• NONCOHERENT AND DIFFERENTIAL DETECTION OF FQPSK WITH MAXIMUM-LIKELIHOOD SEQUENCE ESTIMATION IN NONLINEAR CHANNELS

      Lin, Jin-Son; Feher, Kamilo; University of California (International Foundation for Telemetering, 2002-10)
      This paper presents noncoherent limiter-discriminator detection and differential detection of FQPSK (Feher quadrature phase-shift-keying) with maximum-likelihood sequence estimation (MLSE) techniques. Noncoherent FQPSK systems are suitable for fast fading and cochannel interference channels and channels with strong phase noise, and they can offer faster synchronization and reduce outage events compared with conventional coherent systems. In this paper, both differential detection and limiter-discriminator detection of FQPSK are discussed. We use MLSE with lookup tables to exploit the memory in noncoherently detected FQPSK signals and thus significantly improve the bit error rate (BER) performance in an additive white Gaussian noise (AWGN) channel.
    • OBJECT DETECTION AND LOCALIZATION IN THE WAVELET DOMAIN

      Kandadai, Srivatsan; New Mexico State University (International Foundation for Telemetering, 2002-10)
      We are interested in the problem of detecting and localizing objects in the compressed domain. The practical uses of this research are video surveillance, queries over digital library archives and teleconferencing. Most image operations, such as object recognition, are formulated as sequences of operations in the image domain. Such methods need direct access to pixel information as a starting point, but pixel information is not directly available in a compressed image stream. The standards that have emerged for still-image and video compression each contain steps that are commonly found in compression algorithms, like linear transformations, coefficient quantization, run-length coding and entropy coding. Coders like JPEG 2000 and SPHIT are built around the wavelet transform. Thus as a step toward detection and localization of objects embedded in the compressed bit stream we consider here the problem of localizing and detection in the wavelet domain.
    • ON THE PERFORMANCE OF MULTI-H CPM IN MULTIPATH INTERFERENCE

      Rice, Michael; Perrins, Erik; Brigham Young University (International Foundation for Telemetering, 2002-10)
      The performance of multi-h CPM over multipath interference channels is evaluated with computer simulations using the optimal coherent receiver and a suboptimal noncoherent receiver. For channels with high-amplitude short-delay multipath reflections, the simulations show that both receivers reach an error floor in their performance as the amplitude of the multipath reflections grows. The rate of degradation for the noncoherent receiver is worse than for the coherent receiver. For channels with low-amplitude long-delay reflections the coherent and noncoherent receivers had losses of 1 dB and 3 dB respectively relative to their respective unfaded performance.
    • OPTIMAL LINEAR DETECTION OF SOQPSK

      Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      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.
    • OPTIMIZATION OF A MINATURE TRANSMITTER MODULE FOR WIRELESS TELEMETRY APPLICATIONS

      Osgood, Karina; Burke, Larry; Webb, Amy; Muir, John; Dearstine, Christina; Quaglietta, Anthony; M/A-COM, Inc. (International Foundation for Telemetering, 2002-10)
      M/A-COM, Inc. has previously developed a highly integrated transmitter chip set for wireless telemetry applications for the military L and S band frequencies and the commercial 2.4GHz ISM band. The original chip set is comprised of a voltage controlled oscillator (VCO), a silicon phase locked loop (PLL), and a family of power amplifiers (PA's). Using these components, M/A-COM has produced a miniature IRIG-compliant transmitter module, which has been flight-tested by the U.S. Army’s Hardened Subminiature Telemetry and Sensor System (HSTSS) program. Since the initial offering, several product enhancements have been added. The module performance has been improved by tailoring the VCO specifically for direct frequency modulation applications. In addition to improving noise performance, these enhancements have produced improved modulation linearity, decreased lock time and increased carrier stability. Modulation rates in excess of 10Mbps have been demonstrated. High efficiency power amplifiers operating at 3V have also been added to the family of amplifiers (PAE > 50%). This greatly enhanced efficiency allows higher RF power output while maintaining the same miniature form factor for the transmitter. Further, M/A-COM has added a silicon-on-sapphire PLL to the chip set, which operates at frequencies up to 3.0GHz. This paper details the enhancements to the components within the chip set, and the improvement in performance of the transmitter module. Test data is presented for the transmitter modules and individual components.
    • OPTIMIZED LOW BIT RATE PCM/FM TELEMETRY WITH WIDE IF BANDWIDTHS

