Abstract: Systems and methods may provide location-based security using multipoint cryptography. The method may include receiving, by a controller, an original message for secure delivery to a mobile terminal. The method may also include generating, by the controller, a plurality of messages to be delivered to the mobile terminal using geographic diversity. The method may further include sending, by the controller, the plurality of messages to geographically diverse transmitters for transmission to the mobile terminal.

Abstract: A system for pandemic and connection tracking is provided. The system includes a memory and one or more processors in communication with the memory, and a data collector executing on the one or more processors. The data collector is configured to collect anonymous tracking data from a wireless sensor network. The wireless sensor network is configured to communicate with users' devices using a wireless connection. The system further includes a data validator/augmentor executing on the one or more processors. The data validator/augmentor is configured to validate the collected anonymous tracking data. The system also includes a virus spread tracker executing on the one or more processors. The virus spread tracker is configured to: estimate an exposure time between each pair of users based on the collected anonymous tracking data; and determine a probability of at least one of the users being infected based on the estimated exposure time.

Abstract: Systems, methods, apparatuses, and computer program products for backscatter RFID communication security. In some example embodiments, a system may include a RFID reader, and a passive RFID tag. A desired direction channel H?R between the RFID reader and the passive RFID tag is H?R=[ej2? cos ?R ej? cos ?R e?j? cos ?R e?j2? cos ?R]. In certain example embodiments, a system includes a first RFID reader, a second RFID reader, and a passive RFID tag. The first RFID reader is aware of the location of the second RFID reader and the location of the passive RFID tag. The second RFID reader is aware of the location of the first RFID reader and the location of the passive RFID tag. The first RFID reader and the second RFID reader are aware of each others generated reader signals.

Abstract: The method for generating a secret key for encrypted wireless communications is a physical layer technique that exploits channel randomness between two nodes, the channel being characterized by reciprocity between the two nodes. Reference signals exchanged by the two nodes are used to faun a channel estimate, including gain location and phase location. The gain and phase locations are compared to threshold values, and locations exceeding the respective thresholds are stored in vectors. The moving differences between gain and phase locations at adjacent sampling times define secondary random processes. The moving difference values are quantized and converted to bit streams, which are concatenated to generate the secret key. Measures are provided to reduce parity errors, thereby reducing the bit mismatch rate (BMR).

Abstract: The non-coherent ultra-wideband receiver receives an ultra-wideband (UWB) signal, consisting of pulses (or “symbols”) and uses on-off keying (OOK) modulation so that when a binary “0” is transmitted, the receiver collects noise-only samples. The receiver collects samples during the symbol (pulse) duration and sorts the samples by magnitude of voltage or energy. The receiver uses the known transmission rate and the estimated signal-to-noise ratio to retrieve a sample index from a look-up table. The receiver then compares the signal sample at the index value with a predetermined threshold voltage (or energy). If the selected sample exceeds the threshold, then it is assumed that all succeeding samples also exceed the threshold (assuming the sort is in ascending magnitude) and the pulse is present and binary “1”. Otherwise, the pulse is absent in the sampling period, and binary “0”. The process is repeated for the signal duration.

Abstract: The method and apparatus for angle of arrival estimation are used for estimating the angle of arrival of a received signal by a switched beam antenna array and a single receiver. The switched beam antenna array first collects an omnidirectional signal to be used as a reference signal. A main beam thereof is then switched to scan an angular region of interest. The collected signals from the switched beams are cross-correlated with the reference signal. The cross-correlation coefficient is the highest at the true angle of arrival and relatively negligible otherwise. The collected signal from each beam angle is cross-correlated with the omnidirectional reference signal to determine the angle of arrival of the received signal.

Abstract: Method and system for transmitting a directionally modulated data stream via an antenna array. A first signal processing circuitry receives a data symbol of a first data stream, maps the first data stream to a specified number of sub-beams based on a stream beam-width assignment, assigns a direction angle for transmission of the data stream, and transmits in parallel, for each of the specified number of sub-beams, an instance of the data symbol to a second signal processing circuitry. The second signal processing circuitry generates antenna array element weights based on the data symbol and a matrix having a DFT structure. The matrix is independent of the assigned direction angle. The data symbol is transmitted via the antenna array utilizing the antenna array element weights. The DFT is implemented as a fast Fourier transform. White noise is transmitted in the sub-beams beams outside the beam-width requirement of the data stream.

Abstract: Method and system for transmitting a directionally modulated data stream via an antenna array. A first signal processing circuitry receives a data symbol of a first data stream, maps the first data stream to a specified number of sub-beams based on a stream beam-width assignment, assigns a direction angle for transmission of the data stream, and transmits in parallel, for each of the specified number of sub-beams, an instance of the data symbol to a second signal processing circuitry. The second signal processing circuitry generates antenna array element weights based on the data symbol and a matrix having a DFT structure. The matrix is independent of the assigned direction angle. The data symbol is transmitted via the antenna array utilizing the antenna array element weights. The DFT is implemented as a fast Fourier transform. White noise is transmitted in the sub-beams beams outside the beam-width requirement of the data stream.

Abstract: The method for generating a secret key for encrypted wireless communications is a physical layer technique that exploits channel randomness between two nodes, the channel being characterized by reciprocity between the two nodes. Reference signals exchanged by the two nodes are used to faun a channel estimate, including gain location and phase location. The gain and phase locations are compared to threshold values, and locations exceeding the respective thresholds are stored in vectors. The moving differences between gain and phase locations at adjacent sampling times define secondary random processes. The moving difference values are quantized and converted to bit streams, which are concatenated to generate the secret key. Measures are provided to reduce parity errors, thereby reducing the bit mismatch rate (BMR).

Abstract: The method and apparatus for angle of arrival estimation are used for estimating the angle of arrival of a received signal by a switched beam antenna array and a single receiver. The switched beam antenna array first collects an omnidirectional signal to be used as a reference signal. A main beam thereof is then switched to scan an angular region of interest. The collected signals from the switched beams are cross-correlated with the reference signal. The cross-correlation coefficient is the highest at the true angle of arrival and relatively negligible otherwise. The collected signal from each beam angle is cross-correlated with the omnidirectional reference signal to determine the angle of arrival of the received signal.