Abstract: Low latency beamforming using phased antenna arrays is the key for practical deployment of envisioned millimeter wave (mmWave) Gbps mobile networks. This work aims towards reducing the overhead of the exhaustive sector-level sweep phase of the analog beamforming adopted in the IEEE 802.11ad standard. This system uses a reconfigurable antenna single RF chain in the sub-6 GHz new radio (NR) band to aid codebook-based beam selection in the mmWave band of the NR. The system exploits the congruence between the spatial propagation signatures of signals at both mmWave and sub-6 GHz frequencies to reduce the beam search space.

Abstract: The growing research interest in passive RFID (Radio Frequency Identification)-based devices and sensors in a diverse group of applications calls for flexibility in reader antenna performance. A low-cost, easy-to-fabricate, and pattern reconfigurable UHF (Ultra High Frequency) RFID reader antenna in the RFID ISM band (902-928 MHz in the US) may offer a 54 MHz bandwidth (890 944 MHz) and 8.9 dBi maximum gain. The reconfigurable antenna can radiate four electronically switchable radiation beams in the azimuth plane. The antenna may be LHCP (Left Hand Circularly Polarized) with axial ratio (AR) in the ranging from 0.45 dB to 7 dB in the RFID ISM band.

Abstract: A passive UHF (Ultra High Frequency, 902-928 MHz) RFID-based fabric (such as a diaper) moisture sensor is low-cost, user-friendly, reusable, washable, environment-friendly and comes with an extended on-body read range of 3.6 meters with baby diapers and 4.4 meters with adult diapers. The external reader unit is connected to the internet or a local network, and may automatically notify the parents or caregivers as soon as the presence of moisture is detected.

Abstract: A key-based interleaver for enhancement the security of wireless communication includes a physical layer communication channel key to provide security even when the software encryption key is compromised. A method of creating a secure communication link using a physical layer interleaving system includes implementing a key policy implementation that utilizes temporal dependency and interleaving bits using a flexible inter and intra-block data interleaver.

Abstract: Symmetric keys are generated by an algorithm that uses the randomness from the wireless PHY layer to extract the keys. When used with reconfigurable antennas, the algorithm yields longer keys. By using the randomness from the wireless PHY layer, the algorithm solves the issue of secure information leakage to the wireless channel during key establishment phase. The algorithm also omits transmitting anything secure during this phase and prevents any intruder from obtaining information related to the key. This approach can automatically secure the communications over open wireless networks (those without authentication or encryption) or closed wireless networks using other methods of authentication.

Abstract: On-chip wireless links offer improved network performance due to long distance communication, additional bandwidth, and broadcasting capabilities of antennas. A Through-Silicon Via (TSV)-based antenna design called TSV_A establishes multi-band wireless communication through the silicon substrate medium with only a 3 dB loss over a 30 mm on-chip distance. Simulation results show an improvement in network latency up to ˜13% (average improvement of ˜7%), energy-delay improvements of ˜34% on average, and an improvement in throughput up to ˜34% (average improvement).

Abstract: A physical layer based technique secures wireless communication between a transmitter and receiver. The technique involves obfuscating the preamble data of the baseband signal through unique keys that are generated at the transmitter and the receiver based on channel characteristics known only to them.

Abstract: Low latency beamforming using phased antenna arrays is the key for practical deployment of envisioned millimeter wave (mmWave) Gbps mobile networks. This work aims towards reducing the overhead of the exhaustive sector-level sweep phase of the analog beamforming adopted in the IEEE 802.11ad standard. This system uses a reconfigurable antenna single RF chain in the sub-6 GHz new radio (NR) band to aid codebook-based beam selection in the mmWave band of the NR. The system exploits the congruence between the spatial propagation signatures of signals at both mmWave and sub-6 GHz frequencies to reduce the beam search space.

Abstract: A reactive jamming software defined radio (SDR) apparatus to target Frequency Hopping Spread-Spectrum (FHSS) signals includes a peripheral module for SDR processing; a reactive jamming hardware IP core that implements time-sensitive operations on a field programmable gate array (FGPA); and a host computer that implements non-time-critical operations, such as jammer configuration, logging, and strategy composition.

Abstract: Symmetric keys are generated by an algorithm that uses the randomness from the wireless PHY layer to extract the keys. When used with reconfigurable antennas, the algorithm yields longer keys. By using the randomness from the wireless PITY layer, the algorithm solves the issue of secure information leakage to the wireless channel during key establishment phase. The algorithm also omits transmitting anything secure during this phase and prevents any intruder from obtaining information related to the key. This approach can automatically secure the communications over open wireless networks (those without authentication or encryption) or closed wireless networks using other methods of authentication.

