TRANSMITTER FOR CONSTANT RATE TRANSMISSION OF DIGITAL INFORMATION AND ITS METHOD

PROBLEM TO BE SOLVED: To suppress bit rate distortion and jump to the minimum by controlling a bit rate generated for each prescribed constitution in a finite range by a control signal from a rate controller. SOLUTION: A compressing module 10 receives digital data from an information source 12, and outputs the digital data to a rate buffer 14 at a variable rate. A transmitter 16 makes empty the rate buffer at a constant rate, and transmits the data. A rate controller 20 monitors the level of replenishment of the rate buffer 14, generates a control signal to a line 22, and generates a constitution selection signal C to a line 23. The signal C is feedbacked to the compressing module 10. The module 10 changes a compression rate in response to the signal generated by the controller 20. The rate controller 20 controls the rate of the compressing module 10 so as to be made coincident with the transmission rate of the transmitter 16.