Fast seamless joining of channels in a multi-channel communication system

An apparatus comprising:

• an access node adapted for communication over a plurality of channels with respective customer premises equipment (CPE) of said channels;
• the access node comprising a precoder;
• wherein the access node is operative to join at least one of the channels to a group of active other ones of the channels;
• the access node being operative to transmit control signals to configure respective CPE of the active channels into a joining mode of operation;
• to transmit a joining signature sequence to CPE of the joining channel over a downstream data signal path of the joining channel;
• to receive from the CPE of the active channels respective correlation results;
• to estimate crosstalk from the joining channel into the active channels based on the correlation results;
• to configure the precoder based on the estimated crosstalk;
• and to add the joining channel to the group of active channels.

An apparatus comprising:

• customer premises equipment (CPE) configurable for operation in at least a joining mode of operation and a tracking mode of operation responsive to at least one control signal received from an access node;
• wherein in the joining mode of operation the CPE is configured to generate at least one correlation result and to send the correlation result to the access node;
• wherein in the tracking mode of operation the CPE is configured to generate at least one error sample and to send the error sample to the access node;
• wherein when the CPE is in the joining mode of operation, another CPE associated with a joining channel to be added to a group of active channels is configured to receive a joining signature sequence from the access node over its associated joining channel;
• and
• wherein the correlation result is utilizable by the access node to estimate crosstalk from the joining channel into one of the active channels and the estimated crosstalk is utilizable by the access node to configure a precoder.