• Microcontroller Based Multiple-Input Multiple-Output Transmitter

      Kosbar, Kurt; Kanday, Balaji Madapuci; Missouri University of Science and Technology (International Foundation for Telemetering, 2010-10)
      This paper describes how a microcontroller based system can be used to generate the signals needed in a multiple-input multiple-output (MIMO) system transmitter. The limited computational speed of the microcontroller, along with other tasks which the controller may need to handle, places limits on the throughput of the system, and the complexity of the MIMO signal design. However this can be a low cost design, and the microcontroller can be used to perform other operations in the system, which may make it attractive in some applications.
    • On the Performance of Spectrally Efficient DPM-OFDMA for Aeronautical Telemetry

      Wylie, Marilynn; Green, Glenn; Gem Direct Inc. (International Foundation for Telemetering, 2010-10)
      In this paper, we discuss CPM-OFDMA (Continuous Phase Modulation - Orthogonal Frequency Division Multiple Access) - a novel modulation that maps a discrete-time CPM into a spectrally efficient DFT-spread OFDMA transmission. Three CPM-OFDMA schemes are developed based on discrete-time variants of PCM/FM, SOQPSK-TG and ARTM-CPM telemetry modulations. Simulations reveal that spectrally efficient CPM-OFDMA schemes can outperform the conventionally defined telemetry schemes in the AWGN environment. For example, maximum likelihood sequence detection of conventional PCM/FM yields a BER of 10⁻⁵ at an E(b)/N(0) of 8:4 dB while the least complex CPM-OFDMA scheme that is based on sampling a PCM/FM waveform once per symbol interval achieves the same BER at an E(b)/N(0) of 7:8 dB. Finally, an extensive search to find a subset of the best performing binary schemes shows that there exist very low complexity schemes that can achieve a BER of 10⁻⁶ at an E(b)/N(0) of 7:8 dB, which is an order of magnitude improvement over the performance of PCM/FM at the same E(b)/N(0).
    • Telemetry Architectures for Future Earth Observation Missions: Over 1 Gbit/s in X-Band

      Guérin, A.; Lesthievent, G.; Issler, J.-L.; Centre National d’Etudes Spatiales (CNES) (International Foundation for Telemetering, 2010-10)
      High data rate payload telemetry of Earth Observation missions is classically done in the Earth Exploration Satellite (EES) X-band (8025-8400 MHz) with current max data rates about 600 Mbit/s. While higher frequency bands are often considered to offer higher data rates, this paper deals with on-board architectures that would allow data transmission at more than 1 Gbit/s in X-Band. It presents these new architectures based on spectrally efficient transmission systems and on simultaneous bipolarization transmission, their designs and their performances. Variable Coding and Modulation techniques are described. Interference between channels in cross-polarization is also evaluated.
    • Dynamic Frequency Assignment and Management Technologies for Future Test and Evaluation Operations

      Painter, Michael K.; Fernandes, Ronald; Gohlke, Jason; Ramachandran, Satheesh; Verma, Ajay; Jones, Charles H.; Knowledge Based Systems, Inc.; Edwards Air Force Base (International Foundation for Telemetering, 2010-10)
      There is growing concern that the U.S. military can no longer meet its domestic and international spectrum needs. Demand for this resource is growing at an exponential pace, both within the Department of Defense (DoD) and in the commercial sector (partly due to rapid growth in broadband wireless electronics). A microcosm of these challenges is evident in flight test operations, where there is a growing need for advanced spectrum assignment, frequency deconfliction, and scheduling optimization decision support capabilities. This paper describes research aimed at investigating how to optimize frequency scheduling, dynamic assignment, and real-time metrics adjustment to promote assured access to the electronic spectrum, including emerging technology developments to support that need.
    • Using Variable Coding and Modulation to Increase Remote Sensing Downlink Capacity

