The detection performance is evaluated for our proposed analog multiuser receiver in Ultra-WideBand (UWB) transmitted-reference system. In the presence of dense multipath and multi-access signals,the performance analysis is difficult due to the complicated waveform of received impulse. We develop an approach to analyze the steady-state Signal-to-Interference-plus-Noise (SINR) of the detector output. The multipath-spread impulse is fitted to an exponentially decaying profile in the analysis. A closed-form expression of steady-state SINR is further deduced for the proposed Least Minimum Square (LMS) detector. The analysis is validated by simulations in Line-Of-Sight (LOS) and Non-Line-Of-Sight (NLOS) channel respectively. Based on the theoretical results,the multipath delay spread is employed to determine the optimal width of the integration window of the detector.