Channel estimation method and device, computer device and computer readable storage medium

Abstract

Embodiments of the present application relate to a channel estimation method, device, computer equipment and computer readable storage medium. The channel estimation method comprises: obtaining a first synchronization symbol transmitted by a channel to be estimated, the first synchronization symbol comprising a pilot signal segment and a zero signal segment; obtaining first frequency domain estimation values of a plurality of pilot subcarriers of the pilot signal segment, the pilot signal segment comprising a plurality of pilot subcarriers; obtaining second frequency domain estimation values of a plurality of zero subcarriers of the zero signal segment according to a plurality of the first frequency domain estimation values, the zero signal segment comprising a plurality of zero subcarriers; and obtaining a channel estimation result of the channel to be estimated according to a channel frequency domain response, the channel frequency domain response comprising a plurality of the first frequency domain estimation values and a plurality of the second frequency domain estimation values.

Description

Technical Field

[0001] This application relates to the field of wireless communication, and in particular to a channel estimation method, apparatus, computer device, and computer-readable storage medium. Background Technology

[0002] With the continuous development of wireless communication technology, orthogonal frequency division multiplexing (OFDM) is increasingly widely used in wireless communication processes. OFDM is a frequency division multiplexing technology capable of transmitting high-speed data services, boasting high bandwidth utilization and strong resistance to multipath interference. After receiving OFDM signals, user equipment (UE) needs to demodulate the received signals to obtain the information carried by the signals. However, OFDM signals undergo some distortion during transmission due to the influence of the transmission channel. Therefore, channel estimation is needed to understand the impact of transmitted information on the signal in order to perform correct demodulation. However, current channel estimation methods lack accuracy and can no longer meet user needs. Summary of the Invention

[0003] Therefore, it is necessary to provide a channel estimation method, apparatus, computer device, and computer-readable storage medium with accurate estimation results to address the aforementioned technical problems.

[0004] Firstly, this application provides a channel estimation method, including:

[0005] Acquire the first synchronization symbol transmitted through the channel to be estimated, the first synchronization symbol including a pilot signal segment and a zeroing signal segment;

[0006] Obtain first frequency domain estimates of multiple pilot subcarriers of the pilot signal segment, wherein the pilot signal segment includes multiple pilot subcarriers;

[0007] Second frequency domain estimates of multiple zero-subcarriers of a zero-signal segment are obtained based on multiple first frequency domain estimates, wherein the zero-signal segment includes multiple zero-subcarriers;

[0008] The channel estimation result of the channel to be estimated is obtained based on the channel frequency domain response, wherein the channel frequency domain response includes multiple first frequency domain estimates and multiple second frequency domain estimates.

[0009] Secondly, this application provides a channel estimation apparatus, comprising:

[0010] The symbol acquisition module is used to acquire the first synchronization symbol transmitted through the channel to be estimated, the first synchronization symbol including a pilot signal segment and a zeroing signal segment;

[0011] The first frequency domain response acquisition module is used to acquire the first frequency domain estimate of a plurality of pilot subcarriers of the pilot signal segment, wherein the pilot signal segment includes a plurality of the pilot subcarriers;

[0012] The second frequency domain response acquisition module is used to acquire second frequency domain estimates of multiple zero subcarriers of a zero-signal segment based on multiple first frequency domain estimates, wherein the zero-signal segment includes multiple zero subcarriers;

[0013] The estimation result acquisition module is used to acquire the channel estimation result of the channel to be estimated based on the channel frequency domain response, wherein the channel frequency domain response includes multiple first frequency domain estimates and multiple second frequency domain estimates.

[0014] Thirdly, this application provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method.

[0015] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0016] The aforementioned channel estimation method, apparatus, computer equipment, and computer-readable storage medium, by acquiring the first frequency domain estimate value of each pilot subcarrier, can respectively determine the impact of the channel to be estimated on each pilot subcarrier. Obtaining multiple second frequency domain estimates based on the first frequency domain estimates allows the use of the zero-signal segment, originally used only to isolate different signals in the pilot signal segment, thereby increasing the amount of data in the frequency domain estimates. This achieves more complete coverage of the response value data in both the time and frequency domains, thus improving the utilization rate of the received first synchronization signal and enhancing the accuracy of channel estimation based on the larger data volume. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying 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.

