| US 7,430,402 B2 | ||
| Frequency error estimation and correction | ||
| Aleksej Makarov, San Diego, Calif. (US) | ||
| Assigned to STMicroelectronics, Inc., Carrollton, Tex. (US) | ||
| Filed on Jun. 29, 2006, as Appl. No. 11/480,205. | ||
| Application 11/480205 is a continuation of application No. 10/154233, filed on May 22, 2002, granted, now 7,075,948, filed on Jul. 11, 2006. | ||
| Prior Publication US 2006/0246865 A1, Nov. 02, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. H04B 17/00 (2006.01); H04B 1/10 (2006.01) | ||
| U.S. Cl. 455—130 [455/67.13; 455/226.1; 455/296; 375/325; 375/329] | 28 Claims |
| 1. A frequency error system for measuring a sign and magnitude of a frequency error in a received complex signal, comprising:
a first detector operating to detect at least one quadrant transition of the received complex signal;
a first accumulator that accumulates a net number of quadrant transitions detected by the first detector during a time period;
a second detector operating to detect at least one zero-crossing of the received complex signal;
a second accumulator that accumulates a number of zero-crossings detected by the second detector during the same time period;
and
a processing unit which determines the frequency error sign from a sign of the accumulated net number of quadrant transitions
detected by the first detector, and determines the frequency error magnitude from a value of the accumulated zero-crossings.
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