An ultra accurate inter-node carrier frequency synchronization through wireless link

This paper proposes an ultra accurate inter-node carrier frequency synchronization which keeps carrier frequency offset between wireless nodes less than 1Hz in slowly time-varying Rician fading channels. In the proposed method, one of the two nodes adjusts its carrier frequency to be close to the other node's carrier frequency based on bi-directional channel measurements. We demonstrate that the proposed scheme achieves very small inter-node carrier frequency offset, e.g. less than 0.01 Hz. This synchronization scheme is useful in improving performance of wireless applications, such as cooperative coherent transmission or mobility measurements.