高性能的OFDM频偏估计新方法

频偏估计是OFDM的关键技术.本文提出了一种具有高精度的OFDM频偏估计新方法.新方法首先将接收信号与本地训练序列作相关来消除训练序列的影响,然后进行频率粗同步.补偿粗频偏后再利用消除训练序列影响的序列或循环前缀作相关实现频率精同步.新方法具有频率偏移估计范围大和估计精度高的优点.文中分析并得出这两种估计方法的频偏估计下界.此频偏估计方法使训练序列的设计更加灵活,可按时间同步或信道估计等性能最优来设计.

Novel frequency offset estimation algorithms for OFDM systems with high performance

Frequency offset estimation is the critical part in orthogonal frequency division multiplexing (OFDM) systems. A novel frequency offset estimation algorithm with high performance is proposed in the paper where the received signal is correlated with the local training sequences to eliminate the influence of training sequence firstly and then the coarse frequency offset is realized by short sequence. Once coarse frequency offset compensated, the fine estimation is achieved by delay correlating the compensated data or by using cyclic prefix. In this paper, performance of the new method is analyzed theoretically and the lower bound of the estimation is also presented. The new method has better estimation accuracy and larger estimation span. Furthermore, it gives the flexibility in the training sequence design to acquire the best timing performance or channel estimation etc.