Enhanced gnss receiver

• US 20040113837A1
• Filed: 01/22/2004
• Published: 06/17/2004
• Est. Priority Date: 06/14/2000
• Status: Active Grant

• Current Assignee: Stephen E. Heppe
• Original Assignee: Stephen E. Heppe
• Inventors: Heppe, Stephen
• Granted Patent: US 6,873,288 B2
• Time in Patent Office: Days
• US Class Current: 342/357.12
• CPC Class Codes: G01S 19/22 Multipath-related issues
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 3/74 Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14
• CPC Class Codes: H04B 1/7085 using a code tracking loop, e.g. a delay-locked loop

Abstract

An improved GPS or GNSS receiver can operate at low signal levels and in the presence of RF interference including multipath. Three separate technologies known in the prior art are integrated: a) vector tracking of multiple parameters in a multi-dimensional state space; b) fast correlation processing (107) of GPS or GNSS signals; and c) multiple signal characterization based on eigenvalue/eigenvector analysis of correlation matrices.

Claims

1. A GNSS receiver for tracking desired ranging signals, the GNSS receiver comprising:

a) a vector tracking loop for tracking the desired ranging signals in accordance with estimated direct and reflected signal arrival times of the desired ranging signals; and

b) cross correlation processing means for estimating the direct and reflected signal arrival times and for supplying the estimated direct and reflected signal arrival times to the vector tracking loop.

2. The GNSS receiver of claim 1, further comprising DLL means for forming a local replica of at least one of the desired ranging signals in accordance with a plurality of reflected signals identified by the cross correlation processing means.

3. The GNSS receiver of claim 2, further comprising means for estimating an arrival time of said at least one of the desired ranging signals using a super-resolution technique.

4. The GNSS receiver of claim 3, wherein the super-resolution technique is MUSIC.

5. The GNSS receiver of claim 3, wherein the super-resolution technique is ICON.

6. A GNSS receiver for tracking desired ranging signals, the GNSS receiver comprising:

a) a vector tracking loop for tracking the desired ranging signals in accordance with estimated direct and reflected signal arrival times of the desired ranging signals and in accordance with initialization and acquisition aiding data;

b) cross correlation processing means for estimating the direct and reflected signal arrival times and for applying the direct and reflected signal arrival times to the vector tracking loop; and

c) means for receiving the initialization and acquisition aiding data via an external communications system and for applying the initialization and acquisition aiding data to the vector tracking loop.

7. The GNSS receiver of claim 6, further comprising DLL means for forming a local replica of at least one of the desired ranging signals in accordance with a plurality of reflected signals identified by the cross correlation processing means.

8. The GNSS receiver of claim 7, further comprising means for estimating an arrival time of said at least one of the desired ranging signals using a super-resolution technique.

9. The GNSS receiver of claim 8, wherein the super-resolution technique is MUSIC.

10. The GNSS receiver of claim 8, wherein the super-resolution technique is ICON.