In an aspect of the present invention, provided is a method for receiving an uplink signal by a base station (BS) in a wireless communication system where a reference signal is not used, including: obtaining information bits by demodulating and decoding a signal of a first user equipment (UE) that is modulated through a differential modulation scheme; estimating a channel between the first UE and the BS using the information bits; and performing successive interference cancellation (SIC) using the signal of the first UE restored through the channel estimation results and the information bits. In this case, the BS may estimate the channel between the first UE and the BS by assuming that an Nth modulation symbol among modulation symbols of the information bits modulated through the differential modulation scheme is fixed to a predetermined constellation point.