[0018] Figure 1 One of the flowcharts for a channel estimation method according to an embodiment;

[0019] Figure 2 This is a schematic diagram of the signal segment of the first synchronization symbol in one embodiment;

[0020] Figure 3This is a schematic diagram illustrating an embodiment utilizing a null subcarrier;

[0021] Figure 4 This is a schematic diagram of a pattern that does not utilize null subcarriers;

[0022] Figure 5 This is a flowchart illustrating an embodiment of obtaining the channel estimation result of the channel to be estimated based on the channel frequency domain response;

[0023] Figure 6 One embodiment obtains the time-domain channel estimation result of the channel to be estimated based on the first channel impulse response;

[0024] Figure 7 This is a flowchart illustrating, as one embodiment, the processing of the first channel impulse response using at least one of intra-symbol estimation and inter-symbol estimation based on the scenario information;

[0025] Figure 8 This is a flowchart illustrating the processing of the first channel impulse response using intra-symbol estimation in one embodiment.

[0026] Figure 9 This is a second flowchart of a channel estimation method according to one embodiment;

[0027] Figure 10 This is an internal structural diagram of a computer device according to one embodiment. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0029] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first synchronization signal may be referred to as a second synchronization signal, and similarly, a second synchronization signal may be referred to as a first synchronization signal. Both the first synchronization signal and the second synchronization signal are synchronization signals, but they are not the same synchronization signal.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0031] This application provides a channel estimation method. This channel estimation method can be applied to 5G NR (New Radio) or other wireless access technologies that use orthogonal frequency division multiplexing. This application does not limit the application. Figure 1 One of the flowcharts for a channel estimation method according to an embodiment is shown below. Figure 1 The signal estimation method includes steps 102 to 108.

[0032] Step 102: Obtain the first synchronization symbol transmitted through the channel to be estimated.

[0033] The first synchronization symbol includes a pilot signal segment and a null signal segment. A pilot signal segment refers to a signal segment that includes pilot subcarriers, and the pilot signal segment can be further divided into multiple segments. The functions of each segment within a pilot signal segment are not entirely the same, but each segment includes multiple pilot subcarriers. Null subcarriers can be set between different segments within a pilot signal segment to isolate them.

[0034] In one embodiment, the pilot signal segment may include, for example, a physical broadcast channel segment and a secondary synchronization signal segment, each comprising a plurality of the pilot subcarriers. The first synchronization symbol may be one of a synchronization signal and a PBCH block (SSB). Figure 2 This is a schematic diagram of the signal segment of the first synchronization symbol in one embodiment, with reference to... Figure 2The SSB (Secondary Synchronization Signals) consists of three parts: Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), and the Physical Broadcast Channel (PBCH). Specifically, the SSB comprises four symbols transmitted sequentially in time. The middle 127 subcarriers of the first symbol are used to transmit the primary synchronization signal. The second and fourth subcarriers are entirely used to transmit the first part of the physical broadcast channel. The middle 127 subcarriers of the third symbol are used to transmit the secondary synchronization signal, while the first 48 and last 48 subcarriers are used to transmit the second part of the physical broadcast channel. Zero-signal subcarriers are used for isolation between the subcarriers used to transmit the physical broadcast channel and those used to transmit the secondary synchronization signal. The physical broadcast channel segment refers to the frequency band range of the subcarriers used to transmit the physical broadcast channel; the secondary synchronization signal segment refers to the frequency band range of the subcarriers used to transmit the secondary synchronization signal; and the zero-signal segment refers to the frequency band range of the subcarriers used to transmit the zero-signal subcarriers.

[0035] Step 104: Obtain the first frequency domain estimate of the multiple pilot subcarriers of the pilot signal segment.

[0036] The user equipment can learn about the impact of the channel to be estimated on the frequency of each pilot subcarrier by observing the changes in the pilot subcarriers during transmission. In this way, when receiving data later, the user equipment can obtain the data actually sent by the base station based on the received data and the known impact, so as to achieve accurate data reception.

[0037] Step 106: Obtain second frequency domain estimates of multiple zero-subcarriers of the zero-signal segment based on multiple first frequency domain estimates.

