Abstract:
Acquiring a satellite signal, by, receiving a CDMA-modulated signal; generating a plurality of CDMA-type test signals comprising a reference test signal having a first chip duration, and a plurality of test signals delayed/anticipated of a corresponding time offset from the respective test reference signal, less than the chip duration; calculating correlations between the CDMA-modulated signal and the plurality of test signals for obtaining a plurality of correlation results; selecting, based on the correlation results, acquisition parameters associated to a candidate satellite signal; acquiring or rejecting the acquisition parameters selected based on the correlation results.
Abstract:
An embodiment method comprises receiving a satellite signal in a tracking channel, generating a set of replicas of a pseudo random noise sequence, comprising a punctual replica and a plurality of replicas that are different in time with respect to the punctual replica over a given time spacing, correlating the received signal with each replica to obtain amplitude correlation values, monitoring the tracking channel to detect a spoofed signal by generating a further plurality of replicas of the pseudo random noise sequence having a respective time spacing greater than the given time spacing, correlating the received signal of the tracking channel with each further replica to obtain further amplitude correlation values, calculating a shape anomaly factor based on the further correlation amplitude values, verifying the shape anomaly factor is greater than a given shape anomaly threshold, and signaling detection of a spoofed signal on the tracking channel.
Abstract:
A method of acquiring a satellite signal includes providing a CDMA-modulated signal, defining a first search frequency interval and a first reception sensitivity, and performing a first acquisition of the modulated signal according to the first sensitivity and the first frequency interval in order to provide an acquisition or failed acquisition result. In case of a failed acquisition, performing a second acquisition of the modulated signal as a function of a second search frequency interval, narrower than the first frequency interval, and a second reception sensitivity, greater than the first sensitivity and depending on a power of a side lobe of the modulated signal.
Abstract:
A satellite tracking channel has a frequency loop tracking a carrier frequency of a satellite signal. A first indication of a spoofed signals is generated based on a determined satellite signal noise floor value associated with the satellite tracking channel and a tracking channel signal noise threshold associated with the satellite tracking channel. A second indication of a spoofed signal is generated based on a determining satellite tracking phase noise associated with the satellite tracking channel and a tracking channel phase noise threshold associated with the satellite tracking channel. Reception of a spoofed signal on the satellite tracking channel is detected based on the generated first indication of a spoofed signal and the generated second indication of the spoofed signal.
Abstract:
Acquiring a satellite signal, by, receiving a CDMA-modulated signal; generating a plurality of CDMA-type test signals comprising a reference test signal having a first chip duration, and a plurality of test signals delayed/anticipated of a corresponding time offset from the respective test reference signal, less than the chip duration; calculating correlations between the CDMA-modulated signal and the plurality of test signals for obtaining a plurality of correlation results; selecting, based on the correlation results, acquisition parameters associated to a candidate satellite signal; acquiring or rejecting the acquisition parameters selected based on the correlation results.
Abstract:
An embodiment method comprises receiving a satellite signal in a tracking channel, generating a set of replicas of a pseudo random noise sequence, comprising a punctual replica and a plurality of replicas that are different in time with respect to the punctual replica over a given time spacing, correlating the received signal with each replica to obtain amplitude correlation values, monitoring the tracking channel to detect a spoofed signal by generating a further plurality of replicas of the pseudo random noise sequence having a respective time spacing greater than the given time spacing, correlating the received signal of the tracking channel with each further replica to obtain further amplitude correlation values, calculating a shape anomaly factor based on the further correlation amplitude values, verifying the shape anomaly factor is greater than a given shape anomaly threshold, and signaling detection of a spoofed signal on the tracking channel.
Abstract:
A method of acquiring a satellite signal includes providing a CDMA-modulated signal, defining a first search frequency interval and a first reception sensitivity, and performing a first acquisition of the modulated signal according to the first sensitivity and the first frequency interval in order to provide an acquisition or failed acquisition result. In case of a failed acquisition, performing a second acquisition of the modulated signal as a function of a second search frequency interval, narrower than the first frequency interval, and a second reception sensitivity, greater than the first sensitivity and depending on a power of a side lobe of the modulated signal.