• ENHANCING THE PCM/FM LINK - WITHOUT THE MATH

      Fewer, Colm; Wilmot, Sinbad; ACRA CONTROL INC (International Foundation for Telemetering, 2007-10)
      Since the 1970s PCM/FM has been the dominant modulation scheme used for RF telemetry. However more stringent spectrum availability as well as increasing data rates means that more advanced transmission methods are required to keep pace with industry demands. ARTM Tier-I and Tier-II are examples of how the PCM/FM link can be enhanced. However these techniques require a significant increase in the complexity of the receiver/detector for optimal recovery. This paper focuses on a quantitative approach to improving the rate and quality of data using existing PCM/FM links. In particular ACRA CONTROL and BAE SYSTEMS set themselves the goal of revisiting the pre-modulation filter, diversity combiner and bit-sync. By implementing programmable adaptive hardware, it was possible to explore the various tradeoffs offered by modifying pulse shapes and spectral occupancy, inclusion of forward error correction and smart source selection. This papers looks at the improvements achieved at each phase of the evaluation.
    • ROBUST ADAPTIVE BEAMFORMING WITH BROAD NULLS

      Yudong, He; Xianghua, Yang; Jie, Zhou; Banghua, Zhou; Beibei, Shao; Tsinghua University; China Academy of Engineering Physics (International Foundation for Telemetering, 2007-10)
      Robust adaptive beamforming using worst-case performance optimization is developed in recent years. It had good performance against array response errors, but it cannot reject strong interferences. In this paper, we propose a scheme for robust adaptive beamforming with broad nulls to reject strong interferences. We add a quadratic constraint to suppress the power of the array response over a spatial region of the interferences. The optimal weighting vector is then obtained by minimizing the power of the array output subject to quadratic constrains on the desired signal and interferences, respectively. We derive the formulations for the optimization problem and solve it efficiently using Newton recursive algorithm. Numerical examples are presented to compare the performances of the robust adaptive beamforming with no null constrains, sharp nulls and broad nulls. The results show its powerful ability to reject strong interferences.
    • Network Design Considerations in Telemetry Systems

      Grebe, Andy; Klein, Wayne; Apogee Labs, Inc. (International Foundation for Telemetering, 2007-10)
      In today’s world, computer networking has become common place both in industry as well as home, however all networks are not the same! The Telemetry world, like with many industries, has critical design considerations that need to be evaluated when you begin a new system or just adding on to a current infrastructure. This paper is intended to outline needed considerations when planning or implementing a network design in Telemetry Systems. These applications can range from sensor data transport through High Definition/High Speed Video applications.
    • Evolving Range and DISA Networks Using Pseudo Wire

      Merritt, Joseph; Avtec Systems, Inc. (International Foundation for Telemetering, 2007-10)
      The Eastern and Western Ranges along with DISA share a similar vision around Net-Centricity such that "Anyone, anywhere can get to any data source and exploit the information they are authorized to access." Their legacy infrastructure is built around TDM and ATM transport networks, which are link based and connection oriented. To achieve the vision the infrastructure must evolve towards a packet switched network (PSN) that is meshed based. Consequently, a means to interwork non-IP enabled services is required. Pseudo Wire protocol encapsulation provides the means for extending telemetry, data, voice, and video services in native formats over Ethernet, IP, and MPLS networks in a reliable way that delivers greater operational efficiency and a smooth migration to a single converged network.
    • TELEMETRY TRANSCEIVER DESIGN USING BOC SIGNAL

      Dongkai, Yang; Li, Du; Qishan, Zhang; Beihang University (International Foundation for Telemetering, 2007-10)
      This paper focuses on the transceiver design using BOC signal in the telemetry field, including the transmitter and receiver. The transmitter is similar as that using BPSK except from the sub-carrier modulation. But the receiver design is totally different because the BOC signal has different performance. The acquisition methods of BOC signal have been discussed such as the single-side BPSK-like, double-sides BPSK-like and hybrid processing methods, which can restrain side-peak and eliminate ambiguities. The three acquisition process principles and their performances include arithmetic complexity are described, compared and simulated using MATLAB.
    • A FLEXIBLE SWITCHING ARCHITECTURE FOR DIVERSE SIGNAL TYPES

      Gery, Brian; Apogee Labs, Inc. (International Foundation for Telemetering, 2007-10)
      Modern telemetry systems often require signal switching hardware to facilitate signal routing reconfiguration between missions. As these systems have grown more complex with high signal counts and diverse signal types in the same system, the need for flexible switching hardware that can adapt to these changing requirements has emerged. A novel architecture for diverse signal switching hardware is presented that addresses the changing requirements of modern telemetry systems. While conventional commercial switching gear handles each signal type in a separate group, the proposed architecture allows digital and analog signal types to be switched, multiplexed, scaled, and combined (as the signal types allow) all within the same chassis, and between signal types.
    • A ROADMAP TO STANDARDIZING THE IRIG 106 CHAPTER 10 COMPLIANT DATA FILTERING AND OVERWRITNG SOFTWARE PROCESS

