Abstract: Systems and methods are provided for a correlator system. The system includes a plurality of numerically controlled oscillators and a multiplier configured to receive an input stream representing a received signal. A carrier multiplexer is configured to select between respective outputs of at least two of the plurality of numerically controlled oscillators and provide the selected output to the multiplier. A code generator is configured to provide a replica code. A delay component is configured to provide a delayed code from the replica code. A code multiplexer is configured to selectively provide each of the delayed code and the replica code to the multiplier.

Abstract: A navigation system includes a correlation engine configured to despread a received signal. The correlation engine includes a correlator configured to evaluate the received signal against a replica signal to produce a correlation result, and a packet encoder configured to produce a packet comprising a destination address, a source address, and the correlation result. An input/output interface is configured to provide the packet to another component in the navigation system.

Abstract: One embodiment of the invention includes a radio frequency (RF) receiver system. The system includes an antenna configured to receive an RF input signal and an RF signal front-end system configured to process the RF input signal to generate an equivalent digital signal. The system also includes a spoof detection system configured to analyze a power spectral density (PSD) of the equivalent digital signal and to compare the PSD of the equivalent digital signal with a predetermined baseline PSD to detect the presence of a spoofing signal component in the RF input signal.

Abstract: One embodiment includes an adaptive sample quantization system. The adaptive sample quantization system includes an antenna to receive a radio frequency (RF) signal having data encoded therein, and analog antenna electronics configured to convert the RF signal to an analog electrical signal. The system also includes an analog-to-digital converter (ADC) directly coupled to the antenna and configured to generate a plurality of consecutive digital samples of the RF signal. The system further includes a quantizer to determine a mode based on the plurality of consecutive digital samples and to select at least one threshold based on the determined mode. The quantizer can further compare each digital sample with the at least one threshold to generate a corresponding one of a plurality of output samples having a reduced number of bits relative to the respective digital sample to substantially mitigate potential interference and facilitate extraction of the data.

Abstract: One embodiment of the invention includes a radio frequency (RF) receiver system. The system includes an antenna configured to receive an RF input signal and an RF signal front-end system configured to process the RF input signal to generate an equivalent digital signal. The system also includes a spoof detection system configured to analyze a power spectral density (PSD) of the equivalent digital signal and to compare the PSD of the equivalent digital signal with a predetermined baseline PSD to detect the presence of a spoofing signal component in the RF input signal.

Abstract: Systems and methods are provided for a correlator system. The system includes a plurality of numerically controlled oscillators and a multiplier configured to receive an input stream representing a received signal. A carrier multiplexer is configured to select between respective outputs of at least two of the plurality of numerically controlled oscillators and provide the selected output to the multiplier. A code generator is configured to provide a replica code. A delay component is configured to provide a delayed code from the replica code. A code multiplexer is configured to selectively provide each of the delayed code and the replica code to the multiplier.

Abstract: One embodiment includes an adaptive sample quantization system. The adaptive sample quantization system includes an antenna to receive a radio frequency (RF) signal having data encoded therein, and analog antenna electronics configured to convert the RF signal to an analog electrical signal. The system also includes an analog-to-digital converter (ADC) directly coupled to the antenna and configured to generate a plurality of consecutive digital samples of the RF signal. The system further includes a quantizer to determine a mode based on the plurality of consecutive digital samples and to select at least one threshold based on the determined mode. The quantizer can further compare each digital sample with the at least one threshold to generate a corresponding one of a plurality of output samples having a reduced number of bits relative to the respective digital sample to substantially mitigate potential interference and facilitate extraction of the data.

Abstract: A navigation system includes a correlation engine configured to despread a received signal. The correlation engine includes a correlator configured to evaluate the received signal against a replica signal to produce a correlation result, and a packet encoder configured to produce a packet comprising a destination address, a source address, and the correlation result. An input/output interface is configured to provide the packet to another component in the navigation system.

Abstract: A receiver for continuous carrier phase tracking of low carrier-to-noise ratio (“CNR”) signals from a plurality of radio navigation satellites while the receiver is mobile. The receiver may have: a radio frequency (RF) front-end that provides satellite data corresponding to signals received from the plurality of radio navigation satellites; an inertial measurement unit (IMU) that provides inertial data; and a processor circuit in circuit communication with the RF front end and the IMU, the processor circuit being capable of using satellite data from the RF front-end and inertial data from the IMU to perform continuous carrier phase tracking of low CNR radio navigation satellite signals having a CNR of about 20 dB-Hz, while the receiver is mobile. The receiver may be a GPS receiver for continuous carrier phase tracking of low-CNR GPS signals.

Abstract: A receiver for continuous carrier phase tracking of low carrier-to-noise ratio (“CNR”) signals from a plurality of radio navigation satellites while the receiver is mobile. The receiver may have: a radio frequency (RF) front-end that provides satellite data corresponding to signals received from the plurality of radio navigation satellites; an inertial measurement unit (IMU) that provides inertial data; and a processor circuit in circuit communication with the RF front end and the IMU, the processor circuit being capable of using satellite data from the RF front-end and inertial data from the IMU to perform continuous carrier phase tracking of low CNR radio navigation satellite signals having a CNR of about 20 dB-Hz, while the receiver is mobile. The receiver may be a GPS receiver for continuous carrier phase tracking of low-CNR GPS signals.