Carrier Synchronization for Low Signal-to-Noise Ratio Binary Phase-Shift-Keyed Modulated Signals

A novel information-reduced carrier-synchronization system has been evaluated by means of both analysis and simulation. The idea is to use preliminary estimates of the received binary symbols to reduce the number of transitions before attempting to track the carrier phase, in order to minimize the effects of squaring loss on loop performance. It is shown that this technique indeed yields significantly improved phase estimates with coded input data, even when simple orthogonal block codes are employed. Reductions in squaring loss amounting to as much as 5 dB and more have been demonstrated with this technique in the low signal-to-noise ratio (SNR) regions corresponding to symbol SNR of −8 to −5 dB.