Two EM-type channel estimation algorithms for OFDM with transmitter diversity

Abstract

Combining Orthogonal Frequency Division Multiplexing (OFDM) with transmitter diversity can be used for capacity improvement in high-rate wireless data communication systems. For coherent detection in such systems, channel state information (CSI) is required. In this paper we investigate a Space-Alternating Generalized Expectation-Maximization (SAGE) algorithm to iteratively estimate the channel impulse responses associated with multiple transmitters and the receiver. The performance of the estimator is compared with a previously proposed Expectation-Maximization (EM) based algorithm in terms of convergence rate.