2000 IEEE Digital
Signal Processing Workshop
Fast Time-Domain Equalization for Discrete Multitone Modulation Systems
Biao Lu (1),
Lloyd D. Clark (2),
Guner Arslan (1),
Brian L. Evans (1)
(1) Department of Electrical and Computer Engineering,
Engineering Science Building,
The University of Texas at Austin,
Austin, TX 78712-1084 USA
8311 North FM 620 Road,
Austin, TX 78726 USA
DMT TEQ Matlab Toolbox -
ADSL Research at UT Austin
In discrete multitone receivers, a time-domain equalizer (TEQ) shortens
the effective channel impulse response.
The effective channel impulse response is ideally non-zero inside
a short window and zero elsewhere.
The samples outside of the window cause intersymbol interference.
The ratio between the samples inside and outside of this
window is called the shortening signal-to-noise (SSNR).
In this paper, we develop a suboptimal method for maximum SSNR TEQ design
that requires two orders of magnitude fewer computations than the
original maximum SSNR method.
We reduce computation by using a proposed heuristic to estimate
the optimal delay of the window and a proposed divide-and-conquer method
to compute the TEQ taps.
For typical ADSL channels, the tradeoff for the reduction in computation
is roughly 4 dB SSNR for two-tap TEQs and less than 1 dB for 17-tap TEQs.
Last Updated 11/08/04.