In order to satisfy the requirement for higher data rates, the UWB spatial multiplexing system that combines MB-OFDM UWB and V-BLAST scheme is presented in this paper. And then, various detection algorithms are studied and simulated in this system for the sake of a better performance. Simulation results show that MMSE-BLAST is an appropriate one among the conventional suboptimal algorithms, and the accuracy of the first detected layer determines the degree of error propagation. At last, a modified algorithm with the combination of ML and MMSE-BLAST is employed to reduce error propagation in the UWB channel with rich multipath.