      Berard, Alfredo; Manning, Dennis; Kim, Jeong Min; Eglin Air Force Base (International Foundation for Telemetering, 2007-10)
      High speed digital recorders have revolutionized the way Major Range and Test Facility Bases collect instrumentation data. One challenge facing these organizations is the need for a validated process for the separation of specific data channels and/or data from multiplexed recordings. Several organizations within Eglin Air Force Base have joined forces to establish the requirements and validate a software process compliant with the IRIG-106 Chapter 10 Digital Recording Standard (which defines allowable media access, data packetization, and error controls mechanics). This paper describes a roadmap to standardizing the process to produce this software process, Data Overwriting and Filtering Application (DOFA).
    • A Common Solution to Custom Network Applications

      Yin, Jennifer; Dehmelt, Chris; L-3 Communications – Telemetry East (International Foundation for Telemetering, 2007-10)
      The deployment of networks has become ubiquitous in the avionics world, as they have opened the door to a rich suite of common and open hardware and software tools that provide greater functionality and interoperability. Unfortunately, a number of networked avionic and other related applications can be affected by vendor or application specific proprietary implementations. These “closed” implementations may reduce or eliminate the benefits of a standardized network, requiring the customization of the data acquisition system to allow it to properly operate with the other devices. This paper presents the approach that was recently employed for the development of a network interface module that can be quickly reconfigured to address the changing requirements of network applications, including monitoring of industry standard and proprietary networks, or providing the command and data interface to the data acquisition system itself. This reconfigurability of the module is shown in a review of four different specific applications.
    • The Sum-Rate Capacity of a Cognitive Multiple Access Sensor Network

      Panagos, Adam; Kosbar, Kurt; Dynetic, Inc.; University of Missouri (International Foundation for Telemetering, 2007-10)
      This paper investigates the sum-rate capacity of a cognitive multiple access (MAC) sensor network. The multiple access network consists of K sensors communicating to a common base station. Outside of the network exists another user of the radio spectrum. Each sensor of the MAC network is aware (i.e. cognitive) of this user, denoted the primary user, and transmits in a manner to avoid any interference to this user. No interference transmission is achieved using the dirty-paper coding technique. The sum-rate capacity is the theoretical maximum of the sum of the simultaneously achievable rates of each sensor within the network. Using a recently derived iterative algorithm, we quantify the sum-rate capacity of this network and investigate its behavior as a function of the number of sensors, cognitive signal-to-noise ratio (CSNR) and primary SNR (PSNR) in a Rayleigh fading environment. We also derive bounds and scaling results for the ergodic sum-rate capacity.
    • SIMPLIFIED 2-state Detectors for SOQPSK-TG and SOQPSK-MIL

      Perrins, Erik; Kumaraswamy, Balachandra; University of Kansas (International Foundation for Telemetering, 2007-10)
      We study simple trellis-based detectors for SOQPSK that have a minimal level of complexity. In particular, we show that the state complexity can be cut in half relative to previous approaches—from 4 states down to 2—with asymptotically optimum performance. We give two possible means of achieving this: the pulse amplitude modulation (PAM) technique and the pulse truncation (PT) technique; both of these techniques make use of recent advances in SOQPSK technology based on a continuous phase modulation (CPM) interpretation of SOQPSK. The proposed simplifications are significant since trellis-based SOQPSK detectors are 1–2 dB superior to widely-deployed symbol-by-symbol detectors. These performance gains come at the expense of complexity, and the proposed 2-state detectors minimize this expense. Thus, these simple detection schemes are applicable in settings where high-performance and low complexity are needed to meet restrictions on power consumption and cost.
    • TCP PERFORMANCE ENHANCEMENT OVER IRIDIUM

      Torgerson, Leigh; Hutcherson, Joseph; McKelvey, James; California Institute of Technology (International Foundation for Telemetering, 2007-10)
      In support of iNET maturation, NASA-JPL has collaborated with NASA-Dryden to develop, test and demonstrate an over-the-horizon vehicle-to-ground networking capability, using Iridium as the vehicle-to-ground communications link for relaying critical vehicle telemetry. To ensure reliability concerns are met, the Space Communications Protocol Standards (SCPS) transport protocol was investigated for its performance characteristics in this environment. In particular, the SCPS-TP software performance was compared to that of the standard Transmission Control Protocol (TCP) over the Internet Protocol (IP). This paper will report on the results of this work.
    • THE EVALUATION AND INTEGRATION OF AN INSTRUMENTATION AND TELEMETRY SYSTEM WITH SOQPSK MODULATION AND CONTROL INTEGRATED WITH AVIONICS DISPLAYS

