A wireless communication system includes an RF reception unit configured to receive a radio signal from a terminal; a channel estimation unit configured to estimate channel information of a wireless transmission path with respect to the terminal; a demodulation unit configured to perform soft decision demodulation on the radio signal; a quantization unit configured to quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on the basis of a statistical distribution determined using an average value of the log likelihood ratio determined in accordance with a modulation scheme used in wireless communication with the terminal and a variance of a log likelihood ratio obtained on the basis of the channel information; and a decoding unit configured to perform a decoding process on the log likelihood ratio quantized by the quantization unit.