Multipath channel identification by using global optimization in ambiguity function domain

A new transform domain array signal processing technique is proposed for identification of multipath communication channels. The received array element outputs are transformed to delay–Doppler domain by using the cross-ambiguity function (CAF) for efficient exploitation of the delay–Doppler diversity of the multipath components. Clusters of multipath components can be identified by using a simple amplitude thresholding in the delay–Doppler domain. Particle swarm optimization (PSO) can be used to identify parameters of the multipath components in each cluster. The performance of the proposed PSO-CAF technique is compared with the space alternating generalized expectation maximization (SAGE) technique and with a recently proposed PSO based technique at various SNR levels. Simulation results clearly quantify the superior performance of the PSO-CAF technique over the alternative techniques at all practically significant SNR levels.

► We propose a new array processing technique for multipath channel estimation.
► We use particle swarm optimization (PSO) to estimate the multipath parameters.
► Cross ambiguity function (CAF) is used to exploit the delay–Doppler diversity.
► Performance of the proposed PSO-CAF technique is better than the SAGE technique.
► The PSO-CAF also has better performance than recently proposed PSO based technique.