| 摘要 |
PURPOSE:To prevent the deterioration of received tone quality and to make the sound easy to hear by detecting the occurrence of a multi-path disturbance and selecting a forecasting signal from a digital signal processing circuit by a change-over circuit and converting it to a demodulating signal. CONSTITUTION:Received waves from an antenna 1 are led to an FM receiving part 2, and composite signals are outputted to a stereo demodulator 3 and a multi-path disturbance detecting circuit 11 from the receiving part 2. the demodulating signal from the demodulator 3 is led to the input end of an adder 7 through an A/D converter 4 and the multiplier 51 of a digital signal processing part. The output of the adder 7 is led to a D/A converter 8, and at the same time, led to the another input end of the adder 7 through a signal forecasting section 6 and a multiplier 52. Multipliers 51, 52 have a function as switching circuits that conduct or cut off between input and output according to whether multiplication factor K(a), K(b) are 1 or 0. When the circuit 11 does not detect multi-path disturbance, the multiplier 51 is made on and the multiplier 52 is made off, and when the circuit 11 detects the disturbance, the multiplier 51 is made off and the multiplier 52 is made on, and a estimated value from the circuit 6 is inputted to the adder 7. |
