A non-coherent detection apparatus comprising: a correlation unit obtaining a differential phase signal, d[n], by multiplying a complex conjugate value of a delay signal that is obtained by delaying a received signal, r[n], by N+1 chips, wherein N corresponds to a length of a pseudorandom number, PN, r[n], code, by the received signal, r[n], summing-up resultant values that are obtained by multiplying each component of the differential phase signal, d[n], by each component of a correlation sequence, B m, corresponding to the received signal, r[n], and outputting a correlation signal, the differential phase signal, d[n], and the correlation sequence, B m, having length corresponding the length of the PN code; a frequency offset estimator estimating a frequency offset based on a value that is obtained by accumulatively summing-up the correlation signals corresponding to preamble portions of the received signal, r[n], from among the correlation signals; and a signal detector detecting an original signal from the received signal, r[n], based on a size of a real-number part of a resultant value that is obtained by multiplying the frequency offset estimated by the frequency offset estimator by the correlation signal corresponding to a physical layer, PRY, payload portion of the received signal, r[n], from among the correlation signals, wherein the signal detector detects the original signal by using the following Equation A or B: E ^ m = { 0, Re A 1 m Y 1 * ≥ 0 1, Re A 1 m Y 1 * < 0 where, E └ m ┘ is an original signal corresponding to the received signal, r[n], corresponding to an m-th bit of a PHY protocol data unit, PPDU, A 1 is a correlation signal detected by the correlation unit, and Y 1 is the frequency offset, E ^ m = { 0, Re A 1 m q Y 1 * ≥ 0 1, Re A 1 m q Y 1 * < 0 where, E└ m ┘ is an original signal corresponding to the received signal r[n], corresponding to the m-th bit of the PPDU, A 1 is a correlation signal detected by the correlation unit, q{·} is four-level quantization function that represents approximation in which the four levels are 1, -1, j, and -j, respectively, and Y 1 is the frequency offset. a correlation unit obtaining a differential phase signal, d[n], by multiplying a complex conjugate value of a delay signal that is obtained by delaying a received signal, r[n], by N+1 chips, wherein N corresponds to a length of a pseudorandom number, PN, r[n], code, by the received signal, r[n], summing-up resultant values that are obtained by multiplying each component of the differential phase signal, d[n], by each component of a correlation sequence, B m, corresponding to the received signal, r[n], and outputting a correlation signal, the differential phase signal, d[n], and the correlation sequence, B m, having length corresponding the length of the PN code; a frequency offset estimator estimating a frequency offset based on a value that is obtained by accumulatively summing-up the correlation signals corresponding to preamble portions of the received signal, r[n], from among the correlation signals; and a signal detector detecting an original signal from the received signal, r[n], based on a size of a real-number part of a resultant value that is obtained by multiplying the frequency offset estimated by the frequency offset estimator by the correlation signal corresponding to a physical layer, PRY, payload portion of the received signal, r[n], from among the correlation signals, wherein the signal detector detects the original signal by using the following Equation A or B: E ^ m = { 0, Re A 1 m Y 1 * ≥ 0 1, Re A 1 m Y 1 * < 0 where, E └ m ┘ is an original signal corresponding to the received signal, r[n], corresponding to an m-th bit of a PHY protocol data unit, PPDU, A 1 is a correlation signal detected by the correlation unit, and Y 1 is the frequency offset, E ^ m = { 0, Re A 1 m q Y 1 * ≥ 0 1, Re A 1 m q Y 1 * < 0 where, E└ m ┘ is an original signal corresponding to the received signal r[n], corresponding to the m-th bit of the PPDU, A 1 is a correlation signal detected by the correlation unit, q{·} is four-level quantization function that represents approximation in which the four levels are 1, -1, j, and -j, respectively, and Y 1 is the frequency offset.