Abstract: A method and apparatus for extending the dynamic range of an integer or fixed-point Fast Fourier Transform (“FFT”) system that may be used in communications devices such as ADSL modems. The disclosed FFT system utilizes a shift control module to increase the effective dynamic range of the FFT implementation by selectively choosing at least one stage of an FFT butterfly implementation in which the outputs of the butterfly stage are not divided to otherwise avoid overflow problems.

Abstract: A digital data receiver includes a front end, coupled to receive an input signal transmitted over a communication channel, the signal representing a stream of transmitted symbols with a given input symbol rate, and to generate, responsive to the input signal, a stream of received samples at a processing rate that is a non-integer rational multiple of the input symbol rate. A feed-forward equalizer receives input samples at the processing rate, responsive to the received samples, and generates forward-equalized samples at the input symbol rate. Decision circuitry processes the forward-equalized samples so as to generate a stream of estimated symbols at the input symbol rate.