| 摘要 |
PURPOSE:To attain communication service suitable for the operating mode in response thereto by forecasting the transition of a reception voltage level at a point of time and thereafter from a displayed reception voltage level and a differentiation output. CONSTITUTION:Peak points of time A1, A2 and a notch point of time B1 are repeated alternately in a reception wave because it is subject to fading. The gradient of a curve representing the timewise transition of a reception output level 3 at a time region T1 at the midpoint between the points of time A1 and B1 is negative and that at a time region T2 between points of time B1 and A2 is positive. Thus, the change in the level 3 is forecast by discriminating whether a sign of the differentiation output 5 of the level 3 is positive or negative. Then a reception level state discriminating circuit 8 to which the level 3 and the output 5 of a differentiation circuit 4 are inputted discriminates the radio wave reception state at present and also displays the sign of the level 3 and the output 5. |
