the estimated delay and the offset caused by the frequency offset, and the position of the second correlation peak is the difference between the estimated delay and the offset caused by the frequency offset, subtracting the position of the second correlation peak from the position of the first correlation peak results in the estimated delay components canceling each other out, yielding a second value that is twice the offset. Dividing the second value by the preset second calculation parameter yields the offset caused by the frequency offset. This offset is determined only by the carrier frequency offset and is independent of the actual delay, thus achieving independent extraction of frequency offset information. Subsequently, based on the conversion relationship between the offset and the frequency offset, combined with the index of the first root sequence, the length of the ZC sequence, and the subcarrier spacing of the physical random access channel, the frequency offset can be determined. Through the above summation and difference operations, this embodiment algebraically decouples the mutually coupled delay and frequency offset, eliminating the need for pre-compromising frequency offset compensation and parallel searching for multiple frequency offset assumptions, thereby simultaneously obtaining accurate delay and frequency offset estimates. This reduces receiver complexity and improves the timing advance estimation accuracy and frequency offset estimation reliability in scenarios with large frequency offsets, such as high-speed mobile and non-terrestrial networks.

[0039] In one embodiment, performing time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the positions of the first correlation peak and the second correlation peak includes: performing time-domain correlation detection on the first preamble signal using a first local sequence corresponding to the first root sequence to obtain the position of the first correlation peak; and performing time-domain correlation detection on the second preamble signal using a second local sequence corresponding to the second root sequence to obtain the position of the second correlation peak; wherein the first local sequence and the second local sequence are complex conjugates of each other.

[0040] Complex conjugation refers to the fact that each element of one sequence, when conjugated, is equal to the corresponding element of another sequence. Since the first root sequence and the second root sequence are complementary root sequences, the sum of their indices equals the length of the ZC sequence. The two ZC sequences generated from the complementary root sequences are complex conjugated. Therefore, the first local sequence and the second local sequence stored locally by the receiver are also complex conjugated.

[0041] In one embodiment, the process of generating the first local sequence may be as follows: generating a first ZC sequence based on a first root sequence, mapping the first ZC sequence to a preset subcarrier, performing an inverse Fourier transform on the mapped frequency domain signal to obtain a first time domain reference sequence, and using the first time domain reference sequence as the first local sequence.

[0042] In one embodiment, the process of generating the second local sequence may be as follows: generating a second ZC sequence based on the second root sequence, mapping the second ZC sequence to a preset subcarrier, performing an inverse Fourier transform on the mapped frequency domain signal to obtain a second time domain reference sequence, and using the second time domain reference sequence as the second local sequence.

[0043] For example, when the ZC sequence length is 139, the index of the first root sequence is 10, and the index of the second root sequence is 129, the ZC sequence generated by the root sequence corresponding to index 10 and the ZC sequence generated by the root sequence corresponding to index 129 are complex conjugates of each other. The receiver uses these two sequences as the first local sequence and the second local sequence, respectively, to perform time-domain correlation detection on the first preamble signal and the second preamble signal.

[0044] Therefore, since the first local sequence and the second local sequence are complex conjugates, in the presence of carrier frequency offset, the positions of the first correlation peak detected based on the first local sequence and the second correlation peak detected based on the second local sequence will have offsets of opposite directions and equal magnitudes. Specifically, the frequency offset causes the first correlation peak position to shift in one direction relative to the true time delay, while the second correlation peak position shifts in the opposite direction relative to the true time delay, and the absolute values ​​of their offsets are the same. Thus, by summing the first and second correlation peak positions, the offset components introduced by the frequency offset can be canceled out, thereby obtaining the true time delay unaffected by the frequency offset; by subtracting the first and second correlation peak positions, the true time delay components can be canceled out, thereby independently obtaining the offset introduced by the frequency offset, and determining the frequency offset accordingly. Therefore, using the complex conjugate first and second local sequences for correlation detection provides a symmetry basis for decoupling time delay and frequency offset through algebraic operations, avoiding reliance on prior frequency offset estimation or multiple hypothesis searches.

[0045] In one embodiment, before acquiring the first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time, the method further includes: sending a first signaling message to the user equipment, the first signaling message being used to indicate the multiplexing method adopted by the first random access time and the second random access time, wherein the multiplexing method includes time division multiplexing or frequency division multiplexing; and sending a second signaling message to the user equipment, the second signaling message being used to indicate the random access resources used by the user equipment to send the first preamble signal and the second preamble signal.