      Wegener, John A.; Zettwoch, Robert N.; Roche, Michael C.; The Boeing Company (International Foundation for Telemetering, 2007-10)
      This paper describes the integration activities associated with the instrumentation and telemetry system developed for an F/A-18 Hornet Flight Test program, including bench integration, avionics integration, and aircraft ground and flight checkout. The system is controlled by a Boeing Integrated Defense System (IDS) Flight Test Instrumentation designed Instrumentation Control Unit (ICU), which interfaces to an avionics pilot display and Ground Support Unit (GSU) to set up the instrumentation during preflight and control the instrumentation during flight. The system takes in MIL-STD-1553, analog parameters, Ethernet, Fibre Channel, and video, and records these with onboard recorders. Selected subsets of this data may be routed to the telemetry system, which features two RF streams, each of which contains up to four PCM streams combined into a composite by a data combiner. The RF streams are transmitted by multi-mode digital transmitters capable of PCM-FM or Shaped Offset Quadrature Phase Shift Keying (SOQPSK), with selectable Turbo-Product Code (TPC) Forward Error Correction (FEC). This paper describes integration of the system with the IDS Flight Test Integration Test Bench (ITB), production avionics integration facilities, and final aircraft ground checkout and initial flight tests. It describes results of integration activities and bench evaluation of the telemetry system.
    • SOFT RECOVERY RECORDING SYSTEM FOR INTERIOR AND EXTERIOR BALLISTICS CHARACTERIZATION

      Guevara, Mauricio; Flyash, Boris; Army Research Development and Engineering Center (International Foundation for Telemetering, 2007-10)
      The US ARMY, ARDEC; in cooperation with AMCOM AMRDEC, Missile Guidance and Engineering Directorates; the Office of Naval Research; Naval Surface Fire Support; and the Naval Surface Weapon Center, requires multiphase development of a common, low-cost, high G survivable, high accuracy, Micro Electro-Mechanical Systems (MEMS) Inertial Measurement Unit (IMU) and Common, Deeply Integrated, Guidance and Navigation Unit (DI-GNU) for DoD gun launched guided munition and missile applications. The challenge for the Precision Munition Instrumentation Division (PMID) was to develop a Telemetry System to record the interior and exterior ballistics of a M831 TP-T projectile, which will be used as a carrier for soft recovery testing of IMUs and GNUs. This valuable data that would help The Government and contractors develop and validate multiple MEMS IMU design efforts, culminating with live fire verification performance test of pre-production in the Army’s 155-mm Soft Recovery Vehicle (SRVs) and missiles airframes.
    • DESIGN AND CONSTRUCTION OF AN OPTICAL TELEMETRY SYSTEM

      Spjut, Erik; Acon, Chris; George, Nisha; Kimbrell, Scott; Pivonka, Dan; Rowland, Clarence; Schulze, W. Buck; Harvey Mudd College (International Foundation for Telemetering, 2007-10)
      The Edwards Air Force Base Undergraduate Clinic Team at Harvey Mudd College designed, built and tested a laser-based telemetry system for use on test aircraft at the EAFB Flight Test Center. The system was designed to communicate from an aircraft to a stationary, terrestrial receiver at a distance of up to 60 miles while traveling at speeds up to 230 mph. The transmitter system is restricted to the size of a standard 4’ tall 19" wide equipment rack. The transmitter is designed to maintain a constant laser footprint diameter of 100 meters at the receiver and use both coarse acquisition and closed-loop fine tracking systems. The minimum data rate is 10 Mbps. Sub-system testing and integration was not completed. Completed sub-systems included GPS/INS-based tracking (for coarse-tracking), position-sensitive-detector (PSD) optics (a finetracking system component), a transmitter gimbal assembly, software used to integrate and control hardware at the transmitter and receiver, and a complete receiver system. A PSD-based tracking system and an automatic collimation system were designed and constructed, but only partially tested.
    • A MORE EFFICIENT TRACKING SYSTEM FOR THE SANTIAGO SATELLITE TRACKING STATION

