• Reduced Complexity Viterbi Decoders for SOQPSK Signals over Multipath Channels

      Saquib, Mohammad; Kannappa, Sandeep Mavuduru; University of Texas at Dallas (International Foundation for Telemetering, 2010-10)
      High data rate communication between airborne vehicles and ground stations over the bandwidth constrained Aeronautical Telemetry channel is attributed to the development of bandwidth efficient Advanced Range Telemetry (ARTM) waveforms. This communication takes place over a multipath channel consisting of two components - a line of sight and one or more ground reflected paths which result in frequency selective fading. We concentrate on the ARTM SOQPSKTG transmit waveform suite and decode information bits using the reduced complexity Viterbi algorithm. Two different methodologies are proposed to implement reduced complexity Viterbi decoders in multipath channels. The first method jointly equalizes the channel and decodes the information bits using the reduced complexity Viterbi algorithm while the second method utilizes the minimum mean square error equalizer prior to applying the Viterbi decoder. An extensive numerical study is performed in comparing the performance of the above methodologies. We also demonstrate the performance gain offered by our reduced complexity Viterbi decoders over the existing linear receiver. In the numerical study, both perfect and estimated channel state information are considered.
    • Design and Analysis of a 3-D Gauss-Markov Model for Highly Dynamic Airborne Networks

      Sterbenz, James P. G.; Broyles, Dan; Jabbar, Abdul; University of Kansas (International Foundation for Telemetering, 2010-10)
      Accurate mobility models are needed to simulate the physical movement of nodes in a highly-dynamic aeronautical network. The fundamental problem with many synthetic mobility models is their random, memoryless behavior. Airborne ad hoc networks require a flexible memory-based 3-dimensional mobility model. We present a new 3-dimensional implementation of the Gauss-Markov mobility model for airborne telemetry network simulations, and compare its behavior to memoryless models such as random waypoint and random walk using the ns-3 simulator.
    • A VHDL Implementation of the Soft Output Viterbi Algorithm

      Perrins, Erik; Werling, Brett W.; University of Kansas (International Foundation for Telemetering, 2010-10)
      In this paper we present a VHDL implementation of the soft output Viterbi algorithm (SOVA). We discuss the usefulness of the SOVA in a serially concatenated convolutional code (SCCC) system. We explore various hardware design decisions along with their implications. Finally, we compare the simulated performance of the hardware implementation to a software reference model over an additive white Gaussian noise (AWGN) channel for several bit widths and traceback window lengths.
    • Advanced Hardware-in-the-Loop Testing Assures RF Communication System Success

      Williams, Steve; RT Logic (International Foundation for Telemetering, 2010-10)
      RF Communication (COMMS) systems where receivers and transmitters are in motion must be proven rigorously over an array of natural RF link perturbations such as Carrier Doppler shift, Signal Doppler shift, delay, path loss and noise. These perturbations play significant roles in COMMS systems involving satellites, aircraft, UAVs, missiles, targets and ground stations. In these applications, COMMS system devices must also be tested against increasingly sophisticated intentional and unintentional interference, which must result in negligible impact on quality of service. Field testing and use of traditional test and measurement equipment will need to be substantially augmented with physics-compliant channel emulation equipment that broadens the scope, depth and coverage of such tests, while decreasing R&D and test costs and driving in quality. This paper describes dynamic link emulation driven by advanced antenna and motion modeling, detailed propagation models and link budget methods for realistic, nominal and worst-case hardware-in-the-loop test and verification.
    • Situational Wireless Awareness Network

      Marcellin, Michael W.; Xin, Hao; Scheidemantel, Austin; Alnasser, Ibrahim; Carpenter, Benjamin; Frost, Paul; Nettles, Shivhan; Morales, Chelsie; University of Arizona (International Foundation for Telemetering, 2010-10)
      The purpose of this paper is to explain the process to implementing a wireless sensor network in order to improve situational awareness in a dense urban environment. Utilizing a system of wireless nodes with Global Positioning System (GPS) and heart rate sensors, a system was created that was able to give both position and general health conditions. By linking the nodes in a mesh network line of sight barriers were overcome to allow for operation even in an environment full of obstruction.
    • On the Use of Rapid Prototyping for Designing PCM/FM Demodulators in FPGAS

