Patent ID: 8488664

Claim:
A radio communication system comprising: a transmission device configured to transmit data by changing at least one of a modulation scheme and a coding rate based on information reported from a reception device; and a reception device configured to equalize distortion by a radio propagation channel from a received signal by frequency domain equalization, wherein the reception device sets at least one of the modulation scheme and the coding rate based on a signal-noise ratio after the frequency domain equalization, the signal-noise ratio is calculated based on at least one of an equivalent amplitude gain and a variance of equivalent noise calculated by the frequency domain equalization, the at least one of the equivalent amplitude gain and the variance of equivalent noise is calculated by using a calculation result based on tap coefficient for each frequency and a predetermined value, and the reception device calculates the equivalent amplitude gain by averaging the product of the tap coefficient of each frequency and the frequency response of a propagation channel in the frequency domain in case that the frequency domain equalization is performed based on a minimum mean square error.