Narrowband interference reduction in UWB systems based on spreading sequence spectrum shaping

This paper presents a way to reduce the effect of narrowband interference (due to either an intentional jamming or the effect of traditional non-spread-spectrum transmission) in ultra-wideband (UWB) communication systems based on asynchronous direct-sequence codedivision multiple access (DS-CDMA). To reach this goal, we derive a closed-form expression for the bit error probability in additive white Gaussian noise (AWGN) channel, where both multiple access and narrowband interference are the main cause of nonideality. By leveraging on this, we develop a new approach based on spectrum shaping of the spreading sequences waveforms which allows to significantly improve performance in many applicative scenarios.