Basis Expansion Model (BEM) based MIMO-OFDMA channel capacity and estimation

MIMO-OFDMA has become an efficient method characterizing diversity to multi-user transmission over doubly selective fading channels with high spectral efficiency. In this paper we develop a Basis Expansion Model (BEM) based MIMO-OFDMA system and we analyze the channel capacity for the system. It is shown that, by using BEM based channel approximation for MIMO-OFDMA system we can achieve diversity without any space-time coding. Specifically, BEM based system inherently exploits the receive diversity and maximizes channel capacity similar to existing diversity technique like Maximal Ratio Combining (MRC).