1. A method for establishing or updating filter coefficients in a MIMO precode filter during activation of a new channel, the method comprising: sending a training alert signal from a CO transmitter to one or more CPE receivers associated with active channels; transmitting a training signal from the CO transmitter to a CPE receiver associated with the channel being activated; monitoring, with one or more CPE receivers associated with active channels, for noise, coupling or both generated by transmission of the training signal; isolating noise, coupling, or both generated by the training signal and received at the CPE receivers associated with active channels; transmitting the noise, coupling, or both or information regarding the noise, coupling, or both from the CPE associated with the active channels to the CO; processing the noise, coupling, or both or information regarding the noise, coupling, or both at the CO to establish MIMO precode filter coefficients configured to pre-cancel noise, coupling, or both resulting from signals on the channel being activated.