Under-channel direction finding system and method based on Toeplitz matrix recovery

Abstract

The invention discloses an under-channel direction finding system based on Toeplitz matrix recovery. The system comprises a uniform linear array containing M omnidirectional antennas, a P-channel receiver, P-1 multipath radio frequency change-over switches, a synchronous time sequence controller, a signal acquisition processor and a spectrum estimation direction finding module. The method comprises the following steps: designing a switching mode of the multi-channel radio frequency selector switch, so that antenna array elements can be gated in a time-sharing manner; establishing a mathematical model of gating antenna array element receiving signals; calculating a covariance matrix of gating array element receiving signals; according to the Toeplitz characteristics of the covariance matrixof the uniform linear array, obtaining a covariance matrix corresponding the whole array by recovery through each calculated covariance matrix; and according to the recovered covariance matrix, carrying DOA estimation by using a covariance-based algorithm. According to the method, the characteristics of the Toeplitz matrix are utilized, the overall covariance can be recovered only by calculatingthe sub-covariance, the complexity is low, and physical hardware is easy to implement.

Description

technical field [0001] The invention belongs to the technical field of spatial spectrum estimation, and in particular relates to an applicable under-channel direction finding system and method when the number of receiver channels is less than the number of antennas. Background technique [0002] Direction Of Arrival (DOA) estimation is an important research direction in the field of array signal processing, and it is widely used in radar positioning, tracking and other fields. Super-resolution direction finding technology has become a research hotspot in the field of spectrum monitoring and direction finding because of its high precision, high resolution and excellent performance in anti-multipath interference. At present, there are many super-resolution DOA estimation algorithms, such as multiple signal classification (MUltiple SIgnal Classification, MUSIC) algorithm, based on rotation invariance (Estimation of Signal Parameters via Rotational Invariance Techniques, ESPRIT)...

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Problems solved by technology

However, this method has certain disadvantages: on the one hand, as the number of array elements increases, the number of receivers also increases correspondingly, which will make the cost of the receiving system very expensive, and the cost of system hardware becomes a constraint on application. A major factor; on the other hand, the increase in the number of channels makes it difficult to ensure consistency between the receivers of each channel, and the amplitude and phase errors between the channels will lead to a decrease in the direction finding performance of the algorithm

However, the single-channel direction-finding algorithm has high requirements on the performance indicators of the receiving channel, receiver and switch, and the calculation amount is large, and the direction-finding algorithm takes a lot of time, which affects the real-time performance of the system.

The weighted perturbation method can be applied to a single receiver system, and extended to the case of two-channel and three-channel receivers. The array covariance matrix recovery can be realized through appropriate weighting and weighted perturbation, but this method is difficult to implement in engineering, and in Adding precise perturbation to the RF section is difficult to control

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