Apparatus and method for interference cancellation in a wireless communication system

An interference cancellation device in a wireless communication system and a method thereof are provided to insert a virtual decision signal point corresponding to a zero point into a symbol demapper within an interference canceller, thus the interference canceller can operate in a robust way irrespective of existence of an interference signal. An interference canceller(210) generates decision signal points by adding virtual signal points to zero points and decision signal points in accordance with a modulation mode, and regenerates an interference signal for interference cancellation among receiving signals to output the regenerated signal. The canceller(210) includes a symbol demapper(215) which compares a predetermined threshold value in accordance with system setup with size of a complex value of an inputted signal, maps the virtual signal points of the zero points with the decision signal points to output the mapped points if the size of the complex value is less than the threshold value, and which maps one of the decision signal points in accordance with the modulation mode of the inputted complex value to output the mapped points.