| 摘要 |
<p>PURPOSE:To extract a pulse signal from an input signal accurately, by subjecting the input signal to Walsh conversion after making the input signal into plural signals different in phase. CONSTITUTION:The signal of indistinct pulse width, time point, and crest value is subjected to A/D conversion and is supplied to shift registers 121, 122-12n-1. Signals which are obtained as the result and have phases shifted are supplied to Walsh converting circuits 131, 132-13n of the same phase. Sequence spectrums obtained by this Walsh conversion are supplied to a squaring and averaging circuit 14, and spectrums obtained from this circuit 14 are suplied to a differential circuit 15 and are differentiated sequentially to obtain differences between spectrums in the direction of the time base. The output signal of the differential circuit 15 is given to a cut-off sequence setting circuit 16 to obtain the inclination of the spectrum. This value is supplied to filters 171, 172-17n to remove a high band corresponding to noise components.</p> |
