• SCALABLE TRANSMISSION AND DECODING OF SPACE PACKETS FOR REMOTE SATELLITE IMAGE BROWSING

      Oh, Han; Chang, Jae Young; Kim, Jin-Hyung; Choi, Hae-Jin; Satellite Operation and Application Center, Korean Aerospace Research Center; Future and Converging Technology Research Division, Korean Aerospace Research Center (International Foundation for Telemetering, 2019-10)
      The Consultative Committee for Space Data System (CCSDS) defines a standard for the data compression algorithm applied to the image data from payload instruments. In the CCSDS image data compression (CCSDS-IDC) standard, an image is encoded using a three-level two-dimensional DiscreteWavelet Transform (DWT) and the Bit-Plane Encoder (BPE). Compared to the JPEG2000 standard, the compression performance is reported to be similar at high bit rates with much lower complexity. However, its lack of highly scalable features supported by JPEG2000 hinders smooth browsing of the high-resolution satellite images. In this work, a method of quickly accessing a region of interest in a high-resolution satellite image is introduced. It utilizes parallel processing and the structure of the space packets which contain the strip-based codestream. This method is particularly effective for remote satellite image browsing and the study demonstrates its performance using KOMPSAT (Korea Multi-Purpose Satellite)-3A images.
    • INTERFERENCE MITIGATION OF ADJACENT RADIO FREQUENCY SIGNALS ON A FLEXIBLE SOFTWARE-DEFINED RADIO TESTBED PLATFORM

      Gonzalez, Virgilio; Elahi, Mirza M.; Sandoval, Jose C.; Corral, Pabel; Yasuda, Susumu; Univ Texas, Computational Science Program; Univ Texas, Dept Electrical and Computer Engineering; White Sands Missile Range, U.S. Army Test and Evaluation Command (International Foundation for Telemetering, 2019-10)
      The radio frequency (RF) spectrum is crowded with users and adjacent frequency users are facing an increase in interference from each other. The spectrum governing body Federal Communications Commission (FCC) has the difficult task of allocating spectral bands for new users for mobile devices using 4G LTE technology. Telemetry (TM) is affected by the adjacent band 4G LTE users in terms of signal degradation. To minimize the interference between adjacent frequency users, several methods can be used. A common but inefficient method separates adjacent band frequencies using guard bands which leaves a big portion of the spectrum unused. Alternatively, adjacent RF signals can be separated using digital filtering techniques with the signal of interest being unharmed and reducing the signal power of the interfering signal. A digital filtering technique includes bandpass filter (BPF) rejection, which has the ability to filter out adjacent interfering signals. This is accomplished by designing bandpass digital filters where the passband and stopband frequencies are adjusted to achieve maximum signal power and reject the interfering signal by reducing its power. A flexible software-defined radio testbed is set up to experiment and analyze this scenario with ease and effective measures.
    • THREE-DIMENSIONAL MOTION ESTIMATION AND IMAGE FORMATION WITH ACTIVE ARRAYS

      Lee, Hua; Radzicki, Vincent R.; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      For target imaging and tracking systems, a key signal processing task is motion estimation. Specifically, the trajectory of a maneuvering target undergoing rigid body motion can be described through a series of translational and rotational transformations. Estimation of these motion parameters provides the tracking system enough information to calculate the targets trajectory over time. Determining the rotational motion to a high accuracy is also very important, as the imaging system can then form an image of the target over multiple aspect angles and thus increase the resolution performance. This paper focuses on algorithm development and performance limitations for motion estimation and image formation using active sensing arrays.
    • AN IMPROVED LOG-DOMAIN BELIEF PROPAGATION ALGORITHM OVER GRAPHS WITH SHORT CYCLES

