Automatic vehicle identification system, interrogator and responder included in the same
First Claim
1. A mobile unit identifying system comprising:
- (a) an interrogator having;
spread spectrum signal generation means for generating a spread spectrum coding signal using a predetermined pseudo noise signal; and
a transmitting antenna for transmitting said spread spectrum coding signal; and
(b) a responder having;
storing means for storing data;
modulation means for modulating radio signals including said transmitted spread spectrum coding signal with said data; and
sending means for sending the modulated radio signals to said interrogator, said interrogator further comprising;
a receiving antenna for receiving said sent radio signals; and
mixing means for mixing said received radio signals with said spread spectrum signal to detect said data.
1 Assignment
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Accused Products
Abstract
A mobile unit identifying system comprises: an interrogator having: a spread spectrum signal generation circuit for generating a spread spectrum coding signal using a predetermined pseudo noise signal; and a transmitting antenna for transmitting the spread spectrum coding signal; and a responder having: a memory for storing data; and a modulation unit for modulating radio signals including the transmitted spread spectrum coding signal with the data, the interrogator further comprising: a receiving antenna for receiving the modulated radio signals; and a mixer for mixing the received radio signals with the spread spectrum signal to detect the data. The responder has one or two antennas for receiving or reflecting the spread spectrum coding signal with modulation using a predetermined data. Phase adjusting circuits may be provided in both interrogator and responder to distinguished from reflected waves from reflective objects other than the responder. The responding signal from the responder is distinguished from the reflected waves from the reflective objects through a polarizing transmitting or receiving technique.
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Citations
17 Claims
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1. A mobile unit identifying system comprising:
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(a) an interrogator having; spread spectrum signal generation means for generating a spread spectrum coding signal using a predetermined pseudo noise signal; and a transmitting antenna for transmitting said spread spectrum coding signal; and (b) a responder having; storing means for storing data; modulation means for modulating radio signals including said transmitted spread spectrum coding signal with said data; and sending means for sending the modulated radio signals to said interrogator, said interrogator further comprising; a receiving antenna for receiving said sent radio signals; and mixing means for mixing said received radio signals with said spread spectrum signal to detect said data. - View Dependent Claims (2, 3, 4, 5, 6, 11, 14)
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7. A mobile unit identifying system comprising:
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(a) an interrogator having; spread spectrum signal generation means for generating a spread spectrum coding signal using a predetermined pseudo noise signal; carrier signal generation means for generating a carrier signal; first mixing means for mixing said spread spectrum coding signal with said carrier signal to produce an interrogating signal; and a transmitting antenna for transmitting said interrogating signal; and (b) a responder having; storing means for storing data; modulation means for modulating radio signals including said transmitted spread spectrum coding signal with said data; and sending means for sending said modulated radio signals, said interrogator further comprising; a receiving antenna for receiving said sent radio signals; second mixing means for mixing said received radio signals with said carrier signal; and third mixing means for mixing an output signal of said second mixing means with said spread spectrum signal to detect said data. - View Dependent Claims (15)
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8. A mobile unit identifying system comprising:
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(a) an interrogator having; spread spectrum signal generation means for generating a spread spectrum coding signal using a predetermined pseudo noise signal; a first antenna for transmitting said spread spectrum coding signal; and (b) an responder having; a second antenna for receiving radio signals including said transmitted spread spectrum coding signal; storing means for storing data; modulating means for modulating said received radio signals including said transmitted spread spectrum coding signal with said data; a third antenna for sending said radio signals to said interrogator with modulating in accordance with said modulated radio signals, said interrogator further comprising; a fourth antenna for receiving said sent radio signals; and mixing means for mixing said sent and received radio signals with said spread spectrum signal to detect said data. - View Dependent Claims (9, 10, 16)
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12. An interrogating apparatus for identifying a responder existing in a service area of said interrogating apparatus, comprising:
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(a) spread spectrum signal generation means for generating a spread spectrum coding signal using a predetermined pseudo noise signal; (b) a transmitting antenna for transmitting said spread spectrum coding signal; (c) a receiving antenna for receiving said modulated radio signals which may includes a responding signal made by modulating said transmitted spread spectrum coding signal with data by said responder; and (d) mixing means for mixing said received radio signals including said responding signal to detect said data.
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13. A mobile unit identifying system comprising:
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a responder and an interrogator for identifying said responder existing in a service area of said interrogator, said interrogator comprising; spread spectrum signal generation means for generating a spread spectrum coding signal using a predetermined pseudo noise signal; a transmitting antenna for transmitting said spread spectrum coding signal; a receiving antenna for receiving said modulated radio signals which may include a responding signal made by modulating said transmitted spread spectrum coding signal with data by said responder; and mixing means for mixing said received radio signals including said responding signal to detect said data, said responder comprising; storing means for storing data; modulation means for modulating radio signals including said transmitted spread spectrum coding signal with said data; and sending means for sending said modulated radio signals. - View Dependent Claims (17)
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Specification