A wireless communication system (1, 2) comprising: an RF reception unit configured to receive a radio signal from a terminal; a channel estimation unit (22, 42) configured to estimate channel information of a wireless transmission path with respect to the terminal on a basis of the radio signal received by the RF reception unit; a demodulation unit configured to perform soft decision demodulation on the radio signal on a basis of the channel information estimated by the channel estimation unit (22, 42); characterized by a quantization unit configured to: calculate Gaussian distribution for each symbol on a basis of a proportion and an average value of Gaussian distribution for each symbol determined by the modulation scheme used for wireless communication with the terminal, and a variance of a log likelihood ratio calculated from a power of a noise signal, the noise signal being extracted from the radio signal on a basis of the channel information and a predetermined signal; determine a quantization threshold value and a quantization level on a basis of the calculated Gaussian distribution for each symbol; and quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on a basis of the determined quantization threshold value and quantization level; and a decoding unit configured to perform a decoding process on the log likelihood ratio quantized by the quantization unit. an RF reception unit configured to receive a radio signal from a terminal; a channel estimation unit (22, 42) configured to estimate channel information of a wireless transmission path with respect to the terminal on a basis of the radio signal received by the RF reception unit; a demodulation unit configured to perform soft decision demodulation on the radio signal on a basis of the channel information estimated by the channel estimation unit (22, 42); characterized by a quantization unit configured to: calculate Gaussian distribution for each symbol on a basis of a proportion and an average value of Gaussian distribution for each symbol determined by the modulation scheme used for wireless communication with the terminal, and a variance of a log likelihood ratio calculated from a power of a noise signal, the noise signal being extracted from the radio signal on a basis of the channel information and a predetermined signal; determine a quantization threshold value and a quantization level on a basis of the calculated Gaussian distribution for each symbol; and quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on a basis of the determined quantization threshold value and quantization level; and calculate Gaussian distribution for each symbol on a basis of a proportion and an average value of Gaussian distribution for each symbol determined by the modulation scheme used for wireless communication with the terminal, and a variance of a log likelihood ratio calculated from a power of a noise signal, the noise signal being extracted from the radio signal on a basis of the channel information and a predetermined signal; determine a quantization threshold value and a quantization level on a basis of the calculated Gaussian distribution for each symbol; and quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on a basis of the determined quantization threshold value and quantization level; and a decoding unit configured to perform a decoding process on the log likelihood ratio quantized by the quantization unit.