DIGITAL SIGNAL TRANSMITTER

摘要

PROBLEM TO BE SOLVED: To map an MPEG 2(moving picture experts group)-TS(transport stream) at an optional bit rate on a leased DS3 channel, to transmit the result and to reduce a scale of a realized circuit by decreasing a fixed delay in the signal transmission through the DS 3 channel. SOLUTION: The transmitter is provided with a storage circuit 1 that temporarily stores digital data from a data generator 6, an invalid data generating circuit 2 that generates invalid data, a storage state detection circuit 3 that detects a storage state of the storage circuit 1, and a mapping pattern control circuit 5. Then the control circuit 5 applies switching control to a changeover switch 4 to select an output of the invalid data generating circuit 2 or a read output from the storage circuit 1 to generate a transmission format where a band shared by a digital signal with respect to a transmission band is a little higher than an input bit rate and a transmission format where the band shared by the digital signal is a little lower and either of the two transmission formats is selected adaptively depending on a detection output denoting a storage state by the storage state detection circuit 3.