Optimizing Power Normalization for G.fast Linear Precoder by Linear Programming

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


The use of vectoring for crosstalk cancellation in
the new ITU-T G.fast standard for next generation DSL systems
becomes essential for efficient utilization of the extended
bandwidth (up to 200 MHz). In VDSL2 (up to 30 MHz),
a zero-forcing-based linear precoder is used in downstream
which approaches single-line performance. However, at high
frequencies, the linear precoder may amplify the signal power
substantially since the crosstalk channel is much stronger
than at lower frequencies. Performance could be significantly
degraded by power normalization to keep the PSD below the
mask. In this work, we extended a per-line power normalization
scheme by linear programming (LP) optimization. By
simulations using measured cable data it is shown how the LPbased
scheme further improves the linear precoder and it is
also capable of balancing the data rate between lines. Further,
the simulations also show the non-linear Tomlinson-Harashima
precoder performs better than the linear precoders.


  • Francisco Müller
  • Chenguang Lu
  • Per-Erik Eriksson
  • Stefan Höst
  • Aldebaro Klautau
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Electrical Engineering, Electronic Engineering, Information Engineering
Original languageEnglish
Title of host publication2014 IEEE International Conference on Communications, ICC 2014
PublisherIEEE--Institute of Electrical and Electronics Engineers Inc.
ISBN (Print)9781479920037
Publication statusPublished - 2014
Publication categoryResearch
EventIEEE ICC 2014 - Selected Areas in Communications Symposium - Sydney, Australia
Duration: 2014 Jun 102014 Jun 14


ConferenceIEEE ICC 2014 - Selected Areas in Communications Symposium