Abstract: A method and apparatus for correcting direct current (DC) offset errors of a received signal in a direct conversion receiver (DCR) are provided. DC offset correction algorithms are incorporated into the DCR, each algorithm being optimized for a particular receive signal operating environment. The DC offset correction algorithms remove DC offset errors in baseband In-phase and Quadrature-phase signals received within the direct conversion receiver baseband signal path. Individual DC offset correction algorithms are selected for use as determined by a signal quality estimator component. A DC offset correction component of the direct conversion receiver determines an appropriate DC offset correction algorithm suited for a particular operating environment. A criterion for a signal quality estimate is set to control transitioning between DCOC algorithms.
Type:
Grant
Filed:
December 5, 2008
Date of Patent:
September 27, 2011
Assignee:
Motorola Solutions, Inc.
Inventors:
Darrell J. Stogner, Yadunandana N. Rao, Charles R. Ruelke, Chet A. Lampert