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Self-FEXT cancellation for use with VDSL2 transceivers: Design, implementation and verification of a tool for numerical performance evaluation

: Hincapie Henao, Daniel
: Petrova, Marina; Maierbacher, Gerhard

Aachen, 2014, IX, 116 S.
Aachen, TH, Master Thesis, 2014
Master Thesis
Fraunhofer ESK ()
DSL; VDSL2; far end crosstalk; Torque Vectoring; cancellation; FEXT; multiple input multiple output; MIMO; channel modelling; numerical performance evaluation

Vectoring is a novel technology created to expand the capacity boundaries of Very high-bit-rate DSL 2 (VDSL2) systems. It mitigates the reduction of data rate and reach in VDSL2 systems caused by the crosstalk interference that appears when multiple services share the telephone networks infrastructure. However, the implementation of vectoring on real systems faces numerous challenges that limit its potential to enhance the data rate and reach of VDSL2 systems. Therefore, evaluating its performance in close-to-real scenarios considering different technological aspects has turned into an interesting field of research that also helps in the development of new and faster technologies. This thesis evaluates quantitatively the performance of vectoring on VDSL2 systems. It proposes the extension and parametrization of performance indicators to compare and measure the impact of six different aspects on vectoring systems: network topology, binder occupancy, background noise, channel estimation errors, complexity constraints, and precoding and canceling schemes. Their evaluation requires numerical results that are obtained through a simulation tool, which is designed and implemented as part of this thesis. The obtained results and the conducted analyses give concluding guidelines for the vectoring technology and can be taken into account by manufactures and service providers for the deployment of real systems. In addition, and as a result of the objective of providing an accurate evaluation that represents well the real systems performance, this thesis contributes with the statistical characterization of the Far-end Crosstalk (FEXT) in a 50-pair cable binder commonly used in Germany (DTAG-40) and constructs its stochastic model. The model and the results are verified through real systems measurements, reference documents of the Broadband Forum and existing literature. Thus, the simulation tool and the characterized channel model constitute a contribution for the evaluation of DSL systems that can be used in future works.