Method and system for determining the speed and position of a mobile unit

• US 20060052114A1
• Filed: 10/28/2005
• Published: 03/09/2006
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Cuffaro, Angelo
• Granted Patent: US 7,248,883 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 11/04 using angle measurements
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Apparatus and methods are disclosed for estimating the position and velocity of mobile wireless transmit/receive units (WTRUs) in a wireless communication system. Network stations use directional communication beams to divide service areas into sectors to provide communication services to the WTRUs. A WTRU saves pertinent information such as sector ID, received power and time of reception of the several received signals. The collected information is sent to the network, where it is used to estimate the WTRU'"'"'s position, speed and direction of travel, which information can then be used to improve radio resource management.

Claims

1. A method used by a network station for facilitating the determination of a position, speed and direction of movement of wireless transmit/receive units (WTRUs) within a wireless communication network that provides communication services in a geographic area of service via the network station, the method for the network station comprising:

periodically generating directional beams for providing communication services in sectors of the geographic area of service such that each beam provides service to a predefined sector whereby collectively the directional beams provide service to the entire geographic service area;

generating the directional beams such that each directional beam includes directional beam identifying information data that at least includes transmission sector identification information; and

receiving, from WTRUs receiving transmitted directional beams from the network station, collected data sets with respect to a predetermined number, not less than three, of network station transmitted beams including beam identifying information data and WTRU received signal strength data from which an estimate of location, speed and direction of movement of the respective WTRU can be derived.

2. The method for a network station according to claim 1 wherein:

the periodically generating directional beams is performed such that the directional beam identifying information data for each beam includes the direction the beam is sent, the time the beam is sent and transmission power used to send the beam.

3. The method for a network station according to claim 1 further comprising calculating an estimate of location, speed and direction of movement of WTRUs based on the data sets received from WTRUs receiving transmitted directional beams from the network station.

4. The method for a network station according to claim 3 wherein:

the periodically generating directional beams is performed such that the directional beam identifying information data for each beam includes the direction the beam is sent, the time the beam is sent and transmission power used to send the beam.

5. The method for a network station according to claim 3 wherein

the receiving collected data sets of beam identifying information data is performed such that the beam identifying information data for each beam includes a direction of the beam, a time the beam was sent and a transmit power of the beam;

and

the calculating an estimate of location, speed and direction of movement of a WTRU is performed based on the data sets received from the WTRU related to a plurality of beams by calculating a signal pathloss from the beam identifying information data and received signal strength data, for each of the plurality of beams, estimating, from the calculated pathloss, a distance from the network station known transmission location to the WTRU for each of the plurality of beams, estimating, from the network station known transmission location and the respective estimated distances, a position of the WTRU each of the plurality of beams, and estimating the WTRU'"'"'s speed and direction of movement using the plurality of position estimates in combination with the times the respective beams were sent.

6. The method for a network station according to claim 5 wherein:

the periodically generating directional beams is performed such that the directional beam identifying information data for each beam includes the direction the beam is sent, the time the beam is sent and transmission power used to send the beam.

7. A method for a wireless transmit/receive unit (WTRU) configured for use in a wireless communication network in which network stations transmit wireless communication signals in directional beams such that beams are from time to time transmitted to each area serviced by the respective network station, each beam including beam identifying information, the method for the WTRU comprising:

receiving directional beams including beam identifying information transmitted by a network station and measuring the strength of the received beams;

storing the beam identifying information and received signal strength for a plurality of beams;

transmitting to the network sets of collected beam identifying information data and received signal strength data for a plurality of beams; and

said storing and said transmitting sets of beam identifying information data and received signal strength data is performed with respect to a selected number, no less than three, of successively received beams.