      Raveendran, Nithin; Srinivasa, Shayan G.; Vasic, Bane; Univ Arizona, Dept Electrical and Computer Engineering; Indian Institute of Science, Dept Electronic Systems Engineering (International Foundation for Telemetering, 2019-10)
      We present a modified belief propagation (BP) algorithm for decoding low density parity check codes having graphs with short cycles. The modified algorithm in log domain is superior in terms of numerical stability, precision, computational complexity and ease of implementation when compared to the algorithm in the probability domain. Simulation results show improvement in decoding performance for the modified BP compared to the original algorithm. The modified approach is also generalized for graphs with isolated cycles of arbitrary length by considering the statistical dependency among messages passed in such cycles.
    • A NOVEL FFT-BASED TECHNIQUE FOR RAPID ACQUISITION OF HIGH DYNAMIC DSSS SIGNAL

      Ming, Wang; Taotao, Liang; Guoning, Ma; Yudong, He; Institute of Electronic Engineering, China Academy of Engineering Physics (International Foundation for Telemetering, 2019-10)
      High dynamic direct sequence spread spectrum (DSSS) signal acquisition process is a two-dimensional signal replication process no matter what acquisition methods are used. In this paper, acquisition methods in dynamic surroundings are researched. The analysis tells that, serial acquisition methods cannot meet the requirement of flight application, which requires correct signal capturing possibility of weak signal and less acquisition time. A new improved acquisition approach using partial correlator and Fast Fourier Transform (FFT) is introduced. The method can search Doppler and calculate C/A code phases in parallel. Matlab simulation indicate that, the FFT-based algorithm can work well in high dynamic DSSS receiver.
    • DESIGN OF PROBING WAVEFORMS IN SOFTWARE-DEFINED SENSING AND IMAGING SYSTEMS

      Lee, Hua; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      The probing waveforms play a crucial role in the performance of software-defined sensing-imaging systems. The characteristics of the probing waveforms govern both the computation complexity and accuracy of the estimation. This paper describes the concepts of the design and utilization of the probing waveforms for sensing and imaging applications.
    • Neuro-OSVETA: A Robust Watermarking of 3D Meshes

      Vasic, Bata; Raveendran, Nithin; Vasic, Bane; Univ Arizona, Dept Electrical and Computer Engineering; Univ Nis, Electronic Dept (International Foundation for Telemetering, 2019-10)
      Best and practical watermarking schemes for copyright protection of 3D meshes are required to be blind and robust to attacks and errors. In this paper, we present the latest developments in 3D blind watermarking with a special emphasis on our Ordered Statistics Vertex Extraction and Tracing Algorithm (OSVETA) algorithm and its improvements. OSVETA is based on a combination of quantization index modulation (QIM) and error correction coding using novel ways for judicial selection of mesh vertices which are stable under mesh simplification, and the technique we propose in this paper offers a systematic method for vertex selection based on neural networks replacing a heuristic approach in the OSVETA. The Neuro-OSVETA enables a more precise mesh geometry estimation and better curvature and topological feature estimation. These enhancements result in a more accurate identification of stable vertices resulting in significant reduction of deletion probability.
    • REINFORCEMENT LEARNING FOR HYBRID BEAMFORMING IN MILLIMETER WAVE SYSTEMS

      Peken, Ture; Tandon, Ravi; Bose, Tamal; Univ Arizona, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      The use of millimeter waves (mmWave) for next-generation cellular systems is promising due to the large bandwidth available in this band. Beamforming will likely be divided into RF and baseband domains, which is called hybrid beamforming. Precoders can be designed by using a predefined codebook or by choosing beamforming vectors arbitrarily in hybrid beamforming. The computational complexity of finding optimal precoders grows exponentially with the number of RF chains. In this paper, we develop a Q-learning (a form of reinforcement learning) based algorithm to find the precoders jointly. We analyze the complexity of the algorithm as a function of the number of iterations used in the training phase. We compare the spectral efficiency achieved with unconstrained precoding, exhaustive search, and another state-of-art algorithm. Results show that our algorithm provides better spectral efficiency than the state-of-art algorithm and has performance close to that of exhaustive search.
    • THE EFFECTS OF LOSSY FREQUENCY-DOMAIN EEG COMPRESSION ON CROSS-FREQUENCY COUPLING ANALYSIS

