Performance Analysis of FRESH Filter under CFE and Correction of CFE
CFE下FRESH滤波器性能分析及CFE校正

The researches of FREquency-SHift (FRESH) filter are usually based on the hypothesis that the receivers precisely know the cycle frequencies of signal or interference. However, in the practical application circumstances of FRESH filter, Cycle Frequency Error (CFE) sometimes exists unavoidably. Based on the model of DSSS/BPSK system with FRESH filter to suppress narrow-band interference, the tap coefficients, the estimate error of FRESH filter and the system bit error performance under CFE are analyzed and an improved CFE correction algorithm is proposed in this paper. The results from theoretical analysis and numerical simulations indicate that the performance of FRESH filter is very sensitive to CFE, and the proposed algorithm can correct CFE effectively, keeping FRESH filter robust and excellent under CFE.