CA2525798A1 - Mitigation of multipath effects in global positioning system receivers - Google Patents
Mitigation of multipath effects in global positioning system receivers Download PDFInfo
- Publication number
- CA2525798A1 CA2525798A1 CA002525798A CA2525798A CA2525798A1 CA 2525798 A1 CA2525798 A1 CA 2525798A1 CA 002525798 A CA002525798 A CA 002525798A CA 2525798 A CA2525798 A CA 2525798A CA 2525798 A1 CA2525798 A1 CA 2525798A1
- Authority
- CA
- Canada
- Prior art keywords
- multipath
- signals
- code
- received
- mmw
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
- H04J13/0007—Code type
- H04J13/0022—PN, e.g. Kronecker
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
- Mobile Radio Communication Systems (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
A technique for minimizing or eliminating the effect of multipath signals in a receiver processing pseudorandom (PRN) code signals, such as in a global positioning system (EPS) receiver. The presence of multipath signals adversely affects both node measurements and carrier phase measurements of received PRN signals. One aspect of the invention provides for improved code tracking in the presence of multipath signals, by sampling the received code with a multipath mitigation window (MMW) (FIG. 25D) that results in a code error function (FIG. 25F) that reduces or eliminates the multipath effects. The MMW, which stay by any of a number of preferred waveforms (FIGS. 35b-358), provides a code error function that varies in opposite directions from zero at a desired tracking point (402), but assumes a nearly zero value when the MMW is advanced from the tracking or synchronization point by more than a small fraction of a code chip. Because of this nearly zero code error value on the early side of the desired tracking paint, delayed multipath signals will have a corresponding code error function that is nearly zero (FIG. 25F) at the desired tracking point of the directly received signals, and the multipath signals will, therefore, have little or no effect on the desired tracking point and on code synchronization. The effects of multipath signals on carrier phase measurements are minimized by sampling the received signals, together with their possible multipath components, before and immediately after code transitions (vectors A and B respectively). The vector relationship of the directly received (D) and multipath (M) signals is such that performing a vector average of the two types of samples (A and B) produces the directly received signal (D) and its correct phase, with many, if not all, of the multipath components (M) eliminated.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/449,215 | 1995-05-24 | ||
US08/449,215 US6023489A (en) | 1995-05-24 | 1995-05-24 | Method and apparatus for code synchronization in a global positioning system receiver |
CA002221969A CA2221969C (en) | 1995-05-24 | 1996-05-24 | Mitigation of multipath effects in global positioning system receivers |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002221969A Division CA2221969C (en) | 1995-05-24 | 1996-05-24 | Mitigation of multipath effects in global positioning system receivers |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2525798A1 true CA2525798A1 (en) | 1996-11-28 |
CA2525798C CA2525798C (en) | 2008-08-12 |
Family
ID=35610460
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA2525598A Expired - Lifetime CA2525598C (en) | 1995-05-24 | 1996-05-24 | Mitigation of multipath effects in global positioning system receivers |
CA002525798A Expired - Lifetime CA2525798C (en) | 1995-05-24 | 1996-05-24 | Mitigation of multipath effects in global positioning system receivers |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA2525598A Expired - Lifetime CA2525598C (en) | 1995-05-24 | 1996-05-24 | Mitigation of multipath effects in global positioning system receivers |
Country Status (1)
Country | Link |
---|---|
CA (2) | CA2525598C (en) |
-
1996
- 1996-05-24 CA CA2525598A patent/CA2525598C/en not_active Expired - Lifetime
- 1996-05-24 CA CA002525798A patent/CA2525798C/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
CA2525598C (en) | 2010-04-13 |
CA2525598A1 (en) | 1996-11-28 |
CA2525798C (en) | 2008-08-12 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKEX | Expiry |
Effective date: 20160524 |