      Sinyard, David; ViaSat, Inc. (International Foundation for Telemetering, 2010-10)
      Remote sensing satellites are typically low earth orbit, and often transmit the data gathered with the remote sensors to ground stations at locations on earth. These transmissions are band limited, and must operate within a 375 MHz bandwidth in the X-Band spectrum. This can present a limitation to the amount of data that can be transmitted during the short duration of a pass (typically less than 15 minutes). It is then highly desirable to increase the bandwidth efficiency of a system for data transmission in a remote sensing downlink. This paper describes a method of achieving higher efficiency by pre-programming the satellite to adjust the modulation and coding based in at least part on the slant range to the receiving ground station. The system uses variable coding and modulation to adjust to the slant range to the ground station to achieve a throughput increase of more than 50% of the data transferred during a pass using the currently accepted technology.
    • Dynamic Formatting of the Test Article Data Stream

      Young, Tom; Wigent, Mark; AFFTC; SAIC (International Foundation for Telemetering, 2010-10)
    • Hardware-Efficient Implementation of the SOVA for SOQPSK-TG

      Perrins, Erik; Hosseini, Ehsan; Rea, Gino; University of Kansas (International Foundation for Telemetering, 2010-10)
      In this paper, we present a hardware-efficient architecture of a demodulator for shaped offset quadrature phase shift keying, telemetry group version (SOQPSK-TG). The demodulation is done using the soft-output Viterbi algorithm (SOVA), which is implemented by the two-step traceback method. In this method, two traceback operations are employed to find the maximum-likelihood (ML) path and the competing path. Using the proposed architecture, the tracebacks are done at the same time as the demodulator is generating output bits and their reliabilities. This method has been shown to require less storage than the well-known register-exchange method. Finally, we present the performance results from the FPGA implementation.
    • Low-Complexity Finite Precision Decoders for Low-Density Parity-Check Codes

      Vasic, Bane; Declercq, David; Marcellin, Michael W.; Planjery, Shiva Kumar; University of Arizona (International Foundation for Telemetering, 2010-10)
      We present a new class of finite-precision decoders for low-density parity-check (LDPC) codes. These decoders are much lower in complexity compared to conventional floating-point decoders such as the belief propagation (BP) decoder, but they have the potential to outperform BP. The messages utilized by the decoders assume values (or levels) from a finite discrete set. We discuss the implementation aspects as well as describe the underlying philosophy in designing these decoders. We also provide results to show that in some cases, only 3 bits are required in the proposed decoders to outperform floating-point BP.
    • Channel Equalization and Spatial Diversity for Aeronautical Telemetry Applications

      Saquib, M.; Williams, Ian E.; University of Texas at Dallas (International Foundation for Telemetering, 2010-10)
      This work explores aeronautical telemetry communication performance with the SOQPSK- TG ARTM waveforms when frequency-selective multipath corrupts received information symbols. A multi-antenna equalization scheme is presented where each antenna's unique multipath channel is equalized using a pilot-aided optimal linear minimum mean-square error filter. Following independent channel equalization, a maximal ratio combining technique is used to generate a single receiver output for detection. This multi-antenna equalization process is shown to improve detection performance over maximal ratio combining alone.
    • Decoding and Turbo Equalization for LDPC Codes Based on Nonlinear Programming

      Iltis, Ronald A.; University of California, Santa Barbara (International Foundation for Telemetering, 2010-10)
      Decoding and Turbo Equalization (TEQ) algorithms based on the Sum-Product Algorithm (SPA) are well established for LDPC codes. However there is increasing interest in linear and nonlinear programming (NLP)-based decoders which may offer computational and performance advantages over the SPA. We present NLP decoders and Turbo equalizers based on an Augmented Lagrangian formulation of the decoding problem. The decoders update estimates of both the Lagrange multipliers and transmitted codeword while solving an approximate quadratic programming problem. Simulation results show that the NLP decoder performance is intermediate between the SPA and bit-flipping algorithms. The NLP may thus be attractive in some applications as it eliminates the tanh/atanh computations in the SPA.
    • Compressed Sensing Using Reed-Solomon and Q-Ary LDPC Codes

