Joint channel and frequency offset estimation using sigma point Kalman filter for an OFDMA uplink system

Abstract

In uplink transmissions of a coded orthogonal frequency division multiple access (C-OFDMA) system, a frequency synchronization has to be addressed. Few papers deal with this issue. Expectation - maximization (EM) approaches have been proposed but initialization strategies must be considered because the EM may converge to a local extremum. Here we propose a joint estimation of the channel and the carrier frequency offset (CFO) based on a sigma point Kalman filter. When considering an OFDMA uplink system over a Rayleigh fading channel, simulation results confirm that the proposed algorithm corresponds to a good compromise between CFO and channel estimation, bit error rate and computational cost. Since our approach has a lower computational complexity, the power consumption is lower, which is a great advantage in a wireless system.