Abstract: A tapped delay chain comprises a plurality of delay cells where each cell has at least two output taps: a primary one for feeding forward a delayed signal to a next cell in the chain, and a secondary output tap for feeding a slightly-differently delayed signal to a multiplier unit so that the slightly-differently delayed signal can be multiplied by a weighting coefficient. The split of output taps in each delay cell allows for a corresponding split of loading capacitance. Each output tap of the delay cell is loaded by a smaller capacitance than it would have had to otherwise drive had the split taps been instead lumped together as a common node. The reduced loading capacitance at each of the split taps allows for a wider frequency response range.

Abstract: Systems and methods are disclosed to adaptively pre-distort a signal prior to being used by a non-linear circuit, such as a higher power amplifier (at transmit) or a low noise amplifier (at receive). The signal is compared with a feedback signal from the non-linear circuit and a metric is calculated and minimized. The input signal is adaptively changed, such as by varying tap coefficients, until the metric is sufficiently minimized, resulting in a pre-distorted signal that is substantially linear upon passing through the non-linear circuit.

Abstract: Tap coefficients for fractionally-spaced equalizers are updated iteratively using error statistics from an input bit stream and an output bit stream, such as from a forward error correction circuit. The process continues until the errors converge to a sufficiently small number. Knowledge of the error patterns are used apriori to adaptively change the tap coefficients in a feedforward filter.