Ultra-wideband (UWB) technology is envisioned for future wireless high-data-rate transmission. A UWB system with multiple antennas takes advantage of the rich scattering environment to increase the data rate. On the other hand, given rich multipath, time reversal (TR) uses scatterers to create space and time focalization at a target point by coherent addition of all scattered contributions at that point. This paper analyzes the performance of an impulse TR-multiple-input-multiple-output (MIMO)-UWB system with a simple one-correlator receiver. The performance analyses are based on UWB spatial channels measured in an office environment.