[0046] Both the first and second signaling can be radio resource control (RRC) signaling. The first signaling may contain information elements or fields, with different values ​​of these elements or fields indicating either time-division multiplexing (TDM) or frequency-division multiplexing (FDM) modes, respectively. The second signaling may include physical random access channel configuration index parameters and / or frequency domain multiplexing parameters. The physical random access channel configuration index parameters are used to determine the time-domain resource location within the radio frame where the random access opportunity occurs, and the frequency domain multiplexing parameters are used to determine the frequency-domain resource location of the random access opportunity.

[0047] In one embodiment, the method for sending the first signaling to the user equipment may be as follows: the base station generates the first signaling, which includes information elements or fields for indicating the multiplexing mode, and different values ​​of the information elements or fields correspond to time division multiplexing or frequency division multiplexing, respectively; the base station sends the first signaling to the user equipment via radio resource control signaling. After receiving the first signaling, the user equipment determines whether time division multiplexing or frequency division multiplexing is used between the first random access opportunity and the second random access opportunity based on the value of the information elements or fields.

[0048] In one embodiment, the second signaling can be sent to the user equipment as follows: the base station generates the second signaling, which includes physical random access channel configuration index parameters and / or frequency domain multiplexing parameters; the base station sends the second signaling to the user equipment via radio resource control signaling. After receiving the second signaling, the user equipment determines the time-domain resource location within the radio frame where the random access opportunity occurs based on the physical random access channel configuration index parameters, and determines the frequency-domain resource location of the random access opportunity based on the frequency domain multiplexing parameters.

[0049] In time-division multiplexing, the base station can configure the physical random access channel through the configuration index parameter so that the radio frame containing the random access opportunity contains multiple random access opportunities; the user equipment selects the random access opportunity with an even index from the multiple random access opportunities as the first random access opportunity, and selects the next random access opportunity that is immediately adjacent to the first random access opportunity in the time domain as the second random access opportunity.

[0050] In frequency division multiplexing mode, the base station can configure the number of frequency domain reuse resources to be no less than 2 through frequency domain reuse parameters; the user equipment selects the random access opportunity with an even frequency index as the first random access opportunity, and selects the next random access opportunity in the frequency domain that is immediately adjacent to the first random access opportunity as the second random access opportunity.

[0051] For example, in time-division multiplexing, the base station configures eight random access opportunities within a radio frame, with random access opportunity indices ranging from 0 to 7. The user equipment selects the random access opportunity with index 0 as the first random access opportunity and selects the random access opportunity with index 1 that is immediately adjacent to the first random access opportunity in the time domain as the second random access opportunity. In frequency-division multiplexing, the base station configures two frequency domain reuse resources, with frequency indices of 0 and 1. The user equipment selects the random access opportunity with frequency index 0 as the first random access opportunity and selects the random access opportunity with frequency index 1 that is immediately adjacent to the first random access opportunity in the frequency domain as the second random access opportunity.

[0052] Therefore, by indicating the multiplexing method used for the first and second random access opportunities through the first signaling and by indicating the random access resources used by the user equipment to send the first and second preamble signals through the second signaling, the base station can flexibly configure dual-opportunity PRACH transmission between time-division multiplexing and frequency-division multiplexing modes according to actual scenario requirements. In time-division multiplexing mode, the first and second random access opportunities occupy the same frequency domain resources and are adjacent in the time domain, which is beneficial for maintaining spectral efficiency in scenarios with limited bandwidth resources, while avoiding the transmit power dispersion problem caused by frequency-division multiplexing. In frequency-division multiplexing mode, the first and second random access opportunities occupy adjacent frequency domain resources and are transmitted in parallel in the time domain, which is beneficial for shortening random access latency and is suitable for scenarios with high access latency requirements. At the same time, by configuring dual-opportunity PRACH resources independently from traditional single-opportunity PRACH resources, it can be compatible with terminals with different capabilities and avoid affecting the traditional terminal access process. Therefore, the above signaling configuration method enables the base station to adaptively select the transmission mode based on factors such as channel environment, mobile speed, bandwidth resources and terminal capabilities, so as to ensure the performance of frequency offset estimation and delay estimation while taking into account access delay and spectrum efficiency.

