Communication quality estimation method, communication quality estimation apparatus, and communication system

摘要

An average signal point amplitude detection section 15 A determines an average position of I and Q components when a received QPSK modulated signal is demodulated and a threshold calculation section 15 B determines threshold ths on an IQ plane based on the average signal point position of the received QPSK modulated signal and a theoretical distribution position on the IQ plane of signal points of a 16-value QAM signal. Then, a threshold decision section 14 A makes a threshold-decision on the I and Q components of sequentially received QPSK modulated signals using this threshold ths and thereby calculates a simulated bit error rate of the 16-value QAM signal.