Optimal and suboptimal algorithms for Doppler spread estimation in mobile radio systems

Doppler spread estimation in digital mobile radio systems is described. An optimal approach (in the sense of maximum likelihood estimation) for Doppler spread estimation is derived. Suboptimal approaches, with trading off in performance and complexity, are developed from the optimal algorithm. In practical systems, the Doppler spread must be estimated in the presence of frequency offsets between the transmitter and the receiver. Hence, an algorithm that decouples Doppler estimation from automatic frequency compensation (AFC) is also presented. The proposed algorithms rely on channel estimation over the known fields of a TDMA burst. Such algorithms can be applied easily to systems with pilot symbols or a pilot channel