| 摘要 |
PURPOSE:To improve the detection accuracy of an incoming signal wave by identifying two distributions of a detector output. CONSTITUTION:A detection voltage obtained by detecting a burst signal wave modulated and arrived at random by a detector is given to an amplitude detection circuit 1, in which square of the voltages are summed and rooted and the resulting amplitude is inputted to a moving mean circuit 2, where the amplitude at a time t0 and an amplitude in an optional n-clock preceding time t0-n are averaged. Thus, two distributions of probability density of the detected voltage with respect to the moving mean amplitude are both made steep and its variance is decreased. Since the overlapped part of the Rhys distribution of the probability density of the detection voltage with respect to the amplitude and the Rayleigh distribution at noise only in the absence of the arrival signal is less, the probability of occurrence of non-detection and mis-detection with respect to an input signal wave is considerably reduced. Then the moving mean value is compared with a reference value at a comparator 3 and when the moving mean value is more than the reference value, a demodulator 4 is operated. |
