Adaptive filter with disabling circuit for fast tap weight convergence

摘要

An input signal is supplied to a tapped-delay line adaptive filter to produce tap signals which are equally divided into groups. The tap signals are selectively coupled on a per group basis through a switch to coefficient generators where tap-weight coefficients are produced. The selected tap signals are weighted respectively by the coefficients and summed together to produce a correction signal, which is combined with an output signal which is a replica of the input signal. The coefficients are updated with a residual error of the correction signal. Using the coefficients, the hopping order for selecting a tap group and the dwell time of the tap group are determined. Total power of the selected tap signals is monitored. When the monitored power is lower than a threshold value, the determination of the hopping order and dwell time is disabled and the residual error is nullified for fast convergence.