摘要:
A method and apparatus for collecting subframes of navigation data of satellites are disclosed. In the method of the present invention, the subframe is divided into several sub-units, each sub-units includes one or more words. When a receiver receives a subframe with a subframe ID, the respective required sub-units of the subframe are checked. A dummy sub-unit is not necessary to be considered. Valid ones of the required sub-units are collected. If not all the required sub-units of the subframe have been collected, the absent sub-units are to be collected when the next subframe with the same subframe ID is received. Some protection schemes can be applied to raise the reliability of such sub-unit collection. Especially when the signal is weak or unstable, the present invention may significantly improve the TTFF (Time To First Fix) performance of the receiver.
摘要:
A method and apparatus for collecting subframes of navigation data of satellites are disclosed. In the method of the present invention, the subframe is divided into several sub-units, each sub-units includes one or more words. When a receiver receives a subframe with a subframe ID, the respective required sub-units of the subframe are checked. A dummy sub-unit is not necessary to be considered. Valid ones of the required sub-units are collected. If not all the required sub-units of the subframe have been collected, the absent sub-units are to be collected when the next subframe with the same subframe ID is received. Some protection schemes can be applied to raise the reliability of such sub-unit collection. Especially when the signal is weak or unstable, the present invention may significantly improve the TTFF (Time To First Fix) performance of the receiver.
摘要:
A method and apparatus for collecting subframes of navigation data of satellites are disclosed. In the method of the present invention, the subframe is divided into several sub-units, each sub-units includes one or more words. When a receiver receives a subframe with a subframe ID, the respective required sub-units of the subframe are checked. A dummy sub-unit is not necessary to be considered. Valid ones of the required sub-units are collected. If not all the required sub-units of the subframe have been collected, the absent sub-units are to be collected when the next subframe with the same subframe ID is received. Some protection schemes can be applied to raise the reliability of such sub-unit collection. Especially when the signal is weak or unstable, the present invention may significantly improve the TTFF (Time To First Fix) performance of the receiver.
摘要:
A method of direct RF digitization for multiple RF signal bands such GNSS or wireless communication signal bands and a receiver using the method. By using the method, an optimal sampling frequency to be used in direct RF digitization for signals of multiple RF signal bands can be easily obtained. According to the present invention, one or more of the RF signal bands are selected to be shifted to target band(s). By doing so, the optimal sampling frequency can be easily calculated. Then the obtained sampling frequency is used in executing the direct RF digitization.
摘要:
A jamming detector and jamming detecting method are disclosed. In accordance with the present invention, distribution of a received signal is compared with a reference distribution of a specific signal model. Deviation of the signal distribution from the reference distribution can be obtained according to the comparison results. The existence of jamming is determined according to the deviation. If the signal distribution significantly deviates from the reference distribution, it means that jamming exists. An anti-jamming circuit or algorithm can be activated only when jamming is detected, thereby power consumption is reduced.
摘要:
A method of direct RF digitization for multiple RF signal bands such GNSS or wireless communication signal bands and a receiver using the method. By using the method, an optimal sampling frequency to be used in direct RF digitization for signals of multiple RF signal bands can be easily obtained. According to the present invention, one or more of the RF signal bands are selected to be shifted to target band(s). By doing so, the optimal sampling frequency can be easily calculated. Then the obtained sampling frequency is used in executing the direct RF digitization.
摘要:
A jamming detector and jamming detecting method are disclosed. In accordance with the present invention, distribution of a received signal is compared with a reference distribution of a specific signal model. Deviation of the signal distribution from the reference distribution can be obtained according to the comparison results. The existence of jamming is determined according to the deviation. If the signal distribution significantly deviates from the reference distribution, it means that jamming exists. An anti-jamming circuit or algorithm can be activated only when jamming is detected, thereby power consumption is reduced.
摘要:
A GNSS satellite signal handling method is disclosed. For a specific Doppler bin, when a peak is found, it is checked if the specific Doppler bin is polluted with interference by detection. If the detection result indicates that the specific Doppler bin is polluted with interference, a threshold, which is used to determine whether the actual signal peak is found or not, is then raised to a higher level, so as to increase the searching reliability. To detect interference, it is determined whether the specific Doppler bin is polluted by comparing a statistical value of correlation results of a plurality of code chip hypotheses with a reference or by checking if there are plural peaks existing in the power spectrum.