| 摘要 |
PURPOSE:To prevent deterioration in S/N for a specific signal from being cased by sending plural signals while adding a different quantity of pre-emphasis at each signal period in applying FM transmission where the plural signals are subject to time axis compression based on a different compression rate and each result is arranged in time series. CONSTITUTION:In applying FM transmission where the plural signals are subject to time axis compression based on a different compression rate and each result is arranged in time series, a different quantity of pre-emphasis is applied to the signals at each signal period and the result is transmitted. For example, in order to improve the demodulation S/N of a signal C in a television signal, the emphasis characteristic for the signals C and Y is switched by using an electronic switch SW so as to change over pre-emphasis circuits 30 and 32 having respectively pre-emphasis characteristics PEI and PEII as shown in figure A, and each de-emphasis characteristic for the signals C and Y is switched by changing over at the demodulation de-emphasis circuits 42 and 44 having respectively de-emphasis characteristics FEI and DEII shown in figure B. |
