G - Physics – 01 – S
Patent
G - Physics
01
S
G01S 5/14 (2006.01) H04B 1/10 (2006.01) H04L 7/033 (2006.01) H04B 1/69 (2006.01)
Patent
CA 2525798
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.
Hatch Ronald Ray
Stansell Thomas Atlee Jr.
Borden Ladner Gervais Llp
Hatch Ronald Ray
Leica Geosystems Inc.
LandOfFree
Mitigation of multipath effects in global positioning system... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mitigation of multipath effects in global positioning system..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mitigation of multipath effects in global positioning system... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1747310