      Law, Eugene; NAVAIR (International Foundation for Telemetering, 2002-10)
      This paper will present the results of some experiments with non-coherent, single symbol detection of pulse code modulation (PCM)/frequency modulation (FM) where the receiver intermediate frequency (IF) bandwidth is much wider than the bit rate. The experiments involved varying the peak deviation and measuring the bit error probability (BEP) at various signal energy per bit to noise power spectral density ratios (E(b)/N(o)). The experiments showed that the optimum peak-to-peak deviation was about 0.7 to 0.8 times the –3 dB IF bandwidth and that the E(b)/N(o) required for a given BEP increased as the ratio of IF bandwidth to bit rate increased. Further, bi-phase-level/FM performed slightly better than non-return-to-zero-level (NRZ-L)/FM with an ac coupled RF signal generator and IF bandwidths much wider than the bit rate.
    • OVER QUANTIZING, THE NEXT STEP IN DIGITAL SIGNAL PROCESSING

      Hicks, William T.; L-3 Communications (International Foundation for Telemetering, 2002-10)
      Simplification of the analog front end of a signal conditioning circuit can be accomplished by over-quantizing the input signal and using DSP for gain and offset. In this case, a much higher precision A/D converter is used than required by the desired output accuracy. The excess bits are then used to allow the DSP math to give an effective gain to the signal. By a similar function, offset of over 100% can be mathematically removed as long as the input signal does not exceed the A/D input voltage range.
    • A PARALLEL -SEQUENTIAL SEARCH ALGORITHM IN A HIGH DYNAMIC GPS RECEIVER

      Xingyu, Luo; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      It is need to design acquisition and tracking for code loop and carrier loop to detect the high dynamic Global Position System (GPS) signal. Acquiring signal quickly and shortening acquisition time in the cold case are key technology of a high dynamic GPS receiver. Moreover, fast acquisition of C/A code is the base of code tracking and carrier acquisition and tracking. This paper describes elements and implementation of a new parallel-sequential search Algorithm to acquire C/A code of the high dynamic GPS signal. And combined with a 12-channel correlator named GP2021 produced by GEC Co., the arithmetic implementation to acquire C/A code of the high dynamic GPS signal used sequential search based on DSP technology is also given.
    • Performance of a Bluetooth Based Structural Health Monitoring Telemetry Network

      Kosbar, Kurt; Uchil, Vilas; University of Missouri (International Foundation for Telemetering, 2002-10)
      The Bluetooth standard is intended to provide short-range (10-100 meter) wireless connectivity between mobile and desktop devices. It was developed as a replacement for short cables, and has the ability to form ad-hoc networks. A large inter-connection of piconets can be arranged to form a scatternet for data collection in a Bluetooth based structural health monitoring Telemetry network. The Bluetooth protocol architecture supports the formation of a daisy chain network. However Bluetooth technology was not intended for long daisy chain networks. In this work, we propose to evaluate the throughput and latency for data transmission in a long daisy chained Bluetooth based telemetry network.
    • PERFORMANCE STUDY OF ENHANCED FQPSK AND CONSTRAINED ENVELOPE MODULATION TECHNIQUES

      Borah, Deva K.; Horan, Stephen; New Mexico State University (International Foundation for Telemetering, 2002-10)
      This paper investigates the spectral properties and the bit error rate (BER) performance of enhanced FQPSK (EFQPSK) and constrained envelope modulation (CEM) techniques. Both the techniques are found to provide good spectral efficiencies. The EFQPSK signals are found to generate spectral lines for unbalanced data. An analytical spectral study for the spectral lines is presented. While the performance of CEM techniques has been presented in [6] for an ideal nonlinear amplifier, we present results for more realistic amplifiers with AM/AM and AM/PM effects. It is shown that such an amplifier generates spectral regrowth and a predistorter is required to reduce the adverse effects. A BER performance study with/without channel coding is also presented for the two techniques.
    • PHASE CENTER PROBLEMS WITH WRAP-AROUND ANTENNAS

