An ultra accurate inter-node carrier frequency synchronization for OFDMA/TDD systems

This paper proposes an ultra accurate carrier frequency synchronization for OFDMA/TDD systems, which keeps carrier frequency offset between two wireless nodes less than 0.01Hz in frequency-selective Rayleigh fading environments. In the proposed method, bi-directional channels are measured in multiple subbands of an OFDMA system. One of the two nodes corrects its carrier frequency with high accuracy using the bidirectional channel parameters corresponding to subbands of good channel quality. Numerical results show that appropriate weighting and averaging of relative phases of bi-directional channel parameters over multiple subbands improves performance of inter-node carrier frequency syhcoronization. The proposed method is a promising techology towards cooperative coherent transmission or low-power wireless communications.