Closed loop QR decomposition based receiver for MIMO communication systems

In multiple-input multiple-output (MIMO) communication systems, QR decomposition of the channel matrix can be used in successive cancellation detectors. Here, we propose a power allocation scheme to improve the performance of the QR decomposition based successive interference cancellation (QR-SIC) with alleviated required amount of feedback. The proposed algorithm decreases the overall block error rate (i.e. the probability to have at least one error at the demodulated transmit vector) when QR-SIC detection scheme is used for detection of transmit symbols. We propose two different power allocation strategies for reduction of instantaneous as well as the average block error rates in each layer of transmitted data. Our simulation results show that both proposed algorithms significantly outperform the conventional QR-SIC algorithm with uniform power allocation.