1000BASE-T is the next generation high-speed Ethernet LAN for twisted pair copper medium with a minimum required reach of 100meters. High-speed transmission over distorting channels like copper lines in 1000BASE-T system requires adaptive equalization. The equalizer which has no special training sequences in general uses the decisions of a slicer for its tap adaptation. Evidently, data-aided equalization schemes need a fairly good initial setup of equalizer coefficients to ensure that most of the decoded symbols are correct.
In this paper, we propose the design algorithm of decision feedback equalizer initial tap coefficients for the 1000BASE-T system. The proposed method is based on a minmax optimization and a clustering algorithm. Design results are applied to receiver start-up which include equalization, timing recovery and echo/NEXT cancellations. Start-up simulation results show that robust and fast initialization is achieved by using the decision feedback equalizer with designed initial tap coefficients.
