Phase and timing recovery based on frame synchronization and fractional-spaced frequency domain equalization for CPM

In this paper, a new synchronization receiver architecture for continuous phase modulation (CPM) and relevant carrier phase and symbol timing recovery methods based on frame synchronization and fractional-spaced frequency domain equalization (FDE) are proposed. With frame synchronization and fractional-spaced FDE, frequency selective fading can be equalized for the up-sampled CPM signal. At the same time, carrier phase synchronization and symbol timing recovery can be obtained by canceling the effects of carrier phase and timing error of frame synchronization. Equalized signal in time domain can be demodulated and detected with CPM receivers designed for additive white Gaussian noise (AWGN) channel. Probability distributions of the timing error of frame synchronization algorithm proposed by Minn and bit error rate (BER) performances of ARTM CPM, FQPSK and SOQPSK-MIL modulations are simulated by computer simulations, and simulation results show that the proposed carrier phase and symbol timing recovery methods have better synchronization and equalization performance.