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    MULTIPLEXED ADDRESS CONTROL IN A TDM COMMUNICATION SYSTEM
    52.
    发明专利
    MULTIPLEXED ADDRESS CONTROL IN A TDM COMMUNICATION SYSTEM 未知

    公开(公告)号：CA1313278C

    公开(公告)日：1993-01-26

    申请号：CA587211

    申请日：1988-12-29

    Applicant: QUALCOMM INC

    Inventor： GILHOUSEN KLEIN S ,  ANTONIO FRANKLIN P ,  JACOBS IRWIN M

    IPC: H04B7/212 ,  H04J3/00 ,  H04J3/16 ,  H04J3/24 ,  H04Q7/06 ,  H04Q7/08 ,  H04Q7/12 ,  H04Q7/18 ,  H04Q7/38

    Abstract: MULTIPLEXED ADDRESS CONTROL IN A TDM COMMUNICATION SYSTEM A message communication system employing one or more centralized communication stations transmitting messages through Earth orbit relay satellites to mobile receivers utilizing Time Division Multiplexed (TDM) communication signals having signal time frames divided into a series of transmission channels. A predetermined number of the channels are designated as address channels with the remainder being used for data transfer. Information transmitted on the address channels is used by receivers to determine both the presence of a message and its corresponding data transmission channel. Each system receiver scans, and tracks only the communication signal address channels until a message addressed to that receiver is detected, at which time the selected receiver changes channels to the designated data channel for reception of the message. Thus, demodulation of the entire communication signal is not required and processing time and power is reduced for the typical waiting condition when messages are not being received. While a message is being received only a portion of the communication signal need be received, demodulated and decoded. The decoded message is then displayed on a display screen or similar device for the recipient. ¢2536MPA4.All!

    53.
    发明专利
    未知

    公开(公告)号：MX164485B

    公开(公告)日：1992-08-19

    申请号：MX2358490

    申请日：1990-12-04

    Applicant: QUALCOMM INC

    Inventor： AMES WILLIAM G ,  JACOBS IRWIN M ,  WEAVER LINDSAY A JR ,  GILHOUSEN KLEIN S

    IPC: G01S5/12 ,  G01S5/14 ,  G01S13/87 ,  G01S19/00 ,  G01S19/01 ,  G01S19/38 ,  G01S19/48 ,  H04B7/185 ,  G01S5/02

    Abstract: A method and system for determining the position of an object using a fixed station and a plurality of earth orbit satellites whose positions are known. Separate periodic signals are transmitted from the fixed station via first and second satellites to the object whose postion is to be determined. The phase offset in periodic characteristics of the periodic signals as received from the first and second satellites is measured at the object. The phase offset corresponds to a relative time difference in propagation of the signals traveling two different paths to the object. The object transmits via the first satellite a return signal indicative of the measured relative time difference. This return signal is activated some time in the future according to the object local time, which is slaved to receipt of the periodic signal sent through the first satellite. This future time is the start of the particular time period as decided by the fixed station's schedule. At the fixed station, an instantaneous round trip delay, determined by the time offset of the current transmission clock time relative to the receive clock time of reception of the return signal, along with the measured relative time difference sent back on the return signal, is used to calculate the distances between the first and second satellites to the object. From these distances the position of the object is calculated.

    DUAL SATELLITE NAVIGATION METHOD AND SYSTEM
    56.
    发明专利
    DUAL SATELLITE NAVIGATION METHOD AND SYSTEM 未知

    公开(公告)号：AU7037191A

    公开(公告)日：1991-06-26

    申请号：AU7037191

    申请日：1990-11-30

    Applicant: QUALCOMM INC

    Inventor： AMES WILLIAM G ,  JACOBS IRWIN M ,  WEAVER LINDSAY A JR ,  GILHOUSEN KLEIN S

    IPC: G01S5/12 ,  G01S5/14 ,  G01S13/87 ,  G01S19/00 ,  G01S19/01 ,  G01S19/38 ,  G01S19/48 ,  H04B7/185 ,  G01S5/10

    Abstract: A method and system for determining the position of an object using a fixed station and a plurality of earth orbit satellites whose positions are known. Separate periodic signals are transmitted from the fixed station via first and second satellites to the object whose postion is to be determined. The phase offset in periodic characteristics of the periodic signals as received from the first and second satellites is measured at the object. The phase offset corresponds to a relative time difference in propagation of the signals traveling two different paths to the object. The object transmits via the first satellite a return signal indicative of the measured relative time difference. This return signal is activated some time in the future according to the object local time, which is slaved to receipt of the periodic signal sent through the first satellite. This future time is the start of the particular time period as decided by the fixed station's schedule. At the fixed station, an instantaneous round trip delay, determined by the time offset of the current transmission clock time relative to the receive clock time of reception of the return signal, along with the measured relative time difference sent back on the return signal, is used to calculate the distances between the first and second satellites to the object. From these distances the position of the object is calculated.

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