公开(公告)号：EP1817604B1

公开(公告)日：2009-01-14

申请号：EP05818514.1

申请日：2005-11-08

申请人： SiRF Technology, Inc.

发明人： BABITCH, Daniel ,  GRONEMEYER, Steven, A. ,  GARIN, Lionel, Jacques ,  PANDE, Ashutosh ,  PENG, Leon, Kuo-Liang ,  ZHANG, Gengsheng ,  VANTALON, Nicolas, Patrick

IPC分类号： G01S1/00 ,  G01S5/02 ,  H03L1/02

CPC分类号： H03J7/065 ,  G01S5/021 ,  G01S19/05 ,  G01S19/17 ,  G01S19/235 ,  H03J2200/12 ,  H03L1/022

摘要： A receiver reference oscillator frequency correction system and method are described that provides a receiver with a greater ability to lock onto relatively weak radio frequency signals by determining and estimating an amount of frequency error in a local frequency reference of the receiver, and using the error estimate to maintain frequency coherence with a received signal, thereby allowing tracking over a longer period of time, enabling longer integration times to capture weaker signals without losing frequency coherence.

公开(公告)号：EP1927013A2

公开(公告)日：2008-06-04

申请号：EP06849183.6

申请日：2006-05-09

申请人： SiRF Technology, Inc.

发明人： ANDERSON, Erik ,  BABITCH, Daniel ,  HASHEMI, Majid

IPC分类号： G01S1/00

CPC分类号： H04B1/28 ,  G01S19/37 ,  H04L2027/0053

摘要： A radio frequency integrated circuit for a global positioning system (GPS) application mixes radio frequency GPS signals to obtain a predetermined intermediate frequency that is less than 4fo. In one embodiment, the intermediate frequency is selected to be 1.5fo. An intermediate frequency filter (204) then band-limits the intermediate frequency GPS signals, rolling off at a frequency in the vicinity of 2.5 MHz to achieve substantial attenuation at 3.5-4.0 MHz. An automatic gain control circuit (206) amplifies the filtered intermediate frequency GPS signals to proper voltage levels. The amplified intermediate frequency GPS signals is then digitized by an analog-to-digital converter (207) at a predetermined sampling rate more than twice the intermediate frequency to provide samples of a predetermined number of bits, which are then provided for base band processing by a general purpose microprocessor over an industry- standard serial bus.

公开(公告)号：EP1817604A1

公开(公告)日：2007-08-15

申请号：EP05818514.1

申请日：2005-11-08

申请人： SiRF Technology, Inc.

发明人： BABITCH, Daniel ,  GRONEMEYER, Steven, A. ,  GARIN, Lionel, Jacques ,  PANDE, Ashutosh ,  PENG, Leon, Kuo-Liang ,  ZHANG, Gengsheng ,  VANTALON, Nicolas, Patrick

IPC分类号： G01S1/00 ,  G01S5/02 ,  H03L1/02

CPC分类号： H03J7/065 ,  G01S5/021 ,  G01S19/05 ,  G01S19/17 ,  G01S19/235 ,  H03J2200/12 ,  H03L1/022

摘要： A receiver reference oscillator frequency correction system and method are described that provides a receiver with a greater ability to lock onto relatively weak radio frequency signals by determining and estimating an amount of frequency error in a local frequency reference of the receiver, and using the error estimate to maintain frequency coherence with a received signal, thereby allowing tracking over a longer period of time, enabling longer integration times to capture weaker signals without losing frequency coherence.