Robust Doppler parameter estimation method based on OTFS communication and perception integration

Abstract

The present invention discloses a robust Doppler parameter estimation method based on OTFS communication perception integration, comprising: constructing a communication perception integration signal model and obtaining a communication perception integration transmission signal; obtaining a communication perception integration echo signal based on the communication perception integration transmission signal; performing block processing on the communication perception integration echo signal to obtain a block-processed echo signal; preprocessing the block-processed echo signal to construct a new cyclic prefix signal; selecting a signal threshold to eliminate communication information based on the new cyclic prefix signal to obtain a two-dimensional exponential signal carrying time delay and Doppler information; and performing target parameter estimation on the two-dimensional exponential signal to obtain a target parameter estimation result. The present invention can achieve accurate perception of the distance and speed of high-speed moving targets.

Claims

1. A Doppler robust parameter estimation method based on OTFS communication perception integration, characterized in that: include: Construct a communication-aware integrated signal model and obtain the communication-aware integrated transmission signal; Based on the communication and perception integrated transmission signal, obtaining a communication and perception integrated echo signal; Performing block processing on the communication-sensing integrated echo signal to obtain a block-processed echo signal; Preprocessing the echo signal block processing signal to construct a new cyclic prefix signal; According to the new cyclic prefix signal, a signal threshold is selected to eliminate communication information to obtain a two-dimensional exponential signal carrying delay and Doppler information; performing target parameter estimation on the two-dimensional exponential signal to obtain a target parameter estimation result; The communication and sensing integrated transmission signal adopts a continuous wave system, including subframe signals, each of which includes a cyclic prefix signal, Orthogonal time-frequency-space modulation of communication code elements and pilot signals, wherein the cyclic prefix signal is located at the front part of the subframe signal, and the pilot signal is located at any position of the subframe signal; The communication-sensing integrated signal model transmits Subframe signal The expression is: ； ； in, It is the communication symbol after the binary data stream of 0 and 1 is mapped through PSK or QAM symbols. The number of orthogonal time-frequency-space modulation communication code elements contained in each subframe structure signal, is the number of subcarriers of the orthogonal time-frequency-space modulation communication code, is the total number of subframe structure signals in a signal-sensing integrated transmission signal, is the index of the subcarrier of the orthogonal time-frequency-space modulation communication code, is the index of the number of communication code elements modulated by orthogonal time-frequency space, is the delay index, is the Doppler index, is the natural base, is the imaginary unit, is pi, is the subcarrier spacing, is the length of the orthogonal time-frequency-space modulation communication code element number, is the subframe structure signal length, is the cyclic prefix length in the subframe structure signal, is a rectangular window function, when When , the rectangular window function takes the value of 1, and in other cases the value is 0. For time; Based on the Subframe signal , get the The echo signal received by the subframe structure , whose expression is: ； ； in, is the target index, is the total number of targets, For the transmission path response, is the time delay of the target echo, For the The distance between a target and the communication and perception integrated signal transmitter, is the speed of light, For the The Doppler frequency of a target, , is the target radial velocity, Transmitting signal wavelength for integrated communication perception, is additive Gaussian white noise; The communication sensing integrated echo signal is subjected to block processing to obtain an echo signal block processing signal, including: The communication sensing integrated echo signal is processed in blocks to obtain sub-blocks, where the sampling interval for block processing is , the number of samples in the sub-block is , satisfying the constraints , then the first condition is established, and its expression is: ； Get the The echo signals in the sub-blocks are processed in blocks , whose expression is: ； ； ； ； in, For the modulo operation, is the noise signal, is the signal sampling point, is the total transmitted signal, is the time delay of the target echo; Substitute the expression of the first condition into the The expression of the echo signal in each sub-block is simplified to obtain the echo signal block processing signal , whose expression is: ； Also includes: Block processing is performed on the communication sensing integrated transmission signal to obtain a plurality of sub-blocks, which correspond one-to-one to the sub-blocks of the echo signal, and the sub-blocks of the transmission signal include valid modules and invalid modules; Get the transmitted signal The effective module discrete signal of the sub-block is expressed as: ； in, is the number of valid module sampling points; The signal will be transmitted The effective module discrete signal of the sub-block The sampling point signals are shifted and added, and then the front of each sub-block is removed. sampling point signal, and obtain a new cyclic prefix signal , whose expression is: ； ； ； ； in, To transmit the signal The number of sampling points of the effective module signal cyclic shift of each sub-block, , and are the intra-module interference and inter-module interference of the sub-blocks, is the number of sampling points of target echo delay, is the maximum delay sampling point number of the target echo; According to the new cyclic prefix signal, an appropriate signal threshold is selected to eliminate communication information to obtain a two-dimensional exponential signal carrying delay and Doppler information, including: The new cyclic prefix signal is The discrete-time Fourier transform of the point is used to obtain the Fourier transformed signal, which is expressed as follows: ； ； in, for of Point discrete-time Fourier transform, for of Point discrete-time Fourier transform, for of Point discrete-time Fourier transform, for of Point discrete-time Fourier transform; Set signal threshold ,Will is less than the signal threshold signal, The value of is 0; is greater than the signal threshold signal, The value of As a result, a two-dimensional exponential signal carrying time delay and Doppler information is constructed. , whose expression is: ； ； in, is the signal frequency domain sampling point.

2. The Doppler robust parameter estimation method based on OTFS communication perception integration according to claim 1 is characterized in that The signal threshold Selection is performed using the threshold search method.

3. The Doppler robust parameter estimation method based on OTFS communication perception integration according to claim 1 is characterized in that The performing target parameter estimation on the two-dimensional exponential signal to obtain a target parameter estimation result includes: The Fourier transformed signal is represented by a matrix, which is expressed as follows: ； ； ； ； in, is the echo signal matrix, is the transmission signal block matrix, each column of the transmission signal block matrix represents the spectrum of the sub-block signal, and are the intra-module interference matrix and the inter-module interference matrix, is the noise matrix, For Hadamard, is the Kronecker product, and They are time delay effect and Doppler effect respectively; According to the two-dimensional index signal , element-by-element complex division is used to remove the influence of communication information on target parameter estimation, and its expression is: ； By obtaining the delay effect Target delay in , and Doppler effects Doppler , get the target parameter estimation result; among them, the target delay By calculating the delay effect The discrete Fourier transform of is obtained, and its expression is: ； Doppler By calculating the Doppler effect The discrete Fourier transform of is obtained, and its expression is: ； in, is the inverse discrete-time Fourier transform, for Rearranged into a signal sequence, for Rearranges into a signal sequence.

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