A Theoretical Study on the Effects of Timing Jitter on the Performance of Multiple Access Impulse Radio

In February of 2002, the FCC approved the use of ultra-wideband (UWB) technology for commercial use. UWB has since been considered as a solution for the next generation of personal area networks (PANs) and wireless local area networks (WLANs). UWB (or impulse) radio employs short duration pulses to communicate, thereby spreading signal energy very “thinly” from DC to a few gigahertz [1]. The “ultra-wideband nature of subnanosecond pulses” employed in UWB systems suggests the potential for dramatic increases in capacity; however, this comes at the cost of much more stringent timing tolerances [2]. Timing jitter can cause synchronization errors and multiple access interference (MAI) which can adversely affect multi-user capacity (i.e. the number of users supported). In this project, the UWB group will investigate the effects of timing jitter on UWB systems using Pulse Position Modulation (PPM) and Time-Hopping Multiple Access (THMA), as defined in [3]. The first goal of this project is to verify the effects of timing jitter on multi-user capacity presented in [2]; the second goal is to generalize these effects to formulate an analytical model for probability of error as a function of timing jitter in UWB systems using PPM and THMA. 1.0 INTRODUCTION Ultra-wideband systems have the potential to deliver higher data rates than current narrowband wireless PAN or WLAN standards (e.g. Bluetooth or 802.11) [4]. Some of the possible applications include wireless video, position location, medical imaging, etc. UWB systems also offer promise of coexisting with many narrowband communication systems across the huge bandwidth UWB occupies. The FCC has approved the use of UWB technology using very low transmit power (-41dBm/MHz) [4]. Because of this low transmit power guideline, UWB signals will appear as thermal noise in most coexisting communication systems. The combination of a simple RF architecture, reduced complexity in terms of filtering and linearity [2], interoperability, and tremendous capacity potential makes UWB an attractive alternative to narrowband technology. Many