[0053] Figure 2 This is a flowchart illustrating the generation process of a first preamble signal and a second preamble signal according to an embodiment of this application. (Refer to...) Figure 2 The generation process of the first preamble signal and the second preamble signal includes: Step S201: Generate a first preamble sequence based on the first root sequence, and generate a second preamble sequence based on the second root sequence.

[0054] The preamble sequence can be a sequence generated from the root sequence through cyclic shifting and other processing, used to map to frequency domain subcarriers.

[0055] In one embodiment, the method for generating a first preamble sequence based on a first root sequence and a second preamble sequence based on a second root sequence can be as follows: the user equipment generates a first ZC sequence based on the first root sequence and a second ZC sequence based on the second root sequence; then, the user equipment performs cyclic shifting on the first ZC sequence and the second ZC sequence according to a preset cyclic shifting rule to obtain the first preamble sequence and the second preamble sequence. The first root sequence and the second root sequence are complementary root sequences, and the sum of their indices equals the length of the ZC sequence; therefore, the first ZC sequence and the second ZC sequence are complex conjugates. When the cyclic shift amount is the same, the first preamble sequence and the second preamble sequence are also complex conjugates.

[0056] For example, when the ZC sequence length is 139, the index of the first root sequence is 10, and the index of the second root sequence is 129, the user equipment generates the first ZC sequence and the second ZC sequence based on the root sequence corresponding to index 10 and the root sequence corresponding to index 129, respectively. The two are complex conjugates of each other. Then, the same cyclic shift is applied to the first ZC sequence and the second ZC sequence, and the resulting first preamble sequence and the second preamble sequence are also complex conjugates of each other.

[0057] Therefore, the first preamble sequence generated from the first root sequence and the second preamble sequence generated from the second root sequence are complex conjugates of each other, and they have opposite instantaneous frequency change directions. When there is a carrier frequency offset, the offset introduced by the frequency offset to the two correlation detections has opposite directions and equal magnitudes, thus providing a sequence-level guarantee for subsequent decoupling of time delay and frequency offset by utilizing the symmetry of the correlation peak offset.

[0058] Step S202: Map the first preamble sequence to the first subcarrier set to obtain the first frequency domain signal, and map the second preamble sequence to the second subcarrier set to obtain the second frequency domain signal.

[0059] The subcarrier set can be a set of orthogonal subcarrier resources in the frequency domain. The first subcarrier set and the second subcarrier set are predetermined according to the frequency domain resource configuration of the first random access opportunity and the second random access opportunity, respectively, and correspond to the frequency domain resources of the first random access opportunity and the second random access opportunity, respectively. In time-division multiplexing, the first subcarrier set and the second subcarrier set can be the same; in frequency-division multiplexing, the first subcarrier set and the second subcarrier set can be different.

[0060] In one embodiment, mapping a first preamble sequence to a first subcarrier set to obtain a first frequency domain signal, and mapping a second preamble sequence to a second subcarrier set to obtain a second frequency domain signal, can be achieved by the user equipment mapping each element of the first preamble sequence sequentially to each subcarrier included in the first subcarrier set according to a preset subcarrier mapping order to obtain the first frequency domain signal; and mapping each element of the second preamble sequence sequentially to each subcarrier included in the second subcarrier set according to a preset subcarrier mapping order to obtain the second frequency domain signal.

[0061] Therefore, the first preamble sequence and the second preamble sequence are respectively placed on the frequency-domain subcarrier resources corresponding to their respective random access opportunities, forming two frequency-domain signals. In time-division multiplexing, the two frequency-domain signals correspond to the same set of subcarriers; in frequency-division multiplexing, the two frequency-domain signals correspond to adjacent sets of subcarriers and maintain frequency orthogonality. These two frequency-domain signals serve as the input to the subsequent inverse Fourier transform, providing the basis for generating the time-domain transmit signal.

[0062] Step S203: Perform an inverse Fourier transform on the first frequency domain signal to obtain a first time domain signal, and perform an inverse Fourier transform on the second frequency domain signal to obtain a second time domain signal.

