Simultaneous transmission signal detection system

摘要

In a communication system wherein multiple radio stations communicate with one another over a single channel, an arrangement for indicating to a first user who is transmitting over the channel that there is a simultaneous transmission occurring on the channel by another user, possibly blocking or interferring with transmission by the first user. The arrangement includes means for periodically causing the transmitting first radio station to reduce its transmitting power, listen for a simultaneous transmission on the channel by another station, and then resume full transmitting power. The detection of a simultaneous transmission is annunciated to alert the first user that his transmissions may have been interferred with. Interruption of the first user's transmission may occur either periodically or at detected pauses between the first user's spoken words. The arrangement operates in conjunction with the conventional automatic gain control circuit of the first user's station.