Cancellation system of feedback interference signal using combined antenna

A cancellation system for a feedback interference signal joined to an antenna system is provided to detect and cancel various undesired interference signals when a desired signal and various undesired interference signals coexist, thereby making the various undesired interference signals be inputted to a receiver. A cancellation system for a feedback interference signal comprises an input signal detection/analysis/control unit(300), a 3M algorithm application unit(302), a path signal updating unit(306), a signal comparison/analysis/control unit(308), a signal processing unit(310) and an output signal generating unit(312). The input signal detection/analysis/control unit detects and analyzes the size of a path signal(1) and a path signal(2) and other variables, and controls the size of an input signal. The 3M algorithm application unit generates a precision correspondent signal in response to various interference signals. The path signal updating unit updates the path signal(2) so that the various interference signals included in the path signal(2) have the same size of value as the various interference signals included in the path signal(1). The signal comparison/analysis/control unit generates a control value for compensating an error or sets a new signal processing reference point. The signal processing unit converts the phase of the path signal(1) and the path signal(2) into mutual reverse phases. The output signal generating unit controls gain in comparison with standards which the size of outputted desired signal component requires.