Signal Detection Using Log-Likelihood Ratio Based Sorting QR Decomposition for V-BLAST Systems

In this paper, we propose a novel detection algorithm using log-likelihood ratio (LLR) to detect signals for V-BLAST systems. This algorithm utilizes the sorting QR decomposition (SQRD) of the channel matrix, and applies LLR to determine the order of detection. Simulation results show that the proposed LLR-based MMSE-SQRD algorithm provides a better performance than the conventional SNR-based MMSE-SQRD algorithm with a few additional computations. Approximately, the average BER performance of our algorithm is better than that of the conventional SNR-based MMSE-SQRD algorithm by 4 dB at 10^-4 target BER.