Design and Performance Evaluation of Carrier Lock Detection in Digital QPSK Receiver

Carrier lock detection function based on QPSK digital receiver has been analyzed in details. Beginning with how to construct a carrier lock detector, we point out the conditions that a good carrier lock detection function should conform to. Then a new carrier lock detector was proposed, which surpasses the traditional methods in performance and hardware cost. By comparing the performances of all of these carrier lock detectors, we conclude that the new carrier lock detector has the better performance at lower SNR, which indicate it is more suitable for lower demodulator threshold digital receivers.