      Creusere, Charles D.; Phillips, Andrew J.; New Mexico State University, Klipsch School of Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      This paper analyzes lossy frequency-domain compression in the context of cross-frequency coupling (CFC) analysis of electroencephalograph (EEG) signals. The approach used here for CFC analysis involves a low-complexity signal analysis block followed by a constant false alarm rate (CFAR) detection algorithm. The lossy frequency-domain compression is achieved via the threshold coding method for frequency truncation using the discrete cosine transform (DCT). This method is found to increase CFC detection rates by as much as 30% to 50% depending on the amount of Gaussian noise in the signal and the selected probability of false alarm. Further analysis indicates that these significant improvements in CFC detection rates are due to adaptive frequency-domain noise reduction. These results bode well for lossy frequency-based EEG compression schemes which can greatly improve transmission speeds and decrease storage space requirements while simultaneously enhancing CFC analysis capabilities.
    • USING TENA AND JMETC FOR TELEMETRY APPLICATIONS

      Hudgins, Gene; Secondine, Juana; TENA Software Development Activity (SDA) (International Foundation for Telemetering, 2019-10)
      Often, TM requires operators on location with receive system(s) or at a remote console (with a remote antenna control unit), resulting in TDY for operators and possibly a shortage of operators to support all scheduled operations. A remote-control capability could eliminate existing personnel requirements at both the local system antenna site as well as the control facility, greatly reducing operational costs. TENA provides for real-time system interoperability, as well as interfacing existing range assets, C4ISR systems, and simulations; fostering reuse of range assets and future software systems. JMETC is a distributed, LVC capability using a hybrid network solution for all classifications and cyber. TENA and JMETC allow for the most efficient use of current and future TM range resources via range resource integration, critical to validate system performance in a highly cost-effective manner.
    • JOINT LTE UPLINK INTERFERENCE AND MULTIPATH SUPPRESSION FOR AERONAUTICAL TELEMETRY USING MMSE INTERFERENCE CANCELER

      Shoudha, Shamman Noor; Saquib, Mohammad; Univ Texas, Dept Electrical Engineering (International Foundation for Telemetering, 2019-10)
      This paper addresses the use of a minimum-mean-square-error (MMSE) interference canceler for mitigating the Long-Term Evolution (LTE) uplink interference and multipath in Aeronautical Telemetry system. SOQPSK-TG modulation scheme for the telemetry victim signal and 64-QAM for the LTE interference signal are considered. For a multipath channel derived from the channel sounding data, the interference canceler achieves the target bit error rate (BER) of 10-5 at Carrier-to-Interference (C/I) ratio - 12.7, - 40.7 and – 36 dB for data rates 1, 5 and 10 Mbits/s, respectively. To offer the same performance, an MMSE channel equalizer requires C/I ratio - 10.9, - 25.0 and - 5.0 dB.
    • LDPC CODING FOR FREQUENCY DIVERSITY IN MULTI-CHANNEL AIR-TO-GROUND TELEMETRY

      Deshmukh, Mrugen A.; Wilson, Stephen G.; Univ Virginia, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      We consider the application of LDPC codes for improving performance in multi-channel (spectrum aggregation) for air-to-ground telemetry, by virtue of frequency diversity available on a wideband frequency-selective multipath channel. Our particular interest is in use of multi-channel OFDM transmission on “white spots” in the microwave spectrum. Each such channel is subject to frequency-selective fading over its bandwidth (typically a few MHz) due to multipath, for which typical OFDM equalization is standard. However, some subcarriers within this OFDM channel may experience deep fading at the output of the equalizer, rendering the symbol error probability poor relative to that on an AWGN channel at the same average SNR. We study simulated performance on a multipath channel described by the ETU fading model. Specific performance reported includes error rate of LDPC coding constrained to a single channel (effective diversity order roughly 2) and error rate of coding across eight channels (diversity order roughly 5). Further, performance on this dispersive fading channel is only about 3 dB worse than that on a no-multipath channel, at block error probability 0:01.
    • CLASSIFICATION STYLE REGRESSION FOR SPECTRAL OPENING PMF ESTIMATION

