International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Much modem telemetry is transmitted in a digital format and to be compatible with
existing range equipment the digital data is impressed on the carrier using FM
modulation. The receiving system in common use employs an FM
limiter/discriminator as a detector followed by an integrate and dump matched filter
for bit detection. This system has been studied by previous authors [1] and it is well
known that in the absence of frequency uncertainty the optimum transmission
parameters consist of a modulation index of .7 (peak-to-peak deviation divided by the
bit rate) and an IF filter bandwidth equal to the bit rate followed by a limiter
discriminator.
In many cases, there is a need for some small amount of analog telemetry transmission
in addition to the digital data discussed above. In these cases it is common practice to
include analog subcarriers on the main carrier with the digital data modulating the
carrier at baseband, the resulting system is called PCM/FM + FM/FM. These hybrid
analog/digital systems are the subject of this paper. In particular this paper addresses
the performance of these systems through simulation using the Block Oriented System
Simulator (BOSS) from Comdisco and with analytical techniques to obtain the BER
versus SNR curves for these systems. The simulation is used over a wide range of
parameters to find the optimum values of modulation index and IF bandwidth for
these systems.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/608872 |
| Date | 10 1900 |
| Creators | Osborne, William P., Whiteman, Don, Ara, Sharmin |
| Contributors | New Mexico State University |
| Publisher | International Foundation for Telemetering |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Proceedings |
| Rights | Copyright © International Foundation for Telemetering |
| Relation | http://www.telemetry.org/ |
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