DOA And Polarization Parameter Estimation Based On Multi-population Genetic Algorithm And DSP Implementation

In recent years,with the development of precision guided weapons,multi-mode composite conductors have become a research hotspot.And the use of polarization-sensitive array(PSA)enables the passive direction finding system to be compatible with other guidance mode detection sensors.The PSA can simultaneously observe Direction of Arrival(DOA)information and polarization information of incident electromagnetic waves,which effectively improves the overall performance of the direction-finding system.The Multiple Signal Classification(MUSIC)algorithm has super-resolution characteristics in parameter estimation of array signal processing and is widely used in practical engineering.The algorithm mainly includes two parts: feature decomposition and peak search.The introduction of polarization information makes spectrum peak search from original two-dimensional search to four-dimensional search.Meanwhile,the computational volume grows exponentially.Therefore,the traditional method which searches the whole spectrum peak fails in practical engineering applications.Genetic algorithm has the characteristics of small amount of computation and parallelism.It has unique advantages for solving global optimization problems,but the standard genetic algorithm is easy to fall into immature convergence.In order to reduce the computational complexity of the polarization MUSIC algorithm and overcome the premature convergence problem of the standard genetic algorithm,a new method based on multi-population genetic algorithm to estimate the DOA and polarization parameter is proposed in this paper.Based on the standard genetic algorithm,the multiple populations are introduced.Moreover,it can conduct the optimization search at the same time.An immigration operator is used to exchange information among various populations,and an artificial selection operator is used to retain the optimal individuals in each evolutionary process of each group and save them to elite populations.Through simulation experiments,the multi-population genetic algorithm overcomes the premature convergence problem of the standard genetic algorithm and has good global search capability.In the paper,the multi-population genetic algorithm applied to the spectral peak search part of the polarization MUSIC algorithm was compared with the rank-loss MUSIC algorithm.After conducting many Monte Carlo experiments,both algorithms can meet the accuracy for estimation of DOA and polarization parameters in practical engineering applications.The estimation accuracy of the two algorithms is similar,but the estimation time of DOA and polarization parameters based on multi-population genetic algorithm is half less than therank-loss MUSIC algorithm's,which greatly improves the real-time performance of the algorithm and has a strong engineering application significance.The development of digital signal processors has made real-time super-resolution measurements a reality.The TMS320C6678 is an 8-core DSP(Digital Signal Processor)of the KeyStone architecture.It has powerful fixed-point and floating-point computing capabilities.Therefore,we chooses this hardware platform proposed in the paper to verify the DOA and polarization parameter estimation based on Multi-population genetic algorithms.