[0063] In one embodiment, performing an inverse Fourier transform on the first frequency domain signal to obtain a first time domain signal, and performing an inverse Fourier transform on the second frequency domain signal to obtain a second time domain signal, can be achieved by the user equipment performing an inverse fast Fourier transform on the first frequency domain signal to obtain a first time domain signal; and the user equipment performing an inverse fast Fourier transform on the second frequency domain signal to obtain a second time domain signal. The inverse Fourier transform is used to convert the frequency domain signal to the time domain so that a cyclic prefix can be added subsequently and the signal can be transmitted at the corresponding random access timing. In time-division multiplexing, the user equipment can perform inverse fast Fourier transforms on the first and second frequency domain signals respectively to obtain two time domain signals corresponding to the first and second random access timings, respectively. In frequency-division multiplexing, the user equipment can combine the first and second frequency domain signals into a single frequency domain signal and perform an inverse fast Fourier transform on the combined frequency domain signal to obtain a time domain signal that simultaneously contains both a first preamble signal and a second preamble signal.

[0064] Therefore, through inverse Fourier transform processing, the two frequency domain signals are converted to the time domain to obtain the time domain signal used for subsequent addition of the cyclic prefix; wherein, in the time division multiplexing mode, two time domain signals corresponding to the first random access timing and the second random access timing are obtained respectively; in the frequency division multiplexing mode, a time domain signal containing both the first preamble signal and the second preamble signal is obtained.

[0065] Step S204: Add a cyclic prefix to the first time domain signal to obtain the first preamble signal, and add a cyclic prefix to the second time domain signal to obtain the second preamble signal.

[0066] The cyclic prefix can be a guard interval added before the time-domain signal to suppress inter-symbol interference caused by multipath propagation and reduce sensitivity to timing synchronization errors.

[0067] In one embodiment, adding a cyclic prefix to a first time-domain signal to obtain a first preamble signal and adding a cyclic prefix to a second time-domain signal to obtain a second preamble signal can be achieved as follows: In time-division multiplexing, the user equipment adds cyclic prefixes to both the first and second time-domain signals to obtain the first and second preamble signals, respectively; in frequency-division multiplexing, the user equipment adds a cyclic prefix to the combined time-domain signal to obtain a time-domain signal containing both the first and second preamble signals. Specifically, adding the cyclic prefix can be achieved by copying a segment of data from the end of the time-domain signal to the beginning of the time-domain signal as a guard interval.

[0068] Thus, the user equipment completes the generation and transmission of the first and second preamble signals. The first preamble signal is carried during the first random access opportunity, and the second preamble signal is carried during the second random access opportunity. Both are generated based on complementary root sequences and are transmitted in pairs in the time or frequency domain. The base station can receive and extract these two preamble signals at their respective random access opportunities, providing signal input for subsequent time-domain correlation detection using mutually conjugate local sequences, as well as for summation and difference operations based on the correlation peak positions.

[0069] Figure 3 This is a flowchart illustrating a method for determining frequency offset based on offset provided in an embodiment of this application. (Refer to...) Figure 3 Determining the frequency offset based on the offset includes: Step S301: Determine the conversion factor based on the ratio of the index of the first root sequence to the length of the ZC sequence.

[0070] The conversion factor can be a factor used to convert the time-domain offset into a multiple of the frequency offset relative to the subcarrier spacing.

[0071] In one embodiment, the conversion factor can be determined based on the ratio of the index of the first sequence to the length of the ZC sequence. The receiver determines the conversion factor based on the relationship between the time-domain correlation peak offset caused by the frequency offset and the frequency offset itself. Let the frequency offset be... The PRACH subcarrier spacing is The length of the ZC sequence is The index of the first sequence is u, and the correlation peak shift caused by the frequency offset is... Then the above physical quantities satisfy the following:

[0072] The shift in the position of the time-domain correlation peak caused by frequency offset can be expressed in units of the number of sampling points.

[0073] From the above formula, we can know the frequency offset. With correlation peak shift The relationship is:

[0074] Therefore, the receiver can use the index u of the first root sequence and the length of the ZC sequence. The ratio is determined as a conversion factor, which is used to convert the time-domain offset into the ratio of frequency offset to subcarrier spacing.

[0075] For example, when the ZC sequence length is 139 and the index of the first sequence is 10, the conversion factor is equal to 10 / 139, which is approximately 0.072. If the preset physical random access channel subcarrier spacing is 15 kHz, then the frequency offset corresponding to the offset of each sampling point is approximately 0.072 × 15 kHz = 1.08 kHz, meaning that for every additional sampling point of offset, the frequency offset increases by approximately 1.08 kHz. Thus, in subsequent steps, the receiver only needs to multiply the detected offset by this conversion factor and then by the subcarrier spacing to directly obtain the frequency offset estimate.

