Mobile radio communication system using a sound or voice activity detector and convolutional coding.

摘要

There is disclosed a mobile radio communications system comprising a transmitter section and a receiver section at each of a base station and a mobile station. In the transmitter section, when a sound-absent section is detected in sound data to be transmitted, transmission of the sound data is stopped, and instead, tail bits are transmitted. The transmission power is lowered to zero or to a given value other than zero when the transmission of the tail bits is finished. The lowering of the transmission power is held until a sound-present section is detected. The convolutional encoding is efected to the sound data and the tail bits prior to transmission. In the receiver section, the variation in transmission is monitored to control operation of an associated component in response to the monitored power variation. Viterbi decoding is employed for decoding the convolutional code.