Ja. Gansman et al., OPTIMUM AND SUBOPTIMUM FRAME SYNCHRONIZATION FOR PILOT-SYMBOL-ASSISTED MODULATION, IEEE transactions on communications, 45(10), 1997, pp. 1327-1337
Pilot-symbol-assisted modulation (PSAM) is a method to reduce the effe
cts of fading in mobile communications by periodically inserting known
symbols in the data stream. The receiver uses these pilot symbols to
derive its amplitude and phase reference. One aspect of this procedure
which has not received much attention in the literature is the method
used by the receiver to locate the pilot symbols. This paper uses opt
imum frame synchronization techniques to develop two synchronizers for
PSAM systems; one is barred on a standard maximum likelihood (ML) est
imation formulation, and the other is a sequential testing algorithm.
Both methods use a simple quadratic correlation filter with an energy
correction factor. Simulation results and a theoretical analysis are p
resented.