Research And Implementation Of Adaptive Beamforming Algorithm For High Reliability Communication

Adaptive beamforming is a key technology for array signal processing.It can enable the array to effectively receive interference signals while suppressing interference signals.Research on adaptive beamforming has a long history,and modern research dates back to the 1970s.The adaptive array antenna has excellent advantages in signal anti-fading,system anti-interference and increasing system capacity,which greatly improves the reliability of the communication system.At present,this technology has been widely used in many fields such as radar,sonar,wireless communication,biomedicine and seismic detection.In the future,in the face of more complicated electromagnetic environments,the contribution of adaptive beamforming technology in various fields will be more prominent.The LCMV beamformer is the starting point for the research of adaptive beamforming technology in this paper.It includes two processes:signal arrival direction estimation and adaptive beamforming.From this two perspectives,this paper researches and proposes more reliable beamforming algorithms.The specific work is described as follows:1.Starting from the blind DOA estimation algorithm,a non-blind DOA estimation algorithm based on data assistance is proposed.The traditional blind estimation algorithm cannot effectively distinguish the target signal and the interference signal,and when the number of signals exceeds the limit,it cannot be estimated.The non-blind estimation algorithm proposed in this paper correlates the local sequence with the received signal,uses the correlation value to construct a spatial spectrum,and searches for the peak value of the spectrum to find the estimated angle.Because of the existence of the local sequence,the angle estimation will be theoretically more accurate and the resolution will be stronger,effectively making up for the shortcomings of the blind estimation algorithm;2.Based on the traditional LC-LMS(Linear Constrained LMS)algorithm,an improved Log-sum LC-LMS algorithm is proposed.In this paper,when studying the beamforming algorithm(LC-LMS),the log-sum penalty is introduced into the cost function of the algorithm,and the Log-sum LC-LMS algorithm is derived.Experimental data shows that compared with LC-LMS algorithm,the new algorithm has faster convergence speed and better steady-state performance;3.Coprime arrays can increase the array aperture,reduce array element coupling effects,and improve resolution.In addition to the commonly used uniform linear array model,this paper extends the research on the application of DOA estimation algorithms and beamforming algorithms to coprime arrays to further deepen the theoretical research content of anti-jamming communication;4.This article not only carries out theoretical analysis,but also engineering practice verification.First of all,this paper implements FPGA implementation of non-blind DOA estimation.In the process,we replace the full-range accurate angle search with twice angle searches with different accuracy.While achieving the same function,it effectively saves hardware resources and greatly improves the calculation speed.Then,the LC-LMS algorithm is combined with pipeline technology to complete the hardware programming of the algorithm.The subsequent module simulation data,and the comparison between FPGA simulation results and floating-point Matlab simulation results,verified the validity and reliability of the entire design.