Adaptive transmission with linear computational complexity in MIMO-OFDM systems

A novel adaptive transmission scheme is proposed to improve the computational efficiency of conventional adaptive algorithms for multiple-input multiple-output orthogonal frequency-division multiplexing systems. By exploiting the stationary ergodicity of subchannel amplitudes, the proposed scheme can reduce the complexity of any existing adaptive algorithms to a considerably low level that is linear in the number of subchannels, while it causes little performance degradation. Index Terms--Adaptive transmission, fading channels, multiple-input multiple-output (MIMO) systems, orthogonal frequency-division multiplexing (OFDM).