Novel Algorithm for Frequency Estimation of CW Interference in DSSS Systems

This paper proposes a new technique for frequency estimation of continuous wave (CW) interference, and hence, IIR notch filter is constructed to excise interference in direct sequence spread spectrum (DSSS) systems. The new estimator (Fourier interpolation estimator: FIE) only involves three Fourier components. Both analysis results and numerical simulation results show that the FIE outperforms the adaptive line enhancer (ALE) by comparison, especially in computational simplicity. The IIR notch filter constructed by FIE has better Signal-to-Noise ratio (SNR) improvement than both linear and nonlinear prediction filters.