Analysis of a hybrid OFDM synchronization algorithm for power line communication

This paper outlines a hybrid OFDM synchronization technique for powerline communication. Initially, the timing and frequency offset are estimated by searching for the peak of an evaluated metric provided by a reference block transmitted at the beginning of each OFDM frame, and subsequently, autocorrelation properties induced at cyclic prefix on the time domain are exploited to maintain estimates of the timing and frequency offset without the use of a new reference block for synchronization purpose. This strategy is interesting because once a first synchronization of the first OFDM block (the start point of the frame) is accomplished, any loss in spectral efficiency will occur subsequently. Additionally, we propose an interesting strategy with low computational complexity to improve the timing and frequency estimates after synchronization is carried out at the beginning of the frame. Basically, this strategy consists of averaging the peaks spacing between successive peaks of the evaluated autocorrelation metric. Simulation results reveal good performance in PLC scenarios, specially in the cases of occurrences of impulsive noise.