Patent ID: 8027414

Claim:
An apparatus for recovering a carrier frequency based on phase shift of a receiving signal, comprising: a phase shift estimation means for differentially decoding and down-sampling a preamble signal of the receiving signal into a currently decoded signal and for estimating a phase shift value of the preamble signal using a complex conjugate of the currently decoded signal, wherein the phase shift estimation means includes an averaging down-sampler for summating complex phase shift values acquired in a first multiplication unit as many as a the length of a spread code, for acquiring an average of the complex phase shift values as the currently decoded signal, and for performing the down-sampling to decrease a symbol clock rate as many as the length of the spread code; a compensation means for compensating the currently decoded signal based on the complex conjugate of the currently decoded signal which corresponds to the estimated phase shift value acquired in the phase shift estimation means after differential decoding; and a recovery means for recovering the compensated signal; wherein the compensation means includes multiplication unit for compensating the currently decoded signal by multiplying the currently decoded signal by the complex conjugate of the currently decoded signal.