Performance enhancement of an MB_OFDM based UWB system in multiple SOPs environments

In this paper, we propose a new transmission scheme to support multiple simultaneously operating piconets (SOPs) in an ultra wideband (UWB) system based on multi-band orthogonal frequency division multiplexing (MB_OFDM), where the code division technique is combined with the MB_OFDM. When there are 2 or 3 SOPs, the collision between different piconets is increased and the average probabilities of symbol collision increase up to nearly 55.7% and 70.7%, respectively. Hence, the previous scheme using symbol repeater and erasure can´t effectively reduce the co-channel interference (CCI). We propose to use the MC_CDMA to mitigate the CCI from 2 and 3 SOPs. Our simulation results demonstrate that the proposed scheme is effective in multiple SOPs.