incoming data at a high - speed serial receiver is digitized and then digital signal processing techniques may be used to perform digital equalization . such digital techniques may be used to correct various data anomalies . in particular , in a multi - channel system , where crosstalk may be of concern , knowledge of the characteristics of the other channels , or even the data on those channels , may allow crosstalk to be subtracted out . knowledge of data channel geometries , particularly in the context of backplane transmissions , may allow echoes and reflections caused by connectors to be subtracted out . as data rates increase , fractional rate processing can be employed . for example , the analog - to - digital conversion can be performed at half - rate and then two dsps can be used in parallel to maintain throughput at the higher initial clock rate . at even higher rates , quadrature techniques can allow analog - to - digital conversion at quarter - rate , with four dsps used in parallel .