[0038] The nulling signal segment includes multiple nulling subcarriers. Specifically, the nulling subcarriers do not transmit actual data. Therefore, the frequency points corresponding to the nulling subcarriers can be utilized to further improve the utilization effectiveness of the first synchronization symbol. For example, the second frequency domain estimate of multiple nulling subcarriers can be obtained by interpolation. Optionally, pilot subcarriers and nulling subcarriers used for channel estimation can be determined according to a preset pattern specified in the protocol. The preset pattern can be any of block pilots, comb pilots, and discrete pilots. For example, pilot subcarriers can be determined according to the preset pattern specified in the 38.211 protocol. For example, the 2nd, 6th, 10…46th, 50th, 54th, 58th…182nd, 186th, 190th, 194th…230th, 234th, and 238th subcarriers can be determined as frequency points for channel estimation. Figure 3 This is a schematic diagram illustrating an embodiment utilizing a null subcarrier. Figure 4This is a schematic diagram of a pattern that does not utilize null subcarriers, in conjunction with reference. Figure 3 and Figure 4 When channel estimation is not performed using null subcarriers, the null signal segment does not transmit pilot subcarriers, resulting in some missing areas in the pattern, leading to incomplete data and increased processing complexity. However, when null subcarriers are used to supplement the channel estimation pattern, the subcarriers with the second frequency domain estimate can form a regular channel estimation pattern, thereby increasing the data volume and simplifying the data processing. It is understood that other frequency point sequences can also be used to determine the null subcarriers for which the second frequency domain estimate needs to be obtained. This embodiment does not limit this; specifically, the frequency domain positions of the null subcarriers for which the second frequency domain estimate needs to be obtained, as shown in Table 1, can be used. The example above selects the frequency domain positions of the null subcarriers for which the second frequency domain estimate needs to be obtained when Vshit is 2.

[0039] Table 1. Frequency domain locations of the null subcarriers for which the second frequency domain estimate needs to be obtained.

[0040] Vshift = mod(Nid, 4) The frequency domain location of the null subcarriers for obtaining the second frequency domain estimate needs to be determined. 0 (48,52,184,188) 1 (49,53,185,189) 2 (50,54,186,190) 3 (51,55,183,187,191)

[0041] Step 108: Obtain the channel estimation result of the channel to be estimated based on the channel frequency domain response.

[0042] The channel frequency domain response includes multiple first frequency domain estimates and multiple second frequency domain estimates. In this embodiment, by obtaining the first frequency domain estimates for each pilot subcarrier, the impact of the channel to be estimated on each pilot subcarrier can be determined. Obtaining multiple second frequency domain estimates based on the first frequency domain estimates utilizes the zero-signal segment originally used only to isolate different signals in the pilot signal segment, thereby increasing the amount of data for the frequency domain estimates. This achieves more complete coverage of the response data in both the time and frequency domains, thus improving the utilization rate of the received first synchronization signal and enhancing the accuracy of channel estimation based on the larger data volume.

[0043] In one embodiment, when the pilot signal segment includes a physical broadcast channel segment and a secondary synchronization signal segment, the physical broadcast channel segment and the secondary synchronization signal segment each include a plurality of pilot subcarriers. Obtaining the first frequency domain estimate of the plurality of pilot subcarriers of the pilot signal segment includes: obtaining the first frequency domain estimate of each pilot subcarrier of the physical broadcast channel segment, and obtaining the first frequency domain estimate of each pilot subcarrier of the secondary synchronization signal segment.

[0044] The physical broadcast channel segment and the secondary synchronization signal segment each include multiple pilot subcarriers. A portion of the physical broadcast channel is used to transmit a demodulation reference signal (DMRS). It is understood that the subcarriers used to transmit the demodulation reference signal can be called pilot subcarriers. By demodulating the reference signal, the user equipment can learn about the impact of the channel to be estimated on the pilot subcarriers of that frequency. In related technologies, channel assessment is typically performed using only DMRS. However, it is understood that the secondary synchronization signal is also transmitted according to a preset rule. Therefore, by analyzing the difference between the received and transmitted secondary synchronization signals, the impact of the channel to be estimated on the subcarriers used for the secondary synchronization signal can also be learned, thereby improving the utilization effectiveness of the first synchronization symbol, i.e., increasing the amount of data used for channel estimation. That is, in this embodiment, the subcarriers used for the secondary synchronization signal can also be called pilot subcarriers.

[0045] In one embodiment, obtaining second frequency domain estimates of a plurality of zero-subcarriers of a zero-signal segment based on a plurality of first frequency domain estimates includes the following steps: obtaining second frequency domain estimates of a plurality of the zero-subcarriers based on first frequency domain estimates of two target pilot subcarriers.

