The existence of carrier frequency offset ( CFO) disable sub-carrier to maintain orthogonality, and symbol timing deviation can further arise inter-symbol interference. All of synchronization errors seriously degrade the system performance, which hamper OFDM to manifest its advantages. 载波频偏的存在使得子载波间的正交性不能保持,定时偏差还会引起前后符号间干扰,所有同步误差将严重恶化系统性能,使得OFDM的优势不能得以体现。