DFE TO FFE EQUALIZATION COEFFICIENT CONVERSION PROCESS FOR DOCSIS 2.0

摘要

A method and apparatus for converting FFE and FBE coefficients from a DOCKS compatible cable modem termination system upstream equalizer into FFE only coefficients to be sent down to the cable modem which transmitted the training burst which resulted in convergence on the FFE and FBE coefficients. The method involves programming an DFE like conversion structure comprised of an FFE filter and an FBE filter whose outputs are summed with the FFE and FBE coefficients from CMTS equalizer. The FFE coefficients are stored in the FFE filter of the conversion structure. The FBE coefficients are stored in an FBE filter of the conversion structure. Then, an input vector which simulates the Dirac function (an impulse) is input to the conversion structure to derive coefficients as its output which define the impulse response and transfer function of the conversion structure. These coefficients are the FFE only coefficients which may be used to select a subset of 24 for sending to the cable modem.