      Rice, Michael; Nelson, Brent; Padilla, Marc; Havican, Jared; Brigham Young University (International Foundation for Telemetering, 2010-10)
      This paper describes the use of an efficient FPGA design flow, called Ogre, developed at BYU to design and implement PCM/FM demodulators. Ogre exploits the notion of reuse by taking advantage of a library of specially designed cores parameterized by XML metadata. A judicious choice of library cores, targeted to signal processing functions common to sampled data modulators and demodulators, reduces the design and test cycle time. We demonstrate this by using the tool to construct rapid prototypes of three different versions of FM demodulators and show that the bit error rate performance is comparable to demodulators on the market today.
    • End-to-End ARQ: Transport-Layer Reliability for Airborne Telemetry Networks

      Sterbenz, James P. G.; Pathapati, Kamakshi Sirisha; Rohrer, Justin P.; University of Kansas (International Foundation for Telemetering, 2010-10)
      Due to the mission-critical nature of command-and-control traffic in the telemetry environment, it is imperative that reliable transfer be supported. The AeroTP disruption-tolerant transport protocol is intended for this environment. The mechanism for reliable transfer is ARQ with end-to-end acknowledgments. This has significant performance limitations resulting from the highly-dynamic nature of airborne telemetry networks, since end-to-end paths may not persist long enough for retransmissions to be received. We use ns-3 to analyze the AeroTP ARQ mechanism, along with tunable parameters that may improve performance in reliable transfer mode.
    • Optical Links Capacity for LEO Satellites Over European Ground Networks

      Guérin, A.; Lacoste, F.; Laurens, A.; Azéma, G.; Périard, C.; Grimal, D.; Centre National d’Etudes Spatiales (CNES); Thales, Solutions de Securité et Services; Météo-France (International Foundation for Telemetering, 2010-10)
      Free-space optical communications offer the technology breakthrough required by future Earth Exploration Satellites for their High Rate Payload Telemetry, while they required clear sky propagation conditions leading to locate receiving optical ground stations on favorable sites in terms of atmospheric propagation and to use site diversity to reach classical system availability requirements. This paper presents a methodology that can be used to optimize such a network relying on experimental meteorological satellite data. It also presents quantitative results in terms of link availability over a European ground network and the associated downlink capacity considering possible future Low Earth Orbit satellites.
    • Digital Cross-Polar Interference Canceller

      Thesling, Bill; ViaSat, Inc. (International Foundation for Telemetering, 2010-10)
      Dual-polarized data transmission promises to double the system capacity by transmitting independent signals simultaneously on both polarizations in the same channel. However, the polarization orthogonality of the propagation field can not always be perfectly preserved in various environments. Also the antenna and waveguide networks may not be able to achieve absolute polarization isolation. Therefore cross-polarization interference becomes a severe source of performance degradation in dual-polar systems. This paper presents an all-digital design of the cross-polarization interference canceller (XPIC or CPIC). This canceller is designed to remove the cross-polar interference so that comparable performance to single-polar system can be achieved for each polarization. Specifically, this digital design aims for • Mitigating the cross-polarization interference caused primarily by antenna orientation. (Delay between the signals from both polarizations is considered insignificant.) • Can operate with time varying cross-polar interference varying at rates of 2-3 Hz and beyond. • Initial isolation can be as low as 10 dB. • Is well suited to an all digital modem where clocking from the A/D is independent of symbol timing recovery clocks.
    • Adapting Fourier Analysis for Predicting Earth, Mars and Lunar Orbiting Satellite's Telemetry Behavior

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2010-10)
      Prognostic technology uses a series of algorithms, combined forms a prognostic-based inference engine (PBIE) for the identification of deterministic behavior embedded in completely normal appearing telemetry from fully functional equipment. The algorithms used to define normal behavior in the PBIE from which deterministic behavior is identified can be adapted to quantify normal spacecraft telemetry behavior while in orbit about a moon or planet or during interplanetary travel. Time-series analog engineering data (telemetry) from orbiting satellites and interplanetary spacecraft are defined by harmonic and non-harmonic influences, which shape it behavior. Spectrum analysis can be used to understand and quantify the fundamental behavior of spacecraft analog telemetry and relate the behavior's frequency and phase to its time-series behavior through Fourier analysis.
    • A Reflection Type Phase Shifter for iNET Phase Array Antenna Applications

