• 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.
    • A COMPARISON OF ADAPTIVELY EQUALIZED PCM/FM, SOQPSK, AND MULTI-H CPM IN A MULTIPATH CHANNEL

      Hill, Terrance; Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      It is widely recognized that telemetry channels, particularly airborne channels, are afflicted by multipath propagation effects. It has also been shown that adaptive equalization can be highly effective in mitigating these effects. However, numerous other factors influence the behavior of adaptive equalization, and the type of modulation employed is certainly one of these factors. This is particularly true on modulations which exhibit different operating bandwidths. In this paper, we will examine the effect multipath and adaptive equalization for three modulation techniques which are either already in use, or have been proposed, for airborne telemetry.
    • SPECTRAL EFFICIENCY/BIT ERROR RATE OF FQPSK AND OTHER NON-COHERENT SYSTEMS SUPERIOR TO COHERENT SYSTEMS FOR SMS AND BURSTED TDMA AND CDMA SYSTEMS

      McCorduck, James A.; Feher, Kamilo; MatrixSat, Inc.; University of California; Digcom, Inc. (International Foundation for Telemetering, 2002-10)
      For faster acquisition in bursted environments for SMS (Short Messaging Service) and other lower-bit rate applications, non-coherent detection techniques are proposed. Non-Coherent detection demodulators are proposed because faster acquisition capability in bursted environments can result in a reduced amount of preamble bits in the messaging frame, i.e. less overhead, resulting in an effective increase in spectral efficiency. Reducing the preamble can also provide performance enhancement opportunities for Feher Quadrature Phase Shift Keying (FQPSK) [1] and for other systems. The preamble can also be varied to provide for better Bit Error Rate (BER) performance. The lower bit rate environment also gives the opportunity to employ simpler architectures in lieu of preamble modification. Several non-coherent detection alternatives are described.
    • NETWORKABLE TELEMETRY DATA RECORDERS BASED ON COTS COMPUTER TECHNOLOGY

      Smith, Grant M.; Dewetron Inc. (International Foundation for Telemetering, 2002-10)
      Advances in several related technologies have brought together the previously incompatible goals of incorporating as much COTS technology as possible into the telemetry data recording architecture, providing operators with the kinds of real-time graphical data displays that they are accustomed to, and allowing these same data display systems to share data across a network and write to common database files accessible from centralized workstations.
    • The Impact Of Wireless Security Protocols on Post Processed Telemetry Data Transfer

      Kalibjian, Jeffrey R.; Hewlett Packard Corporation (International Foundation for Telemetering, 2002-10)
      Commercial wireless protocol use (e.g. Wireless Access Protocol, Bluetooth, etc.) is becoming widespread as the demand to access computing devices in remote locations grows. Although not widely prevalent today, wireless access of post processed telemetry data will become a common activity. Essential to the use of such a capability is the security of the wireless links involved in the data transfer. Each wireless protocol has an associated security paradigm. Some protocols have stronger security schemes than others and this should influence protocol selection for particular telemetry data transfer applications.
    • APPLYING RULES FOR ISOCHRONOUS SAMPLING WITHIN ACQUISITION CYCLES TO ALL LEVELS OF FTI SYSTEM DEFINITION

      Fielding, Richard; McNelis, Aaron; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      This paper examines two rules for data acquisition that have advantages for today's Flight Test Instrumentation (FTI) systems where: • Data is acquired from physically separate test equipment • Deterministic (IRIG-106 (Ch. 4)) and non-deterministic networks co-exist • Data Acquisition Units (DAUs) from multiple vendors are required • Signal lists and sampling rates change rapidly • A time-coherent sampling strategy (even for smart sensors) is required These rules may aid not only in the selection of the data acquisition equipment but also the definition of the sampling, transmission, storage and analysis strategies.
    • 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.
    • A DECOUPLED APPROACH TO COMPENSATION FOR NONLINEARITY AND INTERSYMBOL INTERFERENCE

      Lyman, Raphael J.; Wang, Qingsong; New Mexico State University (International Foundation for Telemetering, 2002-10)
      To achieve good efficiency in a space-based radio transmitter, its final amplifier must be operated near the saturation point, in its nonlinear region. Because of strict band limitations, this nonlinear operation is combined with the problem of intersymbol interference. Normally, these problems are addressed using a combination of equalization and power back-off, resulting in reduced power efficiency. Many proposed receiver-based methods, such as Volterra equalization, attempt to compensate for the nonlinearity and ISI in a single block before the detector, allowing higher efficiency operation, but introducing a great deal of complexity. We propose a receiver-based method in which the two effects are dealt with in separate blocks, an equalizer and a linearizer, resulting in considerable simplification. We go further and place the detector before the linearizer, achieving improved performance by eliminating the errors introduced by the linearizer. Simulation results compare favorably with the performance of a linear AWGN channel.
    • 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.
    • THE SYSTEM DESIGN OF DIGITAL TWELVE-CHANNEL GPS SIMULATOR

      Juan, Lu; Qing, Chang; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      With the purpose of testing the performance of GPS receivers, a GPS signal simulator is needed that can emulate the real GPS signals under all kinds of the conditions. This paper analyzes the single channel and multi-channel GPS signals’ characters in time domain and frequency domain, and discusses a mathematic model of the twelve-channel GPS simulator. In order to reduce the difficulties of the hardware design, this model is designed to provide the IF signal directly by applying the idea of “software radio”and the theory of interpolation. Simulation results with SystemView software demonstrate the feasibility of the system scheme. A practical hardware design of this system is described.
    • NETWORKING SATELLITE GROUND STATIONS USING LABVIEW