      Meyer, Steven J.; Kujiraoka, Scott R.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      The Joint Advanced Missile Instrumentation (JAMI) program is integrating Global Positioning System (GPS) technology into missile telemetry systems. The weakest link appears to be the GPS antenna. The antenna on a missile is required to be flush mounted for aerodynamic reasons. Due to the missile’s tendency to roll, the antenna needs to be a multi-element omnidirectional antenna array. Therefore an antenna used on missiles is a wrap-around antenna since it will meet the flush mount and rolling requirements by giving omnidirectional coverage. JAMI has used readily available techniques for designing wrap-around telemetry antennas to develop a GPS wrap-around antenna and has discovered a major problem. The Phase Center of a wrap-around antenna tends to be a surface, not a point, and not necessarily at the centerline of the missile body. GPS measurements have been conducted to determine the Phase Center of the antenna. When the Phase Center is large, the GPS receiver perceives it as multipath and integer ambiguities cannot be resolved. This paper addresses the problems that have been uncovered and outlines the steps that are planned to resolve them.
    • PLASMA TELEMETRY IN HYPERSONIC FLIGHT

      Starkey, Ryan P.; Lewis, Mark J.; Jones, Charles H.; University of Maryland; Edwards Air Force Base (International Foundation for Telemetering, 2002-10)
      Problems associated with telemetry blackout caused by the plasma sheath surrounding a hypersonic vehicle are addressed. In particular, the critical nature of overcoming this limitation for test and evaluation purposes is detailed. Since the telemetry blackout causes great concern for atmospheric cruise vehicles, ballistic missiles, and reentry vehicles, there have been many proposed approaches to solving the problem. This paper overviews aerodynamic design methodologies, for which the required technologies are only now being realized, which may allow for uninterrupted transmission through a plasma sheath. The severity of the signal attenuation is dependent on vehicle configuration, trajectory, flightpath, and mission.
    • PROTOCOL LAYERING

      Grebe, David L.; Apogee Labs, Inc. (International Foundation for Telemetering, 2002-10)
      The advent of COTS based network-centric data systems brings a whole new vocabulary into the realm of instrumentation. The Communications and computer industries have developed networks to a high level and they continue to evolve. One of the basic techniques that has proven itself useful with this technology is the use of a “layered architecture.” This paper is an attempt to discuss the basic ideas behind this concept and to give some understanding of the vocabulary that has grown up with it.
    • PROTOTYPE DUAL-BAND TRANSMITTER FOR AERONAUTICAL TELEMETRY APPLICATIONS

      Jensen, Michael A.; Jones, Charles H.; Brigham Young University; Edwards Air Force Base (International Foundation for Telemetering, 2002-10)
      Recent changes in spectrum availability as well as higher demands for spectrum have motivated the development of telemetry transmit systems capable of fully operating over both L and S telemetry bands. However, enabling operation within these two bands poses new problems in system design. This paper presents a prototype system capable of operating between 1.4 and 2.4 GHz, which supports continuous phase modulation (CPM) waveforms such as pulse code modulation (PCM), frequency modulation (FM), and shaped offset quadrature phase shift keying (SOQPSK). The system architecture is detailed, and the prototype performance is discussed.
    • QAM Multi-path Characterization Due to Ocean Scattering

      Swanson, Richard; Dimsdle, Jeff; Petersen, Tom; Pasquale, Regina; Bracht, Roger; Honeywell Federal Manufacturing & Technologies; Los Alamos National Laboratory (International Foundation for Telemetering, 2002-10)
      A series of RF channel flight characterization tests were recently run to benchmark multi-path performance of high-speed quadrature amplitude modulation (QAM) over the ocean surface. The modulation format was differential-phase/absolute-amplitude two level polar 16 QAM. The bit rate was 100 Megabits per second with a symbol period of 40nS. An aircraft radiated the test signal at 5 different altitudes. It made two inward flights, on two different days, at each altitude with vertical and horizontal polarization, respectively. Receivers, using circular antenna polarization, were in two different locations. Analysis of the resulting data shows flat fading and frequency selective fading effects.
    • RECORDERS IN NETWORKED DATA ACQUISITION SYSTEMS

