-
公开(公告)号：CA2317143A1
公开(公告)日：2001-03-07
申请号：CA2317143
申请日：2000-08-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN , CHIANG TUNG CHING , TEKIN IBRAHIM , CHEN BYRON HUA
Abstract: Disclosed is a method and apparatus for facilitating detection of satellite signals using a dynamic integration technique in which integration time periods of correlators are adjusted according to signal strength measurements of satellite signals received at GPS receivers. Specifically, integration time periods are inversely adjusted, either proportionally or non-proportionally, to received strengths of signals being searched.
-
公开(公告)号：AU3522201A
公开(公告)日：2001-10-25
申请号：AU3522201
申请日：2001-04-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN
Abstract: An integrated wireless-global positioning system determines the location of a wireless terminal from satellite measurements and wireless network measurements. The accuracy of the location identified is dependent upon the quality of the measurement from the wireless network which, unfortunately, can contain measurement errors such as biases. Biases are caused by time delays which occur during the processing and transmission of signals. The time delays vary for each sector/base station and for each type of wireless terminal model being used. Calibration of these biases is important for the success of the integrated wireless global positioning system. For a small network system which has only a handful of base stations/wireless terminals, a specific system to calibrate the time delays for each base station and/or wireless terminal can be set up. The approach is, however, costly, time consuming, and subject to many errors. It is not feasible for a large scale, commercial system where hundreds of base stations and dozens of different types of wireless terminals are involved. This invention is a method of using an integrated wireless global positioning system to obtain pilot phase offset delay parameters, to continuously improve the quality of the values obtained, and to adaptively adjust the parameters for changes that may occur. The method does not require that a particular system be set up for the calibration, and it does not require a team of technical experts to perform field calibrations. With this method, the wireless terminals that have unobstructed reception of global positioning system signals are used to determine an estimate of the pilot phase offset time delay parameters which are then used to update previously obtained parameters in the database. The estimated pilot phase offset time delay parameter is then used to calibrate the pilot phase offset measurements applied to fix the position of a wireless terminal that does not have unobstructed GPS signal reception.
-
公开(公告)号：ID29166A
公开(公告)日：2001-08-09
申请号：ID20010111
申请日：2001-02-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN , VANNUCCI GIOVANNI
Abstract: Estimated Global Position System (GPS) navigation data is used to increase the signal integration interval. In one embodiment, a WAG (wireless assisted GPS) server receives GPS signals and demodulates the navigation data modulated onto the GPS signals. The WAG server utilizes known features of the demodulated navigation data to generate estimated navigation data for the satellite. This estimation can be made several seconds or even minutes ahead of time. The wireless terminal uses this estimated navigation data to perform a data wipe-off operation to enable the integration interval to be increased (e.g., beyond 20 ms), thereby increasing overall signal-detection sensitivity at the wireless terminal. In another embodiment, information from strong GPS signals is used to detect weak GPS signals from other satellites. In this embodiment, strong GPS signals are received directly by the wireless terminal from the satellites. After strong GPS signals have been detected, the strong GPS signals are demodulated to compute satellite ephemerides including navigation data. The demodulated navigation data is then matched with known features of the navigation data to estimate the navigation data for weak GPS signals. The estimated navigation data is then used to increase the integration interval for weak GPS signals so that weak GPS signals can also be detected at the wireless terminal.
-
公开(公告)号：CA2340519C
公开(公告)日：2005-06-07
申请号：CA2340519
申请日：2001-03-13
Applicant: LUCENT TECHNOLOGIES INC
Inventor： VANNUCCI GIOVANNI , DA REN
Abstract: An improved code acquisition scheme for faster acquisition of GPS "coarse acquisition" (C/A) codes leads to faster detection of GPS signals, and thereby a wireless terminal ma y determine its position in a shorter period of time. The scheme is a combination of a frequency-domain an d time-domain code acquisition techniques. The scheme utilizes a frequency-domain code acquisition techniqu e to detect one GPS signal and to create a precise timing reference at the wireless terminal, and then utilizes time-domain code acquisition techniques to detect other GPS signals from the same satellite or other satellites faster. The scheme has the advantage of being able to be used for any wireless communications system without the requirement of maintaining a precise timing reference in the wireless terminals, and withou t the requirement of heavy computational resources that are usually needed in systems that utilize frequency-domain code acquisition techniques.
-
公开(公告)号：BR0100209A
公开(公告)日：2001-10-09
申请号：BR0100209
申请日：2001-01-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN , VANNUCCI GIOVANNI
Abstract: Estimated Global Position System (GPS) navigation data is used to increase the signal integration interval. In one embodiment, a WAG (wireless assisted GPS) server receives GPS signals and demodulates the navigation data modulated onto the GPS signals. The WAG server utilizes known features of the demodulated navigation data to generate estimated navigation data for the satellite. This estimation can be made several seconds or even minutes ahead of time. The wireless terminal uses this estimated navigation data to perform a data wipe-off operation to enable the integration interval to be increased (e.g., beyond 20 ms), thereby increasing overall signal-detection sensitivity at the wireless terminal. In another embodiment, information from strong GPS signals is used to detect weak GPS signals from other satellites. In this embodiment, strong GPS signals are received directly by the wireless terminal from the satellites. After strong GPS signals have been detected, the strong GPS signals are demodulated to compute satellite ephemerides including navigation data. The demodulated navigation data is then matched with known features of the navigation data to estimate the navigation data for weak GPS signals. The estimated navigation data is then used to increase the integration interval for weak GPS signals so that weak GPS signals can also be detected at the wireless terminal.
