An antenna array signal synthesis method with fixed phase center characteristics

Abstract

The invention provides an antenna array signal synthesis method with a fixed phase center characteristic, the antenna array has a fixed phase center characteristic, the phase center does not drift under the condition of low signal-to-noise ratio, and the entire array can adaptively track the reference The phase center of the antenna. The present invention adopts the "1 pair of L-1" antenna grouping method, takes the fixed reference antenna as the phase center, and improves the Sumple algorithm through the coupling matrix and the decoupling matrix, so that it has a fixed phase center characteristic, so that the entire array can be automatically It adapts to tracking the phase center of the reference antenna and realizes the weighted phase estimation equivalent to the Simple algorithm. The performance is equivalent to that of the Simple algorithm, but it solves the problem that the phase center of the Simple algorithm will drift under the condition of low signal-to-noise ratio, and can meet the requirements of the antenna group. The array system requires a fixed phase center characteristic.

Description

technical field [0001] The invention relates to the technical field of antenna communication, in particular to an antenna array signal synthesis method with fixed phase center characteristics. Background technique [0002] Signal synthesis technology is one of the key technologies of antenna array. Its basic principle is to estimate and compensate the time delay and phase difference between antenna signals, and then realize coherent synthesis. At present, the antenna array mainly adopts the Full-Spectrum Combining (FSC) scheme, in which the sub-band phase difference estimation technology has always been the core technology and research hotspot of the antenna array. The most widely studied and applied classical phase difference estimation algorithms at home and abroad mainly include Simple algorithm, Sumple algorithm and Matrix-Free algorithm improved based on Eigen algorithm. Among them, the Sumple algorithm is currently the algorithm with the best comprehensive performance...

AI Technical Summary

Problems solved by technology

Generally speaking, the current Sumple algorithm still has two deficiencies in antenna array signal synthesis: ① using virtual reference antennas in turn, without a fixed phase center; ② under the condition of low signal-to-noise ratio, there is a problem of phase center drift

For example, when the antenna array is used for navigation tasks such as speed measurement and ranging or Very Long Baseline Interferometrey (VLBI), if the equivalent phase center of the array changes randomly, it will inevitably affect the measurement accuracy

For this application background, the simplest and most direct method is to use the Simple algorithm, but the performance of the Simple algorithm is poor under the condition of low signal-to-noise ratio. The phase center is not fixed, and there will be a phase drift problem under low signal-to-noise ratio conditions

In order to overcome the above problems, Shen Caiyao and Yu Hongyi proposed to use the phase weight at a fixed moment after the algorithm converges as a reference to modify the phase weight at other times. Although this algorithm can improve the phase drift problem, it does not consider the change of the phase center of each antenna. In practical applications, the array will not be able to quickly and adaptively track the phase change of the signal, so someone proposed to change the reference antenna of the Sumple algorithm to the weighted sum of all antenna signals. In fact, this becomes the Matrix -Free algorithm, but the autocorrelation component during correlation will cause the weight phase to decrease, which will affect the convergence rate

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