Patent ID: 8023576

Claim:
A sampling offset estimation apparatus, comprising: a pilot sub-carrier refining unit to refine a pilot sub-carrier extracted from a differential demodulated signal, and to generate a reference pilot sub-carrier; an information sub-carrier refining unit to refine an information sub-carrier extracted from the differential demodulated signal, and to generate a reference information sub-carrier; a data sub-carrier refining unit to refine a data sub-carrier extracted from the differential demodulated signal, and to generate a reference data sub-carrier; a sampling offset estimating unit to estimate a sampling offset included in the differential demodulated signal, on a basis of the reference pilot sub-carrier, the reference information sub-carrier, and the reference data sub-carrier, wherein the pilot sub-carrier refining unit comprises: a real component multiplexer to output a real component value of the pilot sub-carrier if a sign of the real component value is positive (+), and to reverse the sign of the real component value and to output the sign reversed value of the real component value if the sign of the real component value is negative (−); an imaginary component multiplexer to output an imaginary component value of the pilot sub-carrier if the sign of the real component value is positive (+), and to reverse the sign of the imaginary component value and to output the sign reversed value of the imaginary component value if the sign of the real component value is negative (−); a subtractor to subtract an output value of the imaginary component multiplexer from an output value of the real component multiplexer, and to output the result of the subtraction as a real component value of the reference pilot sub-carrier; and an adder to add the output value of the imaginary component multiplexer to the output value of the real component multiplexer, and to output the result of the addition as an imaginary component value of the reference pilot sub-carrier.