| 摘要 |
PURPOSE:To make the reception state optimum at all times by selecting a synchronization detection circuit or a delay detection circuit having a good condition according to the state when the reception condition is not good and demodulating a detected digital signal after the selection. CONSTITUTION:A reception signal 301 is transmitted to a digital signal output section 314, and inputted to either of a synchronization detection section 307 and a delay detection section 308. A changeover switch 309 is controlled based on the result discriminated by a switching control section 306 and either of them is selected. The switching control section 306 selects either of the synchronization detection section 307 and the delay detection section 308 having an excellent characteristic (condition) based on an average level 304, a variance 305 and the measured result of a multi-path distortion measurement section 303. Moreover, the switching timing of the changeover switch 309 is based on the boundary of clocks or the boundary of packets or frames obtained from a data demodulation section 312. Thus, a bit error ratio at the switching is suppressed and optimum reception is attained against bad conditions such as fading and multi-path distortion. |
