Patent ID: 7630459

Claim:
A frequency acquisition circuit for compensating a frequency offset of a received signal, comprising: a multiplier compensating the received signal according to a phase compensation signal to generate a first compensation signal, wherein the first compensation signal comprises a preamble and a plurality of adjacent symbols, and each of the symbols has a symbol length; a correlator generating a conjugate value according to the adjacent symbols of the first compensation signal having the same preamble; a normalization unit for normalizing the conjugate value; a phase evaluator generating an angle through a COSTAS circuit according to a real part and a imaginary part of the normalized conjugate value and generating a first phase angle signal according to the angle and the symbol length; a phase accumulator accumulating the first phase angle signals of different symbols to generate an accumulated phase angle signal; and an oscillator generating the phase compensation signal by searching a lookup table according to the accumulated phase angle signal.