Vehicular radar wayside transponder system
First Claim
1. A radar system comprising the combination of:
- a. a vehicle borne radar system for transmitting radar signals and receiving the transmitted radar signals reflected back to the radar system by a target, during a first selected portion of each of a sucession of time interval frames; and
b. a transponder for communicating with the vehicle borne radar system by transmitting signals to be received by the vehicle borne radar system during a second selected portion a time interval frame, the second portion of the time interval frame being different from the first selected portion within each of the succession of time interval frames.
2 Assignments
0 Petitions
Accused Products
Abstract
Doppler control circuit for a CW or pulse Doppler radar system for monitoring not only the phase shift between echo signals from several targets but also the amplitude difference between the several targets and to further provide a phase lock loop which tunes the radar to a particular target among one or more targets from which echo signals return. The control circuit can be used in state of the art CW or pulse Doppler type radar systems. In a further system, a continuously generated radar signal is repeatedly transmitted at three different frequencies in time division fashion to define a succession of transmit and receive frames. The receive frames are divided into a plurality of time interval windows with selected windows being used to detect received signals at the different frequencies. The remaining windows can be used for subsystems of the radar system. The rate of phase shift of received signals at a center frequency is used to determine closing rate, while the phase shift difference between received signals at the other two frequencies is used to determine range. A subsystem of the vehicular radar system is provided, in which communications between the vehicle radar system and a wayside transponder take place within one of the remaining windows of the receive frames. The wayside transponders transmit multi-bit words to the vehicle to provide the vehicle with update information and to warn of possible hazards in particular locations.
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Citations
14 Claims
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1. A radar system comprising the combination of:
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a. a vehicle borne radar system for transmitting radar signals and receiving the transmitted radar signals reflected back to the radar system by a target, during a first selected portion of each of a sucession of time interval frames; and b. a transponder for communicating with the vehicle borne radar system by transmitting signals to be received by the vehicle borne radar system during a second selected portion a time interval frame, the second portion of the time interval frame being different from the first selected portion within each of the succession of time interval frames. - View Dependent Claims (2, 3, 4)
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5. A radar system comprising the combination of:
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a) a vehicle borne radar system capable of transmitting radar signals during a selected time interval window within at least one of a succession of time interval frames and capable of receiving radar signals during the selected time interval window within the succession of time interval frames; and b) a wayside transponder for mounting in a fixed location along a roadway and capable of receiving radar signals from the vehicle borne radar system during the selected time interval window within a succession of time interval frames and capable of transmitting radar signals to the vehicle borne radar system during the selected time interval windows of the succession of time interval frames. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A radar system comprising the combination of:
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a) a vehicle borne radar system having a transmitter capable of transmitting communications signals during a first assigned one of a plurality of windows within each of a plurality of time interval frames to a transponder, and for transmitting radar signals during a second assigned one of the plurality of windows including a receiver for receiving radar signals during the second assigned one of the plurality of windows with each of the plurality of time interval frames and for receiving communications signals during the first assigned one of the plurality of windows within each of the plurality of time interval frames; b) a transponder including; I) a transmitter for transmitting radar signals to the vehicle borne radar system during the first assigned one of the plurality of windows within each of the plurality of time interval frames; and ii) a receiver for receiving and processing radar signals transmitted by the vehicle borne radar system. - View Dependent Claims (12, 13, 14)
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Specification