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 fine-of-sight digital radio system. A closed-form expression for the phase-error 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.