[0076] Therefore, by determining the conversion factor based on the ratio of the index of the first root sequence to the length of the ZC sequence, the conversion relationship between the time-domain offset caused by the frequency offset and the frequency offset is transformed into a constant coefficient related to the root sequence and the sequence length. This provides a clear and calculable parameter for the subsequent conversion of the offset into the frequency offset without the need for iterative search or table lookup operations.

[0077] Step S302: Multiply the offset by the conversion factor to obtain the third value.

[0078] In one embodiment, multiplying the offset by a conversion factor to obtain the third value can be done by the receiver multiplying the offset obtained in step S104 by the conversion factor to obtain the third value, since the offset... Conversion factor With frequency offset PRACH subcarrier spacing The following conditions must be met:

[0079] Therefore, the third value is the ratio of frequency offset to subcarrier spacing. It is used to characterize the frequency offset relative to the subcarrier spacing and is a dimensionless quantity.

[0080] For example, continuing from the previous example, the offset is 5 sampling points, the conversion factor is approximately 0.072, and multiplying the two gives a third value of approximately 0.36, indicating that the frequency offset is approximately 0.36 times the subcarrier spacing. If the preset physical random access channel subcarrier spacing is 15 kHz, then the corresponding estimated frequency offset is approximately 0.36 × 15 kHz = 5.4 kHz.

[0081] Therefore, by multiplying the time-domain offset by a conversion factor, the offset, which was originally measured in the number of sampling points, is converted into a relative frequency offset corresponding to the subcarrier spacing, providing an intermediate result for directly multiplying by the subcarrier spacing to obtain the frequency offset value.

[0082] Step S303: Multiply the third value by the preset subcarrier interval to obtain the frequency offset.

[0083] The preset subcarrier spacing can be the subcarrier spacing used by the physical random access channel, which is determined by the PRACH preamble format. For example, the subcarrier spacing corresponding to the long sequence format (ZC sequence length of 839) can be 1.25 kHz or 5 kHz, and the subcarrier spacing corresponding to the short sequence format (ZC sequence length of 139) can be 15·(2^μ) kHz, where μ∈{0,1,2,3}.

[0084] In one embodiment, the frequency offset can be obtained by multiplying the third value by a preset subcarrier spacing as follows: the receiver multiplies the third value obtained in step S302 by the preset subcarrier spacing to obtain an estimated value of the frequency offset. This is because the third value represents the ratio of the frequency offset to the subcarrier spacing. Multiply it by the subcarrier spacing After that, the frequency offset can be obtained. , thus completing the frequency offset estimation.

[0085] For example, continuing the previous example, when the ZC sequence length is 139 and the index of the first sequence is 10, the subcarrier spacing corresponding to the short sequence format can be 15 kHz. If the third value is approximately equal to 0.36, then multiplying the two yields a frequency offset estimate of approximately 0.36 × 15 kHz = 5.4 kHz. This frequency offset estimate can be directly used for frequency offset pre-compensation in subsequent uplink transmissions, such as correcting carrier frequency offset in the reception processing of the physical uplink shared channel, thereby reducing the performance loss of user equipment due to frequency offset.

[0086] Thus, by multiplying the third value by the preset subcarrier spacing, the complete conversion process from the time-domain correlation peak offset to the frequency offset is completed. The entire frequency offset estimation process only relies on algebraic operations on the positions of the two correlation peaks and constant multiplications related to the root sequence index, sequence length, and subcarrier spacing. It does not require multiple hypothesis searches or iterative estimations, and has the advantages of low computational complexity and high estimation accuracy.

[0087] In one embodiment, summing the positions of the first and second related peaks to obtain a first value includes: obtaining a preset symmetry constraint; and summing the positions of the first and second related peaks to obtain a first value when the first and second related peak positions satisfy the symmetry constraint.

[0088] Among them, the symmetry constraint condition can be used to verify whether the positions of the first correlation peak and the second correlation peak satisfy the symmetric relationship that the correlation peaks of the complementary root sequences have opposite offset directions and equal magnitudes under the influence of frequency offset.

[0089] In one embodiment, a preset symmetry constraint condition is obtained; when the first correlation peak position and the second correlation peak position satisfy the symmetry constraint condition, the first correlation peak position and the second correlation peak position are summed to obtain a first value. This can be achieved by the receiver obtaining the preset symmetry constraint condition, determining whether the first correlation peak position and the second correlation peak position satisfy the symmetry constraint condition, and if the symmetry constraint condition is satisfied, determining that the first correlation peak position and the second correlation peak position are valid peaks, and summing them to obtain a first value; if the symmetry constraint condition is not satisfied, determining that there are false peaks in the two detection results, and not performing the summation operation.