      Ramírez, Eduardo Díaz; Universidad de Chile (International Foundation for Telemetering, 2007-10)
      A digital antenna control system has been designed and installed on a pedestal that was formerly used to drive a VHF array and that has now been replaced with an 11 meter S-Band parabolic reflector. In this Paper, the former analog tracking system will be described, showing all the drawbacks that made it unusable for S-Band. Subsequently, the development and implementation of the digital S-Band tracking system, using Labview, C++ & digital control theory will be discussed. Finally, there will be a comparison between the digital and analog system, too.
    • DEVELOPMENT OF AN UNMANNED AIRBORNE TELEMETRY TRACKING AND RELAY SYSTEM

      Pho, Tam P.; Wysong, Henry D.; Aerocross Systems, Inc. (International Foundation for Telemetering, 2007-10)
      Aerocross Systems, Inc. is developing a low-cost unmanned airborne telemetry relay system to augment the USAF Air Armament Center’s Eglin Gulf Range instrumentation resources. The system is designed to remotely autotrack and relay S-Band telemetry and VHF/UHF voice communications from test articles beyond the line-of-sight of land-based instrumentation. The system consists of a medium altitude/endurance Unmanned Aerial Vehicle (UAV), a Mission Control Station, and a remotely operated telemetry/voice tracking and relay instrumentation suite. Successfully developed and deployed, the system will contribute to lower range costs while enhancing range instrumentation performance.
    • ADAPTIVE MODULATION FOR COGNITIVE RADIO

      Kosbar, Kurt; Sharma, Gaurav; University of Missouri (International Foundation for Telemetering, 2007-10)
      While investigating methods for more efficiently allocating the available spectrum researchers noticed that in many geographical locations, there are broad bands of frequencies that are lightly utilized. Such inefficiencies are inevitable with fixed spectral allocation rules. Cognitive Radios actively measure the spectral utilization and adapt their modulation, frequencies, bandwidths, power, etc. to take advantage of these lightly used “spectral holes” or “white spaces”. Much of the research work in cognitive radios has not taken into account some of the challenges faced in the telemetry community-including multipaths and a guaranteed quality of service. This paper highlights how some mathematical models of adaptive modulation discussed extensively in many research papers and textbooks can be used in Cognitive Radios as well.
    • DESIGN AND PERFORMANCE OF A MULTI-MODE MULTI-RATE TELEMETRY TRANSMITTER

      Ahmed, Walid K. M.; Wougk, Harald; Tyco Electronics Wireless Systems (International Foundation for Telemetering, 2007-10)
      Typical telemetry transmitter designs have focused on analog-circuit implementations, which suffer limitations when required to support multi-mode and multi-rate capabilities. In this paper, we introduce a transmitter design (and associated techniques) that employ an all-digital baseband line-up that utilizes only one single-rate clock. Thus, keeping the analog hardware to a minimum and providing the maximum possible flexibility through digital programmability, in order to efficiently support multi-mode (i.e., various modulation schemes) and multi-rate (i.e., various bit-rates) capabilities. The telemetry standard is defined in the IRIG 106-04 specification document published by the Range Commanders Council (RCC) government telemetry group [1]. The Telemetry standard supports several modulation schemes all of which fall under the general modulation family of continuous phase modulation (CPM). Out of such a family of modulation schemes, the work presented in this paper focuses on two modulation schemes as examples, namely, SOQPSK and the PCM/FM. However, this does not limit the scope of the ideas and techniques proposed in this paper. We present various design techniques as well as implementation considerations. We also present actual measured results using a test-bed and a synthesizer IC that have been developed in our laboratories. Finally, we compare the measured results with simulations in order to validate the performance of our implemented design.
    • STUDY ON GPS RECEIVER ALGORITHMS FOR SUPPRESSION OF NARROWBAND INTERFERENCE

      Yongkang, Hu; Qishan, Zhang; Yanhong, Kou; Dongkai, Yang; Beihang University (International Foundation for Telemetering, 2007-10)
      Despite the inherent resistance to narrowband signal interference afforded by GPS spread spectrum modulation, the low level of GPS signals makes them susceptible to narrowband interference. This paper discusses the application of a pre-correlation adaptive temporal filter for stationary and nonstationary narrowband interference suppression. Various adaptive algorithms are studied and implemented. Comparison of the convergence and tracking behavior of various algorithms is made.
    • COMPARISON OF NONCOHERENT DETECTORS FOR SOQPSK AND GMSK IN PHASE NOISE CHANNELS

      Perrins, Erik; Syed, Afzal; University of Kansas (International Foundation for Telemetering, 2007-10)
      SOQPSK and GMSK are highly bandwidth efficient continuous phase modulation (CPM) schemes with several desirable qualities. In both cases, coherent detectors are available with good performance in AWGN. In this paper, we develop reduced complexity noncoherent detectors for SOQPSK and GMSK; and discuss a phase noise model. This is followed by a performance comparison of both the noncoherent detectors in channels with phase noise.