公开(公告)号：CA860509A

公开(公告)日：1971-01-05

申请号：CA860509D

Applicant: MOTOROLA INC

Inventor： SANDGREN GEORGE E ,  MILLEKER WILLIAM

公开(公告)号：EP0094420A4

公开(公告)日：1985-07-01

申请号：EP83900135

申请日：1982-11-12

Applicant: MOTOROLA INC

Inventor： MILLEKER WILLIAM ,  FREEBURG THOMAS ,  STEPIEN MICHAEL

IPC: H04B1/10 ,  H03G3/34 ,  H04B7/26 ,  H04J3/24 ,  H04J6/00

CPC classification number: H03G3/34

Abstract: Apparatus that mutes data signals communicated between a central station (100) and mobile (120) and portable radios (122) in a dispatch radio system. The centraL station (100) includes a base station (110) having an RF transmitter and RF receiver, a dispatcher console (102), a general communications controller (GCC), (104), a digital communications computer (108) and a display terminal (106). The dispatcher console provides for voice communications. The GCC (104) provides for data communications. The GCC (104) and mobile (120) and portable radios (122) include data muting apparatus embodying the present invention. The data muting apparatus includes a noise detector (210, 602) for detecting the presence of a carrier signal and muting circuitry (220, 606) for muting the receiver output for a predetermined time interval when a carrier signal has been detected. During the predetermined time interval, other circuitry (620) may detect a synchronization word in a received data signal and mute the receiver output until still other circuitry (626) detects the last bit of a following information work and unmutes the receiver output.