A UWB Multiple Antenna System for NBI Mitigation under Rayleigh and Ricean Fading

In this paper, a narrowband interference (NBI) mitigation scheme for ultra-wide bandwidth (UWB) signals using multiple receive antennas is examined. The low spatial fading of UWB signals relative to NBI signals is exploited to provide "interference selection diversity". Whereas classical selection diversity is designed to maximize the desired received signal power, the aim of interference selection diversity is to minimize the effective NBI power. Expressions for the probability of error of the selection diversity scheme are derived for both Rayleigh and Ricean NBI fading scenarios. The improvement in received signal-to-interference ratio is also mathematically investigated. It is shown that doubling the number of antennas results in a 3-dB performance improvement for the Rayleigh fading case. Less substantial gains are observed under Ricean fading.