Self-adaptive digital filter for noise and phase jitter reduction

摘要: A new adaptive digital tuning filter for tracking a sinusoidal signal within frequency band is described. The input representative of both said and noise fed to Hilbert transformer which provides the in-phase quadrature components, x k , respectively, signal. These components are applied having transfer function K where ##EQU1## WHERE φ = 2πFT, f tuned filter, T sampling period constant close unity. output signals y computing means control e such that e.sub.k x.sub.k y.sub.k - above value adjusted through conventional gradient method φ.sub.k + 1 μe.sub.k controls provided adjust in direction change toward zero. Application cancellation main component phase jitter modem also