To provide a CNR deterioration amount estimation method that learns an impact on communication by simple measurement by means of a signal generator and a spectrum analyzer.
A CNR deterioration amount estimation method comprises: a first step of generating CW signals in first and second frequency bands to input them to an antenna, and measuring an intermodulation distortion level X at a third frequency band where Nth intermodulation distortion in the first and second frequency bands occurs; a second step of performing convolution calculation of transmission signal spectra at the first and second frequency bands at the time of modulation wave signal transmission and calculating spectrum distribution of the Nth intermodulation distortion; a third step of calculating a power ratio Y of an intermodulation distortion level in all bands where the Nth intermodulation distortion occurs to an intermodulation distortion level in a reception band of a base station; a fourth step of estimating difference between the intermodulation distortion level X and the power ratio Y as an intermodulation distortion level Z in the reception band of the base station at the time of modulation wave signal transmission; and a fifth step of estimating a CNR deterioration amount by use of the intermodulation distortion level Z.
IHARA TAISUKE
Yukio Nakamura
Yoshimura Munehiro