Bit Rate Maximization in Discrete Multitone Modulation

Mr. Milos Milosevic

Department of Electrical and Computer Engineering
University of Texas at Austin

Thursday, April 18th, 8:30 AM, ENS 637

mmilosevic@austin.rr.com


Abstract

The traditional discrete multi-tone equalizer is a cascade of a time domain equalizer (TEQ) as a single finite impulse response filter, a fast Fourier transform (FFT) multicarrier demodulator, and a frequency domain equalizer (FEQ) as a one-tap filter bank. The TEQ shortens the transmission channel impulse response (CIR) to mitigate inter-symbol interference (ISI). Maximum Bit Rate (MBR) and Minimum ISI (Min-ISI) methods achieve higher data rates at the TEQ output than previously published methods. As an alternative to the traditional equalizer, the per-tone equalizer (PTE) moves the TEQ into the FEQ and customizes a multi-tap FEQ for each tone. In this paper, we propose a time domain TEQ filter bank (TEQFB) and single TEQ that demonstrate better data rates at the FEQ output than MBR, Min-ISI, and least-squares PTE methods with standard CIRs, transmit filters, and receive filters. We develop a new model for the signal-to-noise ratio (SNR) at the FFT output that includes ISI, near-end crosstalk, white Gaussian noise, and the digital noise floor. The contributions of this paper are:

(1) a new achievable upper bound on bit rate performance,
(2) data rate optimal time domain per-tone TEQ filter bank, and
(3) data rate maximization single TEQ design algorithm.

Biography

Milos Milosevic received B.S.E.E. and M.S.E.E. at the Illinois Institute of Technology in Chicago, IL in 1996 and 1998, respectively. He is pursuing his Ph.D. in electrical engineering at The University of Texas at Austin, TX. He is a senior engineer in the Acquisition Department, Telemetry Section of Schlumberger in Austin, TX, where he designs next generation high-speed communication systems for oilfield services. His professional experiences include a systems engineering position in Motorola's Networking and Communication Systems Division where he worked on the design of a ADSL transceiver based on Motorola 56300 core and DSP algorithm design for the Texas Instruments C6000 DSP core at Texas Instruments Broadband Division. His current research interests are multicarrier communication systems such as ADSL or VDSL.


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