Abstract
Orthogonal frequency division multiplexing (OFDM) combining with the coordinated multi-point (CoMP) transmission technique has been proposed to improve the performance of the receivers located at the cell border. However, the inevitable carrier frequency offset (CFO) will destroy the orthogonality between subcarriers and induce strong inter-carrier interference (ICI) in OFDM systems. To relieve the performance degradation, CFO estimation and compensation is essential. However, with the CoMP technology, the conventional CFO estimation schemes are not practical because of mutual interference between the signals from different transmitters. In this paper, we propose a maximum likelihood (ML)-based estimator for the estimation of multiple CFOs, and design the training sequences that are robust to different values of CFOs. To further improve the performance, we also propose an estimation algorithm that incorporates iterative interference cancellation. According to the simulations, our scheme can achieve the mutual interference-free performance.