A method of transmitting a signal in a base station is provided. The method includes filtering a signal to be transmitted through a filter, power amplifying the filtered signal to generate nonlinear harmonic components corresponding to a first frequency band and a second frequency band, separating the nonlinear harmonic components according to the first frequency band and the second frequency band such that nonlinear harmonic components corresponding to the first frequency band passes through a first frequency band duplexer and nonlinear harmonic components corresponding to the second frequency band passes through a second frequency band duplexer, and transmitting the separated nonlinear harmonic components.