An efficient coherent demodulation algorithm for TETRA communication system

This paper describes an efficient coherent demodulation algorithm aiming at the receiver in Terrestrial Trunked Radio (TETRA) communication system. The algorithm proposes frequency offset error twice-estimation and sectioned phase offset compensation to achieve the high precision in carrier synchronization. Odd-even decision is then proposed in the algorithm to avoid signal noise ratio (SNR) loss in differential demodulation. The simulation has confirmed that the precision of frequency offset error twice-estimation is better than that of data-aided (DA) estimation and that compared with differential demodulation, the bit error rate (BER) performance of coherent demodulation is much better.