Summary: | 碩士 === 國立中央大學 === 通訊工程研究所 === 97 === Recently, multi-access orthogonal frequency division multiplexing (OFDMA) has drawn a lot of attention in next-generation multiple access wireless communication technologies. The carrier frequency offsets in OFDMA systems can destroy the orthogonality among subcarriers and produce the 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 by minimizing the mean square error (MSE) for demodulated data subject to the overall users or some specific users. In the scheme, the CCFO is obtained 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.
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