Approaching MIMO-OFDM Capacity with Per Antenna Power and Rate Feedback

For block fading channels, the delay-limited capacity measures the maximum constant-rate achievable over all fading blocks under the availability of complete channel knowledge at both the transmitter and the receiver. In this paper, we consider constant-rate transmissions over MIMO-OFDM block fading channels, under the condition that the channel is known at the receiver but unknown at the transmitter. We consider the well-known V-BLAST architecture that employs independently encoded data for each transmit antenna and present a closed-loop extension of V-BLAST whereby the receiver jointly optimizes the rate and power assignments for each transmit antenna and then informs them to the transmitter via a low-rate feedback channel. Simulation results have confirmed that the closed-loop V-BLAST architecture can approach closely the channel delay-limited capacity if a capacity-achieving scalar code is used at each transmit antenna.