| 摘要 |
PURPOSE:To make a C/N detecting part unnecessary by measuring the C/N by the square output of the correlation value of a digital matched filter. CONSTITUTION:A signal asynchronously dropped into a base band with a mixer 2, a hydrid 9, and an oscillator 10 is firmly decided by an A/D converter 4 and inputted to a 90 deg. phase shifter 11. The correlation value between the input signal and a diffusion code is obtained by obtaining the coincident number between the value of the 90 deg. phase shifter 11 and the value of a shift register 12 and squaring and adding the outputs of both channels, and the diffusion code is caught using this correlation value. Next, a comparing diffusion code to obtain the correlation between the input signal and itself is changed into the diffusion code to be transmitted by its own station, the C/N of the input signal is obtained by the output of the digital matched filter at that time, rainfall attenuation quantity is estimated from the C/N, and transmission power is controlled. Thus, the C/N detecting part becomes unnecessary. |
