U.S. Patent # 7,570,923, August 4, 2009. 32 pages. Also available from the United States Patent and Trademark Office. Website: http://www.uspto.gov.
NOTE: At the time of publication, the author Vladimir Prodanov was not yet affiliated with Cal Poly.
Frequency dependent I/Q imbalance in real I/Q filter pairs compensation may be performed using a simple compensation module, placed in the receiver/transmitter chain, with a gain adjustment coefficient and a delay adjustment coefficient. The gain adjustment coefficient may be determined by amplitude measurements conducted at a selected frequency near the center of the band-pass region of the filters. The delay adjustment coefficient may be determined by phase measurements conducted at a selected frequency near the edge of the band-pass region of the filters. Statistical analysis may be used to determine types of real filters that are better suited for the compensation method and to select the test frequencies that should be used.
Electrical and Computer Engineering