[0046] In this embodiment, both target pilot subcarriers are adjacent to the nulling signal segment, and are located on either side of the nulling signal segment in a one-to-one correspondence. Specifically, the fact that both target pilot subcarriers are adjacent to the nulling signal segment can be understood as selecting the pilot subcarrier closest to the nulling signal segment for calculation. For example, if the frequency domain positions of the nulling subcarriers for which the second frequency domain estimate needs to be obtained are 50 and 54, then the frequency domain positions of the two target pilot subcarriers are 46 and 58, respectively. It is understood that under the influence of the channel to be estimated, subcarriers with closer frequencies have more similar changes. However, in related technologies, since the first frequency domain estimate is obtained only from the pilot subcarriers of the physical broadcast signal segment, it is impossible to analyze based on the data of the frequency domain positions of the two pilot subcarriers closest to the nulling signal segment. Therefore, in this embodiment, given the first frequency domain estimate based on the pilot subcarriers of the auxiliary synchronization signal segment, the second frequency domain estimate can be calculated more accurately, thereby improving the accuracy of channel estimation. Moreover, by adding data from the zero-signal segment, a regular pilot pattern in the time-frequency domain can be obtained, thereby avoiding the complexity and inefficiency of subsequent processing caused by the discontinuous distribution of pilot subcarriers.

[0047] In one embodiment, obtaining second frequency domain estimates of a plurality of nullable subcarriers based on the first frequency domain estimates of two target pilot subcarriers includes the following steps: performing linear interpolation or Lagrange interpolation on the first frequency domain estimates of the two target pilot subcarriers to obtain second frequency domain estimates of a plurality of nullable subcarriers. For ease of explanation, the nullable subcarriers having second frequency domain estimates will be referred to as interpolation point subcarriers. Specifically, taking a single linear interpolation as an example, the second frequency domain estimates satisfy the following relationship:

[0048] H fit = lower *oef+H upper (1-o)e)

[0049] Among them, H fit H is the second frequency domain estimate. lower and H upper These are the first frequency domain estimates of the two target pilot subcarriers, and coef is the coefficient of the first linear interpolation. In this embodiment, the above interpolation method is computationally simple and its accuracy meets the requirements of channel estimation, thus ensuring the data continuity of channel estimation while avoiding excessive computational burden.

[0050] Figure 5 Here is a flowchart illustrating an embodiment of obtaining the channel estimation result of the channel to be estimated based on the channel frequency domain response, with reference to... Figure 5 In one embodiment, the above steps include steps 502 to 506.

[0051] Step 502: Transform the channel frequency domain response from the frequency domain to the time domain to obtain the first channel impulse response.

[0052] Specifically, the channel frequency domain response can be transformed to the time domain using any of the following methods: Inverse Fourier Transform (IFT), Inverse Fast Fourier Transform (IFFT), and Inverse Discrete Fourier Transform (IDFT). The number of sampling points in these inverse transforms must be greater than or equal to the sum of the number of pilot subcarriers and interpolation point subcarriers. For example, if the number of pilot subcarriers in the physical broadcast channel segment is 24, the number of pilot subcarriers in the secondary synchronization signal segment is 32, and the number of interpolation point subcarriers in the nulling signal segment is 4, then the sum of the number of pilot subcarriers and interpolation point subcarriers is 60. Therefore, taking Inverse Fast Fourier Transform as an example, the number of sampling points can be, for example, 64 or 128, etc., and this embodiment is not limited to this.

[0053] Step 504: Obtain the time-domain channel estimation result of the channel to be estimated based on the first channel impulse response.

[0054] Step 506: Transform the time-domain channel estimation result from the time domain to the frequency domain to obtain the frequency-domain channel estimation result of the channel to be estimated.

[0055] Specifically, the time-domain channel estimation result can be transformed to the frequency domain using any of the following methods: Fourier Transform (FT), Fast Fourier Transform (FFT), or Discrete Fourier Transform (DFT). Considering the signal granularity, the number of sampling points in the Fast Fourier Transform should be greater than the number of sampling points in the Inverse Fast Fourier Transform. Therefore, taking the Fast Fourier Transform and Inverse Fast Fourier Transform as examples, if the Inverse Fast Fourier Transform has 64 sampling points, then the number of sampling points in the Fast Fourier Transform can be four times that, i.e., 256.