[0090] Therefore, by suppressing false peaks (abnormal peak values ​​caused by noise or interference) in single-channel detection through symmetry constraints, the probability of false alarms is reduced and the robustness of detection is enhanced.

[0091] In one embodiment, subtracting the second correlation peak position from the first correlation peak position to obtain a second value includes: when the first correlation peak position and the second correlation peak position satisfy the symmetry constraint condition, subtracting the second correlation peak position from the first correlation peak position to obtain a second value.

[0092] Therefore, the difference operation is only performed when the two related peak positions pass the symmetry check, which ensures the reliability of the offset on which the frequency offset estimation is based and further suppresses the interference of false peaks on the frequency offset estimation.

[0093] Figure 4 This is a schematic diagram of a time delay and frequency offset estimation device provided in an embodiment of this application. (Reference) Figure 4 The delay and frequency offset estimation device includes: The acquisition module 41 is used to acquire the first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time, respectively. The first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain. The first preamble signal and the second preamble signal are generated based on the preset first root sequence and the second root sequence, respectively. The sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence. The detection module 42 is used to perform time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the first correlation peak position and the second correlation peak position. The first correlation peak position is used to represent the sum of the time delay to be estimated and the offset caused by the frequency offset to be estimated, and the second correlation peak position is used to represent the difference between the time delay to be estimated and the offset. Calculation module 43 is used to sum the positions of the first correlation peak and the second correlation peak to obtain the first value; The calculation module 43 is also used to divide the first value by a preset first calculation parameter to obtain the time delay; The calculation module 43 is also used to subtract the position of the second correlation peak from the position of the first correlation peak to obtain the second value; The calculation module 43 is also used to divide the second value by a preset second calculation parameter to obtain the offset; The determination module 44 is used to determine the frequency offset based on the offset.

[0094] In one embodiment, the detection module 42 is used for: The first preamble signal is subjected to time-domain correlation detection using the first local sequence corresponding to the first root sequence to obtain the position of the first correlation peak. The second preamble signal is subjected to temporal correlation detection using the second local sequence corresponding to the second root sequence to obtain the position of the second correlation peak. Among them, the first local sequence and the second local sequence are complex conjugates of each other.

[0095] In one embodiment, the system further includes a sending module, configured to send a first signaling to the user equipment before acquiring the first preamble signal and the second preamble signal sent by the user equipment at a preset first random access time and a preset second random access time, the first signaling being used to indicate the multiplexing method used at the first random access time and the second random access time, wherein the multiplexing method includes time division multiplexing or frequency division multiplexing; and to send a second signaling to the user equipment, the second signaling being used to indicate the random access resources used by the user equipment to send the first preamble signal and the second preamble signal.

[0096] In one embodiment, a generation module is further included, for: Generate a first preamble sequence based on the first root sequence, and generate a second preamble sequence based on the second root sequence; The first preamble sequence is mapped to the first subcarrier set to obtain the first frequency domain signal, and the second preamble sequence is mapped to the second subcarrier set to obtain the second frequency domain signal. Perform an inverse Fourier transform on the first frequency domain signal to obtain a first time domain signal, and perform an inverse Fourier transform on the second frequency domain signal to obtain a second time domain signal; A cyclic prefix is ​​added to the first time-domain signal to obtain the first preamble signal, and a cyclic prefix is ​​added to the second time-domain signal to obtain the second preamble signal.

[0097] In one embodiment, the determining module 44 is used for: The conversion factor is determined based on the ratio of the index of the first sequence to the length of the ZC sequence; Multiply the offset by the conversion factor to obtain the third value; Multiply the third value by the preset subcarrier spacing to obtain the frequency offset.

[0098] In one embodiment, the calculation module 43 is used for: Obtain the preset symmetry constraints; When the positions of the first and second correlation peaks satisfy the symmetry constraint, the positions of the first and second correlation peaks are summed to obtain the first value.

[0099] In one embodiment, the calculation module 43 is used for: When the positions of the first and second correlation peaks satisfy the symmetry constraint, the second correlation peak position is subtracted from the first correlation peak position to obtain the second value.

