A frequency domain multiple-antenna and channel estimation approach for facilitation of UWB technologies coexistence in heterogeneous WPANs.

Ultra wideband (UWB) communications is a promising technology which provides high data rates for short-range communications. There are currently two proposals as UWB standards, namely, multiband orthogonal frequency division multiplexing (MB-OFDM) UWB and direct-sequence (DS) UWB. These two standards can cause interference on each other and also to other wireless technologies when they are located in their vicinity. In this paper, we focus on the mutual interference of these two UWB standards. In the first part of the paper, we address the channel estimation issue for DS-UWB receiver, in the presence of multi-user interference (MUI) and MB-OFDM interference within the framework of wireless personal area networks (WPANs). In fact, we use the minimum mean square error estimation (MMSE) to estimate the channel based on a pilot transmission scheme. In the second part, we propose a simple but effective design for the receiver structure of the DS-UWB which utilizes a frequency domain multiple-antenna approach in order to mitigate MUI as well as the MB-OFDM external interference. Channel estimation performed in part one will be used in the detection process in part two. Numerical results are provided to evaluate the effectiveness of the proposed techniques for interference mitigation in DS-UWB.