-
Patent Agency Ranking
公开(公告)号：AU3131801A
公开(公告)日：2001-10-04
申请号：AU3131801
申请日：2001-03-26
Applicant: LUCENT TECHNOLOGIES INC
Inventor： TEKIN IBRAHIM , DA REN , CHEN BYRON HUA
Abstract: Weighted ridge regression (WRR) processing is applied to three or more distance measurements to determine the location of a terminal. For example, in an integrated satellite-based navigation system / wireless network, the location of a mobile unit can be determined by applying WRR processing to at least three distance measurements, where one or more of the distance measurements are satellite-based distance measurements (e.g., GPS pseudorange measurements) and one or more are wireless network-based distance measurements (e.g., round-trip delay or pilot phase offset measurements). WRR processing provides improved accuracy in the determination of mobile unit position over conventional least mean square techniques.
-
公开(公告)号：BR0003858A
公开(公告)日：2001-04-03
申请号：BR0003858
申请日：2000-08-29
Applicant: LUCENT TECHNOLOGIES INC
Inventor： TEKIN IBRAHIM , CHEN BYRON HUA , CHIANG TUNG CHING , DA REN
Abstract: Disclosed is a method and apparatus for facilitating detection of satellite signals using a dynamic integration technique in which integration time periods of correlators are adjusted according to signal strength measurements of satellite signals received at GPS receivers. Specifically, integration time periods are inversely adjusted, either proportionally or non-proportionally, to received strengths of signals being searched.
-
公开(公告)号：CA2338615A1
公开(公告)日：2001-10-20
申请号：CA2338615
申请日：2001-02-27
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN
Abstract: An integrated wireless-global positioning system determines the location of a wireless terminal from satellite measurements and wireless network measurements. The accuracy of the location identified is dependent upon the quality of the measurement from th e wireless network which, unfortunately, can contain measurement errors such as biases. Biases are caused by time delays which occur during the processing and transmission of signals. The ti me delays vary for each sector/base station and for each type of wireless terminal model being used. Calibration of these biases is important for the success of the integrated wireless global positioning system. For a small network system which has only a handful of base stations/wireless terminals, a specific system to calibrate the time delays for each base station and/or wireless terminal can be set up. The approach is, however, costly, time consuming, and subject to many errors . It is not feasible for a large scale, commercial system where hundreds of base stations and dozens of different types of wireless terminals are involved. This invention is a method of usin g an integrated wireless global positioning system to obtain pilot phase offset delay parameters, to continuously improve the quality of the values obtained, and to adaptively adjust the parameters for changes that may occur. The method does not require that a particular system be set up for the calibration, and it does not require a team of technical experts to perform field calibrations. With this method, the wireless terminals that have unobstructed reception of global positionin g system signals are used to determine an estimate of the pilot phase offset time delay parameter s which are then used to update previously obtained parameters in the database. The estimated pilo t phase offset time delay parameter is then used to calibrate the pilot phase offset measurement s applied to fix the position of a wireless terminal that does not have unobstructed GPS signal reception.
-
公开(公告)号：CA2337300A1
公开(公告)日：2001-09-30
申请号：CA2337300
申请日：2001-02-15
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN , CHEN BYRON HUA , TEKIN IBRAHIM
Abstract: Weighted ridge regression (WRR) processing is applied to three or more distance measurements to determine the location of a terminal. For example, in an integrated satellite-based navigation system / wireless network, the location of a mobi le unit can be determined by applying WRR processing to at least three distance measurement s, where one or more of the distance measurements are satellite-based distance measurements (e.g., GPS pseudorange measurements) and one or more are wireless network- based distance measurements (e.g., round-trip delay or pilot phase offset measurements). WRR processing provides improved accuracy in the determination of mobile un it position over conventional least mean square techniques.
-
公开(公告)号：ID27183A
公开(公告)日：2001-03-08
申请号：ID20000759
申请日：2000-09-06
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DA REN , VANNUCCI GIOVANNI
Abstract: Disclosed is a method and apparatus for facilitating detection of satellite signals using a sequential search technique. The sequential search technique is a knowledge based technique that sequentially searches for satellite signals based on search messages and information accumulated during prior searches to effectively reduce the area and code phase search range in which a GPS receiver searches for the satellite signals, thereby enhancing detection of the satellite signals.
-
-
-
-
-
-
-
-
-
Search Results
28
records
(took 0.023 seconds)
