MMSE Solution for OFDMA Systems with Carrier Frequency Offset Correction

The multi-access orthogonal frequency division multiplexing (OFDMA) technology has drawn a lot of attention in next generation wireless mobile communications. It is well-known that carrier frequency offsets in OFDMA systems can destroy the orthogonality among subcarriers and produce intercarrier interference (ICI) and multiuser interference (MUI). In our previous works, we proposed a common carrier frequency offset (CCFO) correction scheme at the OFDMA receiver, which can reduce the ICI/MUI effect and the bit error rate. In the scheme, the CFO correction can be performed by adaptively converging the MSE between the demodulated output and the decision feedback data. This paper studies the minimum MSE solution for the CCFO value, and the result is exploited to verify the adaptive CCFO estimation algorithm by means of the decision feedback. Simulation results show that the adaptive decision feedback scheme for CCFO estimation is effective and the minimum MSE performance is well achieved.