Wideband digital wave beam forming method based on all-pass type variable fractional delay filter

Abstract

The invention discloses a wideband digital wave beam forming method based on an all-pass type variable fractional delay filter. The problem that a needed filter in the prior art is large in order number and high in complexity is solved. The method comprises the steps that (1) according to radar system parameters, sampling rate fs and sampling time ts are determined; (2) according to the radar array geometric structure and the sampling time ts, a propagation time delay tau of each array element relative to a reference array element is calculated; (3) according to the sampling rate fs, an AD chip is selected to digitize analog signals received by the array elements; (4) according to the propagation time delay tau and the digitized received analog signals, the all-pass type variable fractional delay filter is designed; (5) the digitized received signals are filtered; (6) phase delay of the filtered signals is compensated for; (7) a window function is selected to conduct weighted summation on the filtered compensated signals to obtain a wave beam forming result. The wideband digital wave beam forming method can achieve wideband digital beam forming, saves hardware resources, improves instantaneity and can be used for wideband digital array radar.

Description

technical field [0001] The invention belongs to the technical field of radar, relates to wideband digital beam forming, and can be used for wideband digital array radar signal processing. Background technique [0002] Array radar signal processing is to set multiple sensors at different positions in space to form a sensor array, and use it to receive and process space signals, aiming to extract the signals of interest and their characteristic information received by the array, and at the same time Suppresses interference and noise or signals of no interest. It has the advantages of flexible beam control, high processing gain, strong anti-interference ability, and high spatial resolution. It has received widespread attention and rapid development in the fields of radar, radio astronomy, sonar, communication, direction finding, seismology, and medical diagnosis. The research contents of array signal processing mainly fall into two categories: one is spatial spectrum estimatio...

AI Technical Summary

Problems solved by technology

When the frequency is high and the bandwidth is large, a long-length tapped delay line group or a high-order FIR filter is required, the convergence speed is slow, and the amount of calculation is large. At the same time, it is difficult or even impossible to realize the sampling frequency.

In addition, in the existing wideband digital beamforming method, each array element has a different delay relative to the reference array element, and it is necessary to design a different fractional delay filter for each array element, the design complexity is high, and the workload is high. Big

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