• Adaptive Space-Time Waveform Design in Ad hoc Networks using the IMMSE Algorithm

      Iltis, Ronald A.; University of California, Santa Barbara (International Foundation for Telemetering, 2004-10)
      An Ad hoc network with unicasting is considered, in which each node has an M element antenna array. Transmission from node l(i) to i is quasi-synchronous, so that code acquisition is not required. Space-Time (S-T) waveforms are transmitted with temporal dimension Ns Nyquist samples. An adaptive, distributed S-T waveform design algorithm is developed, which maintains QoS while attempting to minimize transmit power. The resulting Iterative Minimum Mean-Square Error{Time Reversal algorithm (IMMSE-TR) sets the transmit S-T vector at node i to the conjugate time-reverse of the linear MMSE S-T detector. It is shown that IMMSE-TR corresponds to a noncooperative game which attempts to minimize transmit power while paying an interference tax. Simulation results are presented demonstrating high power efficiencies for heavily-loaded systems.

      Davis, Rodney; Hupf, Greg; Woolf, Chad; Command and Control Technologies (International Foundation for Telemetering, 2004-10)
      CCT is conducting research to provide a cross platform software capability that enables a common semantic for control and monitor of highly distributed systems-of-systems C^2 architectures by auto-generating semantic processing services from standardized metadata specifications. This new capability is significant because it will reduce development, operations, and support costs for legacy and future systems that are part of ground and space based distributed command and control systems. It will also establish a space systems information exchange model that can support future highly interoperable and mobile software systems.

      Baker, Grady; NAVAIR (International Foundation for Telemetering, 2004-10)
      The purpose of this paper is to present the use of production aircraft equipment and wiring for control of the onboard instrumentation system. The major advantages and challenges associated with the use of existing production equipment versus dedicated instrumentation wiring and hardware will be explored. Many of the issues raised, including non-interference with existing avionics, are complex. It is the hope of the author that this paper will generate awareness and discussion on these issues.

      Rice, Michael; Perrins, Erik; Brigham Young University (International Foundation for Telemetering, 2004-10)
      Since the Advanced Range Telemetry (ARTM) program first proposed the use of multi-h continuous phase modulation (ARTM CPM), there has been much work done to characterize the performance of this waveform. The ideal performance of ARTM CPM is well understood and has been shown to be close to that of PCM/FM and the Tier I modulations (FQPSK-B and SOQPSK). In practice, however, ARTM CPM is very sensitive to phase noise at the receiver and also requires very long synchronization times. These difficulties can be addressed with additional link margin. In this paper we propose an alternate set of modulation indexes which are approximately 2 dB superior in performance with respect to the original set (we use minimum distance concepts to characterize the performance of each set). Brief consideration is also given to frequency pulses other than the existing raised cosine (RC) pulse. We also characterize the effect these new parameters have on the signal spectrum. This 2 dB gain gives ARTM CPM some of the system flexibility currently enjoyed by PCM/FM and the Tier I modulations. One such option is to realize this 2 dB gain using low-complexity coherent detection schemes, which we demonstrate; we also show a noncoherent detection scheme that performs within 2 dB of optimum (or in other words, it has the same performance as the existing coherent detector for ARTM CPM). This is significant since noncoherent detection avoids some of the synchronization burdens that have plagued ARTM CPM thus far.
    • Analysis of FM Demodulator Output Noise With Applications to FM Telemetry

      Kumar, Rajendra; California State University (International Foundation for Telemetering, 2004-10)
      This paper presents analysis for evaluating the probability density function (pdf) of the noise at the output of the frequency demodulator. It is shown that the noise is non-Gaussian and that for low to medium signal-to-noise power ratios, its pdf differs very significantly from the Gaussian pdf commonly assumed in simplified analysis. These results are very important for analyzing the performance of the PCM/FM type of modulation schemes used in telemetry systems as illustrated in the paper.
    • Analysis of Optimized Design Tradeoffs in Application of Wavelet Algorithms to Video Compression

      Wanis, Paul; Fairbanks, John S.; L-3 Communications Corporation (International Foundation for Telemetering, 2004-10)
      Because all video compression schemes introduce artifacts into the compressed video images, degradation occurs. These artifacts, generated by a wavelet-based compression scheme, will vary with the compression ratio and input imagery, but do show some consistent patterns across applications. There are a number of design trade-offs that can be made to mitigate the effect of these artifacts. By understanding the artifacts introduced by video compression and being able to anticipate the amount of image degradation, the video compression can be configured in a manner optimal to the application under consideration in telemetry.

