Adaptive line enhancement (ALE) refers to the case where a noisy signal, x(n) consisting of a sinusoidal component, s(n) is available and the requirement is to remove the noise part of the signal, n(n). This may be achieved by the arrangement shown below. It consists of a de-correlation stage, symbolized by and an adaptive predictor. The de-correlation stage attempts to remove any correlation that may exist between the samples of noise, by shifting them samples apart. As a result, the predictor can only make a prediction about the sinusoidal component of u(n), and when adapted to minimize the instantaneous squared error output, e(n), the line enhancer will be a filter optimized (the Wiener solution) or tuned to the sinusoidal component.