A New Preamble Design and Pattern Matching Aided Timing Synchronization for PLC

A new preamble structure is proposed for Narrowband Power Line Communication (NB-PLC) system, and therefore a corresponding timing estimator with interval detection and pattern matching is put forward . In the new estimator, firstly the received signals are conducted cross-correlation with the preamble in the transmitter, then the cross-correlation values are obtained and divided into several groups averagely. With that the index of the maximum module value of each group is obtained respectively, and judge whether the interval equals to the length of one OFDM symbol. When it does, it is compared with the existing patterns. If they match well, final estimation is got. Or else, continue doing cross-correlation. The proposed timing estimator completes the coarse synchronization and fine synchronization in the meantime. And there is no need for calculating the autocorrelation value and setting the threshold value, which has strong influence on the false alarm probability and false dismissal probability. The simulation results show that, in the presence of colored noise, the proposed timing estimator achieves performance gain in terms of correct synchronization probability about 0.7 at SNR=-4dB and the new timing estimator is robust against the unfavorable channel conditions with bursts.