      Peng, Song; XiaoLin, Zhang; Xue, Cao; Xia, Qi; North China University of Technology; Beijing University of Aeronautics and Astronautics; China Luoyang Optoelectro Technology Development Center (International Foundation for Telemetering, 2004-10)
      Combined with an example of digital telemetry receiver design, this paper mainly discusses the application of software radio in telemetry receiver. The paper begins with an introduction of applying high efficiency digital filter and math analysis in quadrature digital frequency modulation and demodulation to digital frequency conversion technique. Next, Simulink/Matlab is used to simulate digital telemetry receiver. The method of simulation, analysis and calculation of performance and result of simulation are all available. In the end, the paper discusses digital telemetry receiver design and implement by making use of software radio technique, the circuits apply HSP50214 chip of Intersil Co., CPLD implements of Altera Co. and PC Bus. The sample is an expansion card for personal computer. Result of test, performance of the receiver and conclusion are given out, which show fine performance of receiver and can be apply to practice. The lever of this technology has reached first class in the world.
    • An Architecture for Sensor Data Fusion to Reduce Data Transmission Bandwidth

      Lord, Dale; Kosbar, Kurt; University of Missouri – Rolla (International Foundation for Telemetering, 2004-10)
      Sensor networks can demand large amounts of bandwidth if the raw sensor data is transferred to a central location. Feature recognition and sensor fusion algorithms can reduce this bandwidth. Unfortunately the designers of the system, having not yet seen the data which will be collected, may not know which algorithms should be used at the time the system is first installed. This paper describes a flexible architecture which allows the deployment of data reduction algorithms throughout the network while the system is in service. The network of sensors approach not only allows for signal processing to be pushed closer to the sensor, but helps accommodate extensions to the system in a very efficient and structured manner.

      Jones, Charles H.; Edwards Air Force Base (International Foundation for Telemetering, 2004-10)
      One approach to improving spectrum usage efficiency is to manage the scheduling of frequencies more effectively. The use of metrics to analyze frequency scheduling could aid frequency managers in a variety of ways. However, the basic question of what is a good metric for representing and analyzing spectral usage remains unanswered. Some metrics capture spectral occupancy. This paper introduces metrics that change the focus from occupancy to availability. Just because spectrum is not in use does not mean it is available for use. A significant factor in creating unused but unusable spectrum is fragmentation. A mission profile for spectrum usage can be considered a rectangle in a standard time versus frequency grid. Even intelligent placement of these rectangles (i.e., the scheduling of a missions spectrum usage) can not always utilize all portions of the spectrum. The average typical mission availability (ATMA) metric provides a way of numerically answering the question: Could we have scheduled another typical mission? This is a much more practical question than: Did we occupy the entire spectrum? If another mission couldn’t have been scheduled, then the entire spectrum was effectively used, even if the entire spectrum wasn’t occupied.

      Bin, Xu; XiaoLin, Zhang; Guolei, Lu; Weiwei, Hu; Beihang University (International Foundation for Telemetering, 2004-10)
      This paper discusses the design and implementation of the base station telemetry data processing system for the unmanned helicopter. The system designed is composed of code synchronizer, decoding and frame synchronizer as well as PCI bus interface. The functions of the system are implemented with very large integrated circuits and a standard PCI inserted card that is compact and easy to install. The result of flight performance tests shows that the system is reliable and can satisfy the requirements of telemetry system for unmanned helicopters.

      Willis, Donald; Federal Aviation Administration (International Foundation for Telemetering, 2004-10)
      Exclusive and globally allocated radio spectrum is essential for safe and efficient air travel. This paper will focus on the impact of changes in both U.S. and international radio spectrum policy, describe the issues these changes have raised for the aeronautical community, and examine a few proposed solutions. First, the paper will put the Federal Aviation Administration in the context of the test and evaluation community. Common frequency usage will be examined and the major interactions between the Federal Aviation Administration, Department of Defense, and commercial sector test and evaluation activities. The paper will provide a review of several U.S. spectrum policies from the early-to-mid 90’s which set the stage for the current domestic spectrum policy debates. For example, spectrum auctioning was formally established in the Omnibus Budget Reconciliation Act of 1993 and further expanded in the Balanced Budget Act of 1997. Both of these Acts directed the transfer of radio spectrum that was allocated solely for Federal Government use to the private sector. These reallocations also set the stage for more recent domestic spectrum policy debates, such as that over ultrawideband devices, broadband service over powerline carrier, third generation wireless, and other new technologies that claim the ability to “share” radio spectrum with other existing users. The paper will also review international spectrum policy changes that were made within the International Telecommunication Union and their impact on aeronautical radio spectrum. These include reallocation of aeronautical radio spectrum for uses such as wireless local area networks and fixed satellite links. Yet another cause of reduction in the amount of aeronautical radio spectrum will be reviewed…that is, the increase in aeronautical requirements with no attendant increase in the overall aeronautical radio spectrum available. These increasing requirements include such critical spectrum needs as Global Navigation Satellite System modernization, growing applications which use very high frequency (VHF) air/ground radio spectrum, new automatic dependent surveillance-broadcast services, increased aeronautical telemetry needs, and use of unmanned aerial vehicles in the national airspace. This growth has resulted in increasing spectrum congestion in bands that support critical safety services for international civil aviation. Finally, the paper will consider potential solutions to the shortage of aeronautical radio spectrum. These solutions include use of new advanced technologies, “splitting” the current channelization, and changes in radio regulations and frequency engineering criteria. Examples of what the Federal Aviation Administration is doing to implement these solutions will also be briefly addressed.
    • Challenges of Optimizing Multiple Modulation Schemes in Transponder Design

