Invention Grant
- Patent Title: Method and apparatus for acquiring and tracking pilots in a CDMA communication system
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Application No.: US09972514Application Date: 2001-10-05
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Publication No.: US07088955B2Publication Date: 2006-08-08
- Inventor: Raghu Challa , Gilbert Christopher Sih
- Applicant: Raghu Challa , Gilbert Christopher Sih
- Applicant Address: US CA San Diego
- Assignee: Qualcomm Inc.
- Current Assignee: Qualcomm Inc.
- Current Assignee Address: US CA San Diego
- Agent Philip R. Wadsworth; Charles D. Brown; George C. Pappas
- Main IPC: H04B1/00
- IPC: H04B1/00 ; H04B15/00

Abstract:
Techniques to acquire and track pilots in a CDMA system. In an aspect, frequency acquisition of a number of signal instances (i.e., multipaths) in a received signal may be achieved concurrently based on a frequency control loop (RAFC) maintained for each finger processor of a rake receiver. Upon successful acquisition, frequency tracking of acquired multipaths may be achieved based on a combination of a frequency control loop (VAFC) maintained for an oscillator used for downconverting the received signal and the RAFCs for the finger processors. In a tracking mode, the VAFC tracks the average frequency of the acquired multipaths by adjusting the frequency of the oscillator. The RAFC of each finger processor tracks the residual frequency error (e.g., due to Doppler frequency shift) of the individual acquired multipath by adjusting the frequency of a complex sinusoidal signal used in a rotator within the finger processor.
Public/Granted literature
- US20030054768A1 Method and apparatus for acquiring and tracking pilots in a CDMA communication system Public/Granted day:2003-03-20
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