A system and method for constructing an interference component using a detected data symbol and an estimated channel response in a non-orthogonal system and a method of estimating a channel using a structure of the non-orthogonal system and the interference component are provided. The system includes a receiver that receives a reference signal and data transmitted from a transmitter; detects adjacent data symbols around the reference signal; estimates an initial channel state; constructs the interference signal based on the adjacent data symbols and the initial channel state; estimates the channel state on the basis of the constructed interference signal; and perform an iterative process of reconstructing the interference signal based on the basis of the estimated channel state and re-estimates the channel state based on the reconstructed interference signal.