A performance analysis of the high-capacity TH multiple access UWB system using PPM

A time-hopping (TH) multiple access ultrawideband (UWB) system combined with a large modulation level of M-ary pulse position modulation (PPM) is considered and analyzed. Unlike the conventional TH method that the number of the provided TH slots becomes fewer as the adopted modulation level of M-ary PPM is lager and the data rate is fixed, a feasible TH scheme that utilizes the whole frame duration to carry out TH and PPM is proposed in the paper. The advantages of proposed TH system are to use the large modulation level of PPM, reduce the effect of the multiple access interference (MAI) and increase multiple access capability. The characteristic function (CF) of the MAI for proposed sytem is derived to obtain the probability density function of MAI and average symbol error rate. The simulation results of the proposed TH system are provided to verify the analytical results and show the performance improvement over the conventional TH and DS UWB systems.