Pilot-Based Angle-Domain Channel Estimation for MIMO-OFDM Systems

Multiple-input multiple-output combined with orthogonal frequency division multiplexing (MIMO-OFDM) channel estimation could be improved by prior knowledge of the channel spatial correlation. This information is, however, not always unavailable. So, we choose to investigate channel estimation in angle domain, where different channel coefficients can be assumed to be of irrelevance. In this paper, based on traditional LS algorithm using phase shifted orthogonal pilots (PSO-ILS), an algorithm called angle-domain PSO-LS (PSO-ALS) is proposed. This algorithm has low complexity and use most significant taps (MST) to reduce the noise effect. To obtain better performance, an improved PSO-ALS (PSO-AILS) algorithm which exploit MST to improve PSO-LS algorithm firstly and then perform the same course like PSO-ALS algorithm. Simulation results indicate the proposed algorithm perform good MSE performance at low SNRs.