Maximum Likelihood Estimation of the Double-Directional Parameters in the Multiple-Input-Multiple-Output Communication System Using the Particle Swarm Optimization

In this article, we describe and evaluate the performance of the particle swarm optimization (PSO)-based maximum likelihood estimation (MLE), which will be used to estimate the angular parameters of the double-directional (DD) channel model in the multiple-input-multiple-output (MIMO) wireless system. The presented technique is shown to have a performance that is better than that achieved by the genetic algorithm (GA), and, hence, it yields an asymptotically efficient directional parameters estimate. The obtained estimates have approximately 2.5-dB saving in the threshold region over the GA-based MLE or the data-supported grid search. Another advantage of the PSO-based MLE technique is its simple implementation with few operations.