ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Wireless communication systems may use training signals for the receiver to learn the fading coefficients of the channel. Obtaining channel state information (CSI) at the receiver is often times necessary for the receiver to correctly detect and demodulate transmitted symbols. The type of training signal, the length of time to spend training, and the frequency of training are all important parameters in these types of systems. In this work, we derive an analytic expression for calculating the optimal training parameters for continuously fading channels. We also provide simulation results showing why this training scheme is considered optimal.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Many high-performance, reconfigurable data functions can now be integrated into a single PCI circuit board, making possible low-cost and complex systems using PCs or UNIX workstations. FPGA and PCI technologies are an excellent match to telemetry applications where commercial off-the-shelf solutions are desired, but customization is common and performance critical. A Multifunction Telemetry I/O (MFT) module was designed to exploit these technologies for both flight test and space telemetry ground systems. The reconfigurability of the module has facilitated evolutionary hardware enhancements as well as custom applications. These enhancements have been used both as building blocks for system integrators and for commercial-off-the-shelf (COTS) graphic setup, processing, archiving, and display software. The MFT module includes a standard set of telemetry functions: up to two bit synchronizers, an IRIG time decoder, and two independent telemetry serial input and output channels. The MFT module is also available on a 6U VME board. This paper describes some of the proven capabilities and applications of this module.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / This paper describes the design of an inexpensive and scalable transmitter for a Multiple-Input Multiple-Output (MIMO) communication system. The transmitter is intended to be used in aerospace applications, especially in spin stabilized vehicles. A field programmable gate array (FPGA) in the modulator will implement a modified Alamouti space time block code which will take advantage of the cyclostationary nature of the channel to increase the system data rate.

Multiple-Input Multiple-Output (MIMO) communication uses multiple transmit and receive antennas to improve the throughput in wireless channels. In cellular networks, self-interference greatly degrades MIMO's potential gain, especially in multiuser MIMO systems where multiple users in each cell share the spatial channel in order to maximize the total throughput. In a multiuser MIMO downlink, the two main causes of this self-interference are residual inter-user interference due to imperfect spatial separation between the users and other-cell interference due to cochannel transmissions in other cells. This dissertation develops adaptive transmission strategies to deal with both residual inter-user interference and other-cell interference in cellular MIMO networks. For the residual inter-user interference caused by imperfect channel state information at the transmitter, we explicitly characterize the impact of channel quantization and feedback delay. Achievable ergodic rates for both single-user and multiuser MIMO systems with different channel state information are derived. Adaptive switching between single-user and multiuser MIMO modes is proposed to improve the throughput, based on the accuracy of the available channel information. It is then extended to a multi-mode transmission strategy which adaptively adjusts the number of active users to control residual interference and provide additional array gain. To adaptively minimize the other-cell interference, two practical base station coordination strategies are proposed. The first is a cluster based coordination algorithm with different coordination strategies for cluster interior and cluster edge users. It performs full intra-cluster coordination for enhancing the sum throughput and limited inter-cluster coordination for reducing the interference for cluster edge users. A multi-cell linear precoder is designed to perform the coordination. The second is an adaptive intercell interference cancellation strategy, where multiple base stations jointly select transmission techniques based on user locations to maximize the sum throughput. Spatial interference cancellation is applied to suppress other-cell interference. Closed-form expressions are derived for the achievable throughput, and the proposed adaptive strategy is shown to provide significant average and edge throughput gain. The feedback design to assist the interference cancellation is also discussed. / text

This thesis examines the use of ripple correlation control as a maximum power point tracking algorithm with an interleaved SEPIC converter for use with a solar array. The suitability of existing topologies for use with photovoltaic applications and the tradeoffs involved are discussed. The advantages of interleaving in converters are examined and the benefits it provides to photovoltaic applications are discussed. An interleaved SEPIC converter operated in interleaved mode with a photovoltaic array is studied. The operation of ripple correlation control as a maximum power point tracking technique applied to the interleaved SEPIC converter is examined and simulations with results are presented. / text

This document explores the isolated multiple-input single ended primary inductor converter (IMISEPIC) and discusses its application. This thesis proposes the following control methods such as current feed-forward control, voltage feedback control and maximum power point control to analyze the IMISEPIC. Zero-ripple technique is also applied to IMISEPIC in order to increase the converter’s life-time. Design strategy and concerns about the IMISEPIC are also presented, and simulations and circuit experiments are conducted to verify the analysis. Finally, the discussion about control limitation is used for future design consideration. / text

Diagnostic tests are designed to detect and isolate faults in sequential systems. The problem is to evaluate the effectiveness of the design. For stuck faults a diagnostic model can be used. A fault simulation strategy is presented for generating this model. First, definitions, for identifying critical inputs are derived. A definition is a statement of the conditions to sensitize an input. Then a fault free simulation is used to generate a critical value array. A critical path is traced through the sensitized inputs marked in the array using a critical value array tracing algorithm that is developed. This algorithm traces a path back in time, as required for a sequential system, to identify detectable faults for the model.

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Multiple-input multiple-output (MIMO) radar has been receiving increasing attention in recent years due to the dramatic advantages offered by MIMO systems in communications. The amount of energy reflected from a common radar target varies considerably with the observation angle, and these scintillations may cause signal fading which severely degrades the performance of conventional radars. MIMO radar with widely spaced antennas is able to view several aspects of a target simultaneously, which realizes a spatial diversity gain to overcome the target scintillation problem, leading to significantly enhanced system performance. Building on the initial studies presented in the literature, MIMO radar is investigated in detail in this thesis. First of all, a finite scatterers model is proposed, based on which the target detection performance of a MIMO radar system with arbitrary array-target configurations is evaluated and analyzed. A MIMO radar involving a realistic target is also set up, whose simulation results corroborate the conclusions drawn based on theoretical target models, validating in a practical setting the improvements in detection performance brought in by the MIMO radar configuration. Next, a hybrid bistatic radar is introduced, which combines the phased-array and MIMO radar configurations to take advantage of both coherent processing gain and spatial diversity gain simultaneously. The target detection performance is first assessed, followed by the evaluation of the direction finding performance, i.e., performance of estimating angle of arrival as well as angel of departure. The presented theoretical expressions can be used to select the best architecture for a radar system, particularly when the total number of antennas is fixed. Finally, a novel two phase radar scheme involving signal retransmission is studied. It is based on the time-reversal (TR) detection and is investigated to improve the detection performance of a wideband MIMO radar or sonar system. Three detectors demanding various amounts of a priori information are developed, whose performance is evaluated and compared. Three schemes are proposed to design the retransmitted waveform with constraints on the transmitted signal power, further enhancing the detection performance with respect to the TR approach.

Approved for public release; distribution is unlimited / Many 3D training simulations employ static, and to some extent, simplistic natural phenomena representation that often leaves much to be desired. Taking advantage of the latest advancements in computer graphics hardware allows modeling dynamic natural phenomena such as clouds. Specifically, utilizing procedural techniques and high-level shading languages, it is possible to produce considerably more realistic simulations. This thesis designed and implemented a visual simulation component, which renders convincing clouds using procedural noise-based texture mapping techniques. Both traditional rendering and shader-enabled rendering supported by the OpenGL Shading Language are utilized. This component has been included in the Delta3d simulation engine and is used to create convincing clouds in outdoor simulations while the performance penalty imposed is considered acceptable. Custom tools have been developed for easy noise texture parameterization and cross-platform compatibility has been demonstrated. / Lieutenant, Hellenic Navy