FFT windows offset correction for OFDM receiver
Résumé
To reduce the complexity of the aircraft wirings, we propose to use the power line communication technology for the flight control systems. In previous studies we have analyzed the propagation channel and defined an OFDM transmission system. However, in these studies we have assumed that the time and the frequency synchronization were perfect. Due to the severe operating conditions of the aerospace systems, this hypothesis is incorrect and it is necessary to propose a synchronization procedure. Because the flight control systems are subjected to strong real-time constraints, we propose a synchronization process on the phase of the received data. To do this, we estimate the offset of the sampling frequency with the phase difference between the received data and received data demapped and remapped. This estimation is based on the maximum of likelihood. To improve the performance of our estimator, we not only do the estimation on one OFDM symbol but on 20 OFDM symbols.