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SELECTABLE PERMUTATION ENCODER/DECODER FOR A QPSK MODEM

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / An artifact of QPSK modems is ambiguity of the recovered data. There are four variations of the output data for a given input data stream. All are equally probable. To resolve this ambiguity, the QPSK data streams can be differentially encoded before modulation and differentially decoded after demodulation. The encoder maps each input data pair to a phase angle change of the QPSK carrier. In the demodulator, the inverse is performed - each phase change of the input QPSK carrier is mapped to an output data pair. This paper discusses a very simple and unique differential encoder/decoder that handles all possible data pair/phase change permutations.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/605817
Date10 1900
CreatorsWeitzman, Jonathan M.
ContributorsGDP Space Systems
PublisherInternational Foundation for Telemetering
Source SetsUniversity of Arizona
Languageen_US
Detected LanguageEnglish
Typetext, Proceedings
RightsCopyright © International Foundation for Telemetering
Relationhttp://www.telemetry.org/

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