A Robust Beamforming Method Based on Sidelobe Cancellation

Abstract

The invention discloses a robust beamforming method based on sidelobe cancellation, and belongs to the field of adaptive array signal processing. The invention utilizes the area where the incoming wave direction of the desired signal is known to construct the blocking matrix, and obtains more accurate weighting of the main and auxiliary channels by re-estimating the steering vector of the desired signal, so that the beamformer with side lobe cancellation has the ability to target the incoming wave Methods for Robustness to Orientation Mismatches. When there is a mismatch in the direction of arrival of the desired signal, this method has the robustness that the traditional sidelobe cancellation algorithm does not have, and solves the problem of the main channel output due to the weight vector not being aligned with the direction of arrival of the desired signal. Compared with the case of no mismatch, the signal gain has decreased and the blocking matrix constructed by using the mismatched direction of arrival cannot completely block the desired signal in the auxiliary channel, so that the desired signal will also be blocked to a certain extent after the main auxiliary channel is cancelled. Eliminate these two problems.

Description

technical field [0001] The invention belongs to the beam forming technology in the field of adaptive array signal processing, and in particular relates to a robust beam forming method based on side lobe cancellation. Background technique [0002] Sidelobe cancellation technology (sidelobe cancellation) has long been applied to the field of digital beamforming. By adaptively adjusting the complex weighting coefficients of each channel of the array, not only the output response of the main lobe is guaranteed, but also the non-correlated strong interference from each side lobe direction is suppressed to the greatest extent. [0003] Compared with the adaptive beam nulling algorithm, the sidelobe cancellation algorithm has considerable advantages. The sidelobe cancellation algorithm was developed on the basis of adaptive nulling and appeared in the IEEE standard in 1997. The sidelobe cancellation algorithm selects a part of the array elements in the array or adds several array ...

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Problems solved by technology

[0035] As mentioned in the background art, in the traditional sidelobe cancellation algorithm, the direction of arrival of the desired signal θ 0 It is assumed to be known, but this angle is actually inaccurate in practical applications. When the expected signal incoming wave direction θ 0 When there is a mismatch, there will be two problems when using conventional sidelobe cancellation technology for interference suppression: one is that the weight vector of the main channel is not aligned with the direction of arrival of the desired signal, so that the gain of the desired signal in the output of the main channel is compared with that without The other is that the blocking matrix constructed using the mismatched direction of arrival cannot completely block the desired signal in the auxiliary channel, so that the desired signal will also be canceled to a certain extent after the main auxiliary channel is cancelled.

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