A PN sequence-based carrier frequency offset estimation algorithm for generalized-OFDMA uplink

We propose a pseudo-noise (PN) sequence-based carrier frequency offset (CFO) estimation algorithm for generalized-orthogonal frequency division multiple access (generalized-OFDMA) uplink. In proposed algorithm, a PN sequence and its circular-shifting versions are employed as training sequences for different users; Then channel parameters with CFO factors from each user to a base station can be estimated by virtue of autocorrelation characteristic of the PN sequence; Finally we can acquire all users´ CFO estimates simultaneously by calculating channel phase-angle difference between two training periods. We demonstrate from the simulation that the proposed algorithm achieves better CFO estimation performance in comparison with some existing CFO estimation algorithms for OFDMA uplink.