| US 7,590,399 B2 | ||
| Technique for reducing multipath interference in an FM receiver | ||
| Raed S. Shatara, Carmel, Ind. (US); Mathew A. Boytim, Kokomo, Ind. (US); and Steven S. Langston, Kokomo, Ind. (US) | ||
| Assigned to Delphi Technologies, Inc., Troy, Mich. (US) | ||
| Filed on Aug. 11, 2005, as Appl. No. 11/201,883. | ||
| Prior Publication US 2007/0037538 A1, Feb. 15, 2007 | ||
| Int. Cl. H04B 1/06 (2006.01); H04B 7/00 (2006.01) | ||
| U.S. Cl. 455—272 [455/277.1; 455/277.2] | 16 Claims |
| 1. A method for reducing multipath distortion in an FM receiver with a plurality of switchable antennas, comprising the steps
of:
providing a fast distortion detector, wherein the fast distortion detector monitors a received signal for distortion events
less than about fifteen microseconds in duration;
providing a slow distortion detector, wherein the slow distortion detector measures distortions relating to quality of the
received signal;
triggering an antenna search based upon an output of the fast distortion detector;
selecting a trial antenna based upon a recent history of average signal levels measured on each of a plurality of antennas;
providing a quality measure that is averaged based upon a combined average RF signal level received by all of the plurality
of switchable antennas, the quality measure further comprising a determination of an average level of the trial antenna, and
calculating an averaging time based upon the combined RF level, such that the averaging time is utilized to calculate the
quality measure; and
maintaining a present trial antenna as a new reference antenna or selecting another trial antenna based upon a comparison
of the quality measure to a previous measurement for a current reference antenna.
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