Data receiver including hybrid decision feedback equalizer

This invention relates to the reception of encoded signals employing decision feedback equalization. It is particularly though not necessarily exclusively concerned with the reception of data in the form of data packets in Ethernet or ATM data communications systems, particularly dual systems capable of operating at different frequencies such as both 10 MHz and 100 MHz. A decision feedback encoder comprising an analog-to-digital converter for converting an input signal into digital signals representing decision levels, digital processing circuits responsive to signals from the converter for providing a succession of symbol values and a set of coefficients, digital-to-analog converters for converting the coefficients into corresponding analog values and analog circuits for forming a sum of the products of each of the symbol values and a respective one of said analog values to provide a feedback signal for the reduction of inter-symbol interference in the input signal.