Robust, efficient, localization system
First Claim
1. An apparatus for locating a standard, mobile-communications, radio transmitter in a cellularized communications system, comprising:
- at least first and second sensor stations, each sensor station having an antenna and associated signal conditioning means for receiving a signal from the mobile radio transmitter and a timing mechanism to time-tag an identified, representative instant of the received signal to produce time-tagged received signal data;
at least first and second signal characterization processing units at the first and second sensor stations, respectively, each signal characterization processing unit generating replicated signal data, at least first and second signal correlation processing units at the first and second sensor stations, respectively, each correlation processing unit performing matched-replica correlation processing with the time-tagged received signal data and the replicated signal data to produce location-related signal parameters;
a communications system for communicating the location-related signal parameters from the sensor stations to a central site;
means for estimating the position of the mobile transmitter from the location-related signal parameters; and
an output for indicating the estimated position of the mobile transmitter.
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Accused Products
Abstract
Replica correlation processing, and associated representative signal-data reduction and reconstruction techniques, are used to detect signals of interest and obtain robust measures of received-signal parameters, such as time differences of signal arrival and directional angles of arrival, that can be used to estimate the location of a cellularized-communications signal source. The new use in the present invention of signal-correlation processing for locating communications transmitters. This enables accurate and efficient extraction of parameters for a particular signal even in a frequency band that contains multiple received transmissions, such as occurs with code-division-multiple-access (CDMA) communications. Correlation processing as disclosed herein further enables extended processing integration times to facilitate the effective detection of desired communications-signal effects and replication measurement of their location-related parameters, even for the communications signals modulated to convey voice conversations or those weakened through propagation effects. Using prior, constructed, signal replicas in the correlation processing enables elimination of the inter-site communications of the signal representations that support the correlation analyses. Reduced-data representations of the modulated signals for voiced conversation, or for the variable components of data communications, are used to significantly reduce the inter-site communications that support the correlation analyses.
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Citations
19 Claims
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1. An apparatus for locating a standard, mobile-communications, radio transmitter in a cellularized communications system, comprising:
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at least first and second sensor stations, each sensor station having an antenna and associated signal conditioning means for receiving a signal from the mobile radio transmitter and a timing mechanism to time-tag an identified, representative instant of the received signal to produce time-tagged received signal data;
at least first and second signal characterization processing units at the first and second sensor stations, respectively, each signal characterization processing unit generating replicated signal data, at least first and second signal correlation processing units at the first and second sensor stations, respectively, each correlation processing unit performing matched-replica correlation processing with the time-tagged received signal data and the replicated signal data to produce location-related signal parameters;
a communications system for communicating the location-related signal parameters from the sensor stations to a central site;
means for estimating the position of the mobile transmitter from the location-related signal parameters; and
an output for indicating the estimated position of the mobile transmitter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 17)
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11. An apparatus for measuring an angle-of-arrival of a signal from a mobile radio transmitter, comprising:
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a local phased-array antenna and associated signal conditioning means for receiving a signal from the mobile radio transmitter;
a signal characterization processing unit for generating replicated signal data; and
a signal correlation processing unit at the sensor station for performing matched-replica correlation processing with the received signal data and the replicated signal data to produce an angle of arrival of the received signal. - View Dependent Claims (12, 13, 14, 15, 16)
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18. A method of locating a standard, mobile-communications, radio transmitter in a cellularized communications system, comprising:
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receiving a signal from the mobile radio transmitter at at least first and second sensor stations;
time-tagging an identified, representative instant of the received signal to produce time-tagged received signal data;
generating replicated signal data at the first and second sensor stations, performing matched-replica correlation processing with the time-tagged received signal data and the replicated signal data to produce location-related signal parameters;
communicating the location-related signal parameters from the sensor stations to a central site;
estimating the position of the mobile transmitter from the location-related signal parameters obtained at the central site; and
indicating the estimated position of the mobile transmitter.
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19. A method of measuring an angle-of-arrival of a signal from a mobile radio transmitter, comprising:
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receiving a signal from the mobile radio transmitter at a local phased-array antenna;
generating replicated signal data; and
performing matched-replica correlation processing with the received signal data and the replicated signal data to produce an angle of arrival of the signal from the mobile radio transmitter at the local phased-array antenna.
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Specification