A method for processing a frequency division multiplexing signal transmitted in a channel is provided. The method includes the steps of a) receiving the frequency division multiplexing signal having a residual intercarrier interference (ICI) and a channel noise and transmitted by plural subcarriers; b) performing a cyclic prefix removal and a discrete Fourier transform for the frequency division multiplexing signal to obtain a frequency-domain signal; c) analyzing the frequency-domain signal to obtain a plurality of correlation values for the residual ICI and the channel noise; and d) performing a communication signal processing for the frequency division multiplexing signal based on at least one of the plural correlation values.