Cross-modulation Interference Reduction for Pulse-Position Modulated UWB Signals

One of the popular modulation options that is used for ultra wideband (UWB) systems is Pulse Position Modulation (PPM). In spite of many advantages of PPM, the cross-modulation interference (CMI) caused by multipath propagation degrades the performance of the UWB receivers when PPM modulation is used. In this paper, a technique for reducing the effect of CMI for PPM UWB signals is introduced. The proposed approach improves the performance of receivers greatly and eliminates the possibility of catastrophic errors. The proposed technique introduces variable modulation index instead of conventional fixed modulation index.