Abstract—This paper proposes a Lattice-Reduction (LR)-aided Zero-Forcing (ZF) detection method for spatial multiplexing Ultra-Wideband (UWB) Multiple Input Multiple Output (MIMO) systems on indoor log-normal multipath fading channels. It is analytically shown that it can obtain the maximum achievable diversity gain, which is the product of the number of resolvable multipath components and the number of receive antennas. The analytical BER performance is compared with the simulated results. It is also seen through simulations and theoretical results that the LR-based ZF signal detection scheme outperforms the other receivers using ZF detector without LR.