      Fosdick, Garrett; Marefat, Michael; Bose, Tamal; Univ Arizona, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      Dynamic spectrum allocation (DSA) permits unlicensed users to access spectrum owned by a licensed user given they do so without interference to the primary user. To avoid interference with other users, the unlicensed user needs to be aware of channel availability. Spectrum sensing allows a radio to find spectrum holes, but costs energy and time. Predictive methods can be used to decrease the amount of spectrum sensing needed to find an available channel. We designed a novel neural network architecture for spectrum hole prediction. This neural network is capable of creating probability mass functions (PMF) estimates of the length of channel openings with no assumptions of the initial probability distribution or prior knowledge about the traffic. This architecture is shown to work through a mathematical proof, and its performance is measured through simulation.
    • CHANNEL AND SPECTRUM ESTIMATION FOR SOFTWARE DEFINED RADIO

      Lee, Hua; Sanchez, Connor D.; Radzicki, Vincent R.; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      Software defined radios are rapidly increasing in both research and commercial usage for many different applications. As the number of deployed systems increase, a difficult problem that remains is efficient usage of the Radio-Frequency (RF) spectrum to be shared among all these devices. Two key tasks for the radio to perform here include spectral estimation of the RF environment and channel estimation of the communication channel for which the data will be transmitted. These two steps are linked as the communication channel can change over different portions of the RF-spectrum. In this work, an algorithmic approach is presented for passive and active channel estimation procedures for wideband software-defined radios. The algorithm is comprised of first channel quality estimation followed by communication channel planning to optimize the overall performance.
    • Hybridization of wireless technologies for the aerospace instrumentation

      Percie du Sert, François-Gabriel; Zodiac Data Systems (International Foundation for Telemetering, 2019-10)
      Whatever the flight test or space launch vehicle, instrumentation presents strong intrusiveness due to cabling. The industry is resolutely looking for a transition toward wireless architectures for elimination of cabling while not compromising data integrity and network performances. The ideal wireless solution is a single technology that could encompass all the needs. But there is a wide variety of use cases and associated requirements: data throughput, synchronization accuracy, power consumption, robustness of the link, frequency regulation constraints. Today, no technology is able to cover all these needs. However, multiple technologies show specific characteristics that are optimized for some particular use cases. Hybridization of multiple wireless technologies in a complex system is the right solution to address specific applications with the optimal wireless instrumentation solution and no concession on performance.
    • RESILIENT PNT / TSPI ALTERNATIVE SOLUTIONS FOR TELEMETRY DURING GNSS OUTAGE TEST SCENARIOS

      Fischer, John; Perdue, Lisa; Orolia (International Foundation for Telemetering, 2019-10)
      GNSS is key to effective situational awareness, providing critical Positioning, Navigation and Timing (PNT) telemetry data for mobile military operations. Yet GPS/GNSS jamming and spoofing attacks are on the rise. The combination of low-cost hardware, open source software, and tutorials on YouTube have fostered the proliferation of these malicious acts. Beyond intentional disruption, other factors such as environmental conditions and conflicts with other electronic systems can result in unreliable or even unavailable GNSS data. The disruption of GNSS for increasing periods of time through jamming/spoofing must now be an essential test component in most test scenarios today. How can one still provide reliable Time-Space Position Information (TSPI) during periods of GNSS denial? Key mobile military operations that rely on continuous and trusted PNT telemetry data from GNSS include: SatCom on the Move (SOTM), Command, Control, Communications, Computer, Intelligence, Surveillance and Reconnaissance (C4ISR), Airborne Communications Relay, Synthetic Aperture Radar, and Combat Search and Rescue (CSAR). Techniques and technologies used in battlefield systems to provide alternative sources of PNT data during a GNSS outage, can also be used on the test range. This paper will identify technologies, best practices and strategies for GNSS jamming/spoofing detection and protection systems and testing protocols to maintain a state of PNT readiness.
    • Testing the Reliability and Flexibility of Digitizers adapting the RF/IF signals over IP applications using a testbed Platform.