[0056] Based on the above steps, channel estimation results in both the time and frequency domains can be obtained, providing a more reliable basis for signal modulation. Furthermore, in this embodiment, the processing is purely time-domain; the most computationally intensive step is the Fourier transform with 256 sampling points, thus avoiding the complex multi-order sliding filter calculations required for frequency-domain filtering. This significantly saves storage space for coefficients and reduces the computational demands on the hardware. Additionally, it is understood that in the aforementioned steps, the Least Squares Method (LS) can be used for preliminary channel estimation to obtain the first frequency domain estimation values ​​corresponding to each pilot subcarrier. However, LS typically does not consider noise in the received first synchronization symbol or interference between subcarriers, leading to insufficient accuracy of the estimation results when the signal-to-noise ratio is insufficient. Therefore, this embodiment, through further processing in steps 504 and 506, can filter out noise and other issues to a certain extent, thereby improving the accuracy of channel estimation.

[0057] In one embodiment, transforming the time-domain channel estimation result from the time domain to the frequency domain includes the following steps: sequentially performing rearrangement and phase rotation processing on the time-domain channel estimation result; and transforming the rearrangement and phase rotation processed time-domain channel estimation result from the time domain to the frequency domain.

[0058] The rearrangement of time-domain channel estimation results can be understood as the inverse operation of interpolation of frequency-domain channel estimation results. That is, by rearranging the time-domain channel estimation results, the number of data frequency points in the frequency-domain channel estimation results can be increased, thereby providing more refined frequency-domain channel estimation results. Optionally, the time-domain channel estimation results can be rearranged by padding with zeros. It is understood that this embodiment does not limit the position of the zero padding; the zero padding can be placed before or after the time-domain channel estimation results. By rotating the phase of the time-domain channel estimation results, the frequency of the frequency-domain channel estimation results can be shifted, thereby obtaining the frequency points of the desired interpolation subcarriers.

[0059] Figure 6 As an embodiment, the time-domain channel estimation result of the channel to be estimated is obtained based on the first channel impulse response, with reference to... Figure 6 In one embodiment, the above steps include steps 602 to 604.

[0060] Step 602: Obtain scene information when receiving the first synchronization symbol.

[0061] The scenario information includes at least one of the signal-to-noise ratio (SNR) of the channel to be estimated and the connection state of the user equipment (UE). The connection state of the UE includes the Idle state before connection establishment, and also the CELL-PCH state, URA-PCH state, CELL-FACH state, and CELL-DCH state after connection establishment. Specifically, after powering on, the UE is in the Idle state to read system messages and listen for paging information in the cell. In the above steps, the UE needs to synchronize its frequency and symbols with the cell, therefore it needs to receive the first synchronization symbol to establish a connection. By obtaining the SNR, it is possible to determine whether the current communication scenario is a high SNR scenario or a low SNR scenario.

[0062] Step 604: Based on the scenario information, at least one of intra-symbol estimation and inter-symbol estimation is used to process the first channel impulse response to obtain the time-domain channel estimation result of the channel to be estimated.

[0063] In this embodiment, the impact of noise and other factors on the channel estimation results varies depending on the communication scenario. Therefore, by acquiring scenario information when receiving the signal through the state controller, inter-symbol and intra-symbol time-domain processing can be flexibly scheduled, thus adapting flexibly to different demodulation scenarios and accurately obtaining the time-domain channel estimation result with maximum gain.

[0064] Figure 7 This is a flowchart illustrating an embodiment of processing the first channel impulse response using at least one of intra-symbol estimation and inter-symbol estimation based on the scenario information, as shown in the attached flowchart. Figure 7In one embodiment, the above steps include at least one of steps 702 to 706.

[0065] Step 702: When the connection state is the initial network search state, the intra-symbol estimation is used to process the first channel impulse response.

[0066] Step 704: When the signal-to-noise ratio is greater than the first signal-to-noise ratio threshold, the inter-symbol estimation is used to process the first channel impulse response.

[0067] Step 706: When the signal-to-noise ratio is less than the second signal-to-noise ratio threshold, the first channel impulse response is processed by the inter-symbol estimation and the intra-symbol estimation, wherein the second signal-to-noise ratio threshold is less than the first signal-to-noise ratio threshold.

