Pilot-symbol assisted timing recovery for burst transmission

This contribution derives the Cramer-Rao lower bound (CRB) related to the joint estimation of the time delay, the carrier phase, and the frequency offset from a noisy linearly modulated burst signal, containing random data symbols (DS) as well as known pilot symbols (PS). This bound indicates that it is potentially more accurate than the bound which is derived from a burst without PS or limited number of PS only. Further, a new kind of iterative Soft-Decision Directed estimator combined PS initialization is Presented, which performs closely to the derived CRB, and provides a large improvement over the classic Non-Data-Aided or Decision-Directed estimator especially at low and moderate Signal-to-Noise Ratio.