Method for the control of receiver synchronization in a mobile phone
First Claim
1. A method for determining the cause of an incorrect synchronization word pattern in a received mobile telephone signal having a succession of frames, comprising the steps of:
- (1) receiving binary data frames having a synchronization pattern;
(2) a first step of comparing bit-by-bit the received synchronization pattern with a predetermined synchronization pattern;
(3) accepting the received synchronization pattern as correct if the first step of comparing determines no more than two bits of the received synchronization pattern differ from the predetermined synchronization pattern;
(4) if the first step of comparing determines that the received synchronization pattern is not accepted, a second step of comparing bit-by-bit the received synchronization pattern with a phase shifted version of the predetermined synchronization pattern; and
(5) accepting the required synchronization pattern as correct, but out of synchronization, if the second step of comparing determines no more than two bits of the received synchronization pattern differs from the phase shifted version of the predetermined synchronizing pattern, otherwise indicating a loss of received synchronization and not accepting the synchronization pattern as correct.
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Accused Products
Abstract
A receiver synchronization control in signalling messages in TACS/AMPS system in a mobile phone is disclosed. In order to avoid unnecessary setting of hunt mode operation, if the received synchronization pattern is not congruent with the correct reference pattern, the received pattern is checked in a bit-by-bit manner so as to reveal occasional bit errors of one or two bits, which may appear although the receiver is in synchronization. A further check may be conducted by shifting a reference pattern mask by one or at the most two bits in either direction, whereafter rechecking to reveal either fully correct pattern or rechecking for only one or two bits error can be performed.
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Citations
8 Claims
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1. A method for determining the cause of an incorrect synchronization word pattern in a received mobile telephone signal having a succession of frames, comprising the steps of:
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(1) receiving binary data frames having a synchronization pattern; (2) a first step of comparing bit-by-bit the received synchronization pattern with a predetermined synchronization pattern; (3) accepting the received synchronization pattern as correct if the first step of comparing determines no more than two bits of the received synchronization pattern differ from the predetermined synchronization pattern; (4) if the first step of comparing determines that the received synchronization pattern is not accepted, a second step of comparing bit-by-bit the received synchronization pattern with a phase shifted version of the predetermined synchronization pattern; and (5) accepting the required synchronization pattern as correct, but out of synchronization, if the second step of comparing determines no more than two bits of the received synchronization pattern differs from the phase shifted version of the predetermined synchronizing pattern, otherwise indicating a loss of received synchronization and not accepting the synchronization pattern as correct. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification