point is calculated according to a received signal y r at the transmission frequency point in the embodiment the channel response u0125 r can be calculated according to a formula y r h r s r n r in step s 307 a channel response h i at the non transmission frequency point is calculated according to the channel response u0125 r at the transmission frequency point and the interrelation between channel responses at the transmission frequency point and at the non transmission frequency point in the embodiment the channel response u0125 i u03c8 i u0125 r at the non transmission frequency point can be calculated according to the u0125 r calculated in step s 306 and the interrelation between channel responses at the transmission frequency point and at the non transmission frequency point calculated in step s 304 where i 1 2 m and m is an amount of frequency points at which no reference signal is transmitted in step s 308 channel responses in all time domain and frequency domain are estimated by performing interpolation separately or simultaneously in frequency domain and time domain a diagram of a process of acquiring channel responses of a self interference channel via a small amount of reference signals provided in the first embodiment of the invention is shown in fig5 in the embodiment reference signals are transmitted at a small amount of frequency points and then channel responses at all frequency points can be calculated according to the reference signals transmitted at the small amount of frequency points therefore reference signal resource for self interference channel estimation is saved compared with a condition in conventional technology fig6 is a flow chart of.