Multi-access performance of DS UWB system under indoor dense multi-path channel

摘要

The performance of multi-user code to direct spreading bi-phase shift keying (DS-BPSK) direct impulse ultra wideband (UWB) systems under indoor multi-user and multi-path environment is analyzed and simulated.The system output signals with Rake receiver are derived,then a simple and practical code selection scheme is given;i.e.,with a large occupation to empty ratio of the repeating pulses,directly choosing those random or pseudo-random user codes with enough length and good co-relative orthogonal features will make the performance of DS-BPSK approximate the optimum and,so there is no need to carefully design the code or its type.The system multi-access performances are simulated using Gold sequence and PN codes as multi-user codes under CM1-CM4 multi-path channels.Simulation results prove that the proposed scheme is feasible.