针对正交频分复用系统对频率偏移非常敏感的问题, 分析了基于判决反馈算法的性能。通过数学推导相邻符号数据在频域上相位旋转的数值关系, 创新性地提出了一种非数据辅助的残余频偏跟踪算法, 该算法在时域进行残余频偏纠正,无需额外插入导频信息, 提高了系统的传输效率。仿真结果表明, 所提算法能在多径信道下对频偏进行有效跟踪,且跟踪范围为子载波间隔的5%, 跟踪性能更好,具有实际应用价值。

According to the problem of Orthogonal Frequency Division Multiplexing (OFDM) systems are very sensitive to carrier frequency offset, we analyze the performance of decision feedback algorithm. By mathematical deduction the phase rotation value of adjacent symbol data in frequency domain, a Non-Data-Aided (NDA) method without the pilot signals is proposed for correct the Residual Frequency Offset (RFO). The method correct the RFO for the received signal in time domain. The pilot subcarriers are not required to achieve high efficiency. Simulation results show that, the proposed algorithm can track the frequency offset effectively in multipath channel and the tracking range is 5% of the subcarrier space, which has high practical application value.