Performance of UWB multiple access impulse radio systems in multipath environment with antenna array

Impulse radio (IR) is based on the ultra-wideband (UWB) time-hopping spread spectrum technique in which subnanosecond pulses are modulated to convey information by precisely shifting the relative time position of the pulses. The influence of temporal and spatial diversities on the performance of ultra-wideband impulse radio systems is analyzed. We investigate how antenna diversity (uniform linear array and rectangular array) can be used to improve the bit error rate performance and to mitigate multiple user interference (MUI) of an IR system in multipath fading channels. Numerical results show that the bit error rate performance and multiple access capability of the IR system can be improved when the number of array elements and selected multipaths are increased.