Patent ID: 6498929
Filing Date: 2002-12-24
Classification: H03D,H03G,H04B

Abstract:
A receiver having a function of removing a direct current offset, comprising:a receiving section for receiving a radio frequency signal; an analog signal processing section for amplifying, band-converting and frequency-converting an analog signal inputted from the receiving section; an AD converting section for converting an output of the analog signal processing section from an analog signal to a digital signal; a digital signal processing section for processing the digital signal converted by the AD converting section; offset detecting means, provided in the digital signal processing section, for detecting a direct current offset signal produced in the receiving section or a frequency converting section; offset holding means, provided in the digital signal processing section, for holding the direct current offset signal detecting by the offset detecting means; a DA converting section for converting the direct current offset signal detected by the digital signal processing section into an analog signal; first offset correcting means, provided in the analog signal processing section, for correcting the analog signal on the basis of the direct current offset signal converted by the DA converting section into the analog signal; second offset correcting means for digitally decreasing a part of said direct current offset signal held by said offset holding means to decrease said direct current offset; and offset distributing means for correcting at least an offset part exceeding a predetermined threshold by said first offset correcting means when an absolute value of an offset detected by said offset detecting means exceeds the predetermined threshold.