| 摘要 |
<p>An improved communication apparatus for communicating between a first object and a second object wherein the first object includes apparatus for generating and transmitting a transmit signal and the second object includes apparatus for receiving the transmit signal and providing an emitted signal in response thereto, the emitted signal having a frequency coherently related to the frequency of the received transmit signal. The second object also includes an apparatus for encoding an identifying code having a unique code format wherein the beginning and the end of the code format are identifiable, the first object including apparatus for receiving the encoded emitted signal, identifying the code format encoded therein and determining the received emitted signal represents a valid code format. In one aspect, the first object apparatus receives encoded emitted signals via two receivers, identifies the code format encoded in the first-received and the second-received encoded emitted signals, determines that each received signal has a valid code format encoded therein and compares the code formats encoded in the first-received and the second-received emitted signal to determine the signals were emitted via the same second object. In one operational embodiment, the communication apparatus transmits a transmit signal and receives encoded emitted signals from a moving second object in response to the received transmit signal at a first position and a second position of the second object, the first and the second received encoded emitted signals being determined to represent a valid predetermined code format and it being determined that the received code formats are identical, the speed and direction of the moving object being determined in response to such valid determinations, the code format encoded in the received emitted signals being compared with predetermined identification code formats for locating predetermined second objects. The first object apparatus also generates and transmits a modulation signal, the second object apparatus including apparatus for detecting the modulation signal via a pulse width detector and providing an output indication in response thereto. In one particular operational embodiment, the first object apparatus is utilized to detect and monitor vehicle traffic, each vehicle (second object) having apparatus for receiving the transmit signal and providing the encoded emitted signal in response thereto, and for receiving the modulation signal and providing a driver-perceivable output indication in response thereto.</p> |
