Linearly Constrained Constant Modulus Algorithm Based Blind Multi-User Detection for DS-UWB Systems

By exploiting the inherence of quasi-static for indoor ultra-wideband (UWB) transmission environments and employing a constant modulus modulation to ultra-wideband signals, a linearly constrained constant modulus algorithm (LCCMA) based blind adaptive multi-user detection (MUD) is presented for direct sequence Ultra-wideband (DS-UWB) systems. In the proposed approach, the constant modulus algorithm (CMA) is first introduced into MUD for DS-UWB systems. Moreover, the global optimum property of the LCCMA is derived via blind signal processing method. Theoretical analysis and simulation results show that, compared with the training sequence based adaptive MUD, the proposed scheme can increase the transmission capacity of effective information with a loss of no higher than 3dB in terms of both output signal- interference ratio (SIR) and bit error ratio (BER). Therefore, it reaches a preferable tradeoff between transmission capacity and BER performance, and then can be considered as a compromise candidate for indoor DS-UWB high data rate multi-user access scenarios.