[0100] It is worth noting that in the embodiments of the above-mentioned delay and frequency offset estimation device, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the protection scope of the embodiments of this application.

[0101] This application also provides an electronic device that can integrate the delay and frequency offset estimation device provided in this application. Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. (Reference) Figure 5 The electronic device includes: an input device 53, an output device 54, a memory 52, and one or more processors 51; the memory 52 is used to store one or more programs; when one or more programs are executed by one or more processors 51, the one or more processors 51 implement the time delay and frequency offset estimation method provided in the above embodiments. The input device 53, output device 54, memory 52, and processor 51 can be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0102] The memory 52, as a computing device readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as program instructions / modules corresponding to the latency and frequency offset estimation methods provided in any embodiment of this application (e.g., the acquisition module 41, detection module 42, calculation module 43, and determination module 44 in the latency and frequency offset estimation device). The memory 52 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the device, etc. Furthermore, the memory 52 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 52 may further include memory remotely located relative to the processor 51, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0103] Input device 53 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the device. Output device 54 may include display devices such as a display screen.

[0104] The processor 51 executes various functional applications and data processing of the device by running software programs, instructions and modules stored in the memory 52, thereby realizing the above-mentioned time delay and frequency offset estimation methods.

[0105] The delay and frequency offset estimation apparatus, device and computer provided above can be used to execute the delay and frequency offset estimation method provided in any of the above embodiments, and have the corresponding functions and beneficial effects.

[0106] This application embodiment also provides a storage medium storing computer-executable instructions, which, when executed by a computer processor, are used to perform the latency and frequency offset estimation method provided in the above embodiment. The latency and frequency offset estimation method includes: The first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time are respectively acquired. The first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain. The first preamble signal and the second preamble signal are generated based on the preset first root sequence and the second root sequence, respectively. The sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence. Time-domain correlation detection is performed on the first preamble signal and the second preamble signal respectively to obtain the first correlation peak position and the second correlation peak position. The first correlation peak position is used to represent the sum of the time delay to be estimated and the offset caused by the frequency offset to be estimated, and the second correlation peak position is used to represent the difference between the time delay to be estimated and the offset. The positions of the first and second correlation peaks are summed to obtain a first value. The first value is then divided by a preset first calculation parameter to obtain the time delay. Subtract the position of the second correlation peak from the position of the first correlation peak to obtain the second value. Divide the second value by the preset second calculation parameter to obtain the offset. Determine the frequency offset based on the offset.

[0107] Storage medium – any type of memory device or storage device. The term “storage medium” is intended to include: mounting media, such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (e.g., hard disks or optical storage); registers or other similar types of memory elements, etc. Storage media may also include other types of memory or combinations thereof. Furthermore, storage media may reside in a first computer system in which a program is executed, or may reside in a different second computer system connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term “storage medium” can include two or more storage media that may reside in different locations (e.g., in different computer systems connected via a network). Storage media may store program instructions (e.g., specifically implemented as a computer program) executable by one or more processors.

[0108] Of course, the computer-executable instructions provided in the embodiments of this application are not limited to the latency and frequency offset estimation methods provided above, but can also perform related operations in the latency and frequency offset estimation methods provided in any embodiment of this application.

[0109] The delay and frequency offset estimation apparatus, device and storage medium provided in the above embodiments can execute the delay and frequency offset estimation method provided in any embodiment of this application. For technical details not described in detail in the above embodiments, please refer to the delay and frequency offset estimation method provided in any embodiment of this application.

[0110] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments provided herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the claims.

Claims

1. A method for estimating time delay and frequency offset, characterized in that, include: The first preamble signal and the second preamble signal sent by the user equipment at a preset first random access time and a preset second random access time are respectively acquired. The first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain. The first preamble signal and the second preamble signal are generated based on a preset first root sequence and a preset second root sequence, respectively. The sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence. Time-domain correlation detection is performed on the first preamble signal and the second preamble signal respectively to obtain the first correlation peak position and the second correlation peak position. The first correlation peak position is used to represent the sum of the time delay to be estimated and the offset caused by the frequency offset to be estimated, and the second correlation peak position is used to represent the difference between the time delay to be estimated and the offset. The positions of the first and second related peaks are summed to obtain a first value, and the first value is divided by a preset first calculation parameter to obtain the time delay; Subtract the second correlation peak position from the first correlation peak position to obtain a second value. Divide the second value by a preset second calculation parameter to obtain the offset. Determine the frequency offset based on the offset.

