N-Ary Biorthogonal Pulse Position Shape Modulation for Hybrid TH/DS Multiple Access UWB System

A N-ary biorthogonal pulse position shape modulation (BPPSM) for hybrid time hopping/ direct sequence (TH/DS) multiple access ultrawideband (UWB) system is proposed and analyzed in this paper. The characteristic function (CHF) of the multiple access interference (MAI) is derived and, accordingly, the average symbol error rate (SER) of the proposed system can be accurately evaluated. Simulation are carried out to verify the analytical results in additive white Gaussian noise (AWGN) channel and to illustrate the system performance in realistic UWB fading channels. As increasing the number of adopting pulses, the proposed TH/DS Nary BPPSM system can provide better SER performance compared with the TH/DS Nary BPPM scheme. Given the constraints of fixed bit rate and signal bandwidth, the impact of adjusting various system parameters on the system performance is also investigated.