Abstract: A simplified QRD-M algorithm for the IEEE 802.11n STBC-VBLAST is proposed. In order to carry out a limited tree search, each surviving path is expanded only to its partial branches according to the estimation of the symbol to be detected. The proposed scheme can reduce 70% and 90% fundamental operations for 16-QAM and 64-QAM respectively. So the computational complexity is reduced significantly and is more attractive to the VLSI implementation. Simulation results prove that the proposed scheme can achieve a performance very close to the conventional QRD-M algorithm, and yield a tradeoff between the complexity and performance.