2 research outputs found
Per-Tone model for Common Mode sensor based alien noise cancellation for Downstream xDSL
For xDSL systems, alien noise cancellation using an additional common mode
sensor at the downstream receiver can be thought of as interference
cancellation in a Single Input Dual Output (SIDO) system. The coupling between
the common mode and differential mode can be modelled as an LTI system with a
long impulse response, resulting in high complexity for cancellation. Frequency
domain per-tone cancellation offers a low complexity approach to the problem
besides having other advantages like faster training, but suffers from loss in
cancellation performance due to approximations in the per-tone model. We
analyze this loss and show that it is possible to minimize it by a convenient
post-training "delay" adjustment. We also show via measurements that the loss
of cancellation performance due to the per-tone model is not very large for
real scenarios
Signal Processing for Gigabit-Rate Wireline Communications
Signal processing played an important role in improving the quality of
communications over copper cables in earlier DSL technologies. Even more
powerful signal processing techniques are required to enable a gigabit per
second data rate in the upcoming G.fast standard. This new standard is
different from its predecessors in many respects. In particular, G.fast will
use a significantly higher bandwidth. At such a high bandwidth, crosstalk
between different lines in a binder will reach unprecedented levels, which are
beyond the capabilities of most efficient techniques for interference
mitigation. In this article, we survey the state of the art and research
challenges in the design of signal processing algorithms for the G.fast system,
with a focus on novel research approaches and design considerations for
efficient interference mitigation in G.fast systems. We also detail relevant
VDSL techniques and points out their strengths and limitations for the G.fast
system.Comment: 20 pages, Accepted for publication in the IEEE Signal Processing
Magazine, May 201