Frequency estimation of phase-modulated carriers

Conventional approach for frequency estimation usually assume a single tone without data modulation. In many applications such an assumption, realized by using either a separate pilot beacon or synchronization preamble is not feasible. This paper deals with frequency estimation of phase-modulated ca rriers in the absence of timing information and known data pattern. We intr oduce new frequency estimators that are based on the generalized maximum li kelihood principle. The communication channels under consideration include both additive white Gaussian noise (AWGN) channels and correlated Rician fa ding channels. For the latter class, we distinguish between the case when t he fading (amplitude) process is tracked and that when it is not tracked.