Using receive diversity to extend standby time in QPCH mode

The standby time of a CDMA cell phone is extended by using two receive chains to monitor the Quick Paging Channel (QPCH) when the signal-to-noise ratio falls within a predetermined range. Monitoring the QPCH saves battery power by obviating the need to monitor the general paging message unless quick...

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Bibliographic Details
Main Authors Tu, Kuang-Hsuan, Kurapati, Nagabhushana Rao
Format Patent
LanguageEnglish
Published 08.09.2009
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Summary:The standby time of a CDMA cell phone is extended by using two receive chains to monitor the Quick Paging Channel (QPCH) when the signal-to-noise ratio falls within a predetermined range. Monitoring the QPCH saves battery power by obviating the need to monitor the general paging message unless quick paging (PI) bits are set. The QPCH is not monitored, however, in noisy environments where PI bits are incorrectly detected causing the paging message to be needlessly monitored. Power is saved by monitoring the QPCH in noisier environments without increasing the incorrect detection rate. Incorrect detection is reduced in the predetermined range by using an additional receive chain to achieve receive diversity. Although additional power is consumed by the second receive chain in the predetermined range, the power saved by not demodulating the paging message at each slot more than compensates for the additional power consumed by the second receive chain.