Code transmission system having buffers of approximately equal capacities on both transmitting and receiving sides

In a code transmission system which comprises a transmitter and a receiver, said transmitter comprising synchronization means for producing synchronization codes of a predetermined code pattern regularly with respect to time, encoder means coupled to said synchronization means and responsive to information to be transmitted for successively producing information codes representative of said information between two adjacent synchronization codes, a first buffer memory for storing codes supplied thereto, first means coupled to said synchronization and said encoder means and to said first buffer memory for supplying the synchronization and the information codes from said synchronization and said encoder means to said first buffer memory, means coupled to said first buffer memory for reading the codes stored in said first buffer memory to transmit the read out codes at a predetermined transmission rate, and second means coupled to said first buffer memory for producing a first buffer occupancy code indicative of buffer occupancy of said first buffer memory, said receiver comprising a second buffer memory for storing the codes transmitted from said transmitter, decoder means for decoding, at a decoding rate, information codes supplied thereto into an output signal, third means coupled to said second buffer memory and to said decoder means for reading the synchronization and the information codes stored in said second buffer memory to supply the read out codes to said decoder means thereby making said output signal represent said information, and fourth means coupled to said second buffer memory for producing a second buffer occupancy code indicative of buffer occupancy of said second buffer memory, the improvement wherein:

• said transmitter further comprises fifth means coupled to said first and said second means and to said first buffer memory for supplying the first buffer occupancy codes from said second means to said first buffer memory in a predetermined relation to the synchronization codes supplied from said synchronization means to said first buffer memory and
• said receiver further comprises sixth means coupled to said third means for reading the first buffer occupancy codes stored in said second buffer memory, seventh means coupled to said sixth and said fourth means and responsive to the first buffer occupancy codes supplied from said sixth means and to the second buffer occupancy codes supplied from said fourth means for producing, when the buffer occupancy indicated by the supplied second buffer occupancy codes has a difference from a predetermined value, a control signal of an amplitude representative of said difference, and eighth means coupled to said seventh means and to said decoder means and responsive to the amplitude of said control signal for controlling said decoding rate.