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    SELF-CALIBRATING SIGNAL STRENGTH DETECTOR
    1.
    发明专利
    SELF-CALIBRATING SIGNAL STRENGTH DETECTOR 未知

    公开(公告)号：CA1224848A

    公开(公告)日：1987-07-28

    申请号：CA485869

    申请日：1985-06-28

    Applicant: MOTOROLA INC

    Inventor： THRO STUART W

    IPC: H03J3/12 ,  H03G3/34 ,  H04B1/16 ,  H04B7/08 ,  H04B7/26 ,  H04Q7/34

    Abstract: SELF-CALIBRATING SIGNAL STRENGTH DETECTOR A self-calibrating signal strength detector is described. The present invention utilizes a relatively narrow dynamic range receiver sensitivity threshold indicator circuit (268) to calibrate the output signal of a relatively wide dynamic range signal strength detector (260). In accordance with the present invention, a processing device (502) monitors the outputs of the signal strength detector (260) and receiver sensitivity threshold indicator circuit (268) simultaneously, and determines a correction factor to be applied to the output of the signal strength detector (260) when the receiver sensitivity threshold indicator circuit (268) indicates that a received signal is at the receiver sensitivity threshold (268).

    TRUNKED COMMUNICATION SYSTEM FOR VOICE AND DATA
    3.
    发明专利
    TRUNKED COMMUNICATION SYSTEM FOR VOICE AND DATA 未知

    公开(公告)号：CA1296773C

    公开(公告)日：1992-03-03

    申请号：CA557450

    申请日：1988-01-27

    Applicant: MOTOROLA INC

    Inventor： ZDUNEK KENNETH J ,  THRO STUART W

    IPC: H04W84/08 ,  H04B7/00 ,  H04B7/14

    Abstract: CM-00284H TRUNKED COMMUNICATION SYSTEM FOR VOICE AND DATA A trunked voice/data communication system (100 is provided wherein a plurality of the trunked voice repeaters (104) are adapted (122) to accommodate both voice and data traffic. Data channels are assigned for a dynamically varying period of time depending upon traffic load or time of day. Once a data channel is established, any data unit (114 or 116) may transmit without re-requesting a data channel. In this way, the protracted request grant delay times are avoided. After the time interval, or if higher priority voice traffic exits, the data channel is reallocated to voice traffic. Thereafter, another data channel request may result in a data channel grant for another time interval.

    SUBSCRIBER UNIT FOR A TRUNKED VOICE/DATA COMMUNICATION SYSTEM
    4.
    发明专利
    SUBSCRIBER UNIT FOR A TRUNKED VOICE/DATA COMMUNICATION SYSTEM 未知

    公开(公告)号：CA1275746C

    公开(公告)日：1990-10-30

    申请号：CA557449

    申请日：1988-01-27

    Applicant: MOTOROLA INC

    Inventor： ABLAY SEWIM F ,  THRO STUART W ,  ZDUNEK KENNETH J

    IPC: H04W84/08 ,  H04B7/00

    Abstract: SUBSCRIBER UNIT FOR A TRUNKED VOICE/DATA COMMUNICATION SYSTEM A trunked voice/data subscriber (114) is provided that operates in either a voice mode, or one of three data modes. In a first data mode (406), the voice/data subscriber monitors the voice control channel to enable rapid participation in a voice call. In a second data mode (408), the subscriber monitors an assigned data channel until either commanded to change modes or until there has been no data activity for a predetermined time interval. Lastly, the subscriber may operate to remain in the last mode used so that, over time, the subscriber resides primarily in the mode predominately used. According to the invention, the voice/data subscriber must request a channel for each voice transmission. However, a data channel request need only be transmitted if no data channels are currently reallocated. If a data channel has been allocated, the subscriber may transmit at any time without first requesting access.

    RANDOM FREQUENCY OFFSETTING APPARATUS FOR MULTI- TRANSMITTER SIMULCAST RADIO COMMUNICATIONS SYSTEMS
    7.
    发明专利
    RANDOM FREQUENCY OFFSETTING APPARATUS FOR MULTI- TRANSMITTER SIMULCAST RADIO COMMUNICATIONS SYSTEMS 未知

    公开(公告)号：CA1202085A

    公开(公告)日：1986-03-18

    申请号：CA414363

    申请日：1982-10-28

    Applicant: MOTOROLA INC

    Inventor： THRO STUART W

    IPC: H04B1/707 ,  H04B7/06 ,  H04B7/26 ,  H04H20/67 ,  H04B7/00

    Abstract: Apparatus for randomly offsetting the frequencies of each transmitter in a simulcast radio communications system is described. The random frequency offsetting apparatus includes a random noise source for generating a noise signal which is amplified and low-pass filtered before application separately or in combination with an information signal to the frequency modulation input of a corresponding transmitter. In frequency modulated systems, the noise signal and information signal are combined and modulated onto the transmitters; whereas, in envelope modulated systems, the noise signal is frequency modulated onto the transmitter, and the information signal is envelope modulated onto the transmitter. Since the frequency of each simulcasting transmitter is randomly varying, deep cancellation nulls created in the overlap areas between transmitters by multi-transmitter interference will be randomly distributed in randomly varying locations. Therefore, communications between a central station and remote stations located in the overlap areas will not be interrupted by the nulls for long periods of time, as was possible in prior art simulcast systems.

    9.
    发明专利
    未知

    公开(公告)号：BR8907586A

    公开(公告)日：1991-07-30

    申请号：BR8907586

    申请日：1989-06-26

    Applicant: MOTOROLA INC

    Inventor： ABLAY SEWIN F ,  THRO STUART W ,  ZDUNEK KENNETH J ,  BIANCALANA PETER

    IPC: H04M11/00 ,  H04W84/08 ,  H04M1/27

    Abstract: A method for transmitting a data message to a voice/data subscriber unit (114) in a trunked voice/data communication system (100). When the subscriber unit (114) is in a voice mode, the system transmits a paging message regarding the existence of the data message via the voice channel thus, solving the problem of the voice using partly not knowing data is waiting. The system can then transmit the data message via a data channel.

    10.
    发明专利
    未知

    公开(公告)号：FI910918A0

    公开(公告)日：1991-02-26

    申请号：FI910918

    申请日：1991-02-26

    Applicant: MOTOROLA INC

    Inventor： ABLAY SEWIM F ,  THRO STUART W ,  ZDUNEK KENNETH J ,  BIANCALANA PETER

    IPC: H04M11/00 ,  H04W84/08 ,  H04M

    Abstract: A method for transmitting a data message to a voice/data subscriber unit (114) in a trunked voice/data communication system (100). When the subscriber unit (114) is in a voice mode, the system transmits a paging message regarding the existence of the data message via the voice channel thus, solving the problem of the voice using partly not knowing data is waiting. The system can then transmit the data message via a data channel.

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