Maximum Likelihood Based Joint Angle-Frequency Estimation Using QPSO Algorithm

In this paper, the Maximum Likelihood (ML) method using Quantum-behaved Particle Swarm Optimization (QPSO) algorithm is applied to the problem of estimating the direction-of-arrival (DOA) and the Doppler frequency of multiple signal sources impinging on an antenna array simultaneously. The extended observability matrix containing the angle and frequency parameters is established using state-space model. The ML method is used to estimate the parameters accurately and convert the problem from parameter estimation to a nonlinear multidimensional function optimization. Then the DOA and Doppler frequency are estimated by optimizing the likelihood function using QPSO algorithm. The proposed method reserves the asymptotic unbiased estimation of the ML method and reduces the computational burden of calculating the solution. Besides, the estimated parameters can be paired automatically.