1.
    发明专利
    未知

    公开(公告)号:DE69131715T2

    公开(公告)日:2000-04-27

    申请号:DE69131715

    申请日:1991-11-07

    Applicant: MOTOROLA INC

    Abstract: A time division multiplexed system is disclosed in which communication messages among a wide area site and a plurality of substantially scattered local sites are communicated on a radio frequency channel which is divided into a plurality of time slots, wherein at least one of the time slots is further divided into a plurality of subslots. Communication units operating in the wide area site communicate communication messages during the time slots, and the communication units operating in the local sites communicate communication messages during the subslots which are assigned to each of the local sites.

    3.
    发明专利
    未知

    公开(公告)号:DE69131715D1

    公开(公告)日:1999-11-18

    申请号:DE69131715

    申请日:1991-11-07

    Applicant: MOTOROLA INC

    Abstract: A time division multiplexed system is disclosed in which communication messages among a wide area site and a plurality of substantially scattered local sites are communicated on a radio frequency channel which is divided into a plurality of time slots, wherein at least one of the time slots is further divided into a plurality of subslots. Communication units operating in the wide area site communicate communication messages during the time slots, and the communication units operating in the local sites communicate communication messages during the subslots which are assigned to each of the local sites.

    4.
    发明专利
    未知

    公开(公告)号:DE69131503D1

    公开(公告)日:1999-09-09

    申请号:DE69131503

    申请日:1991-12-16

    Applicant: MOTOROLA INC

    Abstract: A transceiver compatible with both wide channel constant envelope 4 level FSK FM modulation and narrow channel pi /4 differential QPSK linear modulation allows compatible interaction between modified constant envelope and non-constant envelope transmitters. All Nyquist filtering occurs in the transmitters, and none in the receiver.

    5.
    发明专利
    未知

    公开(公告)号:DE69131503T2

    公开(公告)日:2000-03-23

    申请号:DE69131503

    申请日:1991-12-16

    Applicant: MOTOROLA INC

    Abstract: A transceiver compatible with both wide channel constant envelope 4 level FSK FM modulation and narrow channel pi /4 differential QPSK linear modulation allows compatible interaction between modified constant envelope and non-constant envelope transmitters. All Nyquist filtering occurs in the transmitters, and none in the receiver.

    6.
    发明专利
    未知

    公开(公告)号:DE69228376T2

    公开(公告)日:1999-09-23

    申请号:DE69228376

    申请日:1992-10-19

    Applicant: MOTOROLA INC

    Abstract: A method for measuring channel delay measures the delay for a message to propagate from a prime site (100, 400) to a remote site (200, 500) via the channel (300, 600). The prime site includes a clock for providing a first value, T1, based on the current time at the prime site. The remote site includes a clock for providing a second value, T2, based on the current time at the remote site. Both clocks are synchronized with a common timing source, such as a GPS satellite timing signal. Therefore, T2 equals T1. In one embodiment, the prime site determines T1, and simultaneously sends a message to the remote site via the channel, the message including T1. Upon receiving the message, the remote site simultaneously determines T2. The remote site decodes the message to determine T1, and then determines the delay based on the difference between T2 and T1.

    7.
    发明专利
    未知

    公开(公告)号:DE69228376D1

    公开(公告)日:1999-03-18

    申请号:DE69228376

    申请日:1992-10-19

    Applicant: MOTOROLA INC

    Abstract: A method for measuring channel delay measures the delay for a message to propagate from a prime site (100, 400) to a remote site (200, 500) via the channel (300, 600). The prime site includes a clock for providing a first value, T1, based on the current time at the prime site. The remote site includes a clock for providing a second value, T2, based on the current time at the remote site. Both clocks are synchronized with a common timing source, such as a GPS satellite timing signal. Therefore, T2 equals T1. In one embodiment, the prime site determines T1, and simultaneously sends a message to the remote site via the channel, the message including T1. Upon receiving the message, the remote site simultaneously determines T2. The remote site decodes the message to determine T1, and then determines the delay based on the difference between T2 and T1.

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