Adaptive decision feedback equalization for multi-Gbps data links

Channel equalization combats the effects of the imperfection of wire channels. This dissertation deals with adaptive decision feedback channel equalization. The dissertation starts with an in depth study of the challenges encountered in the design of adaptive DFE and techniques that address these challenges. Various 2-dimensional eye-opening monitors (EOMs) based adaptive DFE are proposed and implemented. A novel 2-dimensional hexagon EOM is proposed and its effectiveness is validated using simulation. A simplified and power efficient 2-dimensional hexagon EOM is also introduced. Both EOMs are capable of differentiating the severity of the violation of the minimum eye-opening so as to allow the DFE to take different actions adaptively and achieve desired eye-opening more rapidly. A maximum-jitter EOM-based adaptive DFE is also introduced to greatly reduce system complexity. The adaptive DFE is taped out in a 130nm 1.2V CMOS technology and finally an improved adaptive engine that outperforms DFE utilizing sign-sign least-mean-square is proposed.