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1. (WO2001039698) MULTIPATH AND TRACKING ERROR REDUCTION METHOD FOR SPREAD-SPECTRUM RECEIVERS
Latest bibliographic data on file with the International Bureau   

Pub. No.: WO/2001/039698 International Application No.: PCT/US2000/032770
Publication Date: 07.06.2001 International Filing Date: 01.12.2000
IPC:
G01S 1/00 (2006.01) ,H04B 1/707 (2011.01)
G PHYSICS
01
MEASURING; TESTING
S
RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
1
Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
H ELECTRICITY
04
ELECTRIC COMMUNICATION TECHNIQUE
B
TRANSMISSION
1
Details of transmission systems, not covered by a single one of groups H04B3/-H04B13/123; Details of transmission systems not characterised by the medium used for transmission
69
Spread spectrum techniques
707
using direct sequence modulation
Applicants:
BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY [US/US]; Suite 350 900 Welch Road Palo Alto, CA 94304, US
Inventors:
PHELTS, R., Eric; US
ENGE, Per; US
Agent:
KAMINSKY, Rena; Suite 110 45 Cabot Avenue Santa Clara, CA 95051, US
Priority Data:
60/168,47201.12.1999US
Title (EN) MULTIPATH AND TRACKING ERROR REDUCTION METHOD FOR SPREAD-SPECTRUM RECEIVERS
(FR) PROCEDE DE REDUCTION D'ERREURS DE RECHERCHE DE TRAJETS MULTIPLES POUR RECEPTEURS A SPECTRE ETALE
Abstract:
(EN) In wireless communications and navigation systems such as GPS, pseudorange measurements are made between a signal transmitter and a signal receiver based on pseudorandom noise codes modulating the transmitted signals. The receiver employes a multipath mitigation method. The method consists of locating a multipath-invariant (MPI) point of an ideal autocorrelation function (126) and measuring the distance between the MPI point and the DLL (130). The same MPI point (134) is located in a received correlation function (132), and the distance between the point and the DLL (136), now affected by multipath, is measured. The difference between the ideal distance and the actual distance is the code tracking error resulting from multipath. The error is substracted from the computed pseudorange or used to control the DLL (138). The method can be used to reduce the effect of all types of tracking error sources, such as signal transmission failure or code noise (140).
(FR) Dans des communications et des systèmes de navigation sans fil tels que le GPS, des mesures de pseudodistance sont effectuées entre un émetteur de signal et un récepteur de signal sur la base de codes de bruit pseudo-aléatoire modulant les signaux transmis. Le récepteur utilise un procédé de restriction de trajets multiples. Le procédé comporte les étapes consistant à localiser un point invariant de trajets multiples (MPI) d'une fonction d'autocorrélation (126) idéale, et à mesurer la distance entre le point MPI et la DLL (130). Ce point MPI (134) est localisé dans une fonction (132) de corrélation reçue, et la distance entre le point et la DLL (136), maintenant affectée par trajets multiples, est mesurée. La différence entre la distance idéale et la distance réelle est l'erreur de recherche de code résultant des trajets multiples. L'erreur est soustraite de la pseudodistance calculée ou utilisée pour commander la DLL (138). Le procédé peut être utilisé pour réduire les effets de tous types de sources d'erreurs de recherche, telles que des défaillances de transmission de signal ou le bruit de code (140).
Designated States: JP
European Patent Office (EPO) (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, TR)
Publication Language: English (EN)
Filing Language: English (EN)