| 摘要 |
For so-called ''variable dynamics'', a time-variant control signal is transmitted in exact time-correlated association with the radio programme signal. The control signal contains an information concerning the varying modulation of the original radio programme signal and is used in the receiver during the repetition of the radio programme signal to make the broadcasting studio modulation at least partially reversible in the sense of a variable dynamic. According to the invention, the broadcasting studio incorporates the time-variant control signal in the data stream of a radio data signal (RDS) in a manner appropriate to the data format. The RDS signal supplemented in this manner is transmitted from the broadcasting studio to terrestrial transmitters. In each transmitter, the respective supplemented RDS signal received is modulated to an auxiliary carrier, incorporated in the modulated time-correlated radio programme signal present in the form of a time-correlated multiplex signal, and broadcast terrestrially together with the multiplex signal. In the receiver, the multiplex signal received is retrieved from the RDS signal. The varying control signal is separated from the data stream of the RDS signal and used to control the dynamics (difference in level between the softest and loudest tones) of the retrieved useful signal component of the multiplex signal. Radio transmitters and receivers. |
