Efficient Transmit Power Allocation and Feedback Reduction Algorithm for SQRD based V-Blast Systems

The closed-loop multiple-input multiple-output (MIMO) systems can provide considerably improved system performances by taking advantage of channel information at the transmitter. In this paper, we propose an efficient transmit power allocation utilizing a fraction of channel feedback for the sorted QR decomposition (SQRD) based vertical Bell labs layered space-time (V-BLAST) systems. With the proposed transmit power allocation, the bit error rate (BER) performance can be improved significantly compare to the conventional open-loop SQRD based V-BLAST systems. Furthermore, the feedback overhead of the system can be reduced efficiently by employing the feedback reduction technique. Simulation results with some numerical analysis demonstrate the validity of the proposed algorithm.