Abstract
The significant features of ultra-wideband (UWB) technology are broader spectrum and lower power transmission, which can be applied to increase data rate and reduce interference in wireless communications. In order to meet the demand for high data rate, the pulse shape modulation (PSM) with guard-time technology is applied to UWB system. It uses several orthogonal pulses to modulate the data bits and transmits them at the same time to achieve high data rate and uses the guard-time technique to suppress inter symbol interference (ISI). However, one major problem associated with PSM is that its capacity is seriously limited by multiple-pulse interference (MPI). To overcome this problem, we employ parallel interference cancellation (PIC) technique to deal with the MPI problem for PSM UWB systems. Unlike CDMA systems, PSM system uses the orthogonal pulses to distinguish different information. It is difficult to reconstruct the continuous signals when we use the PIC technique to cancel the interference. Therefore, we use a special training sequence structure to estimate the equivalent baseband interference between different pulses. That can make the interference reconstruction more easily. Finally, we show some computer simulation results of the proposed scheme. It shows that the proposed scheme can actually improve the system performance in different situations. We also show some performance comparisons between PSM and DS-CDMA to illustrate that the PSM is more suitable than DS-CDMA in high data rate transmission for UWB systems when the system load is light.