公开(公告)号：EP1969729A2

公开(公告)日：2008-09-17

申请号：EP06846522.8

申请日：2006-12-07

申请人： SiRF Technology, Inc.

发明人： RAMAN, Sundar ,  ABTAHI, Reza ,  GRONEMEYER, Steven, A. ,  CHOU, Andrew

IPC分类号： H04B1/707

CPC分类号： G01S19/30 ,  G01S19/21 ,  H04B1/7075 ,  H04B1/70755 ,  H04B1/708 ,  H04B1/7085 ,  H04B1/7097 ,  H04B1/7103 ,  H04B2201/70715

摘要： A communication device with cross-correlation detection based upon statistical tests to determine whether the off-peak signal energy is consistent with auto-correlation or cross-correlation energy levels.

公开(公告)号：EP1565762A2

公开(公告)日：2005-08-24

申请号：EP02773144.7

申请日：2002-02-11

申请人： Sirf Technology, Inc.

发明人： VAN ROY, Benjamin ,  TSITSIKLIS, John ,  CHOU, Andrew

IPC分类号： G01S1/00

CPC分类号： G01S19/09 ,  G01S19/42 ,  G01S2205/008

摘要： Some embodiments of the invention provide a location-determination system that includes a number of transmitters and at least one receiver. Based on a reference signal received by the receiver, this location-determination system identifies an estimated location of the receiver within a region. In some embodiments, the system selects one or more locations within the region. For each particular selected location, the system calculates a metric value that quantifies the similarity between the received signal and the signal that the receiver could expect to receive at the particular location, in the absence or presence of interference. Based on the calculated metric value or values, the system identifies the estimated location of the receiver.

公开(公告)号：EP1419401B1

公开(公告)日：2009-08-12

申请号：EP02783975.2

申请日：2002-09-07

申请人： SiRF Technology, Inc.

发明人： SAHAI, Anant ,  CHOU, Andrew

IPC分类号： G01S1/04

CPC分类号： G01S19/29 ,  G01S19/09 ,  G01S19/22 ,  G01S19/30

摘要： System and method to determine the location of a receiver are provided. The received signal is decomposed into signal chunks that are then correlated with the reference signals of the transmitting sources. In some embodiments, the signal chunks may be shorter than the period of the reference signals. For each signal source, a grid of correlation values is constructed containing one column of correlation values for each signal chunk. Each column contains correlation values for several code-phases. Probes are executed in the grid to acquire the location-determining signals. In some embodiments, a probe includes calculating the fourier transform of a row in the grid, yielding correlation values associated with a refined set of frequency values. Potential acquisitions are verified by processing increasing portions of the received signal. Confirmed acquisition may be used to aid further acquisitions. Some embodiments eventually compress the received signal down to a one period duration by means of an ultra-stacking method. Additional verification, comprising multi-peak tests and multi-path tests, may be performed on the correlation magnitude curve obtained from the ultra- stacked signal. Finally, refined code-phase values are extracted from these correlation magnitude curves.

公开(公告)号：EP1449005B1

公开(公告)日：2009-03-25

申请号：EP02752163.2

申请日：2002-06-21

申请人： SiRF Technology, Inc.

发明人： SAHAI, Anant ,  TSITSIKLIS, John ,  VAN ROY, Benjamin ,  CHOU, Andrew ,  MANN, Wallace ,  STONE, Jesse, R. ,  FONG, WungKum

IPC分类号： G01S1/04

CPC分类号： G01S19/30

摘要： According to one aspect of the invention, sampled data that is received from a receiver is divided into segments of data of increasing length. A current value range for a delay value and a current value range for a modulation frequency value are calculated relative to each signal source from a set of signal sources that are overhead the signal receiver. An estimate for the delay value and an estimate for the modulation frequency value are calculated by iteratively updating the current value range for the delay value and for the modulation frequency value. The iterative update of the current value range for the delay value and for the modulation frequency value is performed overthe set of signal sources and over the segments of data of increasing length. According to another aspect of the technique, for each signal source, I and Q correlation integrals and their magnitude value are calculated corresponding to the estimate of the modulation frequency value and the estimate of the delay value. In addition, for each signal source, I and Q correlation integrals and thier magnitude values are calculated corresponding to a set of delay values that surround the estimate of the delay value. A shape of a magnitude-curve is interpolated using the magnitude values corresponding to the estimate of the delay value and corresponding to the set of delay values that surround the estimate of the delay value. The location of the receiver is calculated using the shape of the magnitude-curve to represent the I and Q correlation integrals for each signal source.

公开(公告)号：EP1449005A2

公开(公告)日：2004-08-25

申请号：EP02752163.2

申请日：2002-06-21

申请人： SiRF Technology, Inc.

发明人： SAHAI, Anant ,  TSITSIKLIS, John ,  VAN ROY, Benjamin ,  CHOU, Andrew ,  MANN, Wallace ,  STONE, Jesse, R. ,  FONG, WungKum

IPC分类号： G01S1/04

CPC分类号： G01S19/30

摘要： According to one aspect of the invention, sampled data that is received from a receiver is divided into segments of data of increasing length. A current value range for a delay value and a current value range for a modulation frequency value are calculated relative to each signal source from a set of signal sources that are overhead the signal receiver. An estimate for the delay value and an estimate for the modulation frequency value are calculated by iteratively updating the current value range for the delay value and for the modulation frequency value. The iterative update of the current value range for the delay value and for the modulation frequency value is performed overthe set of signal sources and over the segments of data of increasing length. According to another aspect of the technique, for each signal source, I and Q correlation integrals and their magnitude value are calculated corresponding to the estimate of the modulation frequency value and the estimate of the delay value. In addition, for each signal source, I and Q correlation integrals and thier magnitude values are calculated corresponding to a set of delay values that surround the estimate of the delay value. A shape of a magnitude-curve is interpolated using the magnitude values corresponding to the estimate of the delay value and corresponding to the set of delay values that surround the estimate of the delay value. The location of the receiver is calculated using the shape of the magnitude-curve to represent the I and Q correlation integrals for each signal source.