摘要 |
A wireless station device determines whether a carrier to noise ratio of a vertical polarization wave is lower than a first threshold value, determines that a present modulation method for the vertical polarization wave is to be changed to another modulation method having a small multilevel number when the carrier to noise ratio of the vertical polarization wave is lower than the first threshold value, and transmits modulation method information to the facing wireless station device. Further, the facing wireless station device transmits a radio signal to the wireless station device using the modulation method indicated by the received modulation method information for the vertical polarization wave. |