      Gonzalez, Virgilio; Sandoval, Jose Carlos; Elahi, Mirza; Corral, Pabel; Yasuda, Susumu; Univ Texas, Dept Electrical and Computer Engineering; White Sands Missile Range, U.S. Army Test and Evaluation Command (International Foundation for Telemetering, 2019-10)
      Many disadvantages from physical limitations in RF Telemetry can now be eliminated using RF over IP Networks. Digitizers mitigate the problem of signal degradation that RF has due to physical restrictions and provide reliability and flexibility to the signal. The digitizers are also able to preserve both frequency and timing characteristics, and then accurately reconstructing the original Telemetry signals to enable processing, recording or retransmission at another location. The digitizers along with the software-defined radios forms a flexible testbed platform which enables us to simulate both communication systems to qualify and quantify their behavior, while studying the interference between systems. In addition, quantization of noise is a critical parameter to determine the bit error rate in the testbed. Digitizers can be configured at a certain bandwidth and additional gain, in order to make this layer almost a transparent transmission.
    • AN APPROACH FOR BER DETERMINATION USING LOGGED AERONAUTICAL TELEMETRY DATA

      Tamakuwala, Jimmy B.; Sonar, Souvik; Jena, Avijit; Integrated Test Range, DRDO Chandipur; Defense Research and Development Organization (International Foundation for Telemetering, 2019-10)
      BER is regarded as the link-performance metric in a digital communication system. It is a function of Eb/N0 and is dependent on the modulation scheme used. This relation is often used in prediction of ground telemetry systems performance for a mission configuration. However, there is no objective way of comparing the post flight results, as BER measurement in a flight test is not practically feasible for want of transmitting sufficient reference bit patterns. In this paper, an indirect way of computing BER and, in turn, link Eb/N0 is proposed for a PCM/FM link based on the frame synchronised data logged by the ground telemetry equipment. Using known quantities like bit rate and frame rate, a quantity defined as frame loss rate is computed. Applying the relations between frame loss probability, frame sync pattern and SFID information in the PCM format, an approach for bit error probability is demonstrated based on field data. By using a sliding window over a fixed length of data, BER for the entire flight duration can be determined as a function of flight time with the step size of the length of data window.
    • CO-EXISTENCE OF AERONAUTICAL MOBILE TELEMETRY AND LTE SYSTEMS IN THE S-BAND

      Shoudha, Shamman Noor; Saquib, Mohammad; Univ Texas, Dept Electrical Engineering (International Foundation for Telemetering, 2019-10)
      This paper analyzes the effect of Long-Term Evolution (LTE) uplink interference on the performance of Aeronautical Telemetry S-band users. A MATLAB simulation environment is used to analyze the interference effect using SOQPSK-TG and 64-QAM modulation schemes for telemetry and LTE transmitters, respectively. An ideal Surface Acoustic Wave (SAW) filter followed by a 2-by-2 symbol detector is used in the telemetry receiver. To ensure a target bit error rate (BER) of 10-5, depending on the LTE spectrum mask, the Carrier-to-Interference (C/I) ratio requirement is -15.4, -32.4 and -30 dB for data rates 1; 5 and 10 Mbits/s, respectively.
    • CSI Estimation Using Artificial Neural Network

      Gajjar, Viraj; Kosbar, Kurt; Missouri University of Science and Technology (International Foundation for Telemetering, 2019-10)
      We propose using machine learning to estimate channel state information (CSI) for MIMO communication links. The goal is to use information such as atmospheric conditions, amount of path loss, and Doppler shift to improve the accuracy of CSI estimates. We start by designing an algorithm which estimates the CSI based on previously mentioned factors. Using this algorithm, we simulate a dataset of CSI over varying atmospheric conditions, receiver position, and receiver velocity. We then use this dataset to train an artificial neural network, which is able to estimate the CSI by using the current atmospheric condition, receiver position, and velocity.