A method of demodulating a plurality of multiplexed modulation signals is provided, including: i) inputting the plurality of multiplexed modulation signals, each of which being outputted from a plurality of outputs of a communication partner, wherein each modulation signal in the multiplexed modulation signals includes a pilot symbol sequence consisting of a plurality of pilot symbols used for demodulation, ii) estimating respective channels of the multiplexed modulation signals based on one or more of the pilot symbol sequences; and iii) demodulating each modulation signal in the plurality of multiplexed modulation signals based on the channel estimation. Each of the pilot symbol sequences is inserted at a same temporal point in each modulation signal among the multiplexed modulation signals. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the modulation signals in the multiplexed modulation signals, and each pilot symbol has a non-zero amplitude.