Maximum multipath delay spread estimation methods, apparatus, equipment and media

Abstract

This invention provides a method, apparatus, device, and medium for estimating maximum multipath delay spread. The method includes: acquiring a pilot point channel estimation sequence; performing an inverse Fourier transform on the pilot point channel estimation sequence to obtain a first time-domain channel impulse response sequence; calculating windowing coefficients based on the first time-domain channel impulse response sequence; applying windowing processing to the first time-domain channel impulse response sequence based on the windowing coefficients to obtain a second time-domain channel impulse response sequence; calculating a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; adaptively calculating a first-path threshold and an effective path threshold based on the SNR estimate and the maximum path power; calculating the first-path position and the maximum multipath delay position; and performing filtering processing based on the maximum multipath delay position to obtain a maximum multipath delay spread estimate. This method is used to obtain an accurate maximum multipath delay spread estimate to improve channel estimation performance.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and more particularly to a method, apparatus, device, and medium for estimating maximum multipath delay spread. Background Technology

[0002] Currently, the maximum multipath delay spread estimation method is as follows: First, perform an inverse fast Fourier transform on the frequency domain channel response to obtain the time domain channel impulse response; calculate the maximum path power and average power of the time domain channel impulse response; calculate the effective path threshold based on the maximum path power and average power; and calculate the maximum multipath delay position based on the effective path threshold.

[0003] Existing technologies suffer from insufficient anti-interference capabilities. Due to the complexity of the wireless environment, terminals are often subjected to noise and interference from neighboring cells during channel estimation. Furthermore, the path corresponding to the maximum multipath delay spread is often weak; therefore, when encountering even slightly larger interference, this path is often submerged by background noise. Inaccurate estimation of the maximum multipath delay spread leads to inaccurate channel estimation results. Therefore, a new method, apparatus, device, and medium for estimating the maximum multipath delay spread is urgently needed to improve these problems. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, device, and medium for estimating maximum multipath delay spread. This method is used to obtain accurate estimates of maximum multipath delay spread to improve channel estimation performance.

[0005] In a first aspect, the present invention provides a method for estimating maximum multipath delay spread, comprising: S1, obtaining a pilot point channel estimation sequence; S2, performing an inverse Fourier transform on the pilot point channel estimation sequence to obtain a first time-domain channel impulse response sequence; S3, calculating a windowing coefficient based on the first time-domain channel impulse response sequence, and performing windowing processing on the first time-domain channel impulse response sequence based on the windowing coefficient to obtain a second time-domain channel impulse response sequence; S4, calculating a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; adaptively calculating a first-path threshold and an effective path threshold based on the SNR estimate and the maximum path power; S5, calculating the first-path position and the maximum multipath delay position based on the SNR estimate, the maximum path power, the first-path threshold, and the effective path threshold; S6, performing filtering processing based on the maximum multipath delay position to obtain a maximum multipath delay spread estimate.

[0006] The beneficial effects of the method of the present invention are as follows: The present invention calculates the signal-to-noise ratio (SNR) estimate and the maximum path power based on the second time-domain channel impulse response sequence; it adaptively calculates the first path threshold and the effective path threshold based on the SNR estimate and the maximum path power, which can improve the accuracy of identifying the first path and the effective path; the present invention calculates the first path position and the maximum multipath delay position based on the SNR estimate, the maximum path power, the first path threshold, and the effective path threshold, and performs filtering processing based on the maximum multipath delay position to obtain the maximum multipath delay spread estimate, which reduces the impact of channel noise interference on the maximum multipath delay spread estimate and is conducive to improving the accuracy and robustness of the maximum multipath delay spread estimate.

[0007] In one possible embodiment, in S3, when windowing the first time-domain channel impulse response sequence, the Wiener filtering algorithm is used, or / and the algorithm is implemented by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

[0008] In one possible embodiment, the signal-to-noise ratio (SNR) estimate and maximum path power are calculated based on the second time-domain channel impulse response sequence; the first-path threshold and effective path threshold are adaptively calculated based on the SNR estimate and the maximum path power, including: calculating the maximum path energy based on the maximum path power; calculating the first-path threshold based on the maximum path energy and the SNR estimate; traversing the first-path search interval of the second time-domain channel impulse response sequence based on the first-path threshold to obtain a set of first-path positions; recalculating the SNR estimate based on the first-path position set; and calculating the effective path threshold based on the recalculated SNR estimate and the maximum path energy.

