Patent ID: 6332028
Filing Date: 2001-12-18
Classification: H03H,H04R

Abstract:
A dual-processing interference canceling system for processing an input signal containing a target signal component originating from a target source and an interference signal component originating from one or more interference sources and for producing an output signal representing the target signal component with a substantially reduced interference signal component, comprising:a main-channel generator capable of receiving said input signal and for generating therefrom a broadband main channel having said target signal component and said interference component;a reference-channel generator capable of receiving said input signal and for generating one or more broadband reference channels representing signals received from said one or more interference sources;a first low-pass filter, connected to the reference-channel generator, for filtering said one or more broadband reference channels into one or more low-frequency reference channels;an adaptive filter, connected to the first low-pass filter and having filter weights, for filtering said one or more low-frequency reference channels into one or more low-frequency canceling signals approximating the low-frequency interference signal component present in the broadband main channel;an interpolator, connected to the adaptive filter, for interpolating said one or more low-frequency canceling signals into one or more broadband canceling signals;a subtractor, connected to the main-channel generator and the interpolator, for generating a broadband output by subtracting said one or more broadband canceling signals from the broadband main channel;a second low-pass filter for filtering the broadband output to produce a low-frequency output; andsaid adaptive filter having filter-weight-updating means for determining updated filter weight values for the adaptive filter such that the difference between the low-frequency output and said one or more low-frequency canceling signals is substantially minimized; said adaptive filter also having weight constraining means for truncating said updated filter weight values to predetermined threshold values when the updated filter weight value exceeds the corresponding threshold value.