Performance of ultra-wideband transmission with pulse position amplitude modulation and rake reception

Recently, pulse position amplitude modulation (PPAM) has been proposed for ultra-wideband (UWB) communication systems. PPAM combines pulse position modulation (PPM) and pulse amplitude modulation (PAM) to provide better performance and higher system capacity with low computational complexity. A rake receiver can make use of the rich multipath of UWB systems to improve system performance and capacity. In this paper we present the performance of a rake receiver employing maximal ratio combining (MRC) in a time hopping (TH) UWB system with PPAM modulation. Performance in a practical multipath fading channel is considered. The error probability and a union bound on performance are derived for a block fading environment Numerical results are given to illustrate the system performance.