[0009] In one possible embodiment, calculating the first path location set and the maximum multipath delay location set based on the signal-to-noise ratio estimate, the maximum path power, the first path threshold, and the effective path threshold includes: calculating the effective path threshold based on the recalculated signal-to-noise ratio estimate; traversing the effective path search interval of the second time-domain channel impulse response sequence based on the effective path threshold to obtain the effective path location set; and calculating the maximum multipath delay location based on the effective path location set.

[0010] In one possible embodiment, recalculating the signal-to-noise ratio estimate based on the first-path position set includes: obtaining a useful signal sample set and a noise sample set based on the first-path position set; and recalculating the signal-to-noise ratio estimate based on the useful signal sample set and the noise sample set.

[0011] Secondly, embodiments of the present invention also provide a maximum multipath delay spread estimation apparatus, comprising: an acquisition unit for acquiring a pilot point channel estimation sequence; and a processing unit for performing an inverse Fourier transform on the pilot point channel estimation sequence to obtain a first time-domain channel impulse response sequence; calculating windowing coefficients based on the first time-domain channel impulse response sequence, and performing windowing processing on the first time-domain channel impulse response sequence based on the windowing coefficients to obtain a second time-domain channel impulse response sequence; calculating a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; adaptively calculating a first-path threshold and an effective path threshold based on the SNR estimate and the maximum path power; calculating the first-path position and the maximum multipath delay position based on the SNR estimate, the maximum path power, the first-path threshold, and the effective path threshold; and performing filtering processing based on the maximum multipath delay position to obtain a maximum multipath delay spread estimate.

[0012] In one possible embodiment, when the processing unit performs windowing processing on the first time-domain channel impulse response sequence, it employs the Wiener filtering algorithm, or / and implements the algorithm by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

[0013] In another possible embodiment, the processing unit calculates a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; and adaptively calculates a first-path threshold and an effective path threshold based on the SNR estimate and the maximum path power. Specifically, this involves: calculating the maximum path energy based on the maximum path power; calculating the first-path threshold based on the maximum path energy and the SNR estimate; traversing the first-path search interval of the second time-domain channel impulse response sequence based on the first-path threshold to obtain a first-path position set; recalculating the SNR estimate based on the first-path position set; and calculating the effective path threshold based on the recalculated SNR estimate and the maximum path energy.

[0014] In another possible embodiment, the processing unit calculates the first path position and the maximum multipath delay position based on the signal-to-noise ratio estimate, the maximum path power, the first path threshold, and the effective path threshold. Specifically, it is used to: calculate the effective path threshold based on the recalculated signal-to-noise ratio estimate; traverse the effective path search interval of the second time-domain channel impulse response sequence based on the effective path threshold to obtain the effective path position set; and calculate the maximum multipath delay position based on the effective path position set.

[0015] In another possible embodiment, the processing unit recalculates the signal-to-noise ratio estimate based on the first-path position set, specifically by: obtaining a useful signal sample set and a noise sample set based on the first-path position set; and recalculating the signal-to-noise ratio estimate based on the useful signal sample set and the noise sample set.

[0016] Thirdly, embodiments of the present invention also provide an electronic device, including a memory and a processor, wherein the memory stores a program executable on the processor, and when the program is executed by the processor, the electronic device performs the method described in any one of the first aspects.

[0017] Fourthly, embodiments of the present invention also provide a readable storage medium storing a program, which, when executed, implements the method described in any one of the first aspects. Attached Figure Description

[0018] Figure 1 A flowchart illustrating a maximum multipath delay spread estimation method provided by the present invention;

[0019] Figure 2 A schematic diagram of the signal-to-noise ratio versus time delay for 128 pilot points provided by the present invention;

[0020] Figure 3 A schematic diagram of the signal-to-noise ratio versus time delay for 64 pilot points provided by the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of a maximum multipath delay spread estimation device provided by the present invention;

[0022] Figure 5 This is a schematic diagram of the structure of an electronic device provided by the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0024] Figure 1 This is a flowchart illustrating a maximum multipath delay spread estimation method provided by the present invention.

