Browsing by Subject "Detectors"
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Item Gambit: An autonomous chess-playing robotic system(IEEE, 2011-08-15) Matuszek, Cynthia; Mayton, Brian; Aimi, RobertoThis paper presents Gambit, a custom, mid-cost 6-DoF robot manipulator system that can play physical board games against human opponents in non-idealized environments. Historically, unconstrained robotic manipulation in board games has often proven to be more challenging than the underlying game reasoning, making it an ideal testbed for small-scale manipulation. The Gambit system includes a low-cost Kinect-style visual sensor, a custom manipulator, and state-of-the-art learning algorithms for automatic detection and recognition of the board and objects on it. As a use-case, we describe playing chess quickly and accurately with arbitrary, uninstrumented boards and pieces, demonstrating that Gambit's engineering and design represent a new state-of-the-art in fast, robust tabletop manipulation.Item Interweave Cognitive Radio for 4G Long Term Evolution and 5G New Radio Self-Reliant Networks(2022-01-01) Stevens, Brian Wayne; Younis, Mohamed F; Computer Science and Electrical Engineering; Engineering, ComputerExisting cellular networks have untapped radio frequency resources, also known as white space, available for cognitive radio applications. A secondary network can opportunistically interweave communication within the white space of an existing cellular signal by leveraging cognitive radio. This thesis presents a novel methodology for forming a cognitive interwoven self-reliant secondary network with no additional physical infrastructure, collaboration from the existing primary network, or software or hardware changes in the primary network. The methodology is tested first with 4G and later with 5G cellular technological standards. For the physical layer, this thesis optimizes synchronization as the initial step in aligning to a cellular signal in time, frequency, and sector identity. We improve synchronization through sensitivity, execution time, and applies a threshold to form a "cell detector” instead of the traditional "cell search,” which only considers the most detectable signal. After synchronization, resource detectors monitor the available spectral resources of the entire cellular infrastructure. Modern cellular networks have grown in complexity and become an ecosystem that includes the host technologies, such as 4G Long Term Evolution (LTE) and 5G New Radio (NR), along with subsystems such as narrowband internet of things (NB-IoT), category M1 (Cat-M1/LTE-M), observed time difference of arrival (OTDOA), and support for 4G/5G coexistence using dynamic spectrum sharing (DSS). Such an increased complexity has driven the need for network monitoring to enable load tracking, congestion control, spectral efficiency analysis, intrusion detection, and cognitive radio communications. This thesis develops resource monitoring that can passively monitor the entire cellular ecosystem, including reservations configured with high-layer messages that are only accessible to in-network, active, and sometimes user-specific equipment. Resource monitoring provides white-space reservations for cognitive communications. We define interference control to prevent interference with the primary network through physical layer access schemes and power control cluster protocols to access resources safely. With the added complexity of 5G as a host technology, our research leverages geospatial beamforming of known signals as spatially dependent white space. In this case, the known synchronization signal burst must be detected with a "beam detector” instead of a "beam search” to properly use beam resources that are not close to cognitive radio nodes. The thesis applies the self-reliant methodology, which defines opportunistic access and power control protocols that limit interference between cellular networks in both the time and frequency domains with additional support in the geospatial domain for 5G NR. Our research determines that an adapted version of Slotted ALOHA for medium access control (MAC) with a no-back-off contention fits the self-reliant approach of our work and timing constraints found in 4G LTE and 5G NR networks.Item Non-Invasive Imaging of Object Behind Scattering Media via Cross-Spectrum(IEEE, 2022-05-10) Zhao, Xingchen; Peng, Tao; Zhang, Lida; Zubairy, M. Suhail; Shih, Yanhua; Scully, Marlan O.We develop a method based on the cross-spectrum of an intensity-modulated CW laser, which can extract a signal from an extremely noisy environment and image objects hidden in scattering media. We theoretically analyzed our scheme and performed the experiment by scanning the object placed in between two ground glass diffusers. The image of the object is retrieved by collecting the amplitudes at the modulation frequency of all the cross-spectra. Our method is non-invasive, easy-to-implement, and can work for both static and dynamic media.