The Research Of Circular Array DOA Algorithm And Implementation Base On DSP

The underwater acoustic beacon search system needs to detect and estimate the direction of the underwater target with the acoustic beacon.In order to achieve the purpose of the direction finding of the target,and provide a theoretical and application basis for the development of the direction estimation module of the subsequent search equipment,this paper studies the DOA estimation algorithm based on a uniform circular array and implements it on the DSP hardware platform.Firstly,aiming at the problem of DOA estimation of underwater acoustic beacons,the thesis studied the classic DOA estimation algorithm based on uniform circular array.It focuses on the theoretical research and computer simulation of Conventional Beamforming,Minimum Variance Distortionless Response(MVDR)method,Multiple Signal Classification(MUSIC)method and classic split beam method.Aiming at the shortcomings of the classic splitting method that the element utilization is not high and the low signal-to-noise ratio estimation accuracy is poor,an improved split beam method with sub-array coincidence is proposed.The simulation results show that the improved split-beam method can effectively improve the performance of DOA estimation under low signal-to-noise ratio,and the amount of calculation is low,which is suitable for hardware platform implementation.Secondly,the thesis conducts theoretical research and simulation analysis on the DOA estimation algorithm based on sparse Bayesian learning,focusing on the in-depth research on SBL and SBL1 algorithms.Compared with the classic algorithm,the sparse Bayesian algorithm has better resolution,and the mean square error of the DOA estimation is close to that of the MUSIC algorithm.However,this kind of method has a large amount of calculation and is difficult to process in real time on a hardware platform,and is suitable as a post-processing algorithm for collecting data.After the theoretical analysis is completed,the paper designs and implements the DOA estimation software based on uniform circular array based on the TMS320C6748 hardware platform.The software modules such as u PP communication,Ethernet data transmission,received signal preprocessing,position estimation module and multitasking and multithreading under SYS/BIOS operating system are designed and implemented.In the DOA estimation module,software implementation is focused on conventional beamforming,MVDR,MUSIC,classic split beam method,and improved split beam algorithm.Verified by the DSP platform,the calculation result of the above-mentioned DOA estimation algorithm is consistent with the computer simulation result,which meets the requirements of position estimation.Finally,the paper carried out functional tests and verifications on the u PP communication module,Ethernet transmission module,data preprocessing module and position estimation module.A pond experiment was designed and carried out,and the experimental data was collected and processed using a hardware system.The DOA estimation results were consistent with the actual situation,which verified the correctness of the algorithm.The research results of the thesis can provide high-precision direction estimation function for underwater acoustic beacon search equipment,which can effectively improve the accuracy of search results.