Efficient Transmit Strategy Using a Fraction of Feedback for QRD Based V-BLAST Systems

In this paper, we propose an efficient transmit strategy utilizing the partial channel information feedback for the QRD based V-BLAST systems. In the proposed scheme, after QR decomposition (QRD) of the channel matrix, positive real-valued diagonal elements of R are forwarded to the transmitter through the feedback channel. Based on the feedback information, the transmitter allocates the optimum transmit power to minimize the bit error rate (BER) of the system. With small feedback overhead, the proposed scheme shows significantly improved BER performance compare to the conventional sorted QR decomposition (SQRD) based V-BLAST systems. Moreover, we can reduce the receiver complexity by removing the unnecessary sorting process at the receiver.