Coherent Signal Direction Finding With Sensor Array Based on Back Propagation Neural Network

An algorithm based on back propagation neural network and particle swarm optimization is proposed to solve the direction of arrival (DOA) estimation of coherent signals received by the sensor array in colored noise environment. First, a spatial differential smoothing algorithm is adopted to eliminate colored noise and the independent signals to obtain a covariance matrix only containing the coherent sources. Then, the first line of the covariance matrix is extracted as an input characteristic parameter vector, meanwhile, the DOA of the coherent signals are taken as output. Finally, the trained back propagation neural network optimized by particle swarm algorithm is exploited to reckon the directions of coherent signals. The algorithm put forward in this paper does not require eigen-decomposition and spectral peak searching, so the computational burden is low. Theoretical analysis and simulations demonstrate that the proposed algorithm has high angular resolution and direction finding accuracy in colored noise environment.