Open AccessBandwidth utilization maximization of scientific RF communication systems
Author(s) -
David Rey,
W.E. Ryan,
M. D. Ross
Publication year - 1997
Publication title -
osti oai (u.s. department of energy office of scientific and technical information)
Language(s) - English
Resource type - Reports
DOI - 10.2172/434435
Subject(s) - computer science , trellis modulation , bandwidth (computing) , viterbi decoder , electronic engineering , coding (social sciences) , digital signal processing , data transmission , real time computing , computer hardware , decoding methods , telecommunications , fading , engineering , mathematics , statistics
A method for more efficiently utilizing the frequency bandwidth allocated for data transmission is presented. Current space and range communication systems use modulation and coding schemes that transmit 0.5 to 1.0 bits per second per Hertz of radio frequency bandwidth. The goal in this LDRD project is to increase the bandwidth utilization by employing advanced digital communications techniques. This is done with little or no increase in the transmit power which is usually very limited on airborne systems. Teaming with New Mexico State University, an implementation of trellis coded modulation (TCM), a coding and modulation scheme pioneered by Ungerboeck, was developed for this application and simulated on a computer. TCM provides a means for reliably transmitting data while simultaneously increasing bandwidth efficiency. The penalty is increased receiver complexity. In particular, the trellis decoder requires high-speed, application-specific digital signal processing (DSP) chips. A system solution based on the QualComm Viterbi decoder and the Graychip DSP receiver chips is presented
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