Patent ID: 8081675

Claim:
An extended equalizer circuit for equalizing a digital communication signal transmitted over a transmission medium, the transmission medium causing a frequency-dependent attenuation of the digital communication signal, comprising: an equalizer that includes a linear equalization circuit and a non-linear equalization circuit, the linear equalization circuit being configured to apply a linear filter to the digital communication signal to compensate for the frequency-dependent attenuation caused by a first portion of the transmission medium and the non-linear equalization circuit being configured to apply one or more non-linear operations to the digital communication signal, wherein the first portion of the transmission medium includes up to a maximum length that the equalizer is configured to equalize; and a de-emphasizing equalizer circuit coupled in series between the transmission medium and the equalizer, the de-emphasizing equalizer circuit being analog equalizer circuit that is configured to apply an additional linear filter to the digital communication signal in order to compensate for the frequency-dependent attenuation caused by a second portion of the transmission medium, wherein the de-emphasizing equalizer circuit applies no non-linear operations to the digital communication signal, and wherein the second portion of the transmission medium includes a length of the transmission medium beyond the maximum length that the equalizer is configured to equalize.