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A prototype 4800 bps voice terminal for the mobile satellite experimentThe authors report the final stage of a research project for the NASA mobile satellite experiment (MSAT-X). The work has resulted in two alternative coding techniques which have achieved good communications quality at 4.8 kb/s while tolerating vehicle noise, fading, and a fairly high-error-rate, bursty channel. The authors have constructed a circuit board based on three AT&T 32-bit floating-point DSP32 digital signal processors (DSP) and providing both excess processing power and considerable flexibility for handling different variations of the algorithms. A Motorola 68HC11 microcomputer chip serves as the board controller and interface handler. Mounted on a wirewrapped card, the prototype's circuit footprint amounts to only 225 cm2 and consumes about 13 W of power. A description is given of the architecture, signal processing and communication functions, circuitry, and firmware of the prototype. Issues such as synchronization, framing, error control, and modem interface are also addressed.
Document ID
19880049219
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Chan, Wai-Yip
(California Univ. Santa Barbara, CA, United States)
Davidson, Grant
(California Univ. Santa Barbara, CA, United States)
Chen, Juin-Hwey
(California Univ. Santa Barbara, CA, United States)
Gersho, Allen
(California, University Santa Barbara, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Subject Category
Space Communications, Spacecraft Communications, Command And Tracking
Meeting Information
Meeting: GLOBECOM ''87 - Global Telecommunications Conference
Location: Tokyo
Country: Japan
Start Date: November 15, 1987
End Date: November 18, 1987
Sponsors: IEEE, Institute of Electronics, Information and Communication Engineers, Ministry of Posts and Telecommunications of Japan, et al.
Accession Number
88A36446
Distribution Limits
Public
Copyright
Other

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