摘要:
In a geo-security system, a device receives RF signals from multiple distinct classes of RF communication systems and extracts location-dependent signal parameters. A current geotag is computed from the parameters by fuzzy extractors involving quantization of the parameters and Reed-Solomon decoding to provide a reproducible unique geotag. The current geotag is compared with a stored geotag, and a geo-secured function of the device is executed based on the result of the comparison. The use of multiple signal sources of different types, combined with special fuzzy extractors provides a robust geotag that allows both lower false rejection rate and lower false acceptance rate.
摘要:
In a geo-security system, a device receives RF signals from multiple distinct classes of RF communication systems and extracts location-dependent signal parameters. A current geotag is computed from the parameters by fuzzy extractors involving quantization of the parameters and Reed-Solomon decoding to provide a reproducible unique geotag. The current geotag is compared with a stored geotag, and a geo-secured function of the device is executed based on the result of the comparison. The use of multiple signal sources of different types, combined with special fuzzy extractors provides a robust geotag that allows both lower false rejection rate and lower false acceptance rate.
摘要:
A data encryption and decryption system securely geoencrypts data using location-dependent navigation signals. To increase the entropy of the cryptographic key to guard against a brute-force attack, geoencryption is made to depend on largely time-independent characteristics of the navigation signals that are not easily spoofed, including the time difference of arrival, the envelope-to-cycle difference, the differential signal-to-noise, the signal envelope shape, and the directions of arrival of the navigation signal set.
摘要:
Location systems and methods are implemented using a variety of arrangements and methods. Using one such system location information is provided in response to a utility-line arrangement propagating signals that represent a wireless radio-frequency (RF) communication originating from one or more remote transmitters. The system includes a receiver circuit communicatively coupled and responsive to the utility-line arrangement. The system also includes a signal-processing logic circuit, communicatively coupled and responsive to the utility-line arrangement. The signal processing logic circuit is arranged to derive location information from characteristics of the signals that are indicative of a location of the receiver circuit relative to the remote transmitters.
摘要:
Location systems and methods are implemented using a variety of arrangements and methods. Using one such system location information is provided in response to a utility-line arrangement propagating signals that represent a wireless radio-frequency (RF) communication originating from one or more remote transmitters. The system includes a receiver circuit communicatively coupled and responsive to the utility-line arrangement. The system also includes a signal-processing logic circuit, communicatively coupled and responsive to the utility-line arrangement. The signal processing logic circuit is arranged to derive location information from characteristics of the signals that are indicative of a location of the receiver circuit relative to the remote transmitters.
摘要:
Aspects are applicable to secure encryption such as in the generation of a cryptographic key from location information as may be useful in portable/wireless communication devices. As an example, one embodiment is implemented as a method of generating cryptographic keys from location information derived from a signal received from a publicly-used wireless communication system. The location information is protected from fraudulently generated signals using direction of arrival of the received signal. The method attempts to verify that the direction of arrival corresponds to an expected direction of arrival for a received signal of the primary signal type, and in response to the direction of arrival being verified for the direction of arrival, and then enables use of an encryption key that is generated from positional information derived from the received signal
摘要:
Various systems, methods and devices are implemented for processing received signals. Consistent with one such embodiment, a method is implemented for use in a signal-communication receiver having a carrier-tracking loop and a processor for operating adaptive algorithms. The method involves interpreting a received signal using space time adaptive processing (STAP). A convergence speed of the adaptive algorithms is set based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop. A carrier-phase de-rotation constraint is implemented into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.
摘要:
Various systems, methods and devices are implemented for processing received signals. Consistent with one such embodiment, a method is implemented for use in a signal-communication receiver having a carrier-tracking loop and a processor for operating adaptive algorithms. The method involves interpreting a received signal using space time adaptive processing (STAP). A convergence speed of the adaptive algorithms is set based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop. A carrier-phase de-rotation constraint is implemented into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.
摘要:
A multipath mitigation method consists of locating a multipath-invariant (MPI) point of an ideal autocorrelation function and measuring the distance between the MPI point and DLL. The same MPI point is located in a received correlation function, and the distance between the point and the DLL, now affected by multipath, is measured. The difference between the ideal distance and the actual distance is the code tracking error resulting from multipath. The error is subtracted from the computed pseudorange or used to control the DLL. The method can be used to reduce the effects of all types of tracking error sources, such as signal transmission failure or code noise.
摘要:
A Loran-C communications technique and system are disclosed involving appropriate encoding of communication messages and logical multiplication and inversion of encoded signals prior to phase modulation of the Loran-C pulses, with novel bit-flip connections for producing complementary plus and minus modulation position shifts in the first and third and second and fourth, etc., of the Loran-C pulse groups, and with perfect balance irrespective of the nature of the raw data and irrespective of skywave interference.