| 摘要 |
PURPOSE: To effectively reduce noise by compressing a stereophonic sound difference signal and sending the compressed signal by a phase rectangular to a stereophonic subcarrier. CONSTITUTION: A stereophonic sound difference signal L-R is applied to the input side of a modulator 14 and its output is applied to an adder 12. The signal L-R is also applied to a compression circuit 16 to be a proper noise reducing compounder. A compressed stereophonic difference signal S' outputted from the circuit 16 is applied to the input side of a 2nd modulator 18 and its output is also sent to the adder 12 for linearly synthesizing the input signal with a monophonic signal M and the signal from the modulator 14. In the case of receiving a conventional two-channel stereophonic signal, signals M, S are obtained from the output side of a demultiplexer 24, and in order to extend the arrival range of the system, the compressed difference signal S' is applied to the input side of an extender 30. The extender 30 extends the compressed signal to the original dynamic range. |
