Method of selecting the most desirable code search mode in a pager in the case of frame async
First Claim
1. A method of selecting between a preamble search mode and a frame search mode when a pager falls into frame asynchronization during said frame search mode, said pager including a front end, a bit synchronizer and a controller, said bit synchronizer being coupled to said front end and said controller and generating a clock in synchronism with bits of an incoming signal applied thereto from said front end, said method comprising the steps of:
- (a) determining, at said controller, that said bit synchronizer has gone out of bit synchronization;
(b) selecting said frame search mode, by periodically issuing frame synchronization pulses from said controller, when said bit synchronizer immediately restores the bit synchronization; and
(c) selecting said preamble search mode, by periodically applying preamble search pulses to said front end from said controller, when said bit synchronizer fails to immediately restore the bit synchronization.
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Accused Products
Abstract
In the event that a radio pager falls into frame async while receiving information, an appropriate code search mode is desirably selected. Firstly, a controller of the pager checks to see if a bit sync indicating signal obtained from a bit synchronizer demonstrates bit sync. If the bit sync indicating signal indicates bit synchronization, the controller selects an operation mode for searching for synchronization code (SC). On the other hand, if the bit sync indicating signal indicates bit async, the controller selects a preamble code search mode. Accordingly, in the case where the pager becomes out of synchronism and immediately thereafter restores same during information acquisition, the pager is able to successfully obtain subsequent information by means of very simplified arrangement.
14 Citations
5 Claims
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1. A method of selecting between a preamble search mode and a frame search mode when a pager falls into frame asynchronization during said frame search mode, said pager including a front end, a bit synchronizer and a controller, said bit synchronizer being coupled to said front end and said controller and generating a clock in synchronism with bits of an incoming signal applied thereto from said front end, said method comprising the steps of:
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(a) determining, at said controller, that said bit synchronizer has gone out of bit synchronization; (b) selecting said frame search mode, by periodically issuing frame synchronization pulses from said controller, when said bit synchronizer immediately restores the bit synchronization; and (c) selecting said preamble search mode, by periodically applying preamble search pulses to said front end from said controller, when said bit synchronizer fails to immediately restore the bit synchronization. - View Dependent Claims (2, 3)
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4. A pager for selecting between a preamble search mode and a frame search mode when said pager falls into frame asynchronization during said frame search mode, said pager comprising:
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a front end; a controller; and a bit synchronizer coupled to said front end and said controller which generates a clock in synchronism with bits of an incoming signal applied thereto from said front end; said controller performing the following functions; determining that said bit synchronizer has gone out of bit synchronization; selecting said frame search mode, by periodically issuing frame synchronization pulses to said front end, when said bit synchronizer immediately restores the bit synchronization; and selecting said preamble search mode, by periodically applying preamble search pulses to said front end, when said bit synchronizer fails to immediately restore the bit synchronization. - View Dependent Claims (5)
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Specification