      Mauldin, Kendall; New Mexico State University (International Foundation for Telemetering, 2002-10)
      A multi-platform network design that is automated, bi-directional, capable of store and forward operations, and low-bandwidth has been developed to connect multiple satellite ground stations together in real-time. The LabVIEW programming language has been used to develop both the server and client aspects of this network. Future plans for this project include implementing a fully operational ground network using the described concepts, and using this network for real-time satellite operations. This paper describes the design requirements, RF and ground-based network configuration, software implementation, and operational testing of the ground network.
    • Network Telemetry: Practical Experiences and Unique Features

      D’Amico, William P.; Stadter, Patrick A.; Lauss, Mark H.; Hooper, Andrew; Johns Hopkins University; Materiel Test Center (International Foundation for Telemetering, 2002-10)
      The US Army’s Yuma Proving Ground (YPG) uses a wireless local area network (WLAN) to gather test data. It is desired to extend this WLAN to support tests of gun-launched munitions where miniature and rugged data acquisition hardware will be required. The Two Way Robust Acquisition of Data (2-RAD) program has been initiated under the Central Test and Evaluation Investment Program (CTEIP) to develop a process to expand the use of WLAN technology, which is now primarily used at YPG for internal ballistic test data acquisition.
    • EMBEDDED GIS IN INTELLIGENT NAVIGATION SYSTEM

      Xiaobo, Xie; Qishan, Zhang; Xingjian, Huang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      Embedded GIS in Intelligent Navigation System is a special information system. This paper puts forward several basic principles and constraints during design for Embedded GIS at first, and then analyzes the feature of embedded platform and the function of Intelligent Navigation System, and presents a realization scheme of Embedded GIS.
    • WHO MOVED MY TAPE RECORDER FLAVORED CHEESE

      Berard, Alfredo J.; Chalfant, Tim; Lloyd, Joe; Small, Marty; Buckley, Mark; Bagó, Balázs; Lockard, Michael; Eglin Air Force Base; Edwards Air Force Base; Navair; et al. (International Foundation for Telemetering, 2002-10)
      For the last 30 years Magnetic Tape Systems have been the primary means of recording data from airborne instrumentation systems. Increasing data rates and harsh environmental requirements have often exceeded the ability of tape-based systems to keep pace with platform technology. This paper examines operational and data reduction benefits when employing the IRIG 106 Chapter 10 Solid State Recorder Standard introduced by the Range Commanders Council (RCC) Telemetry Group (TG). The Standard and this paper address media formatting, data formatting for a variety of different data types, data downloading, and data security, along with serial command and control and discrete command and control of the recorder. This paper also addresses software data processing and raw data reconstruction of Chapter 10 data.
    • THE VEHICLE MONITORING SYSTEM BASED ON GPRS

      Xu, Liu; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      The Vehicle Monitoring System based on GPRS is a system using GPRS network to transmit data, including location data, time data and so on .It has many advantages compared with those systems based on other communication modes. The key of the system lies in how to build up the connection with exterior data network. In this paper, the constitution of the system is introduced, and the course of building up connection with exterior data network is described in detail.
    • HARDWARE SYSTEM DESIGN FOR VEHICLE NAVIGATOR

      Li, Chen; Qi-shan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      This paper introduces the essential points for designing a navigating system, and describes the modules of a typical vehicle navigator. This paper also gives a practical navigator example. Some experience for design is also mentioned.
    • MAGNETIC TAPE CARE & RESTORATION

      Wheeler, Jim; Tape Restoration & Forensic Services (International Foundation for Telemetering, 2002-10)
      For the past thirty years, many people around the world have been engaged in studies to determine how long tape will last. We have learned how to extend the life of tapes but no one has come up with a method for predicting the life of a tape. This paper will summarize the present-day recommended practices for tape care and storage and will also describe the most common tape problems and how to overcome them. The most common problem with playing an old tape is finding a machine to play it. Machine obsolescence is probably a bigger problem than tape degradation.
    • 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.
    • 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.
    • ANALYSIS OF CYCLOSTATIONARY AND SPECTRAL CORRELATION OF FEHER-KEYING (FK) SIGNALS

      Chang, Soo-Young; Gonzalez, Maria C.; McCorduck, James A.; Feher, Kamilo; University of Suwon; University of California; Digcom, Inc. (International Foundation for Telemetering, 2002-10)
      Feher Keying (FK) signals are clock shaped baseband waveforms with the potential to attain very high spectral efficiencies. Two FK signals which have different level rectangular waveforms (named as FK-1) or sinusoidal waveforms (named as FK-2) for two binary symbols are considered in this paper. These signals have periodic components in the time domain. Therefore they have cyclostationary properties. This means that spectral correlation exists in the frequency domain. For each type of waveforms, spectral correlation has been investigated. FK signals can be expressed mathematically into two parts in the frequency domain – discrete part and continuous part. The discrete part has one or more discrete impulse(s) in their spectra and the continuous part has periodically the same shape of harmonics in their spectra. The correlations of their spectra have been obtained mathematically and by simulation. It is shown that FK signals have high correlation related to the symbol rate. Finally, some suggestions how these properties can be used to improve their performance by devising better demodulators are discussed. These properties can be used for interference rejection at the receiver, which results in low bit error rate performance.