Approaching MIMO-OFDM Capacity with Closed-Loop V-BLAST.

In this paper, power-efficient transmission schemes are studied for MIMO-OFDM block-fading channels under the assumption that the channel is perfectly known at the receiver but unknown at the transmitter. Based on the well-known V- BLAST architecture that employs the horizontal encoding and the interference-nulling based successive decoding, this paper presents a closed-loop V-BLAST extension for MIMO-OFDM whereby the transmit rate and power as well as the assigned transmit antenna for each data stream at different OFDM tones are jointly optimized at the receiver and then fed back to the transmitter. Simulation results have confirmed that the closed- loop V-BLAST architecture is able to approach closely the MIMO-OFDM channel capacity attained through the eigenmode transmission that requires the complete channel feedback from the receiver to the transmitter.