Disclosed is a method for simplifying a signal processing process of a base station that receives signals through four branches using two two-branch polarized antennas for each sector. The base station receives signals through first and second branches of the first polarized antenna and third and fourth branches of the second polarized antenna, time-delays the signals received at the second and fourth branches so as to distinguish an offset thereof from an offset of the signals received at the first and third branches, adds the signal received at the first branch and the signal received at the second branch and time-delayed, and adds the signal received at the third branch and the signal received at the fourth branch and time delayed. A modem processor separates an offset distinguishable signal from the added signals.