Carrier frequency offset estimation in power line communication networks

As the Power Line Communication (PLC) network standard, IEEE 1901 uses OFDM for its uplink and downlink transmissions, the sensitivity of the network to the timing and frequency errors are prominent. The frequency errors are due to the carrier frequency offsets caused by instabilities in local oscillators and ageing effects. A novel recursive algorithm for carrier frequency offset estimation is proposed. The algorithm updates the offset estimated value in terms of the previous estimate and a weighing factor based on the power line channel conditions. The carrier frequency offset in the PLC network is studied for various cyclic prefix and IFFT lengths. The performance of the recursive algorithm is evaluated with respect to the maximum likelihood algorithm and it is observed that it out performs the latter if the channel conditions are good.