An IIR adaptive line enhancer with controlled bandwidth

An IIR adaptive line enhancer (ALE), previously proposed by David, Stearns, Elliott and Etter (1983) is explored further. We propose a mechanism for controlling the bandwidth of the ALE, in an adaptive manner. The proposed mechanism increases the bandwidth of the ALE whenever its peak is not close to a spectral line of the input signal, to assure its fast convergence, and decreases the bandwidth of the ALE when its peak matches a spectral line of the input signal, to enhance that spectral line further. Also, a new algorithm for robust adaptation of the ALE is proposed.<>