SPREAD SPECTRUM TIME DIVISION MULTIPLEXER FOR HIERARCHICAL TRANSMISSION AND TIME DIVISION MULTIPLEX SIGNAL DEMULTIPLEXER

摘要

PURPOSE: To obtain a spread spectrum time division multiplexer for hierarchical transmission and time division multiplex signal demultiplexer in which hierarchical transmission with high degree of freedom is attained regardless of employment of the TDM system with respect to the width and depth of hierarchical processing in the hierarchical digital transmission when a nonlinear amplifier of a satellite channel is used. CONSTITUTION: The spread spectrum time division multiplexer for hierarchical transmission 1 at a transmitter side uses a check information addition circuit 10 to receive hierarchical digital information and to add check information thereto. A rate conversion circuit 11 applies rate conversion to the hierarchical digital information and applies rate conversion to digital information of each layer so that a ratio of rates of hierarchical signals is power of 2 and the information of each layer is not in duplicate on a time base. Then plural switch circuits 12 inverting sign are used to generate a spread spectrum time division multiplex signal. The time division multiplex signal demultiplexer at a receiver side is configured to conduct signal processing reverse to the time division multiplexer at a transmitter side.