      Fairbanks, John S.; L-3 Communications, Inc. (International Foundation for Telemetering, 2004-10)
      Increasing gate counts in FPGA’s create an option of offering multiple waveform demodulation and modulation within a single transponder transceiver. Differing data rates, channel schemes, and network protocols can be addressed with the flexibility of software-based demodulation and modulation. Increased satellite longevity and reliability are benefits of software-based transceiver design. Newer packaging technology offers additional capability in reducing form factor and weight of a transponder. A review of the challenges in combining each of the above to produce the next generation of transponders is the subject of this paper.

      Roth, Heinz; EADS Military Aircraft (International Foundation for Telemetering, 2004-10)
      The system architecture of an onboard FTI-System is specifically designed to fulfil highly demanding flight test requirements. Since these flight test requirements are steadily increasing with the growing complexity of test aircraft and mission systems, a corresponding improvement in the performance of the FTI-Systems is mandatory to satisfy those flight test demands. In addition, the individual test flights have to provide the maximum of flight test data obtainable in order to improve test efficiency and to cut project costs. Increased performance, miniaturisation, more reduced design and installation costs are the challenges for future system architectures. The developments of commercial and consumer electronics have an increasing influence on the layout of FTI-Systems.

      Jensen, Michael A.; Rice, Michael D.; Anderson, Adam L.; Brigham Young University (International Foundation for Telemetering, 2004-10)
      The placement of two antennas on an air vehicle is one possible practice for overcoming signal obstruction created by vehicle maneuvering during air-to-ground transmission. Unfortunately, for vehicle attitudes where both antennas have a clear path to the receiving station, this practice also leads to self-interference nulls, resulting in dramatic degradation in the average signal integrity. This paper discusses application of unitary space-time codes such as the Alamouti transmit diversity scheme and unitary differential space-time codes to overcome the self-interference effect observed in such systems.

      Rice, Michael; Satorius, Ed; Brigham Young University; Jet Propulsion Laboratory (International Foundation for Telemetering, 2004-10)
      The performance of two adaptive equalization techniques applicable to ARTM Tier-1 waveforms over a frequency selective multipath channel is summarized. Adaptive equalization based on the constant modulus algorithm (CMA) and the decision-directed minimum mean squared error (DF-MMSE) concept are shown to be effective in reducing the bit error rate in the presence of frequency selective multipath interference. The performance of the DF-MMSE equalizer is slightly better than the CMA equalizer. Implementation trade-offs between the two types of equalizers are also discussed.
    • Comparison of Wireless Ad-Hoc Sensor Networks

      Spinden, David; Jasper, Jeffrey; Kosbar, Kurt; University of Missouri – Rolla (International Foundation for Telemetering, 2004-10)
      There are a number of telemetry applications where it would be helpful to have networks of sensors that could autonomously discover their connectivity, and dynamically reconfigure themselves during use. A number of research groups have developed wireless ad-hoc sensor network systems. This paper reviews the state-of-the-art in wireless ad-hoc networks, examining the features, assumptions, limitations and unique attributes of some of the more popular solutions to this problem.

      Horan, Sheila B.; New Mexico State University (International Foundation for Telemetering, 2004-10)
      Reduction of bandwidth for signal transmission is of paramount concern to many in the telemetry and wireless industry. One way to reduce bandwidth is to reduce the amount data being sent. There are several techniques available to reduce the amount of data. This paper will review the various types of data compression currently in use for telemetry data and how much compression is achieved.

      Hicks, William T.; Yantorno, Robert E.; Temple University (International Foundation for Telemetering, 2004-10)
      IRIG-106 Chapter 5 describes a method for encoding voice using a simple circuit to reduce the overall bit rate and still achieve good quality voice. This well described Continuously Variable Slope Delta Modulation (CVSD) circuit can be obtained using analog parts. A more stable implementation of CVSD can be obtained by designing an anti-aliasing input filter, an A/D converter, and logic. This paper describes one implementation of the CVSD using a standard A/D converter and logic.

      Fitzgerald, Alan; Adtron Corporation (International Foundation for Telemetering, 2004-10)