[0025] In response to the problems existing in the current technology, such as Figure 1As shown, this invention provides a method for estimating maximum multipath delay spread, comprising: S1, obtaining a pilot point channel estimation sequence; S2, performing an inverse Fourier transform on the pilot point channel estimation sequence to obtain a first time-domain channel impulse response sequence; S3, calculating windowing coefficients based on the first time-domain channel impulse response sequence, and applying windowing processing to the first time-domain channel impulse response sequence based on the windowing coefficients to obtain a second time-domain channel impulse response sequence; S4, calculating a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; adaptively calculating a first-path threshold and an effective-path threshold based on the SNR estimate and the maximum path power; S5, calculating the first-path position and the maximum multipath delay position based on the SNR estimate, the maximum path power, the first-path threshold, and the effective-path threshold; and S6, performing filtering processing based on the maximum multipath delay position to obtain a maximum multipath delay spread estimate.

[0026] It is worth noting that this invention calculates the signal-to-noise ratio (SNR) estimate and maximum path power based on the second time-domain channel impulse response sequence, and adaptively calculates the first-path threshold and effective path threshold based on the SNR estimate and maximum path power, thereby improving the accuracy of first-path and effective path identification. Furthermore, this invention calculates the first-path position and maximum multipath delay position based on the SNR estimate, maximum path power, first-path threshold, and effective path threshold, and performs filtering based on the maximum multipath delay position to obtain the maximum multipath delay spread estimate. This reduces the impact of channel noise interference on the maximum multipath delay spread estimate, which is beneficial for improving the accuracy and robustness of the maximum multipath delay spread estimate.

[0027] In one possible embodiment, in S3, when windowing the first time-domain channel impulse response sequence, the Wiener filtering algorithm is used, or / and the algorithm is implemented by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

[0028] Specifically, when windowing the first time-domain channel impulse response sequence, the Wiener filtering algorithm is used.

[0029] In other specific embodiments, when windowing the first time-domain channel impulse response sequence, the algorithm is implemented by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

[0030] In some specific embodiments, when windowing the first time-domain channel impulse response sequence, the Wiener filtering algorithm is first used, and then the algorithm is implemented by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

[0031] In some specific embodiments, when windowing the first time-domain channel impulse response sequence, the algorithm is first implemented by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0, and then the Wiener filtering algorithm is used.

[0032] In one possible embodiment, a signal-to-noise ratio (SNR) estimate and a maximum path power are calculated based on the second time-domain channel impulse response sequence. Adaptive calculation of a first-path threshold and an effective path threshold based on the SNR estimate and the maximum path power includes: calculating the maximum path energy based on the maximum path power; calculating the first-path threshold based on the maximum path energy and the SNR estimate; traversing the first-path search interval of the second time-domain channel impulse response sequence based on the first-path threshold to obtain the first-path position; recalculating the SNR estimate based on the first-path position; and calculating the effective path threshold based on the recalculated SNR estimate and the maximum path energy.

[0033] Specifically, the first diameter threshold Th tap0 satisfy:

[0034]

[0035] Among them, Tap max The second time-domain channel impulse response sequence h w The maximum path energy of (n) is given by α, which is the first weighting factor, and SNR1 is the estimated signal-to-noise ratio.

[0036] In other specific embodiments, the calculation of the effective path threshold Th tapvalid satisfy:

[0037]

[0038] Among them, Tap max It is the second time-domain channel impulse response sequence h w The maximum path energy of (n) is given by β, which is the second weighting factor, and SNR2 is the recalculated signal-to-noise ratio estimate.

[0039] In some specific embodiments, recalculating the signal-to-noise ratio (SNR) estimate based on the first-path position set includes: obtaining a useful signal sample set and a noise sample set based on the first-path position set; and recalculating the SNR estimate based on the useful signal sample set and the noise sample set.

[0040] In one possible embodiment, calculating the first path position and the maximum multipath delay position based on the signal-to-noise ratio estimate, the maximum path power, the first path threshold, and the effective path threshold includes: calculating the effective path threshold based on the recalculated signal-to-noise ratio estimate; traversing the effective path search interval of the second time-domain channel impulse response sequence based on the effective path threshold to obtain a set of effective path positions; and calculating the maximum multipath delay position based on the set of effective path positions.

