Adaptive MIMO-OFDM Based on Partial Channel State Information

P. Xia, S. Zhou, G.B. Giannakis
2004 IEEE Transactions on Signal Processing  
Relative to designs assuming no channel knowledge at the transmitter, considerably improved communications become possible when adapting the transmitter to the intended propagation channel. As perfect knowledge is rarely available, transmitter designs based on partial (statistical) channel state information (CSI) are of paramount importance not only because they are more practical, but also because they encompass the perfect-and no-knowledge paradigms. In this paper, we first provide a partial
more » ... SI model for orthogonal frequency division multiplexed (OFDM) transmissions over multi-input multioutput (MIMO) frequency selective fading channels. We then develop an adaptive MIMO-OFDM transmitter, by applying an adaptive two-dimensional coder-beamformer we derived recently, on each OFDM subcarrier, along with an adaptive power and bit loading scheme across OFDM subcarriers. Relying on the available partial CSI at the transmitter, our objective is to maximize the transmission rate, while guaranteeing a prescribed error performance, under the constraint of fixed transmit-power. Numerical results confirm that the adaptive two-dimensional space-time coder-beamformer (with two basis beams as the two "strongest" eigenvectors of the channel's correlation matrix perceived at the transmitter) combined with adaptive OFDM (power and bit loaded with M -ary QAM constellations) improves the transmission rate considerably.
doi:10.1109/tsp.2003.819986 fatcat:ki6em6j2h5hpheq3h3zjsvwhwe