      Shrestha, Bikram; Morgan State University (International Foundation for Telemetering, 2010-10)
      In this article we present results from modeling and simulation of a L-band reflection type phase shifter (RTPS) that provides continuous phase shift of 0° to 360°. The RTPS circuit uses a 90º hybrid coupler and two reflective load networks consisting of varactor diodes and inductors. Proper design of 90° hybrid coupler is critical in realizing maximum phase shift. The RTPS circuit implemented on a Rogers Duroid substrate is large in size. We discuss methods to reduce the size of L-band RTPS.
    • High Data Rate ARTM Tier II Telemetry Waveforms Receiver Analysis and Design

      Dourbal, Paul; Bouglo, Yuriy; Fleyshman, Val; Mayer, Robert; Okoro, Jerry; Shikhalev, Boris; L-3 Telemetry East (International Foundation for Telemetering, 2010-10)
      In this article we show how phase noise and demodulator complexity define the potential performance of high data rate telemetry receivers for ARTM continuous phase modulation (ARTM CPM) signals. Given a level of phase noise and demodulator complexity, we can predict the potential performance of a receiver. We also provide the results of actual receiver performance measurements (obtained using RCB-4000 Telemetry Receiver). We develop a simplified analytical model for an ARTM CPM signal transmission and present the resulting equation for phase increment difference between close signal sequences. The analysis of demodulator performance deterioration due to inter-symbol interference and due to receiver phase noise is then provided. Actual receiver phase noise data is included and is used to analyze demodulator performance.
    • IHAL and Web Service Interfaces to Vendor Configuration Engines

      Hamilton, John; Darr, Timothy; Fernandes, Ronald; Sulewski, Joe; Jones, Charles; Knowledge Based Systems, Inc.; L-3 Telemetry East; Edwards Air Force Base (International Foundation for Telemetering, 2010-10)
      In this paper, we present an approach towards achieving standards-based multi-vendor hardware configuration. This approach uses the Instrumentation Hardware Abstraction Language (IHAL) and a standardized web service Application Programming Interface (API) specification to allow any Instrumentation Support System (ISS) to control instrumentation hardware in a vendor neutral way without requiring non-disclosure agreements or knowledge of proprietary information. Additionally, we will describe a real-world implementation of this approach using KBSI‟s InstrumentMap application and an implementation of the web service API by L-3 Communications Telemetry East.
    • Describing Telemetry Systems with the Metadata Description Language

      Moore, Michael S.; Price, Jeremy C.; Cormier, Andrew R.; Thibodeaux, Ryan J.; Abbott, Ben A.; Malatesta, William A.; Southwest Research Institute; Naval Air Systems Command (NAVAIR) (International Foundation for Telemetering, 2010-10)
      The integrated Network-Enhanced Telemetry (iNET) project has developed standards to enhance telemetry systems for the twenty-first century. A foundational component of these standards is the Metadata Description Language (MDL). MDL is an eXtensible Markup Language (XML)-based language for describing requirements, design choices, and configuration parameters of a Telemetry Network System (TmNS). Within a TmNS, MDL guides the exchange of information between applications and the configuration of network devices. Recent initial evaluations assessed MDL in terms of the expressive power of the language and the level of effort in developing applications that utilize MDL Instance Documents. Performing these initial evaluations required the generation of MDL Instance Documents to describe scenarios representative of both near-term and future telemetry systems that express different levels of iNET interoperability. These initial evaluations determined quantitative metrics such as file size, memory requirements, and required parsing time for MDL Instance Documents, and further evaluations judged the efficacy and complexity of MDL for describing and configuring a TmNS.
    • A New Standard for Temperature Measurement in an Aviation Environment