[0041] In other specific embodiments, the method includes: calculating a maximum multipath delay estimate based on the maximum multipath delay location, wherein the maximum multipath delay estimate is filtered to obtain a maximum multipath delay spread estimate.

[0042] It is worth noting that the maximum multipath delay spread estimate is used to determine the timing advance setting and also for calculating the frequency domain correlation coefficient. This embodiment improves channel estimation performance and thus receiver performance by obtaining an accurate maximum multipath delay spread estimate.

[0043] Figure 2 This invention provides a schematic diagram of the signal-to-noise ratio (SNR) of 128 pilot points as a function of time delay.

[0044] Specifically, a simulation experiment was conducted with a Fast Fourier Transform (FFT) length of 128 pilot points. The relationship between the channel's SNR and time delay was plotted with time delay on the ordinate and signal-to-noise ratio (SNR) on the abscissa, as shown in the figure. Figure 2 As shown, Figure 2 The dashed line in the figure represents the root mean square delay spread (Trms) channel curve. Figure 2 The solid line in the figure represents the channel curve provided in this embodiment. It can be seen that the maximum multipath delay estimates for each channel provided in this embodiment are close to the ideal values, and the estimated delay differences between different channels are greater than the delay differences between channels estimated by the root mean square delay spread, making it easier to distinguish different types of channels.

[0045] Figure 3 This invention provides a schematic diagram of the signal-to-noise ratio (SNR) of 64 pilot points versus time delay.

[0046] In other specific embodiments, a Fast Fourier Transform (FFT) length of 64 pilot points was set for simulation experiments. The relationship curve between the channel's SNR and time delay was plotted with time delay as the ordinate and signal-to-noise ratio (SNR) as the abscissa, as shown below. Figure 3 As shown, Figure 3 The dashed line in the figure represents the root mean square delay spread channel curve. Figure 3The solid line in the figure represents the channel curve provided in this embodiment. It can be seen that the maximum multipath delay estimates for each channel provided in this embodiment are close to the ideal values, and the estimated delay differences between different channels are greater than the delay differences between channels estimated by the root mean square delay spread, making it easier to distinguish different types of channels.

[0047] It is worth noting that, referring to Figure 2 and Figure 3 As can be seen, for the same channel, the curve with 128 pilot points is smoother than the curve with 64 pilot points. It is easy to see that the more pilot points there are, the higher the accuracy of delay prediction.

[0048] Figure 4 This is a schematic diagram of the structure of a processing module provided by the present invention.

[0049] like Figure 4 As shown, in some embodiments of the present invention, a maximum multipath delay spread estimation apparatus is also provided, comprising: an acquisition unit 120, configured to acquire a pilot point channel estimation sequence; and a processing unit 110, configured to perform an inverse Fourier transform on the pilot point channel estimation sequence to obtain a first time-domain channel impulse response sequence; calculate windowing coefficients based on the first time-domain channel impulse response sequence, and perform windowing processing on the first time-domain channel impulse response sequence based on the windowing coefficients to obtain a second time-domain channel impulse response sequence; calculate a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; adaptively calculate a first-path threshold and an effective path threshold based on the SNR estimate and the maximum path power; calculate the first-path position and the maximum multipath delay position based on the SNR estimate, the maximum path power, the first-path threshold, and the effective path threshold; and perform filtering processing based on the maximum multipath delay position to obtain a maximum multipath delay spread estimate.

[0050] It should be understood that all relevant content of each step involved in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here.

[0051] Figure 5 This is a schematic diagram of the structure of an electronic device provided by the present invention.

[0052] like Figure 5 As shown, in some other embodiments of the present invention, an electronic device is also provided, including a memory and a processor, wherein the memory stores a program that can run on the processor, and when the program is executed by the processor, the electronic device performs the method described in any of the above embodiments.

[0053] Specifically, the electronic device may include: one or more processors 501, a memory 502, a display 503, one or more application programs (not shown), and one or more computer programs 504. These devices can be connected via one or more communication buses 505. The one or more computer programs 504 are stored in the memory 502 and configured to be executed by the one or more processors 501. The one or more computer programs 504 include instructions that can be used to perform actions such as... Figure 1 Each step in the corresponding embodiment.