8. A wireless communication network in which communication services for wireless transmit/receive units (WTRUs) is provided by network stations that transmit wireless communication signals in directional beams such that beams are from time to time transmitted to each area serviced by the respective network station, each beam including beam identifying information, the network comprising:

at least one network station having a transmitter configured to transmit wireless communication signals in directional beams from a known location such that beams are from time to time transmitted to each area serviced by the network station, each beam including beam identifying information;

at least one WTRU having a receiver configured to receive a plurality of network station transmitted directional beams, including beam identifying information for each of the received beams and to measure respective received signal strength for each of the plurality of beams received;

said at least one WTRU having a memory configured to store respective beam identifying information data with respective measured received signal strength data;

said at least one WTRU having a transmitter configured to transmit to the network station stored beam identifying information data and received signal strength data for the plurality of received beams; and

said memory of said at least one WTRU configured to store and said transmitter of said at least one WTRU configured to transmit sets of beam identifying information data and received signal strength data for a selected number, no less than three, of successively received beams.

9. A network according to claim 8 wherein said at least one network station includes:

a receiver configured to receive sets of beam identifying information data and received signal strength data from WTRUs; and

an associated controller configured to estimate the position, speed and direction of movement of a particular WTRU using beam identifying information data and received signal strength data for a plurality of received beams received from the particular WTRU in a data set.

10. The network according to claim 9 wherein:

said memory of said at least one WTRU is configured to store beam identifying information data for each beam that includes a direction of the beam, a time the beam was sent and a transmit power of the beam; and

said controller of said at least one network station is configured to;

calculate a signal pathloss from the beam identifying information data and received signal strength data, for each of the plurality of beams;

estimate, from a calculated pathloss, a distance from the network station known transmission location to the WTRU for each of the plurality of beams;

estimate, from a network station known transmission location and respective estimated distances, a position of the WTRU each of the plurality of beams; and

estimate a WTRU'"'"'s speed and direction of movement using the plurality of position estimates in combination with the times the respective beams were sent.

11. The network according to claim 10 wherein said controller of said at least one network station is configured to estimate the distance from the network station to a WTRU using one of:

an environmental factor, a cost-231 Hata model, a plane earth propagation model or a free space model.

12. A network according to claim 8 wherein said at least one network station includes:

a receiver configured to receive from WTRUs receiving transmitted directional beams from the network station collected data sets with respect to a predetermined number, not less than three, of network station transmitted beams including beam identifying information data and WTRU received signal strength data from which an estimate of location, speed and direction of movement of the respective WTRU can be derived.

13. A network according to claim 9 wherein said transmitter of said at least one network station is configured to generate the directional beams such the directional beam identifying information data for each beam includes the direction the beam is sent, the time the beam is sent and transmission power used to send the beam.

14. A network according to claim 12 wherein said at least one network station includes a controller operatively associated with the receiver of said at least one network station and configured to calculate an estimate of location, speed and direction of movement of WTRUs based on the data sets received from WTRUs receiving transmitted directional beams from the network station.

15. A network according to claim 14 wherein said transmitter of said at least one network station is configured to generate the directional beams such the directional beam identifying information data for each beam includes the direction the beam is sent, the time the beam is sent and transmission power used to send the beam.

16. A network according to claim 14 wherein said receiver of said at least one network station is configured to receive data sets of beam identifying information data where the beam identifying information data for each beam includes a direction of the beam, a time the beam was sent and a transmit power of the beam;

and

the controller is configured to calculate an estimate of location, speed and direction of movement of a WTRU based on the data sets received from the WTRU related to a plurality of beams by calculating a signal pathloss from the beam identifying information data and received signal strength data, for each of the plurality of beams, estimating, from the calculated pathloss, a distance from the network station known transmission location to the WTRU for each of the plurality of beams, estimating, from the network station known transmission location and the respective estimated distances, a position of the WTRU each of the plurality of beams, and estimating the WTRU'"'"'s speed and direction of movement using the plurality of position estimates in combination with the times the respective beams were sent.

17. A network according to claim 16 wherein said transmitter of said at least one network station is configured to generate the directional beams such the directional beam identifying information data for each beam includes the direction the beam is sent, the time the beam is sent and transmission power used to send the beam.