Diversity gain in ultra wideband impulse radio (UWB-IR)

In this paper, we propose a time interleave (TI)-ultra wideband (UWB)-impulse radio (IR) system where N_f monocycle pulses per information symbol are transmitted not continuously but discontinuously through the time interleaver to get more time diversity. Moreover, we compare the diversity gains of the UWB-IR systems on block fading channels with the fading block size q: the UWB-IR system with a single transmit antenna, the space time (ST)-UWB-IR system with N_t transmit antennas, and the TI-UWB-IR system with a single transmit antenna. Simulation results show that when the number of transmit antennas N_t is larger than or equal to the fading block size q, all the systems can achieve the same diversity gain. When the number of transmit antennas N_t is smaller than the fading block size q, the TI-UWB-IR system can achieve the largest diversity gain, and the ST-UWB-IR system and the UWB-IR system follow in order.