US 10,705,222 B2Granted

GNSS multipath mitigation using slope-based code discriminator

AssigneeTrimble Inc.

InventorsWilliam Lentz, Nicholas Talbot

Life of this patent

Estimating the term…

Loading patent…

Abstract

A GNSS receiver for generating distance estimates from multiple GNSS satellites. The GNSS receiver includes an antenna and an RF front end coupled to the antenna configured to generate a plurality of samples related to a received signal. The GNSS receiver includes a correlator coupled to the RF front end configured to perform various operations including performing three correlations on the plurality of samples with three local code to generate three correlation results, where the three local codes are shifted in time or distance with respect to each other. The GNSS receiver includes a processor for defining a first slope using the first correlation result and the second correlation result, defining a second slope using the second correlation result and the third correlation result, and defining a code discriminator as a sum of the first slope and the second slope.

Claims12

Dependent claims

A global navigation satellite system (GNSS) receiver comprising:

an antenna for receiving wireless signals transmitted by a GNSS satellite;
a radio frequency (RF) front end coupled to the antenna and configured to generate a plurality of samples related to the wireless signals;
a correlator coupled to the RF front end, the correlator configured to perform operations including:
receiving the plurality of samples from the RF front end;
performing a first correlation on the plurality of samples with a first local code using a first multiplier to generate a first correlation result;
performing a second correlation on the plurality of samples with a second local code using a second multiplier to generate a second correlation result;
and
performing a third correlation on the plurality of samples with a third local code using a third multiplier to generate a third correlation result, wherein the first local code, the second local code, and the third local code are shifted in time or distance with respect to each other;
and
a processor coupled to the correlator, the processor configured to perform actions including:
defining a first slope as a first difference between the first correlation result and the second correlation result;
defining a second slope as a second difference between the second correlation result and the third correlation result;
scaling the second slope by a weighting factor greater than zero and less than one;
and
defining a code discriminator as a sum of the first slope and the scaled second slope.

12 more elements

A correlator for processing a plurality of samples related to wireless signals received from a global navigation satellite system (GNSS) satellite, the correlator configured to perform operations including:

receiving the plurality of samples from a radio frequency (RF) front end coupled to an antenna, the RF front end configured to generate the plurality of samples related to the wireless signals;
performing a first correlation on the plurality of samples with a first local code using a first multiplier to generate a first correlation result;
performing a second correlation on the plurality of samples with a second local code using a second multiplier to generate a second correlation result;
and
performing a third correlation on the plurality of samples with a third local code using a third multiplier to generate a third correlation result, wherein the first local code, the second local code, and the third local code are shifted in time or distance with respect to each other;
wherein a first slope is defined as a first difference between the first correlation result and the second correlation result;
wherein a second slope is defined as a second difference between the second correlation result and the third correlation result;
wherein the second slope is scaled by a weighting factor greater than zero and less than one;
wherein a code discriminator is defined as a sum of the first slope and the scaled second slope.

6 more elements

A method for processing samples related to wireless signals received from a global navigation satellite system (GNSS) satellite, the method comprising:

receiving a plurality of samples from a radio frequency (RF) front end coupled to an antenna, the RF front end configured to generate the plurality of samples related to the wireless signals;
performing a first correlation on the plurality of samples with a first local code to generate a first correlation result;
performing a second correlation on the plurality of samples with a second local code to generate a second correlation result;
performing a third correlation on the plurality of samples with a third local code to generate a third correlation result, wherein the first local code, the second local code, and the third local code are shifted in time or distance with respect to each other;
defining a first slope as a first difference between the first correlation result and the second correlation result;
defining a second slope as a second difference between the second correlation result and the third correlation result;
scaling the second slope by a weighting factor greater than zero and less than one;
and
defining a code discriminator as a sum of the first slope and the scaled second slope.

6 more elements

Dependencies are inferred from the claim text.