[0068] Optionally, it can be determined whether the current state is the initial network search state. If not, selection can be made based on the signal-to-noise ratio (SNR). Specifically, during the initial network search, inter-symbol interference has a relatively small impact on the time-domain channel estimation result, so inter-symbol estimation is unnecessary. However, in other connected states, the impact of inter-symbol interference is relatively large, so inter-symbol estimation must be performed to overcome inter-symbol interference during demodulation. Moreover, when the SNR is low, the impact of intra-symbol interference gradually increases, so inter-symbol interference needs to be estimated. Based on the above-mentioned multiple processing methods for scene information, the accuracy of the time-domain channel estimation result can be effectively improved. It is understood that the examples of the above three steps are for some typical scenarios, and the actual applicable scope includes, but is not limited to, the above scenarios.

[0069] Figure 8 This is a flowchart illustrating the processing of the first channel impulse response using intra-symbol estimation in one embodiment, referencing... Figure 8 In one embodiment, the above steps include steps 802 to 806.

[0070] Step 802: Obtain the noise power based on the first channel impulse response.

[0071] The channel to be estimated includes multiple transmission paths (tap), and the acquired noise power is the noise power within the current window. Specifically, each transmission path can be used as a first path, set at the starting position of the window, and the corresponding window can be adjusted as a given time-domain position to obtain the total power and the power at the given time-domain position. Then, the difference between the total power and the power at the given time-domain position is averaged to obtain the noise power, specifically satisfying the following relationship:

[0072]

[0073] The given time-domain position includes the start and end positions of the time domain, which can be provided by the external parameter estimation module. It is understood that the noise power calculation can be performed on a separate basis for each symbol, or by combining the results from all symbols; this embodiment does not specify a particular method.

[0074] Step 804: Determine the weighting coefficients corresponding to each transmission path based on the noise power.

[0075] Specifically, the weighting coefficients can be obtained using the power value of each transmission path and the aforementioned noise power according to the following formula, satisfying the following relationship:

[0076]

[0077] in, τ is the power value. k The coefficients are calculated.

[0078] Step 806: Extract the first channel impulse response according to the weighting coefficient.

[0079] The effective window refers to the window mentioned in step 802 above. Specifically, the truncation can be achieved by setting the first channel impulse response outside the effective window to zero, thereby realizing signal noise reduction, and satisfying the following relationship:

[0080]

[0081] In this embodiment, through the above steps, the first channel impulse response outside the effective window can be set to zero, and a higher weight coefficient can be set for the transmission path with lower noise power within the effective window, thereby reducing the impact of noise on the final channel estimation result and improving the accuracy of channel estimation.

[0082] Figure 9 A second flowchart of a channel estimation method according to an embodiment, see reference. Figure 9 In one embodiment, the channel estimation method includes steps 902 to 918. That is, Figure 1 Before obtaining the channel estimation result of the channel to be estimated based on the channel frequency domain response, the embodiment further includes steps 904 and 910. Step 904 can be placed before step 902, and step 910 can be placed before step 906. Processing the first channel impulse response using inter-symbol estimation includes steps 916 to 918. It is understood that the implementation methods of other steps can refer to the foregoing embodiment, and will not be repeated here.

[0083] Step 902: Obtain the first synchronization symbol transmitted through the channel to be estimated.

[0084] Step 904: Obtain the second synchronization symbol transmitted through the channel to be estimated.

[0085] Step 906: Obtain the first frequency domain estimate of multiple pilot subcarriers based on the physical broadcast channel segment and the auxiliary synchronization signal segment.

[0086] Step 908: Obtain second frequency domain estimates of multiple zero-subcarriers of the zero-signal segment based on multiple first frequency domain estimates.

[0087] Step 910: Obtain the second channel impulse response based on the physical broadcast channel segment of the second synchronization signal.

[0088] Specifically, the second synchronization symbol can be the second or fourth symbol in the SSB, as it includes the physical broadcast channel segment. It is understood that obtaining the second channel impulse response based on the physical broadcast channel segment of the second synchronization signal can be achieved using the same method as obtaining the first channel impulse response described in the foregoing embodiments, or using other related techniques; this embodiment does not limit this method.

[0089] Step 912: Obtain scene information when receiving the first synchronization symbol.

[0090] Step 914: Perform inter-symbol estimation processing based on the scene information.