Abstract: On-chip wireless links offer improved network performance due to long distance communication, additional bandwidth, and broadcasting capabilities of antennas. A Through-Silicon Via (TSV)-based antenna design called TSV_A establishes multi-band wireless communication through the silicon substrate medium with only a 3 dB loss over a 30 mm on-chip distance. Simulation results show an improvement in network latency up to ˜13% (average improvement of ˜7%), energy-delay improvements of ˜34% on average, and an improvement in throughput up to ˜34% (average improvement).

Abstract: A learning protocol for distributed antenna state selection in directional cognitive small-cell networks is described. Antenna state selection is formulated as a nonstationary multi-armed bandit problem and an effective solution is provided based on the adaptive pursuit method from reinforcement learning. A cognitive small cell testbed, called WARP-TDMAC, provides a useful software-defined radio package to explore the usefulness of compact, electronically reconfigurable antennas in dense small-cell configurations. A practical implementation of the adaptive pursuit method provides a robust distributed antenna state selection protocol for cognitive small-cell networks. Test results confirm that directionality provides significant advantages over omnidirectional transmission which suffers high throughput reduction and complete link outages at above-average jamming or cross-link interference power.

Abstract: Ultrasonic through metal communication systems are an effective solution for transmitting data across a metal barrier when the structural integrity of the barrier cannot be compromised by physically penetrating it. Substantial improvements in through metal communication systems have been made in recent years, enabling high speed communications of up to 15 Mbps, as well as power transmission up to 30 W across flat walls. A system is described that allows for ultrasonic through metal communication across the wall of a steel tube. Primary challenges of 1) transducer contact, 2) curvature effect on echoes, and 3) alignment are analyzed and addressed through the use of radial mode piezoelectric transducers, transducer “horns”, and Electromagnetic Acoustic Transducers (EMATs). The resulting system shows no significant loss due to changes in alignment, allows for the use of either piezoelectric transducers or EMATs externally, and achieves max data rates of approximately 600 kbps without echo equalization.

Abstract: Presenting a visualization of antenna radiation patterns may include sending a request to a server for up-to-date information regarding an antenna mode; receiving the request at the server and reading a register value for the antenna mode; responding, by the server, with updated antenna mode information; and overlaying antenna radiation patterns on an image based on the mode information.

Abstract: A physical layer based technique secures wireless communication between a transmitter and receiver. The technique involves obfuscating the preamble data of the baseband signal through unique keys that are generated at the transmitter and the receiver based on channel characteristics known only to them.

Abstract: A key-based interleaver for enhancement the security of wireless communication includes a physical layer communication channel key to provide security even when the software encryption key is compromised. A method of creating a secure communication link using a physical layer interleaving system includes implementing a key policy implementation that utilizes temporal dependency and interleaving bits using a flexible inter and intra-block data interleaver.

Abstract: A reactive jamming software defined radio (SDR) apparatus to target Frequency Hopping Spread-Spectrum (FHSS) signals includes a peripheral module for SDR processing; a reactive jamming hardware IP core that implements time-sensitive operations on a field programmable gate array (FGPA); and a host computer that implements non-time-critical operations, such as jammer configuration, logging, and strategy composition.

Abstract: Channel based authentication schemes for intrusion detection that operates at the physical layer are described that apply the capabilities of a pattern reconfigurable antenna for improved performance. Performance gains are achieved by the schemes as a function of the number of antenna modes. The first scheme relies on a channel based fingerprint for differentiating between transmitters whereas another scheme poses the intruder detection problem as a generalized likelihood ratio (GLR) test problem that operates on the channel realizations corresponding to different modes present in a reconfigurable antenna. The benefits of these two schemes over single element antennas are demonstrated. General guidelines are provided on how to choose the different elements of the decision metric in order to realize better performance for physical layer based authentication schemes based on any diversity scheme.

Abstract: Presenting a visualization of antenna radiation patterns may include sending a request to a server for up-to-date information regarding an antenna mode; receiving the request at the server and reading a register value for the antenna mode; responding, by the server, with updated antenna mode information; and overlaying antenna radiation patterns on an image based on the mode information.

Abstract: A planar reconfigurable antenna that is capable of generating omnidirectional and directional radiation patterns over a wide frequency band or over multiple frequency bands includes a substrate, one or more pairs of conductive elements on at least one side of the substrate, a common RF feed point, and respective switches that selectively connects one or all of the conductive elements to the common RF feed point. An omni-directional radiation pattern is generated when all of the conductive elements are connected to the common RF feed point, while a directional radiation pattern is generated when only a pair of conductive elements on opposite sides of the substrate are connected to the common RF feed point. In the directional radiation mode, the conductive elements that are not connected to the common RF feed point act as a reflector for other conductive elements that are connected to the common RF feed point.