| 摘要 |
PURPOSE:To measure a median of a reception level correctly by detecting a median in a measuring time of a reception level of a radio channel and detecting number of times when the reception level crosses a prescribed level within the measuring time and varying the measuring time in response to the ratio of the prescribed level to the median and number of times of crossing. CONSTITUTION:A median detector 60 detects a median Rm of a reception level stored in an instantaneous value memory 50, a cross number of time detector 80 detects a predetermined level R in terms of number of times NLCR in which a reception waveform stored in the instantaneous value memory 50 crosses at a positive slope and inputs the result to a control circuit 90. The control circuit 90 estimates a maximum Doppler frequency fD from the median Rm of the inputted reception level, the crossing number of times NLCR and the predetermined level R. Moreover, the measuring time T to make the fD.T constant from the maximum Doppler frequency fD and it is inputted to a sampling device 40. Thus, the median of the reception level of the radio channel is correctly measured. |
