No description available.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Shaped Offset Quadrature Phase Shift Keying (SOQPSK) has the advantages of low sidelobes and high detection probability; however, its main lobe has a fixed width set by the number of constellation points. By slightly modifying the modulation scheme, the four constellation points of quadrature shift keying can be changed to M constellation points where M is a power of 2. After this change, the power spectral density (PSD) retains low sidelobes, and the desirable property of being able to detect the signal by integrating over two symbol periods is retained.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / FQPSK is the abbreviation for Feher Quadrature Phase Shift Keying (FQPSK) patented systems [1]. Digcom, Inc. licensed FQPSK products demonstrated significant spectral saving and RF power efficient robust BER performance advantages. These bit rate agile modems and Non Linearly Amplified (NLA) transceivers, DSP and hardware implementations, and in some instances “software-radios” (20kb/s to more than 100Mb/s) and RF frequency agile (from 150MHz to more than 40GHz) developments and systems have recently been demonstrated and deployed. The spectral efficiency, i.e., data throughput capability of the 1st generation of FQPSK, as demonstrated in initial Advanced Range Telemetry (ARTM) flight tests, approximately doubles while 2nd generation “FQPSK-2” systems have the potential to quadruple the spectral efficiency of operational PCM/FM telemetry systems and be backward compatible with the 1st generation of FQPSK technologies. It is also demonstrated that the spectral efficiency advantage of FQPSK over that of NLA power efficient GMSK, OQPSK and QPSK modulated transceivers is in the 50% to 300% range and that the potential spectral efficiency advantage of FQPSK-2 over GMSK [1] is in the 200% to 500% range. Based on extensive multi-year studies of alternative solutions for spectral and RF power efficient, robust BER performance systems, several commercial US and international organizations, AIAA, CCSDS, NASA, ESA, CCSDS and various programs of the US Department of Defense (DoD) concluded that FQPSK offers the most spectrally efficient high performance-high speed proven technology solutions and recommended FQPSK standardization for several data links. Initial DoD-ARTM Program Office Air-to-Ground L-band and S-band jet airborne telemetry Test and Evaluation (T&E) data, obtained during the summer of 1998 are briefly highlighted. These include simultaneosly tested FQPSK and PCM/FM. In these tests the following ARTM objectives have been demonstrated: (a) FQPSK approximately doubles the spectral efficiency of currently operational PCM/FM; (b) The Data Link Performance of these two systems is comparable. The American Institute of Aeronautics and Astronautics (AIAA) draft modulation standard recommended to the DoD, NASA and CCSDS, was approved by the AIAA [23]. The AIAA standard recommends “that FQPSK modulation be immediately adopted as the interim increment–1 standard.”

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Presentation of Alcatel Espace last studies and developments regarding TT&C receiver Products for satellite. This document lays on 3 parts: · a technical point of view showing digital demodulation principles used (base band recovery, analytical head, PM or FM demodulation) and their related offered possibilities(digital controlling loop, lock status detection, jammer detection,....) · a technology/design description · a synthesis showing performance and results

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The Nova HYPERMOD demodulator operates in three modes, the classic pulse-code modulation/frequency modulation (PCM/FM), sometimes known as continuous phase frequency shift keying (CPFSK) mode, shaped offset quadrature phase shift keying (SOQPSK) mode, and continuous phase modulation (CPM) mode. Of interest to this paper is SOQPSK mode which is a waveform similar to the Advanced Range Telemetry (ARTM) Tier I waveform, Feher’s Quadrature Phase Shift Keying, B version (FQPSK-B) revision (Rev) A1. Also considered is another variant, FQPSK-JR. This paper will outline the cross compatibility and resynchronization speed of these waveforms based upon ARTM-adopted demodulator performance tests. The results of these laboratory tests comparing the HYPERMOD demodulator, the enhanced Tier I demodulator, and the current Tier I reference demodulator, both from RF Networks, will be presented.

Today, wireless sensor networks (WSNs) are no longer a nascent technology and future networks, especially Cyber-Physical Systems (CPS) will integrate more sensor-based systems into a variety of application scenarios. Typical application areas include medical, environmental, military, and commercial enterprises. Providing security to this diverse set of sensor-based applications is necessary for the healthy operations of the overall system because untrusted entities may target the proper functioning of applications and disturb the critical decision-making processes by injecting false information into the network. One way to address this issue is to employ en-route-filtering-based solutions utilizing keys generated by either static or dynamic key management schemes in the WSN literature. However, current schemes are complicated for resource-constrained sensors as they utilize many keys and more importantly as they transmit many keying messages in the network, which increases the energy consumption of WSNs that are already severely limited in the technical capabilities and resources (i.e., power, computational capacities, and memory) available to them. Nonetheless, further improvements without too much overhead are still possible by sharing a dynamically created cryptic credential. Building upon this idea, the purpose of this thesis is to introduce an efficient and secure communication framework for WSNs. Specifically, three protocols are suggested as contributions using virtual energies and local times onboard the sensors as dynamic cryptic credentials: (1) Virtual Energy-Based Encryption and Keying (VEBEK); (2) TIme-Based DynamiC Keying and En-Route Filtering (TICK); (3) Secure Source-Based Loose Time Synchronization (SOBAS) for WSNs.

No description available.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / 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.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Space-time Coding (STC) for Multiple-Input Multiple-Output (MIMO) wireless communication systems is an effective technique for providing robust wireless link performance in telemetry systems. This paper investigates the degradation in system performance when synchronization errors between the transmitter and receiver are present. Specifically, expressions that quantify the increase in symbol-error-rate as a function of symbol synchronization error are derived for a two-transmit and single receive antenna MISO system using binary frequency shift keying waveforms. These results are then extended to the MIMO case. The analytic results are verified with simulation results that show close agreement between the theoretical expressions and Monte Carlo simulation runs.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / We derive bounds on the performance of data-aided joint estimators for timing offset, carrier phase offset, and carrier frequency offset for use in an APSK packet-based communication link. It is shown that the Cramér-Rao Bound (CRB) is a function of the training sequence, the signal-to-noise ratio (SNR), and the pulse shape. We also compute APSK training sequences of different lengths that minimize the CRB for each of the parameters.