2. The time delay and frequency offset estimation method according to claim 1, characterized in that, The step of performing time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the positions of the first correlation peak and the second correlation peak includes: The first preamble signal is subjected to time-domain correlation detection using the first local sequence corresponding to the first root sequence to obtain the position of the first correlation peak. The second preamble signal is subjected to time-domain correlation detection using the second local sequence corresponding to the second root sequence to obtain the position of the second correlation peak. The first local sequence and the second local sequence are complex conjugates of each other.

3. The time delay and frequency offset estimation method according to claim 1, characterized in that, Before acquiring the first preamble signal and the second preamble signal sent by the user equipment at the preset first random access time and the second random access time, the method further includes: Send a first signaling message to the user equipment, the first signaling message being used to indicate the multiplexing method adopted by the first random access opportunity and the second random access opportunity, wherein the multiplexing method includes time division multiplexing or frequency division multiplexing; A second signaling message is sent to the user equipment, the second signaling message being used to instruct the user equipment on the random access resources used to send the first preamble signal and the second preamble signal.

4. The time delay and frequency offset estimation method according to claim 1, characterized in that, The generation process of the first preamble signal and the second preamble signal includes: A first preamble sequence is generated based on the first root sequence, and a second preamble sequence is generated based on the second root sequence; The first preamble sequence is mapped to the first subcarrier set to obtain the first frequency domain signal, and the second preamble sequence is mapped to the second subcarrier set to obtain the second frequency domain signal. Perform an inverse Fourier transform on the first frequency domain signal to obtain a first time domain signal, and perform an inverse Fourier transform on the second frequency domain signal to obtain a second time domain signal; A cyclic prefix is ​​added to the first time-domain signal to obtain the first preamble signal, and a cyclic prefix is ​​added to the second time-domain signal to obtain the second preamble signal.

5. The time delay and frequency offset estimation method according to claim 1, characterized in that, Determining the frequency offset based on the offset includes: The conversion factor is determined based on the ratio of the index of the first root sequence to the length of the ZC sequence; Multiply the offset by the conversion factor to obtain the third value; The frequency offset is obtained by multiplying the third value by the preset subcarrier interval.

6. The time delay and frequency offset estimation method according to claim 1, characterized in that, The step of summing the positions of the first and second related peaks to obtain the first value includes: Obtain the preset symmetry constraints; When the positions of the first and second correlation peaks satisfy the symmetry constraint condition, the positions of the first and second correlation peaks are summed to obtain a first value.

7. The time delay and frequency offset estimation method according to claim 6, characterized in that, The step of subtracting the second relevant peak position from the first relevant peak position to obtain the second value includes: When the positions of the first and second correlation peaks satisfy the symmetry constraint, the position of the first correlation peak is subtracted from the position of the second correlation peak to obtain the second value.

8. A time delay and frequency offset estimation device, characterized in that, include: The acquisition module is used to acquire the first preamble signal and the second preamble signal sent by the user equipment at a preset first random access time and a preset second random access time, wherein the first random access time and the second random access time are adjacent in the time domain or adjacent in the frequency domain, and the first preamble signal and the second preamble signal are generated based on a preset first root sequence and a preset second root sequence, respectively, and the sum of the index of the first root sequence and the index of the second root sequence is equal to the length of the preset ZC sequence. The detection module is used to perform time-domain correlation detection on the first preamble signal and the second preamble signal respectively to obtain the first correlation peak position and the second correlation peak position, wherein the first correlation peak position is used to represent the sum of the time delay to be estimated and the offset caused by the frequency offset to be estimated, and the second correlation peak position is used to represent the difference between the time delay to be estimated and the offset. The calculation module is used to sum the positions of the first and second related peaks to obtain a first value; The calculation module is also used to divide the first value by a preset first calculation parameter to obtain the time delay; The calculation module is also used to subtract the second related peak position from the first related peak position to obtain a second value; The calculation module is also used to divide the second value by a preset second calculation parameter to obtain the offset; A determination module is used to determine the frequency offset based on the offset.

9. An electronic device, characterized in that, include: Memory and one or more processors; The memory is used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the delay and frequency offset estimation method as described in any one of claims 1-7.

10. A storage medium for storing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the delay and frequency offset estimation method as described in any one of claims 1-7.

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