Voice unit communications system - phase or frequency keys composite data blocks which check bits whilst voice link is suppressed during transmission

摘要

The voice communications system uses phase or frequency shift keying to transmit binary data blocks with check bits during breaks in voice communication. A data coupler gives up its stored data bits in response to a timing circuit. The timing circuit also controls a parallel/serial converter coupled to the coupler's outputs. The check bit is inserted into the data block at the converter's output. The composite blocks are then phase or frequency keyed and the voice communication suppressed during the subsequent transmission of a composite block.