On the Multiple Access Performance of Prerake DS UWB System

In this paper, we study the multiple access performance of a Prerake DS UWB system. Prerake technique not only simplifies the receiver structure significantly, but also provides low probability of detection and spatial security in communication. These features are very desirable in military/commercial applications. We present the system signal model in presence of inter-chip interference and inter-symbol interference. The bit error rate (BER) formula is derived based on this signal model. A degradation factor is defined to investigate the multiple access performance of the system. The relationship between the degradation factor and the number of users/bit rate are derived. We also explore the multiple access capacity per user. The BER formula is validated by simulation results in various UWB channel models. In numerical analysis, we highlight the tradeoff between the bit rate and BER performance. The plots on degradation factor vs number of users/bit rate further reveal the constraint between the bit rate and the number of users