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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Iterative Equalization for SOQPSK in Multipath Fading

Lei, Qiang, Rice, Michael 10 1900 (has links)
ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / This paper investigates the application of iterative equalization techniques to overcome multipath fading for shaped offset QPSK (SOQPSK) in aeronautical telemetry. Two iterative equalization techniques for turbo encoded SOQPSK are presented. The first is the optimal-MAP turbo equalizer for OQPSK. The second equalizer is the adaptive decision feedback equalizer. Simulation shows that in the presence of frequency selective multipath typically encountered in aeronautical telemetry, both of these equalizers exhibit impressive performance.
2

BENEFITS AND TECHNIQUES FOR INCREASED POWER EFFICIENCY IN MODERN TELEMETRY TRANSMITTERS

Bozarth, Don, Horcher, Greg 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 / With recent developments in telemetry transmitter technologies, significantly greater DC to RF power efficiencies can be achieved. These new high efficiency transmitter designs may impact overall system design trade-offs by reducing the system size and weight requirements for batteries, heat sinks, and cabling. Furthermore, these fully DC isolated, next generation ARTM Tier 0, I and II enabled devices offer unique options to the platform designer in EMI/EMC control and system design. Advanced manufacturing techniques coupled with adaptive microprocessor control promises enhanced functionality, improved performance and reduced unit costs. The paper presents the performance of a new, high efficiency, telemetry transmitter topology and the possible system benefits involved with the application of this advanced transmitter technology within modern and legacy telemetry platforms. Specific sub-assembly circuit design techniques will be discussed and compared with prior design approaches.
3

OPTIMAL LINEAR DETECTION OF SOQPSK

Geoghegan, Mark 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Shaped Offset QPSK (SOQPSK), as proposed and analyzed by Terrance Hill, is a family of constant envelope waveforms that is non-proprietary and exhibits excellent spectral containment and detection efficiency. Detection results using the filtering found in conventional OQPSK demodulators have been published for two variants of SOQPSK, namely SOQPSK-A and –B. This paper describes a method of synthesizing an optimal linear detection filter, with regard to bit error probability (BEP), and presents the resulting performance.
4

The Effects of Phase Noise on Trellis FM & SOQPSK Data Links

O'Cull, Douglas C. 10 1900 (has links)
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Current IRIG standards provide guidelines for system phase noise and several manufactures provide receivers and transmitters that perform within this standard. However, legacy receivers and transmitters that do not meet the current IRIG standards are sometimes still used during a mission. This paper will address how phase noise outside of the current IRIG standard affects the performance of an FM data link when using a trellis demodulator, as well as the performance of an SOQPSK data link in a high phase noise environment. Bit error rate performance and test results at several different rates with various phase noise masks are presented in this paper.
5

ORTHOGONAL DUAL-ANTENNA TRANSMIT DIVERSITY FOR SOQPSK IN AERONAUTICAL TELEMETRY CHANNELS

Jensen, Michael A., Rice, Michael D., Nelson, Thomas, Anderson, Adam L. 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Transmit diversity schemes such as the Alamouti space-time code have been shown to be viable candidates to enable robust dual-antenna transmission from maneuvering air vehicles. However, due to the complicated structure of shaped offset quadrature phase shift keying (SOQPSK) modulation, the Alamouti approach has not been applicable to SOQPSK systems. This paper develops a precoding and detection algorithm which allows implementation of dual-antenna Alamouti signaling for SOQPSK modulation. Performance simulations demonstrate the performance of the scheme for a realistic flight scenario.
6

The Performance Evaluation of an OFDM-Based IP Transceiver at Eglin AFB

Berard, Alfredo, Cook, Paul, Roach, John 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / The 46th Test Wing, 846th Test Support Squadron (846 TSS/TSI) at Eglin AFB is currently evaluating their airspace for the use of SOQPSK transmitters and receivers for telemetry. The Squadron will incorporate an IP-compatible OFDM transceiver from Teletronics Technology Corporation (TTC) that will provide a two-way communication channel for controlling configuration settings of the airborne SOQPSK transmitter and receiver. This provides an opportunity to evaluate the effectiveness of an airborne network instrumentation system and measure some critical parameters, with an opportunity to assess the performance and reliability of streaming telemetry and OFDM-based IP communication systems. This paper describes the experimental test setup created for this evaluation and summarizes the measurement and evaluation process.
7

INTERFERENCE CANCELLATION USING ARTM TIER-1 WAVEFORMS IN AERONAUTICAL TELEMETRY

Ali, Tariq M., Saquib, Mohammad, Rice, Michael 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper describes and interference cancellation technique appropriate for ARTM Tier-1 waveforms. The technique requires the estimators for the bit sequences for the adjacent channels as well as the power levels of the adjacent channels. Simulation results show that the interference canceller allows a more dense “channel packing” thereby creating a channel utilization 67% ~ 100% greater than the current IRIG 106 recommendations.
8

IN-SERVICE DETECTION OF MULTIPATH FADING

Jefferis, Robert 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Multipath (MP) fading is the dominant channel impairment in many aeronautical telemetry links. One product of a recent multipath mitigation study is the discovery of a simple technique for detecting its presence over a useful range of conditions. The technique also detects significant random noise levels in the channel. This paper describes the “Signal Degradation Indicator” (SDI) and its application to FQPSK-B and SOQPSK [2] modulation. Laboratory emulation data is presented and implementation considerations are discussed.
9

WSMR Telemetry Capabilities: Today's Technology in Telemetry

Aguirre, Zoe, Beltran, Gabe 10 1900 (has links)
ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / White Sands Missile Range is the largest overland test range in North America occupying over 3,200 square miles in Southern New Mexico and nearby territory. One of the most critical test elements at White Sand Missile Range is it's capabilities in the telemetry field. Much significant advancement in technology has given WSMR and the entire electronics world the ability to achieve new levels of data acquisition that were not achievable a decade ago. And as attention to our nation's defense is of high priority, White Sands Missile Range provides to highest levels of telemetry competence in the Western Hemisphere.
10

HIGH-RATE WIRELESS AIRBORNE NETWORK DEMONSTRATION (HiWAND) FLIGHT TEST RESULTS

Franz, Russell 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 / An increasing number of flight research and airborne science experiments now contain network-ready systems that could benefit from a high-rate bidirectional air-to-ground network link. A prototype system, the High-Rate Wireless Airborne Network Demonstration, was developed from commercial off-the-shelf components while leveraging the existing telemetry infrastructure on the Western Aeronautical Test Range. This approach resulted in a cost-effective, long-range, line-of-sight network link over the S and the L frequency bands using both frequency modulation and shaped-offset quadrature phase-shift keying modulation. This paper discusses system configuration and the flight test results.

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