      Grebe, David L.; Apogee Labs Inc. (International Foundation for Telemetering, 2002-10)
      The role of recorders in telemetry applications has undergone many changes throughout the years. We’ve seen the evolution from multi-track tape to disk to solid state technologies, both for airborne and ground based equipment. Data acquisition and collection system design has changed as well and a recent trend in airborne is to merge acquisition and recording. On the ground, increased decentralization of data collection and processing has generated the requirement to provide backup storage to protect against communication circuit outages. This paper explores the trend to adopt network based data acquisition, collection, and distribution systems for telemetry applications and the impact on recording techniques and equipment. It shows that in this emerging approach the recorder returns to its root mission of attempting to provide the fastest, largest capacity for the least amount of investment. In a network based architecture the recorder need only accept and reproduce data operating independently from the acquisition process.
    • SIGNAL PROCESSING ABOUT A DISTRIBUTED DATA ACQUISITION SYSTEM

      Kolb, John; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      Because modern data acquisition systems use digital backplanes, it is logical for more and more data processing to be done in each Data Acquisition Unit (DAU) or even in each module. The processing related to an analog acquisition module typically takes the form of digital signal conditioning for range adjust, linearization and filtering. Some of the advantages of this are discussed in this paper. The next stage is powerful processing boards within DAUs for data reduction and third-party algorithm development. Once data is being written to and from powerful processing modules an obvious next step is networking and decom-less access to data. This paper discusses some of the issues related to these types of processing.
    • SOFTWARE RADIO TECHNOLOGY AND CHALLENGES

      Chapin, John; Shah, Alok; Vanu, Inc. (International Foundation for Telemetering, 2002-10)
      This paper provides an overview of software radio and its current state in the industry. Software radio is a technology in which all of the waveform processing, including the physical layer, of a wireless device moves into software. If designed properly, this approach leads to dramatically improved device flexibility, software portability, and reduced development costs. Of course, such a technology brings with it numerous challenges, from hardware components to power constraints to the regulatory environment.
    • SPACE COMMUNICATION DEMONSTRATION USING INTERNET TECHNOLOGY

      Israel, Dave; Parise, Ron; Hogie, Keith; Criscuolo, Ed; National Aeronautics and Space Administration; Computer Sciences Corp (International Foundation for Telemetering, 2002-10)
      This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of Internet communication technologies to space communication. The goal is to provide global addressability and standard network protocols and applications for future space missions. It describes the communication architecture and operations concepts that will be deployed and tested on a Space Shuttle flight in July 2002. This is a NASA Hitchhiker mission called Communication and Navigation Demonstration On Shuttle (CANDOS). The mission will be using a small programmable transceiver mounted in the Shuttle bay that can communicate through NASA’s ground tracking stations as well as NASA’s space relay satellite system. The transceiver includes a processor running the Linux operating system and a standard synchronous serial interface that supports the High-level Data Link Control (HDLC) framing protocol. One of the main goals will be to test the operation of the Mobile IP protocol (RFC 2002) for automatic routing of data as the Shuttle passes from one contact to another. Other protocols to be utilized onboard CANDOS include secure login (SSH), UDP-based reliable file transfer (MDP), and blind commanding using UDP. The paper describes how each of these standard protocols available in the Linux operating system can be used to support communication with a space vehicle. It will discuss how each protocol is suited to support the range of special communication needs of space missions.
    • SPACE-TIME CODING FOR WIRELESS COMMUNICATIONS

      Jensen, Michael A.; Rice, Michael D.; Brigham Young University (International Foundation for Telemetering, 2002-10)
      Signal fading and intersymbol interference created by multipath propagation have traditionally limited the throughput on wireless communications systems. However, recent research has demonstrated that by using multiple antennas on both transmit and receive ends of the link, the multipath channel can actually be exploited to achieve increased communication throughput over single-antenna systems. This paper provides an introductory description of such multi-antenna communications systems, focusing on basic explanations of how they achieve capacity gains. Computed and measured capacity results are used to demonstrate the potential of these systems.