DS UWB Research Articles

A Reduced Complexity Algorithm for Multi User Detection in DS UWB Systems

UWB is the latest technology to cause huge advances in wireless communication, networking, and radar and positioning systems. Many novel algorithms for the multiuser detection have been proposed for a DS-UWB multiuser communication system. In this paper we have proposed a reduced complexity Multi User detector based on minimum mean square error (MMSE).The algorithm exploit the inherent multipath diversity and also mitigate the effects of both inter symbol interference(ISI) and multiuser interference (MUI) with the reduced complexity. Simulation results show that the algorithm perform better than the other known detectors with the same complexity in literature

A Novel High Data Rate Prerake DS UWB Multiple Access System: Interference Modeling and Tradeoff Between Energy Capture and Imperfect Channel Estimation Effect

A novel high data rate (HDR) Prerake DS UWB multiple access system is proposed, in which the number of taps in the Prerake filter is set to a large value while keeping the number of taps in a chip sufficiently small. Thus high data rate can be achieved via superposition of the chip waveforms, where the inter-chip interference introduced is small due to signal energy focusing. We derive the higher order moments of Multiple Access Interference (MAI) and fit the distribution of MAI using a generalized Gaussian distribution. Numerical results show that the generalized Gaussian distribution is a more appropriate statistical model for the distribution of MAI than the Gaussian distribution. Using the characteristic function (CF) method, an accurate BER formula is derived and validated by numerical results. The effect of imperfect channel estimation is discussed in detail. We highlight that under imperfect channel estimation, there is a tradeoff between the signal energy captured and the channel estimation noise introduced.

Performance Analysis of Prerake DS UWB Multiple Access System Under Imperfect Channel Estimation

In this paper, the performance of Prerake DS UWB multiple access system under imperfect channel estimation is studied. The signal model of the system is derived in matrix form, which clearly shows the components of inter-chip interference, inter-symbol interference and multiple access interference. The BER formula is derived based on this signal model and validated by simulations. We highlight that the BER performance does not monotonically decrease with the growth of data rate under imperfect channel estimation. The effect of imperfect channel estimation in different cases is also discussed.