Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"waveform design"”.
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Resilient Waveform Design for OFDM-MIMO Communication Systems
… 3) developing antijam (AJ) MIMO systems, and 4) designing null space projected overlapped-MIMO radar waveform for spectrum sharing between radar and communications system. First, we consider OFDM systems under various jamming attacks. Previous research is focused on jamming OFDM data …
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Waveform design and processing techniques in OFDM radar
… investigated OFDM radar, which uses OFDM waveforms instead of the classic linear frequency mod- ulated waveforms. Being a wideband signal, the OFDM symbol offers spectral efficiency along with improved range resolution, two enticing characteristics for radar. Historically a communication …
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MIMO radar: signal processing, waveform design, and applications to synthetic aperture imaging
This dissertation analyzes the capability of multiple-input, multiple-output (MIMO) radar techniques to improve the image quality and area-coverage rate of synthetic aperture imaging systems. A signal processing architecture for MIMO radar is used to understand the applicability of MIMO for …
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Practical Considerations for Radar Embedded Communication
… examining some of the practical aspects of the waveform design. Communication waveform mismatches between the tag and receiver due to multipath distortion, sampling rate differences and using different lengths for the radar waveform are explored for each of the three previously developed design …
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New methods of partial transmit sequence for reducing the high peak-to-average-power ratio with low complexity in the ofdm and f-ofdm systems
… most important components for the multicarrier waveform design in the wireless communication standards. Consequently, the OFDM system has been adopted by many high-speed wireless standards. However, the high peak-to-average- power ratio (PAPR) is the main obstacle of the OFDM system in the real …
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Combined Space-Time Diversity and Interference Cancellation for MIMO Wireless Systems
… evaluate the corresponding channel capacity, and design and analyze a simple orthogonal transmit waveform for MIMO channels in mobile radio environments. We also evaluate the system performance of various interference cancellation techniques when employing multiple-receive antenna in …
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Design of Software Defined Radio for SuperDARN Radar
… This study investigated the benefits and design of a high frequency (HF) SDR receiver for the next generation of Super Dual Auroral Network (SuperDARN) radars. This work analyzed digital beamforming and waveform design approaches that would be enabled by the adoption of a SDR based radar …
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Novel Electrochemical Methods for Human Neurochemistry
… expository experiments tested assumptions about waveform design to detect dopamine concentrations by reducing amplitude and duration of forcing functions, as well as distinguishing norepinephrine concentrations. Next, large data sets collected on mixtures of dopamine, serotonin and pH validated a …
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A Practical Approach to Rapid Prototyping of SCA Waveforms
… need for a rapid prototyping approach to radio design. In the past, radios have traditionally been designed to have a static implementation with the express goal of implementing a specific type of communication, such as 802.11b, CDMA voice communication, or just a simple FM tuner. However, when …
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New method of polar channel coding for reducing the bit error rate with low complexity in the F-OFDM underwater acoustic communications
… software simulation, where F-OFDM refers to the waveform design candidate in the new technology. The efficiency of the proposed method is verified by comparing the results with the existing channel coding in the literature using MATLAB software simulation. The results obtained using the proposed …
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Adaptive OFDM Radar for Target Detection and Tracking
… and provides spectral efficiency. We first design the spectrum of the OFDM signal to improve the radar's wideband ambiguity function. Our designed waveform enhances the range resolution and motivates us to use adaptive OFDM waveform in specific problems, such as the detection and tracking of …
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Advanced signal processing solutions for ATR and spectrum sharing in distributed radar systems
… confirmthe validity of the algorithm.Finally, a waveform design framework for joint radar-communication systems is presented. The waveform is composed by quasi-orthogonal chirpsub-carriers generated through the Fractional Fourier Transform (FrFT),with the aim of preserving the radar performance …
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Magnetic resonance spectroscopic imaging using parallel transmission at 7T
… are corrected for using RF pulses designed for new RF excitation hardware at 7T, so-called parallel transmission (pTx). The B1 homogeneity of the pTx excitations improved at least by a factor of 4 (measured by the normalized spatial standard deviations) compared to conventional …
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Cognitive Radar Detection in Nonstationary Environments and Target Tracking
… achieve better performance, cognitive radars are designed to sense, learn from, and adapt to environments. In this dissertation, we introduce cognitive radars for target detection in nonstationary environments and cognitive radar networks for target tracking.For target detection, many algorithms …
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High Resolution Continuous Active Sonar
<p>This dissertation presents waveform design and signal processing methods for continuous active sonar (CAS). The work presented focuses on methods for achieving high range, Doppler, and angular resolution, while maintaining a high signal-to-interference plus noise ratio (SINR).</p><p>CAS systems …
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Design and Optimization of Physical Waveform-Diverse and Spatially-Diverse Radar Emissions
With the advancement of arbitrary waveform generation techniques, new radar transmission modes can be designed via precise control of the waveform's time-domain signal structure. The finer degree of emission control for a waveform (or multiple waveforms via a digital array) presents an opportunity …
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Designing a Localized Lower Body Negative Pressure Garment for Long-Duration Spaceflight
… (S.K.I.N.), a flexible, wearable structure designed to support the application of localized LBNP. The goal was to evaluate whether targeted negative pressure applied through the S.K.I.N. could replicate the fluid shift effects of a traditional LBNP chamber while improving comfort, mobility, …
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Spectrum Sharing between Radar and Communication Systems
… two- and three-dimensional channel models are designed that capture azimuth and elevation angles of communication systems and helps in placing accurate nulls. In addition, interference coming from communication systems into radar receivers is analyzed and radar performance is accessed. Using …
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Unitary Space-Time Waveform Scheduling for High-Resolution Delay-Doppler MIMO Radar Sensing
… we deal with radar systems where multiple radar waveforms are simultaneously transmitted from different antennas. The goal is to process the returns in a way that the overall ambiguity function is a sum of individual ambiguity functions, such that the sum better approximates the ideal thumbtack …
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