Multipath fading effects on carrier recovery of BPSK signal in digital radio

Abstract

Tracking performance of the I-Q carrier recovery loop for BPSK signal in bandlimited channel with multipath interference is analysed. The multipath fading channel is characterised by the Rummler's model (a simplified three-ray model) for line-of-sight digital radio system. A closed-form expression for the phaseerror variance related to the multipath interference, intersymbol interference and channel noise. is derived. Excess phase offset induced from the multipath interference is also examined. The closed-form expression of the jitter variance can be evaluated numerically to assess the degradation of synchroniser performance. Asymptotic limits of the performance are also discussed.