Adaptive loading for MIMO and MIMO-OFDM channels

Adaptive bit loading algorithms are proposed for MIMO and MIMO-OFDM systems, thus better exploiting space and frequency diversity. Constant power allocation is assumed over all subchannels while the bit error rate is unconstrained. An efficient bit loading algorithm, which maximizes system bit rate under target mean BER constraint is formulated for a multiple antenna system. Simulation results validate that the BER improvement achieved by using the BER-allocation algorithm in the MIMO-OFDM case is significant.