Joint pilot and soft information assisted carrier synchronization for short burst SOQPSK signals
Xiao‐Jun Wu · Journal of Xidian University · 2013
To solve the carrier recovery problem with large frequency offset in short burst communication systems using shaped-offset quadrature phase shift keying(SOQPSK),a joint pilot and demodulation soft information assisted carrier synchronization algorithm is proposed.First,coarse synchronization based on a few short pilot sequences is carried out.Then,further fine search is done around the coarse synchronization estimation region.The precise carrier synchronization parameters are obtained based on the maximum-mean-square soft output of SOQPSK.Simulation results show that at EbN0≥ 0 dB the proposed algorithm can eliminate large carrier offsets by as much as half the symbol rate,resist phase confusion and achieve effective carrier synchronization with 30 pilot bits and low computation complexity,achieving a BER performance which is very near the optimal coherent demodulation performance.When BER is in the region of 10-2～10-5,SNR degradation is below 0.3 dB.