Frequency and DOA joint measurement method and device based on Chinese remainder theorem

Abstract

The invention discloses a frequency and DOA joint measurement method and device based on the Chinese remainder theorem. The method comprises the following steps: arranging a non-uniform linear array comprising L antenna array elements, A/D converters on the antenna array elements each carrying out parallel undersampling to obtain L-path sample sequences; carrying out N-point DFT on the L-path sample sequences and carrying frequency and phase correction on the DFT results through an estimator to obtain L pairs of frequency estimation values and phase estimation values after correction; and carrying out frequency and phase reconstruction through the L pairs of frequency estimation values and phase estimation values and the closed-type Chinese remainder theorem to obtain signal frequency and direction of arrival (DOA) estimation values. The multi-path low-rate undersampling scheme is adopted to realize measurement of high-frequency signals; in the method, the limitation is broken through, and a flexible sparse array layout plan is designed; array parameters are reasonably set with practical engineering requirements being combined; and with the method, DOA parameters can be reconstructed accurately.

Description

technical field [0001] The present invention relates to the field of array signal processing, in particular to a method and device for under-sampling incident signals by using an antenna array in time domain and space domain, and obtaining high-precision joint estimation of frequency and direction of arrival by processing snapshot data. Background technique [0002] The joint estimation of carrier frequency and direction of arrival (DOA) of spatially incident signals is a research hotspot in array signal processing, and it is widely used in many fields such as sonar, radar, and wireless communication systems. [1] . The two-dimensional extended version of the traditional spectral estimation algorithm based on subspace decomposition (such as MUSIC, ESPRIT method) can achieve the goal of parameter joint estimation [2-4] , however, these methods have a large amount of computation, and their theoretical premise requires that the sampling of the signal in both the space domain an...

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Problems solved by technology

Literature [9] proposes a robust CRT algorithm and uses it to estimate the frequency of complex exponential signals, and greatly reduces the sampling rate by multi-channel sampling; however, the reconstruction process in this algorithm requires multiple two-dimensional At the same time, it is required that the number of DFT points of each sample must be equal to the sampling rate value, and its frequency resolution can only be accurate to 1Hz and consumes a large amount of calculation; literature [10] uses the Candan frequency estimator [11] with closed CRT algorithm [12] In combination, the undersampled complex exponential signal frequency estimation in literature [9] is extended to the real cosine signal frequency estimation, which reduces the amount of computation when the number of snapshots is small; however, the estimation accuracy of the algorithm under low SNR It needs to be improved; literature [13] proposes to use CRT for signal azimuth estimation under spatial undersampling and demonstrates its feasibility, which lays the foundation for further research and expansion in the future. However, literature [13] does not mention specific The array layout scheme and phase residue extraction method

In view of the defects of existing methods such as high computational complexity, fixed resolution, low precision under low signal-to-noise ratio, and lack of specific layout schemes for arrays, the present invention combines closed CRT [12] and the AM spectrum estimator [14] , discloses a method and device for high-precision joint measurement of signal frequency and DOA under time-space undersampling

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