Patent ID: 8233376

Claim:
A system comprising: a central office including a plurality of central modems; and at least one remote modem configured to communicate with said plurality of central modems, wherein said remote modem is further configured to perform automatic channel adjustment, and to provide to said central office a channel adjustment parameter wherein one or more symbols transmitted via said plurality of central modems to said remote modem are transformed by a channel response having a direct channel response and a far end cross talk (FEXT) response, wherein said central office includes a precoder configured to precode one or more symbols by applying an estimation precoding matrix to said symbols prior to any of said central modems transmitting any of said precoded symbols; and a controller configured to select a set of coefficients of the far end cross talk (FEXT) response between said plurality of central modems and said at least one remote modem, calculate said estimation precoding matrix as a first function of said set of selected coefficients, wherein precoding said symbols by said calculated matrix and transmitting said precoded symbols via said central modems causes said channel adjustment parameter at said remote modem to converge to a second function of said selected coefficients, and receive said channel adjustment parameter from said at least one remote modem in response to said central modems transmitting said precoded symbols to said remote modem.