[0091] Step 916: Obtain the inter-symbol coefficients based on the Doppler value of the channel to be estimated and the signal-to-noise ratio.

[0092] Understandably, for a time-invariant channel to be estimated, its properties are relatively stable. However, for a time-varying channel, its properties change rapidly. For example, if the user terminal (UE) is in a high-speed moving state, the time-varying nature of the channel is more pronounced, and the correlation of the channel frequency domain response on the same subcarrier of different synchronization symbols will also occur. Time-varying properties lead to Doppler frequency shift, which in turn causes frequency offsets on each transmission path, resulting in the generation of new frequency components and thus distorting the evaluation results. Doppler values ​​can reflect the time-varying nature of the signal to obtain accurate inter-symbol coefficients. For example, inter-symbol coefficients can be obtained through interpolation using the sinc function.

[0093] Step 918: Combine the first channel impulse response and the second channel impulse response according to the inter-symbol coefficient.

[0094]

[0095] Among them, h l For the channel impulse response of each synchronization symbol, α lThe inter-symbol coefficients are for each synchronization symbol. In this embodiment, by obtaining the inter-symbol coefficients and calculating the channel impulse response of different symbols based on the inter-symbol coefficients, the channel to be estimated can be estimated together with the first and second synchronization symbols, thereby obtaining a more accurate signal estimation result.

[0096] It should be understood that although the steps in each flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in each flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0097] This application also provides a channel estimation apparatus, including a symbol acquisition module, a first frequency domain response acquisition module, a second frequency domain response acquisition module, and an estimation result acquisition module. The symbol acquisition module acquires a first synchronization symbol transmitted through the channel to be estimated, the first synchronization symbol including a pilot signal segment and a null signal segment. The first frequency domain response acquisition module acquires first frequency domain estimates of a plurality of pilot subcarriers of the pilot signal segment, the pilot signal segment including the plurality of pilot subcarriers. The second frequency domain response acquisition module acquires second frequency domain estimates of a plurality of null subcarriers of the null signal segment based on the plurality of first frequency domain estimates, the null signal segment including the plurality of null subcarriers. The estimation result acquisition module acquires the channel estimation result of the channel to be estimated based on the channel frequency domain response, the channel frequency domain response including a plurality of first frequency domain estimates and a plurality of second frequency domain estimates.

[0098] The division of modules in the above-described channel estimation device is for illustrative purposes only. In other embodiments, the channel estimation device can be divided into different modules as needed to complete all or part of the functions of the channel estimation device. Specific limitations of the channel estimation device can be found in the limitations of the channel estimation method described above, and will not be repeated here. Each module in the above-described channel estimation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0099] In one embodiment, a computer device is provided, which may be a terminal. Figure 10 This is an internal structural diagram of a computer device according to an embodiment. The computer device includes a processor, memory, communication interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a channel estimation method. The display screen can be a liquid crystal display (LCD) or an e-ink display. The input device can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0100] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0101] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0102] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described method embodiments.

[0103] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0104] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0105] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The above-described embodiments are merely illustrative of several implementation methods of the embodiments of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the embodiments of this application, and these all fall within the protection scope of the embodiments of this application. Therefore, the protection scope of the patent for the embodiments of this application should be determined by the appended claims.

Claims

1. A method of channel estimation, characterized by, The method comprises: obtaining a first synchronization symbol transmitted through a channel to be estimated, the first synchronization symbol comprising a pilot signal segment and a zero signal segment; obtaining first frequency domain estimation values of a plurality of pilot subcarriers of the pilot signal segment, the pilot signal segment comprising the plurality of pilot subcarriers; obtaining second frequency domain estimation values of a plurality of zero subcarriers of the zero signal segment according to the plurality of first frequency domain estimation values, the zero signal segment comprising the plurality of zero subcarriers; obtaining a channel estimation result of the channel to be estimated according to a channel frequency domain response, the channel frequency domain response comprising the plurality of first frequency domain estimation values and the plurality of second frequency domain estimation values.

2. The channel estimation method of claim 1, wherein, The pilot signal segment comprises a physical broadcast channel segment and a secondary synchronization signal segment, and the physical broadcast channel segment and the secondary synchronization signal segment each comprise the plurality of pilot subcarriers. The method comprises:

3. The channel estimation method of claim 1, wherein, obtaining first frequency domain estimation values of the pilot subcarriers of the physical broadcast channel segment respectively, and obtaining first frequency domain estimation values of the pilot subcarriers of the secondary synchronization signal segment respectively. The method comprises: obtaining second frequency domain estimation values of the plurality of zero subcarriers according to the first frequency domain estimation values of two target pilot subcarriers.