      Ryan, William E.; Marcellin, Michael W.; Goodman, Nathan A.; Jagiello, Kristin M.; University of Arizona (International Foundation for Telemetering, 2010-10)
      We consider the use of Reed-Solomon (RS) and q-ary LDPC codes for compressed sensing of sparse signals. Signals sensed using the RS parity-check matrix are recovered using Berlekamp-Massey and those sensed using the LDPC parity-check matrix are recovered using majority-logic decoding. Results are presented for both types of sensing. In addition, a hardware architecture is discussed.
    • Role of a Small Switch in a Network-Based Data Acquisition System

      Hildin, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2010-10)
      Network switches are an integral part of most network-based data acquisition systems. Switches fall into the category of network infrastructure. They support the interconnection of nodes and the movement of data in the overall network. Unlike endpoints such as data acquisition units, recorders, and display modules, switches do not collect, store or process data. They are a necessary expense required to build the network. The goal of this paper is to show how a small integrated network switch can be used to maximize the value proposition of a given switch port in the network. This can be accomplished by maximizing the bandwidth utilization of individual network segments and minimizing the necessary wiring needed to connect all the network components.
    • Switched for Networked FTI

      Cranley, Nikki; ACRA Control (International Foundation for Telemetering, 2010-10)
      Ethernet technology offers numerous benefits for networked Flight Test Instrumentation (FTI) systems such as increased data rates, flexibility, scalability and most importantly interoperability owing to the inherent interface, protocol and technological standardization. In a networked FTI system, the switch is a key component that allows data to be routed between Data Acquisition Units (DAU's), networked recorders, data processing and analysis stations. This paper provides an introduction to network switching concepts with a focus on its operation in a networked FTI system. The features of Commercial Off-The-Shelf (COTS) and FTI switches are compared demonstrating the benefits of FTI switches in terms of reliability, routing, throughput, latency, and start-up delays.
    • Analysis of a Geolocation-Assisted Routing Protocol for Airborne Telemetry Networks

      Sterbenz, James P. G.; Peters, Kevin; Çetinkaya, Egemen K.; Jabbar, Abdul; University of Kansas (International Foundation for Telemetering, 2010-10)
      Emerging networked telemetry systems require domain-specific routing protocols, such as AeroRP, to cope with the challenges faced by the aeronautical environment. We present an ns-3 based performance analysis of the geolocation-based forwarding and store-and-haul mechanisms used by AeroRP. The analysis of the simulations shows AeroRP has several advantages over other MANET routing protocols and offers tradeoffs for different performance metrics in the form of different AeroRP modes.
    • An Open Architecture Approach to Networked Telemetry System

      Woolridge, Daniel 'Shane'; GDP Space Systems; Delta Digital Video (International Foundation for Telemetering, 2010-10)
      When designing data transport systems, Telemetry and Communications engineers always face the risk that their chosen hardware will not be available or supported soon after the hardware has been installed. The best way to reduce this risk and ensure the longevity of the system is to select an open architecture standard that is supported by multiple manufacturers. This open architecture should also have the ability to be easily upgraded and provide for all of the features and flexibility that are required to be a reliable carrier-grade edge-device. The PCI Industrial Computer Manufacturers Group (PICMG) developed the MicroTCA open standard to address the specific needs of these Communications and Network System Engineers. This paper describes the MicroTCA architecture and how it can be applied as the ideal edge-device solution for Networked Telemetry Systems applications.
    • A TDMA-MAC Protocol for a Seismic Telemetry-Network with Energy Constraints

      Mayer, Gerhard; Höller, Peter; Höller, Yvonne; University of Salzburg (International Foundation for Telemetering, 2010-10)
      The requirements for a seismic telemetry-network are even more stringent than the well known problems of sensor networks. Existing medium access control (MAC) protocols suggest reducing energy consuming network activity by reducing costly transmissions and idle listening. Furthermore, it is required to set up communication patterns in different priority levels as well as ensuring fast handling of critical events. A protocol is proposed that operates with two parallel sets of time schedules in a time-division-multiple-access (TDMA) sense of periodic activity for listening and for transmitting. Synchronization packets sent from a central base station ensure optimal response times.
    • Latest Status on Adding FTS Capability to a Missile Telemetry Section

