| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a processing time and power consumption required for demodulation without deteriorating the characteristics of a demodulator in a receiver side of a system to which no threshold for amplitude demodulation is transmitted from a transmitter side. <P>SOLUTION: A threshold calculating section 34 calculates a threshold required when a demodulating section 32 performs demodulation of 16QAM from a demodulator input signal. An SN fluctuation estimating section 33 estimates a Doppler frequency from SN fluctuation of the demodulator input signal. The section 33 performs control so that a threshold calculation frequency in a threshold calculating section 34 increases if the Doppler frequency is high, and performs control so that the threshold calculation frequency in the section 34 decreases if the Doppler frequency is low. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
