Display Full Text | Download Full Text
1.98 MB PDF file

Degree

MS, University of Cincinnati, Engineering : Environmental Engineering, 2001.

Abstract

With the arrival of High Definition Television and in general all spectrally efficient modulation techniques like Eight Levels Vestigial Side Band (8VSB), whose peak to average power ratios is far greater than the traditional modulation methods, the broadcast manufacturer has encountered a new and very serious design challenge. The increased dynamic range combined with the strict maximum allowed levels of out-of-band spectral emission dictated by the Federal Communications Commission requires from all the power amplification stages more linearity than what is actually achievable by means of analog Radio Frequency design alone. In order to solve this problem a compromise solution has been proposed. It allows for some nonlinearity in the amplifiers while controlling the out of band emissions using sharp analog filtering. Unfortunately, severe degradation of the in-band signal parameters takes place as a consequence of Inter Symbol Interference caused by this analog filter, leaving no other choice but to equalize it. This thesis presents the results of Adaptive Digital Equalization of the Linear Distortion phenomena in a Television Transmitter. The characteristics of the Digital TV modulation standard used in the U.S. are examined. The design methodology of adaptive filtering is reviewed. An equalization algorithm suitable to the problem is chosen and implemented in a Digital Signal Processor. Different versions of the hardware/software implementation of the digital equalizer are reviewed and compared. Results of the final system are analyzed. Conclusions include successful applications, recommendations for improvement, as well as the foreseen conditions where the system could potentially fail.

Keywords

adaptive equalization

Advisor

Dr. Marios Polycarpou

Pages

129p.

Document number: ucin983391684
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=ucin983391684

★

This ETD has been downloaded 1213 times (through March 2013)

This ETD was one of the top ten most frequent downloads of December 2003.