Time-hopping sequence design for narrowband interference suppression

In this paper, we present a simple interference mitigation solution for the coexistence of ultra-wideband (UWB) systems with other wireless systems. Specifically, we consider the design of time-hopping (TH) codes for UWB systems that deploy an impulse radio architecture. We give a methodology for the construction of TH sequences that minimize the imposed UWB interference on a given narrowband system. To illustrate the effectiveness of our designed codes, we conduct physical layer simulations of the interference induced by UWB signals on close proximity wireless local area networks (WLANs) that deploy the IEEE 802.11a standard. Our performance measure is the IEEE 802.11a client rate degradation vs. distance from its access point. Our results show that, when using optimized TH codes, UWB systems can have no impact on the achievable data-rates and range of IEEE 802.11a WLAN devices; regardless of the position of the UWB system with respect to these devices.