In this book, we have considered multiuser communication scenario with Ultra Wideband (UWB) communication. Different issues under multiuser communication are considered with focus on capacity issue. In literature two widely discussed techniques for multiple access for UWB are based on Time Hopping (TH) and Orthogonal Frequency Division Multiplexing (OFDM). In our investigations we have considered both these techniques for UWB system and addressed different issues. TH based technique has been available for long in literature for UWB communication, while new standard for UWB is based on OFDM. We have considered downlink communication with UWB. Under this scenario we have considered the case wherein UWB device collects the data from different multimedia sources and transmits the combined data over link. We have proposed scheme based on DS-CDMA based OFDM. For this scheme we have proposed two system models named system model-I and system model-II. Model-I is considered without MUI and in Model-II we have considered the effect of MUI. we have evaluated the performance under AWGN channel, multipath Rayleigh channel and SV channel.