Multi-user multiple-input and multiple-output for digital subscriber line

Abstract

A method implemented in a wireless network element (NE), comprising obtaining, via a processor of the wireless NE, a plurality of encoded signals associated with a plurality of downstream (DS) channels in a wireless communication network, wherein the plurality of DS channels form a plurality of DS multiple-input and multiple-output (MIMO) groups, performing, via the processor, MIMO pre-coding on the plurality of encoded signals according to the plurality of DS MIMO groups to produce MIMO pre-coder output signals of the plurality of DS MIMO groups, performing, via the processor, a crosstalk pre-coding across the MIMO groups using a crosstalk pre-coding matrix on the MIMO pre-coder output signals of the plurality of DS MIMO groups to produce a plurality of output signals, with the crosstalk pre-coding matrix computed according to a first DS channel matrix and a DS MIMO channel matrix, wherein the first DS channel matrix comprises first diagonal entries representing first direct channel estimates of the plurality of DS channels at a first subcarrier and first off-diagonal entries representing co-channel interference estimates of the plurality of DS channels at the first subcarrier, a first diagonal block of the first DS channel matrix representing MIMO channels in a first DS MIMO group of the plurality of DS MIMO groups, and wherein the DS MIMO channel matrix comprises a second diagonal block and off-diagonal blocks, the second diagonal block corresponding to the first diagonal block of the first DS channel matrix, and with the off-diagonal blocks comprising values of zeros, and synchronously transmitting, via one or more transmitters of the wireless NE, the plurality of output signals to a plurality of remote wireless NEs via the plurality of DS channels.