Interference from MB-OFDM UWB Systems: Exact, Approximate, and Asymptotic Analysis

Ultra-wideband (UWB) radio is widely perceived as a promising technology for efficient utilization of spectrum and as an enabler of new or improved wireless applications. Besides technological challenges, the potential of causing harmful interference to incumbent narrowband (NB) systems is the major obstacle to successful commercialization of UWB communication systems. It is therefore important to accurately investigate the impact of UWB signals on coexisting NB receivers. In this paper, we describe an analytical approach to study the performance of NB binary phase-shift keying (BPSK) receivers in the presence of multiband orthogonal frequency-division multiplexing (MB-OFDM) UWB interference. MB-OFDM has recently been adopted by the European Computer Manufacturers Association (ECMA) as physical-layer standard for high-rate short-range data communication. Our analysis includes expressions for the exact and asymptotic bit-error rate (BER) a Gaussian approximation (GA) and an impulsive GA (IGA) of the interference signal, and expressions for the amplitude probability distribution (APD) of MB-OFDM interference. We show that GA and IGA may be used for NB signals with, respectively, much smaller and much larger bandwidths than the MB-OFDM subcarrier spacing. For other signal bandwidths and most NB channel models the exact BER analysis has to be used to obtain meaningful results