Abstract: A decision feedback equalizer and a method for updating tap coefficients of the decision feedback equalizer are provided. The decision feedback equalizer (DFE) includes a first equalizer for reducing channel interference noise in an input signal, a second equalizer for generating a feedback signal for reducing remaining interference noise, and an update controller for controlling the first and the second equalizers so as to freeze the second equalizer when the first equalizer is updated and to freeze the first equalizer when the second equalizer is updated. The tap coefficients of the feedforward equalizer and the feedback equalizer are alternately initialized. It then becomes possible to stably converge the levels of respective tap coefficients without diverging them and to reduce the power used for updating the tap coefficients in a steady state.

Abstract: A digital subscriber line receiving apparatus having resilience to HAM radio interference noise and a method therefore includes an automatic gain controller for amplifying a received signal level to a signal level having a predetermined magnitude, a timing recoverer for recovering timing from a signal output from the automatic gain controller, an equalizer for removing interference noise from a signal received from the timing recoverer, a slicer for detecting a digital value from a signal received from the equalizer, an initialization controller for resetting the receiving apparatus and initializing the automatic gain controller, the timing recoverer, and the equalizer when the signal to noise ratio of the output signal of the equalizer is smaller than a reference signal to noise ratio, and an update controller for preventing automatic gain controller and equalizer from being initialized by the initialization controller when HAM radio interference noise is detected in the received signal.