Joint pilot and iterative decoding carrier synchronization for short burst transmission system

Considering low estimation accuracy and small synchronization range of carrier synchronization algorithms in low signal-to-noise ratio (SNR) for short burst communication systems, a joint pilot and iterative decoding soft-output carrier synchronization algorithm is proposed, which utilizes the time-domain correlation algorithm for coarse estimation and makes hard decision directly for systematic soft-information and parity soft-information from extended Turbo decoder, and obtains the prior probability for fine estimation which is based on ML algorithm. Theoretical analysis and simulation results show that Turbo decoder can obtain more reliable soft-output information with small residual frequency offset after initial coarse synchronization when the normalized frequency offset is less than 1.5×10^-3, then joint pilot and soft-output from the decoder are used to estimate fine carrier parameters, which can make turbo code achieve optimal BER performance.