A receiver for receiving digital signals including frames, wherein each frame comprises a binary modulated cyclic preamble and the binary modulated cyclic preamble comprises a pseudo noise sequence, wherein, bits of the pseudo noise sequence in a frame is shifted from those of a pseudo noise sequence in a previous frame, said receiver being characterized in that it comprises: a shifter for shifting at least one of a first pseudo noise sequence in a first cyclic preamble of a first frame and a second pseudo noise sequence in a second cyclic preamble of a second frame if there is a phase rotation between the first pseudo noise sequence and the second pseudo noise sequence; a delayer for delaying the first pseudo noise sequence; a complex conjugate unit for calculating conjugate complex of the second pseudo noise sequence; a multiplexer for multiplexing the delayed first pseudo noise sequence and the conjugate complex of the second pseudo noise sequence; a correlator for correlating the first pseudo noise sequence and the second pseudo noise sequence by using multiplexing result from the multiplexer, and a phase estimator for determining a carrier frequency offset based on the result of the correlation performed by said correlator, wherein if the following equation: p m p n = p m + L p n + L is met, then it is determined that there is the phase rotation, wherein p(m) is the first pseudo noise sequence, p(n) is the second pseudo noise sequence, p(m+L) is a third pseudo noise sequence in a third cyclic preamble of the first frame which is spaced-apart from the first pseudo noise sequence by an guard interval L, and p(n+L) is a fourth pseudo noise sequence in a fourth cyclic preamble of the second frame which is spaced-apart from the second pseudo noise sequence by the guard interval L. a shifter for shifting at least one of a first pseudo noise sequence in a first cyclic preamble of a first frame and a second pseudo noise sequence in a second cyclic preamble of a second frame if there is a phase rotation between the first pseudo noise sequence and the second pseudo noise sequence; a delayer for delaying the first pseudo noise sequence; a complex conjugate unit for calculating conjugate complex of the second pseudo noise sequence; a multiplexer for multiplexing the delayed first pseudo noise sequence and the conjugate complex of the second pseudo noise sequence; a correlator for correlating the first pseudo noise sequence and the second pseudo noise sequence by using multiplexing result from the multiplexer, and a phase estimator for determining a carrier frequency offset based on the result of the correlation performed by said correlator, wherein if the following equation: p m p n = p m + L p n + L is met, then it is determined that there is the phase rotation, wherein p(m) is the first pseudo noise sequence, p(n) is the second pseudo noise sequence, p(m+L) is a third pseudo noise sequence in a third cyclic preamble of the first frame which is spaced-apart from the first pseudo noise sequence by an guard interval L, and p(n+L) is a fourth pseudo noise sequence in a fourth cyclic preamble of the second frame which is spaced-apart from the second pseudo noise sequence by the guard interval L.