4. The channel estimation method of claim 3, wherein The two target pilot subcarriers are each arranged adjacent to the zero signal segment and each correspond to one side of the zero signal segment. The method comprises:

5. The channel estimation method of any of claims 1 to 4, characterized by, performing linear interpolation processing or Lagrange interpolation processing on the first frequency domain estimation values of the two target pilot subcarriers to obtain the second frequency domain estimation values of the plurality of zero subcarriers. The method comprises: transforming the channel frequency domain response from the frequency domain to the time domain to obtain a first channel impulse response; obtaining a time domain channel estimation result of the channel to be estimated according to the first channel impulse response; 6. The channel estimation method of claim 5, wherein, transforming the time domain channel estimation result from the time domain to the frequency domain to obtain a frequency domain channel estimation result of the channel to be estimated. The method comprises: sequentially performing rearrangement processing and phase rotation processing on the time domain channel estimation result; 7. The method for channel estimation according to claim 5, wherein transforming the time domain channel estimation result after the rearrangement processing and the phase rotation processing from the time domain to the frequency domain. The method comprises: obtaining scene information when the first synchronization symbol is received, the scene information comprising at least one of a signal-to-noise ratio of the channel to be estimated and a connection state of a user equipment; 8. The channel estimation method of claim 7, wherein, processing the first channel impulse response according to the scene information by using at least one of intra-symbol estimation and inter-symbol estimation to obtain the time domain channel estimation result of the channel to be estimated. The method comprises: processing the first channel impulse response by using intra-symbol estimation. acquire noise power according to the first channel impulse response; determine each weight coefficient corresponding to each transmission path according to the noise power, the to-be-estimated channel including a plurality of the transmission paths; intercept the first channel impulse response according to the weight coefficient.

9. The channel estimation method of claim 7, wherein, Before the acquiring the channel estimation result of the to-be-estimated channel according to the channel frequency domain response, the method further includes: acquire a second synchronization symbol transmitted through the to-be-estimated channel, the second synchronization symbol including a physical broadcast channel segment; acquire a second channel impulse response according to the physical broadcast channel segment of the second synchronization symbol; perform processing on the first channel impulse response by using inter-symbol estimation, including: acquire an inter-symbol coefficient according to the Doppler value of the to-be-estimated channel and the signal-to-noise ratio; combine the first channel impulse response and the second channel impulse response according to the inter-symbol coefficient.

10. The method for channel estimation according to claim 7, wherein, The processing on the first channel impulse response by using at least one of intra-symbol estimation and inter-symbol estimation according to the scene information includes at least one of: when the connected state is an initial network searching state, processing the first channel impulse response by using the intra-symbol estimation; when the signal-to-noise ratio is greater than a first signal-to-noise ratio threshold, processing the first channel impulse response by using the inter-symbol estimation; when the signal-to-noise ratio is less than a second signal-to-noise ratio threshold, processing the first channel impulse response by using the inter-symbol estimation and the intra-symbol estimation, the second signal-to-noise ratio threshold being less than the first signal-to-noise ratio threshold.

11. A channel estimation apparatus characterized by comprising: include: a symbol acquisition module, configured to acquire a first synchronization symbol transmitted through a to-be-estimated channel, the first synchronization symbol including a pilot signal segment and a zero signal segment; a first frequency domain response acquisition module, configured to acquire first frequency domain estimation values of a plurality of pilot subcarriers of the pilot signal segment, the pilot signal segment including the plurality of pilot subcarriers; a second frequency domain response acquisition module, configured to acquire second frequency domain estimation values of a plurality of zero subcarriers of the zero signal segment according to a plurality of the first frequency domain estimation values, the zero signal segment including the plurality of zero subcarriers; an estimation result acquisition module, configured to acquire a channel estimation result of the to-be-estimated channel according to a channel frequency domain response, the channel frequency domain response including a plurality of the first frequency domain estimation values and a plurality of the second frequency domain estimation values.

12. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor executes the computer program to implement the steps of the method in any one of claims 1 to 10.

13. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 10.

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