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Mobile communication system

  • US 5,875,183 A
  • Filed: 12/26/1996
  • Issued: 02/23/1999
  • Est. Priority Date: 01/10/1996
  • Status: Expired due to Term
First Claim
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1. A mobile communication system for providing radio communication channels for information transmission between a mobile station mounted on a vehicle traveling on a road and a fixed communication network installed on a roadside,wherein said fixed communication network includes a base station comprising a first transmitting and receiving device for carrying out radio communications with said mobile station by transmitting and receiving a data packet,wherein said mobile station comprises a second transmitting and receiving device for carrying out radio communications with said first transmitting and receiving device by transmitting and receiving a data packet,wherein each of said first and second transmitting and receiving devices comprises:

  • a transceiver for carrying out radio communications with its party;

    two or more receiving antennas separated apart by a predetermined distance;

    a direction finder for determining, in response to a radio signal caught by each of said receiving antennas, an incident angle of the radio signal on said receiving antennas; and

    a controller for controlling transmitting and receiving of a data packet to and from said party,wherein said controller measures a distance between said first and second transmitting and receiving devices in response to a transmitting time of said data packet and a received time of said radio signal from said party, and a direction with respect to said party in response to said incident angle detected by said direction finder,wherein said transceiver of each of said first and second transmitting and receiving devices comprises;

    a packet assembler for assembling data packet to which a synchronizing code is added;

    transmitting means for modulating an output of said packet assembler and radiating a modulated signal as radio waves;

    a timer for measuring a time period from transmitting said data packet to receiving a data packet transmitted from said party;

    a first synchronization detector for detecting said synchronizing code from said output of said packet assembler to start said timer;

    receiving means for demodulating said data packet from an output from said receiving antenna;

    a second synchronization detector for detecting said synchronizing code from an output of said receiving means to stop said timer; and

    a packet disassembler for extracting said data packet from the output of said receiving means, andwherein said controller calculates the distance to said party in accordance with a difference between a transmitting time of a signal carrying said data packet and a received time of a response signal from said party to said data packet measured by said timer.

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