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AssigneeSierra Wireless, Inc.
InventorsMarek K. Dutkiewicz, Philip J. Houghton
Estimating the term…
A method for reducing the effects of transients on the DC off-set tracking stage and the symbol timing recovery stage in a full duplex or half duplex packet switched data communication system-in which transients occur in the receiver portion of the subscriber when the transmitter portion of a subscriber is keyed ON and OFF is described. The method is dynamically implemented such the DC tracking stage and the symbol timing recovery stage are set in a first "distortion ready" mode during the time that the transmitter is keyed on and off and is set back to a second "normal" mode after the transmission event is over. In the "distortion ready" mode, the symbol timing recovery stage is set in a "freeze" state such that it makes no further timing adjustments to a decision clock that it generates and the DC off-set recovery stage is set to a narrow bandwidth mode such that it does not track large variations in the DC off-set and amplitude in the received signal. As a result, the Tx/on and Tx/off transients do not upset the decision clock synchronization with the forward channel data stream and the DC off-set tracking stage remains stable.
In a system having a receiver for receiving an information signal on a first channel, said receiver including a first stage for tracking a characteristic of said information signal and a second stage for deriving information from said information signal, said information signal having an associated amplitude and frequency offset, a method for minimizing effects of distortion on said first and second stage, said distortion corresponding to a preknown distortion event and having associated event onset and event termination times, said method comprising the steps of:
In a system having a receiver for receiving an information signal on a first channel, said receiver including a means for deriving a decision clock from said information signal, said information signal having an associated amplitude and DC off-set, a method for minimizing effects of distortion on said decision clock derivation means, said distortion corresponding to a preknown distortion event and having associated event onset and event termination times, said method comprising the steps of:
Dependencies are inferred from the claim text.