Interference of Spread-Spectrum Modulated Disturbances on Digital Communication Channels

In this paper, the effects of random spread spectrum (SS) electromagnetic interference (EMI) on digital communications are addressed. For this purpose, the influence of EMI on a communication channel is described in the framework of information theory in terms of an equivalent channel capacity loss, which is analytically predicted and validated by experimental results. The EMI-induced channel capacity loss for non-modulated and SS-modulated interference generated by a switching-mode DC-DC power converter are then evaluated for different EMI and channel characteristics so that to compare different scenarios of practical interest.