New iterative time and frequency synchronization scheme for MC-CDMA systems over power line channels

We develop a suitable time and frequency synchronization algorithm for multicarrier code division multiple access transmissions over power lines. The proposed time and frequency offset estimator works iteratively from frame to frame and uses one training symbol per frame. The basis of the algorithm consists in tracking the phase gradient of the received training symbol, which enables joint correction of frequency and symbol offsets. Additive white Gaussian noise effects are mitigated by a specific process applied on the subcarriers of the training symbol. Simulation results are presented when the generated signal is corrupted by power line channel impulse responses and Gaussian noise. The algorithm is shown to meet tough frequency synchronization constraints and to correct perfectly the symbol offset remaining from a coarse time synchronization stage.