Patent ID: 7050389

Claim:
A DC-offset eliminating method for a receiving circuit of a receiver which receives signals comprising a plurality of frames continuously sent to the receiving circuit, each of the frames comprises an alignment portion and a signal-end indication portion showing as to whether other frames continuosly follow said frames and a preamble portion added only at the head of each single frame or each group of frames, wherein the method comprises: calculating a DC-offset component depending upon the received signals; subtracting said DC-offset component from the received signals; and performing a DC-offset eliminating operation based on the subtracted result, wherein a reduction in DC offset follow-up speed is initiated when said preamble portion is being received, regardless of a time when a continuous reception is performed in which all of said frames are received to recognize the timing of the frame number to be received or a time when an intermittent reception is executed in which only a frame destined for said receiver itself is received, said DC-offset eliminating operation changing said DC-offset follow-up speed in accordance with a frame-continuation detection signal and a received frame signal.