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Space-Time Coding with Offset ModulationsNelson, N. Thomas 26 November 2007 (has links) (PDF)
In this dissertation it is shown that the telemetry versions of Feher-patented QPSK (FQPSK-JR) and shaped offset QPSK (SOQPSK-TG) can be interpreted as both cross-correlated, trellis-coded quadrature modulation (XTCQM) and continuous phase modulation (CPM). Based on these representations, both modulations can be detected with near optimal bit error rate performance using a common detector that is formulated as either an XTCQM detector, a traditional CPM detector, or a pulse amplitude modulation (PAM) detector (due to the PAM decomposition of the CPM representations of these modulations). In addition it is shown that the complexity of the XTCQM detector for SOQPSK-TG can be reduced by a factor of 128 with only a 0.2 dB loss in detection efficiency relative to the optimum detector. Three decoders for STC encoded OQPSK are presented. One decoder has a bit error rate performance that matches the SISO case but with much higher complexity than that of the QPSK decoder. A second decoder matches the simplicity of the decoder for STC encoded non-offset QPSK but with a loss of 3 dB relative to the single-input, single-output (SISO) case. A third decoder matches SISO performance with lower complexity than the first one. These results for STC encoded OQPSK are extended to STC SOQPSK. It is shown that the maximum likelihood decoder is not computationally feasible. Two suboptimal decoders based on the STC OQPSK decoders are presented. These decoders have much higher complexity than their OQPSK counterparts, and they provide inferior bit error rate performance. In addition, a least squares decoder for STC encoded SOQPSK is presented which is less complex and has better performance (within 1 dB of the SISO bound) than the previous two decoders. This decoder also handles the differential delays that can occur on aeronautical telemetry channels.
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THE EVALUATION AND INTEGRATION OF AN INSTRUMENTATION AND TELEMETRY SYSTEM WITH SOQPSK MODULATION AND CONTROL INTEGRATED WITH AVIONICS DISPLAYSWegener, John A., Zettwoch, Robert N., Roche, Michael C. 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper describes the integration activities associated with the instrumentation and telemetry system developed for an F/A-18 Hornet Flight Test program, including bench integration, avionics integration, and aircraft ground and flight checkout. The system is controlled by a Boeing Integrated Defense System (IDS) Flight Test Instrumentation designed Instrumentation Control Unit (ICU), which interfaces to an avionics pilot display and Ground Support Unit (GSU) to set up the instrumentation during preflight and control the instrumentation during flight. The system takes in MIL-STD-1553, analog parameters, Ethernet, Fibre Channel, and video, and records these with onboard recorders. Selected subsets of this data may be routed to the telemetry system, which features two RF streams, each of which contains up to four PCM streams combined into a composite by a data combiner. The RF streams are transmitted by multi-mode digital transmitters capable of PCM-FM or Shaped Offset Quadrature Phase Shift Keying (SOQPSK), with selectable Turbo-Product Code (TPC) Forward Error Correction (FEC). This paper describes integration of the system with the IDS Flight Test Integration Test Bench (ITB), production avionics integration facilities, and final aircraft ground checkout and initial flight tests. It describes results of integration activities and bench evaluation of the telemetry system.
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ADVANCED RANGE TELEMETRY (ARTM) TIER I COMPATIBLE DEMODULATOR TESTING AND RESULTSTemple, Kip 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The Nova HYPERMOD demodulator operates in three modes, the classic pulse-code
modulation/frequency modulation (PCM/FM), sometimes known as continuous phase frequency shift
keying (CPFSK) mode, shaped offset quadrature phase shift keying (SOQPSK) mode, and continuous
phase modulation (CPM) mode. Of interest to this paper is SOQPSK mode which is a waveform similar
to the Advanced Range Telemetry (ARTM) Tier I waveform, Feher’s Quadrature Phase Shift Keying, B
version (FQPSK-B) revision (Rev) A1. Also considered is another variant, FQPSK-JR. This paper
will outline the cross compatibility and resynchronization speed of these waveforms based upon
ARTM-adopted demodulator performance tests. The results of these laboratory tests comparing the
HYPERMOD demodulator, the enhanced Tier I demodulator, and the current Tier I reference
demodulator, both from RF Networks, will be presented.
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AN INITIAL LOOK AT ADJACENT BAND INTERFERENCE BETWEEN AERONAUTICAL MOBILE TELEMETRY AND LONG-TERM EVOLUTION WIRELESS SERVICETemple, Kip 11 1900 (has links)
With National Telecommunications & Information Administration (NTIA) Advanced Wireless
Services (AWS-3) auction of frequencies in the 1695-1710 MHz, 1755-1780MHz, and 2155-
2180MHz bands, users of the Aeronautical Mobile Telemetry (AMT) band from 1755-
1850MHz, known as Upper L-Band, could be greatly affected. This paper takes an initial look at
how the 1755-1780MHz band will be used by the cellular carriers and presents some preliminary
testing results of adjacent channel (band) interference that could be experienced by AMT users.
This paper should be considered as the stepping off point for future interference discussions,
required analysis, and further testing.
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Multipath Mitigation in Frequency Selective Channels with an Emphasis on 5G Cellular Mobile Networks and Aeronautical Mobile Telemetry ApplicationsArabian, Farah 16 March 2022 (has links)
This dissertation explores the role of polarization, combining, and equalization operating over frequency-selective channels to improve the reliability of wireless communications systems in terms of BER for two applications: 5G mobile networks (operating in the mmWave band and NR FR1), and aeronautical mobile telemetry systems (operating in L band). The equivalent discrete-time models for a variety of spatial combining techniques at 5G mmWave bands were derived to investigate the performance of co-located cross-polarized antenna elements when polarization diversity is used and also when a combination of spatial and cross-polarized antennas is exploited. In both cases, ML combining has the lowest BER and EPC produced the worst results. The use of co-located cross-polarized antenna elements also is examined in 5G FR1 assuming post-FFT processing of the two antenna element outputs in a mobile-to-mobile setting. The optimum strategy, in the ML sense, for incorporating the two antenna outputs is developed. The optimum combining strategy together with a FDE is compared to the traditional combining techniques: MRC, EGC, and SC, where the last two also require a FDE. Computer simulations performed over a stochastic channel model with polarization state information show that the difference between ML detection and MRC (the best performing methods) and SC with FDE (the worst performing method) is 2 dB. The similar results were observed with pilot based channel estimators, however the difference in this case was the presence of a BER floor at low values of $N_0$ and caused by channel estimation errors. In aeronautical mobile telemetry applications, the ML combiner is derived and shown to be equivalent to the summing the outputs of two filters matched to the channels in the horizontal and vertical polarization states. For historical reasons, current systems combine right-hand and left-hand circularly polarized antenna feed outputs using a MRC. To compare the two combining approaches, the aeronautical telemetry multipath channel was extended to include polarization state information. The simulation results for SOQPSK-TG with a CMA equalizer show that the post-equalizer BER for the two approaches is the same.
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