Joint Frame Synchronization and CFO Estimation in Frequency Selective Fading Channels for Continuous Phase Modulation

In this paper, we address the problem of frame synchronization and Carrier Frequency Offset (CFO) estimation for Continuous Phase Modulation (CPM) in frame-based transmission. We present an efficient algorithm to estimate the start of signal and CFO simultaneously. The state of art methods for frame synchronization mostly adopt the AWGN channel model and suffer from real-world multipath and frequency-selective channels to estimate the start of signal. By using spectral analysis in the estimation procedure over a specific length of the received signal, we propose a method which is robust to multipath channels. When the start of signal is detected, the CFO estimation is performed on the preamble part of the received frame in the frequency domain. Simulation results show that the proposed algorithm detects the start of signal at signal-to-noise ratios (SNRs) below 0dB with a probability not exceeding . We show that our algorithm outperforms the pervious methods in the frame synchronization even with short preamble lengths.