February 2017
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28 Reads
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19 Citations
IEEE Transactions on Aerospace and Electronic Systems
This paper describes the use of Alamouti-encoded shaped offset QPSK version TG (SOQPSK-TG) to solve the two-antenna problem in aeronautical telemetry. The Alamouti spacetime block code is used to encode the phase states in the complex exponential representation of SOQPSK-TG. Because SOQPSKTG possesses memory, the Alamouti decoder is a sequence estimator. Maximum likelihood and least squares sequence decoders are derived. To reduce the number of states, the 8-waveform cross-correlated trellis-coded quadrature modulation (XTCQM) approximate representation of SOQPSK-TG is used. A prototype decoder based on the least squares decoder and the estimators described in Part I and operating at a data rate of 10 Mbits/s, was tested in the laboratory in test flights at the Air Force Test Center, Edwards AFB. The test flights demonstrate that Alamouti-encoded SOQPSK-TG, as described in this paper using the least squares decoder based on the estimators described Part I solves the two antenna problem in aeronautical telemetry.