Patent ID: 8754809

Claim:
A method of providing automatic frequency control (AFC) tracking for reception of GLONASS signals, the method comprising: determining whether a channel signal to noise ratio (CNo) exceeds a threshold; when the CNo exceeds the threshold, performing pull-in using a first series of predetection integration (PDI) periods (PDIs) with activated decision-directed flips (DDFs) until a N ms boundary of a GLONASS data bit is found, wherein N is a positive integer, and wherein the activated DDFs selectively adjust polarities of cross-dot pairs generated based on the PDIs; and using a receiver, performing updates to an AFC loop, wherein performing includes: using a N ms update interval and PDI=(N/2)ms for every other update; and using a setting for an update between N ms updates, the setting using PDI=(N/4)ms.