[0054] It is worth noting that the electronic device may be a communication chip, a terminal, or a base station.

[0055] In some other embodiments of the present invention, a computer-readable storage medium is also provided, wherein a program is stored therein, and when the program is executed, it implements the method described in any one of the above embodiments.

[0056] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for estimating maximum multipath delay spread, characterized in that, include: S1, Obtain the pilot point channel estimation sequence; S2, perform an inverse Fourier transform based on the pilot point channel estimation sequence to obtain the first time-domain channel impulse response sequence; S3, calculate the windowing coefficient based on the first time-domain channel impulse response sequence, and perform windowing processing on the first time-domain channel impulse response sequence based on the windowing coefficient to obtain the second time-domain channel impulse response sequence; S4, calculate the signal-to-noise ratio estimate and maximum path power based on the second time-domain channel impulse response sequence; calculate the maximum path energy based on the maximum path power; calculate the first path threshold based on the maximum path energy and the signal-to-noise ratio estimate; The first path search interval of the second time-domain channel impulse response sequence is traversed according to the first path threshold value to obtain the first path position set; the signal-to-noise ratio estimate is recalculated according to the first path position set; and the effective path threshold value is calculated according to the recalculated signal-to-noise ratio estimate and the maximum path energy. S5, according to the effective path threshold value, traverse the effective path search interval of the second time-domain channel impulse response sequence to obtain the effective path location set; calculate the maximum multipath delay location according to the effective path location set; S6, perform filtering based on the location of the maximum multipath delay to obtain an estimate of the maximum multipath delay spread.

2. The method according to claim 1, characterized in that, In S3, when windowing the first time-domain channel impulse response sequence, the Wiener filtering algorithm is used, or / and the algorithm is implemented by setting the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

3. The method according to any one of claims 1 to 2, characterized in that, The signal-to-noise ratio estimate is recalculated based on the set of initial diameter positions, including: Based on the set of initial diameter positions, obtain a set of useful signal samples and a set of noise samples; The signal-to-noise ratio estimate is recalculated based on the useful signal sample set and the noise sample set.

4. A maximum multipath delay spread estimation device, characterized in that, include: The acquisition unit is used to acquire the pilot point channel estimation sequence; The processing unit is configured to perform an inverse Fourier transform on the pilot point channel estimation sequence to obtain a first time-domain channel impulse response sequence; calculate a windowing coefficient based on the first time-domain channel impulse response sequence; perform windowing processing on the first time-domain channel impulse response sequence based on the windowing coefficient to obtain a second time-domain channel impulse response sequence; calculate a signal-to-noise ratio (SNR) estimate and a maximum path power based on the second time-domain channel impulse response sequence; calculate a maximum path energy based on the maximum path power; calculate a first-path threshold based on the maximum path energy and the SNR estimate; traverse the first-path search interval of the second time-domain channel impulse response sequence based on the first-path threshold to obtain a first-path position set; recalculate the SNR estimate based on the first-path position set; calculate an effective path threshold based on the recalculated SNR estimate and the maximum path energy; traverse the effective path search interval of the second time-domain channel impulse response sequence based on the effective path threshold to obtain an effective path position set; calculate the maximum multipath delay position based on the effective path position set; and perform filtering processing based on the maximum multipath delay position to obtain a maximum multipath delay spread estimate.

5. The apparatus according to claim 4, characterized in that, When the processing unit performs windowing processing on the first time-domain channel impulse response sequence, it employs the Wiener filtering algorithm, or / and an algorithm that sets the window coefficient of the signal region to 1 and the window coefficient of the noise region to 0.

6. The apparatus according to claim 5, characterized in that, The processing unit recalculates the signal-to-noise ratio estimate based on the set of initial diameter positions, specifically for: Based on the set of initial diameter positions, obtain a set of useful signal samples and a set of noise samples; The signal-to-noise ratio estimate is recalculated based on the useful signal sample set and the noise sample set.

7. An electronic device, characterized in that, The device includes a memory and a processor, wherein the memory stores a program that can run on the processor, and when the program is executed by the processor, causes the electronic device to perform the method of any one of claims 1 to 3.

8. A readable storage medium storing a program, characterized in that, When the program is executed, it implements the method of any one of claims 1 to 3.

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