      Grossman, Hy; Teletronics Technology Corporation (International Foundation for Telemetering, 2010-10)
      Accurate temperature measurement is an essential requirement in modern aircraft data acquisition systems. Both thermocouples and Platinum resistance temperature detectors (RTD) are used for this purpose with the latter being both more accurate and more repeatable. To ensure that only the sensor limits the accuracy of a temperature measurement, end-to-end system accuracy forward of the sensor, should be significantly greater than that of the sensor itself. This paper describes a new digital signal processing (DSP) based system for providing precision RTD based temperature measurements with laboratory accuracy in an aviation environment. Advantages of the new system include, true 3-wire RTD measurement, linear temperature output, on-board ultra-precision resistance standards and transparent dynamic calibration.
    • Network System Integration: Migrating Legacy Systems into Network-Based Architectures

      Newton, Todd A.; Moodie, Myron L.; Thibodeaux, Ryan J.; Araujo, Maria S.; Southwest Research Institute (International Foundation for Telemetering, 2010-10)
      The direction of future data acquisition systems is rapidly moving toward a network-based architecture. There is a handful of these network-based flight test systems already operating, and the current trend is catching on all over the flight test community. As vendors are churning out a whole new product line for networking capabilities, system engineers are left asking, "What do I do with all of this non-networked, legacy equipment?" Before overhauling an entire test system, one should look for a way to incorporate the legacy system components into the modern network architecture. Finding a way to integrate the two generations of systems can provide substantial savings in both cost and application development time. This paper discusses the advantages of integrating legacy equipment into a network-based architecture with examples from systems where this approach was utilized.
    • The Performance Evaluation of an OFDM-Based IP Transceiver at Eglin AFB

      Berard, Alfredo; Cook, Paul; Roach, John; Eglin Air Force Base; Teletronics Technology Corporation (International Foundation for Telemetering, 2010-10)
      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.
    • iNET Standards Validation: End-to-End Performance Assessment

      Moodie, Myron L.; Araujo, Maria S.; Grace, Thomas B.; Malatesta, William A.; Abbott, Ben A.; Southwest Research Institute; Naval Air Systems Command (NAVAIR) (International Foundation for Telemetering, 2010-10)
      The integrated Network-Enhanced Telemetry (iNET) project has developed standards for network-based telemetry systems. While these standards are based largely on the existing body of commercial networking protocols, the Telemetry Network System (TmNS) has more stringent performance requirements in the areas of latency, throughput, operation over constrained links, and quality of service (QoS) than typical networked applications. A variety of initial evaluations were undertaken to exercise the interfaces of the current standards and determine real-world performance. The core end-to-end performance initial evaluations focus collectively on the movement of telemetry data through the TmNS. These initial evaluations addressed two areas: end-to-end data delivery and parametric data extraction. This paper presents the approach taken by these ongoing efforts and provides initial results. The latest results will be presented at ITC 2010.
    • iNET System Operational Flows

      Grace, Thomas B.; Abbott, Ben A.; Moodie, Myron L.; Southwest Research Institute; Naval Air Systems Command (NAVAIR) (International Foundation for Telemetering, 2010-10)
      The integrated Network-Enhanced Telemetry (iNET) project is transitioning from standards development to deployment of systems. In fielding a Telemetry Network System (TmNS) demonstration system, one must choose and integrate technological building blocks from the suite of standards to implement new test capabilities. This paper describes the operation of a TmNS and identifies the management, configuration, control, acquisition, and distribution of information and operational flows. These items are discussed utilizing a notional system to walk through the mechanisms identified by the iNET standards. Note that at the time of this paper the efforts discussed are only at the very beginning of the design process and will likely evolve throughout the design process.
    • Using Oracol® for Predicting Long-Term Telemetry Behavior for Earth and Lunar Orbiting and Interplanetary Spacecraft

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2010-10)
      Providing normal telemetry behavior predictions prior to and post launch will help to stop surprise catastrophic satellite and spacecraft equipment failures. In-orbit spacecraft fail from surprise equipment failures that can result from not having normal telemetry behavior available for comparison with actual behavior catching satellite engineers by surprise. Some surprise equipment failures lead to the total loss of the satellite or spacecraft. Some recovery actions from a surprise equipment failure increase spacecraft risk and involve decisions requiring a level of experience far beyond the responsible engineers.