      Kujiraoka, Scott; Fielder, Russell; Jones, Johnathan; Sandberg, Aliva; NAVAIR (International Foundation for Telemetering, 2010-10)
      Development is currently underway to produce a dual redundant Flight Termination System (FTS) capable Missile Telemetry Section. This FTS will mainly consist of a conformal wraparound antenna, two flight termination safe & arm (FTS&A) devices, two flight termination receivers (FTR), two explosive foil initiators (EFI) and destruct charge. This paper will discuss the current status of the development of these FTS components along with the process of obtaining the Flight Certification from Range and System Safety to fly this newly outfitted missile on a governmental test range.
    • Integrating Wireless Sensor Technologies into Instrumentation and Telemetry Systems

      Araujo, Maria S.; Moodie, Myron L.; Willden, Greg C.; Thibodeaux, Ryan J.; Abbott, Ben A.; Southwest Research Institute (International Foundation for Telemetering, 2010-10)
      Recent technological advancements in low-power, low-cost, small-footprint embedded processors, sensors, and radios are resulting in the very rapid growth of wireless sensor network deployments. Wireless sensor networks merge the scalability and distributed nature of networked systems with the size and energy constraints of remote embedded systems. With the ever increasing need to develop less intrusive, more scalable solutions for instrumentation systems, wireless sensor technologies present several benefits. They largely eliminate the need for power and network wiring, thus potentially reducing cost, weight, and deployment time; their modularity provides the flexibility to rapidly change instrumentation configurations and the capability to increase the coverage of an instrumentation system. While the benefits are exciting and varied, as with any emerging technology, many challenges need to be overcome before wireless sensor networks can be effectively and successfully deployed in instrumentation applications, including throughput, latency, power management, electromagnetic interference (EMI), and band utilization considerations. This paper describes some approaches to addressing these challenges and achieving a useful system.
    • An Integrated Data Acquisition System for Parachute Development and Qualification Testing

      Starbuck, Philip; PSG and Associates (International Foundation for Telemetering, 2010-10)
      The development and qualification of personnel and cargo aerial delivery parachute systems present unique challenges to the instrumentation and data analysis engineers. Some of the areas that must be addressed include: a) system must be low in cost, b) system often has to be operated on ranges that have limited telemetry or other range instrumentation and support (i.e. commercial skydiving centers), c) system is often rigged and operated by parachute support personnel and test jumpers rather than instrumentation engineers, and d) system must be able to be reconfigured in the field to support a variety of test card requirements during a typical test day, e) data must be available for review and the system be prepared for the next test within a few minutes of parachute recovery, and f) system must withstand ground impact velocities as high as 50 ft/sec (15.24 m/sec) without damage. This paper describes such a system as it is being used for the development and qualification testing of a number of parachute systems for sport skydiving, military personnel, as well as cargo parachute systems. This modular system has been developed as a result of previous experience in other parachute development and qualification projects to address the need for a flexible Data Acquisition System (DAS) system that meets the above requirements. This paper describes some of the tools used to meet these requirements.
    • Using Generic Telemetry Prognostic Algorithms for Launch Vehicle and Spacecraft Independent Failure Analysis Service

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2010-10)
      Current failure analysis practices use diagnostic technology developed over the past 100 years of designing and manufacturing electrical and mechanical equipment to identify root cause of equipment failure requiring expertise with the equipment under analysis. If the equipment that failed had telemetry embedded, prognostic algorithms can be used to identify the deterministic behavior in completely normal appearing data from fully functional equipment used for identifying which equipment will fail within 1 year of use, can also identify when the presence of deterministic behavior was initiated for any equipment failure.