A method for signal demodulation by a base station in a wireless communication system, the method comprising: receiving at least one subframe through at least one antenna from a terminal by a base station; combining a pre-configured number of subframes comprising identical consecutive data, by the base station; and demodulating received subframes, based on the combined subframes wherein the combining comprises: determining, by the base station, a time transmission interval TTI through which subframes comprising identical consecutive data are received, based on a communication scheme between the base station and the terminal; estimating a channel of each subframe in the TTI group by the base station; and combining subframes in the TTI group, based on the estimated channel of each subframe, by the base station, the method being characterized in that the estimating of the channel comprises: estimating a channel of each subframe received in a pre-configured interval, by the base station; configuring a weight or window of a channel of each subframe received in the pre-configured interval, based on a signal-to-noise ratio SNR of a channel of each subframe in the pre-configured interval wherein the window is configured around a subframe in a predefined channel state; and estimating a channel of each subframe in the TTI group, based on a weight or window of a channel of each subframe received in the pre-configured interval, wherein the pre-configured interval is determined by X = N R * Z * N hop, wherein X indicates a pre-configured interval, N R indicates the number of antennas, Z indicates a TTI group, and N hop indicates the number of TTI groups allocated in an identical band. receiving at least one subframe through at least one antenna from a terminal by a base station; combining a pre-configured number of subframes comprising identical consecutive data, by the base station; and demodulating received subframes, based on the combined subframes wherein the combining comprises: determining, by the base station, a time transmission interval TTI through which subframes comprising identical consecutive data are received, based on a communication scheme between the base station and the terminal; estimating a channel of each subframe in the TTI group by the base station; and combining subframes in the TTI group, based on the estimated channel of each subframe, by the base station, the method being characterized in that the estimating of the channel comprises: estimating a channel of each subframe received in a pre-configured interval, by the base station; configuring a weight or window of a channel of each subframe received in the pre-configured interval, based on a signal-to-noise ratio SNR of a channel of each subframe in the pre-configured interval wherein the window is configured around a subframe in a predefined channel state; and estimating a channel of each subframe in the TTI group, based on a weight or window of a channel of each subframe received in the pre-configured interval, wherein the pre-configured interval is determined by X = N R * Z * N hop, wherein X indicates a pre-configured interval, N R indicates the number of antennas, Z indicates a TTI group, and N hop indicates the number of TTI groups allocated in an identical band. determining, by the base station, a time transmission interval TTI through which subframes comprising identical consecutive data are received, based on a communication scheme between the base station and the terminal; estimating a channel of each subframe in the TTI group by the base station; and combining subframes in the TTI group, based on the estimated channel of each subframe, by the base station, the method being characterized in that the estimating of the channel comprises: estimating a channel of each subframe received in a pre-configured interval, by the base station; configuring a weight or window of a channel of each subframe received in the pre-configured interval, based on a signal-to-noise ratio SNR of a channel of each subframe in the pre-configured interval wherein the window is configured around a subframe in a predefined channel state; and estimating a channel of each subframe in the TTI group, based on a weight or window of a channel of each subframe received in the pre-configured interval, wherein the pre-configured interval is determined by X = N R * Z * N hop, wherein X indicates a pre-configured interval, N R indicates the number of antennas, Z indicates a TTI group, and N hop indicates the number of TTI groups allocated in an identical band.