METHOD AND APPARATUS FOR USE IN CARRIER RECOVERY IN A COMMUNICATIONS SYSTEM

摘要

A receiver includes a digital phase locked loop (PLL) for performing carrier recovery. The digital PLL further includes a phase error estimator driven by hard decisions and an integrator, which accumulates a phase error signal provided by the phase error estimator. To reduce the acquisition time, the digital PLL is run in an open-loop mode during which an estimate of the carrier frequency offset is determined as a function of the phase error signal. After the estimate of the carrier frequency offset is determined, the integrator is pre-loaded with the determined estimate and the digital PLL is run in a closed-loop mode.