Application and performance of a dual-loop adaptive RLS Kalman estimator for carrier recovery in a Q/sup 2/PSK system

This article describes the application of a dual-loop digital phase-locked loop (DPLL) in a Q/sup 2/PSK modem for carrier recovery. The DPLL consists of an adaptive Kalman estimator which estimates the phase and frequency offsets of a received data bearing passband signal. The parameters of the Kalman estimator are updated by means of a recursive least squares (RLS) algorithm. The performance of this carrier recovery strategy is evaluated for some typical mobile channel carrier frequency offsets.