Telefonaktiebolaget Lm Ericsson (publ)

Ronaldo Zampolo

Boris Dortschy

Aldebaro Klautau

Jaume Rius I Riu

Rodrigo Bastos Moraes

Moraes Rodrigo Bastos

A method, central unit, and modem for reducing crosstalk in a Digital Subscriber Line (DSL) system. A virtual line referred to as a ghost line is introduced in the system as a substitution for all of the lines except a first line to induce crosstalk to the first line. The Power Spectral Density (PSD) on the first line is allocated to optimize against the ghost line. A modem on the first line reports to a central Spectrum Management Center (SMC), a measure indicating crosstalk impact from the ghost line. This process is repeated for each line. The SMC calculates updated ghost line parameters for each line, which reflect current crosstalk characteristics between each modem and the remaining modems, and sends the updated parameters to the modems. The modems then reallocate PSDs with respect to the updated ghost line parameters to either maximize the rate or minimize the power on their respective lines.

Method central unit, and modem in a digital subscriber line network

A method and transmitter unit in a multi-tone multi-line based transmission system such as a digital subscriber line system for determining a Power Spectral Density (PSD) of a plurality of users over a physical channel for at least one tone. Each of the users has a minimum required data rate and a maximum allowed power. A Power Minimization Problem (PMP) is formulated mathematically introducing Lagrangian multipliers and by utilizing a dual decomposition approach for the objective function of the PMP in order to solve the PMP on a per-tone basis.

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Belém, Brazil

Ronaldo Zampolo