| The Ultra-wideband (UWB) system is allowed to operate in the 3.1 to 10.6 GHz portion of the spectrum, with an emissions mask for the lower and upper bands outside this range. Due to the inherent huge bandwidth of the UWB systems and its desired application, the mutual interference between the UWB system and other narrowband wireless communication systems, and the interference among nearby UWB systems are inevitable.;In this research, we investigate the UWB interference problem, analyzing the impact of UWB on a narrowband wireless communication system and the mutual interference among UWB users. Firstly, we study the Multi-Band Orthogonal Frequency Division Multiplexed (MB-OFDM) UWB system, including its temporal and spectral properties, and its performance in UWB multipath channel environment. We then analyze the effects of the UWB signal on a narrowband receiver in a multipath environment. A closed form expression for the Bit Error Rate (BER) was also derived to characterize the interference effect. Next, we characterize the multiuser interference among UWB systems, determining its statistical behavior, and derive a theoretical upper bound on BER to quantify the performance of a UWB system in a dense UWB environment.;We complete the research by performing Universal Mobile Telecommunication System (UMTS) performance simulations under various conditions of UWB interference, with the purpose of assessing the impact of UWB interference upon a typical narrowband RF communication device in a more realistic environment. The current literature on UWB-3G coexistence is inconclusive, and even contradictory, as to the impact UWB can have on the performance of third-generation wireless systems. While some studies show that UWB can be highly detrimental to the performance of 3G UMTS/WCDMA systems [29], [30], others have concluded that both systems can gracefully coexist [31] . Through this study, we found that at the current FCC emission limits regulated for UWB, the UWB radio can negatively affect the performance of 3G UMTS/WCDMA system when there two radios are co-located in a same device. |
