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Active and Passive Electronic Components
Volume 2012 (2012), Article ID 596481, 5 pages
http://dx.doi.org/10.1155/2012/596481
Research Article

Time-Domain Predistortion Method Based on Raised Cosine Signaling in Real Transmission Channels

Faculty of Electrical Engineering and Communication, Brno University of Technology, 61600 Brno, Czech Republic

Received 8 March 2012; Revised 14 May 2012; Accepted 14 May 2012

Academic Editor: G. Ghibaudo

Copyright © 2012 Bretislav Sevcik. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The concept of time-domain predistortion method based on raised cosine signaling is applied in real transmission channels. The proposed PWM-RC method uses raised-cosine pulse shaping instead of conventional rectangular digital signals and pulse-width modulation (PWM) scheme to achieve better output channel data response in harsh channel environment. The conventional predistortion methods based on pulse amplitude adjusting are not compatible with modern low-power CMOS design. Currently existing time-domain predistortion methods which are only based on a PWM scheme show many highfrequency signal harmonic components for both fast and slow signal transitions. It can cause more system crosstalk susceptibility if the crosstalk is dominant factor in transmission channel. In this case, the additional preemphasis boosted undesirable high-frequency components. Finally, the real channel transfer functions in connection with ADS Agilent development studio are used to compare the performance of proposed method with other predistortion methods.