Aided Decision Feedback Equalization for Wired Communication

Abstract

An analytic model of the Cat-5 subclass cable structure, as described in TIA cabling standards (2001), is developed and derived and a simple FIR filter model based on physical measurements is found which accurately represents the developed model. Taking advantage of the properties of the cable impulse response, a new equalizer structure (dubbed aided decision feedback equalizer - ADFE) is proposed that is a classical decision feedback equalizers (DFE) with a fixed infinite impulse response (IIR) in the feedback loop. An algorithm is given for training the new equalizer and it is shown that the proposed IIR filter reduces to a single pole filter if the feedback is chosen to be sufficiently long. The new equalizer is shown to have significantly better performance than the conventional DFE both in terms of bit error rate (BER) and signal to noise ratio (SNR) with reduced hardware complexity