Apparatus and method for locating user equipment using global positioning system and dead reckoning

• US 20040027278A1
• Filed: 01/07/2003
• Published: 02/12/2004
• Est. Priority Date: 01/07/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Byung-Jun
• Granted Patent: US 7,298,323 B2
• Time in Patent Office: Days
• US Class Current: 342/357.14
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled

Abstract

An apparatus and method for locating a UE using a GPS and a dead-reckoning sensor are disclosed. At an initial time, the UE calculates its initial position and the initial position of a serving Node B using a received GPS satellite signal and calculates a first distance between the UE and the Node B based on a first RTT received from the Node B. A predetermined time later, the UE calculates a second distance between the UE and the Node B based on a second RTT received from the Node B, calculates the distance that it has moved using the first and second distances and its position angle measured the predetermined time later, and calculates a displacement in correspondence with the distance using the position angle. Then the position of the UE is obtained by adding the displacement to the initial position of the UE.

Claims

1. An apparatus for locating a UE (User Equipment) using a GPS (Global Positioning System) and dead reckoning, comprising:

a dead-reckoning (DR) sensor for sensing the position angle of the UE with respect to a reference DR point;

a GPS processor for receiving a signal from a GPS satellite and calculating a code pseudorange and a carrier pseudorange rate between the UE and the GPS satellite using the received signal; and

a position detector for calculating the initial positions of the UE and a serving Node B using the code pseudorange and the carrier pseudorange rate at an initial time, calculating a first distance between the UE and the Node B using information about a first RTT (Round Trip Time) received from the Node B at the initial time, calculating a second distance between the UE and the Node B using information about a second RTT received from the Node B at a predetermined time after the initial time, calculating a distance that the UE has moved from the initial time to the predetermined time using the first and second distances and the position angle of the UE at the predetermined time, calculating a displacement using the distance and the position angle, and determining the position of the UE at the predetermined time by adding the displacement to the initial position of the UE.

2. The apparatus of claim 1, wherein the position detector comprises:

a MODEM for receiving information about the first and second RTTs from the Node B; and

a position estimator for calculating the initial positions of the UE and the Node B using the code pseudorange and the carrier pseudorange rate at the initial time, calculating the first distance using the first RTT, calculating the second distance using the second RTT at the predetermined time after the initial time, calculating the distance that the UE has moved from the initial time to the predetermined time using the first and second distances and a position angle of the UE measured at the predetermined time, calculating the displacement in correspondence with the distance using the position angle, and estimating the sum of the displacement and the initial position of the UE as the position of the UE at the predetermined time.

3. The apparatus of claim 1, wherein the DR sensor is a gyro sensor.

4. An apparatus for locating a UE (User Equipment) using a GPS (Global Positioning System) and dead reckoning, comprising:

a dead-reckoning (DR) sensor for sensing the position angle of the UE with respect to a reference DR point;

a GPS processor for receiving a signal from a GPS satellite and calculating a code pseudorange and a carrier pseudorange rate between the UE and the GPS satellite using the received signal;

a velocity sensor for sensing the velocity of the UE;

a position detector for calculating the initial positions of the UE and a serving Node B using the code pseudorange and the carrier pseudorange rate at an initial time, calculating a distance that the UE has moved from the initial time to a predetermined time after the initial time using a velocity of the UE measured at the predetermined time, calculating a displacement in correspondence with the distance using a position angle of the UE measured at the predetermined time, and determining the position of the UE at the predetermined time by adding the displacement to the initial position of the UE.

5. The apparatus of claim 4, wherein the DR sensor is a gyro sensor.

6. The apparatus of claim 4, wherein the position detector calculates the distance that the UE has moved by integrating the velocity measured at the predetermined time over the time between the initial time and the predetermined time.

7. A method of locating a UE (User Equipment) using a GPS (Global Positioning System) and dead reckoning, comprising the steps of:

calculating the initial positions of the UE and a serving Node B using a signal received from a GPS satellite at an initial time;

calculating a first distance between the UE and the Node B using information about a first RTT (Round Trip Time) received from the Node B at the initial time;

calculating a second distance between the UE and the Node B using information about a second RTT received from the Node B at a predetermined time after the initial time; and

calculating a distance that the UE has moved from the initial time to the predetermined time using the first and second distances and a position angle of the UE measured at the predetermined time, calculating a displacement in correspondence with the distance using the position angle, and determining the position of the UE at the predetermined time by adding the displacement to the initial position of the UE.

8. The method of claim 7, wherein the initial position calculation step comprises the steps of:

calculating a code pseudorange and a carrier pseudorange rate between the GPS satellite and the UE using the received GPS satellite signal; and

calculating the initial positions of the UE and the Node B at the initial time using the code pseudorange and the carrier pseudorange rate.

11. The method of claim 7, wherein the position angle is measured with respect to a predetermined reference dead-reckoning (DR) point.

9. A method of locating a UE (User Equipment) using a GPS (Global Positioning System) and dead reckoning, comprising the steps of:

calculating the initial positions of the UE and a serving Node B at an initial time; and

calculating a distance that the UE has moved from the initial time to a predetermined time after the initial time using a velocity of the UE measured at the predetermined time, calculating a displacement in correspondence with the distance using a position angle of the UE measured at the predetermined time, and determining the position of the UE at the predetermined time by adding the displacement to the initial position of the UE.

10. The method of claim 9, wherein the initial position calculation step comprises the steps of:

calculating a code pseudorange and a carrier pseudorange rate between the GPS satellite and the UE using a signal received from a GPS satellite at the initial time; and

calculating the initial positions of the UE and the Node B at the initial time using the code pseudorange and the carrier pseudorange rate.

12. The method of claim 9, wherein the position angle is measured with respect to a predetermined reference DR point.