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

• US 7,123,924 B2
• Filed: 12/27/2002
• Issued: 10/17/2006
• Est. Priority Date: 06/28/2002
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Cuffaro, Angelo
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US10/330,637
• Publication Number:
  US 20040203905A1
• Time in Patent Office: 1,390 Days
• Field of Search: 455/427, 455429-430, 455/435.1, 455/435.2, 455/436, 455439-441, 455/67.11, 455/550.1, 455/561, 455/562.1, 342/107, 342/113
• US Class Current: 455/456.1
• 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 for determining a position, speed and direction of movement of a wireless transmit/receive unit (WTRU), the method comprising:

transmitting wireless communication signals from a network station 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;

a WTRU receiving a plurality of the transmitted directional beams, including beam identifying information for each of the received beams;

for each of the plurality of received beams, the WTRU measuring the respective received signal strength and storing respective beam identifying information data with respective measured received signal strength data;

the WTRU transmitting to the network station stored beam identifying information data and received signal strength data for the plurality of received beams; and

the WTRU receiving, measuring, storing and transmitting steps being performed with respect to a selected number of no less than three directional beams successively transmitted from the network station; and

estimating the position, speed and direction of movement of the WTRU using beam identifying information data and received signal strength data for the plurality of received beams received from the WTRU, the WTRU receiving, measuring, storing and transmitting steps being performed with respect to a selected number of no less than three directional beams successively transmitted from the network station.

2. The method according to claim 1 wherein:

the storing of beam identifying information data for each beam includes storing a direction of the beam, a time the beam was sent and a transmit power of the beam; and

the estimating the position, speed and direction of movement of the WTRU includes;

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.

3. The method according to claim 2 wherein the distance from the network station to the WTRU is estimated using one of:

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

4. The method according to claim 1 wherein the transmitting directional beams is performed by a network station of a wireless communication network.

5. A network station for a wireless communication network configured to provide communication services in a geographic area of service to wireless transmit/receive units (WTRUs), the network station comprising:

a transmitter configured to periodically generate 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;

the transmitter configured to generate the directional beams such that each directional beam includes directional beam identifying information data that at least includes transmission sector identification information; and

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 for a plurality of network station transmitted beams from which an estimate of location, speed and direction of movement of the respective WTRU can be derived.

6. The network station according to claim 5 wherein:

the transmitter 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;

the receiver is configured to receive data sets of beam identifying information data and WTRU received signal strength data with respect to a predetermined number, not less than three, of network station transmitted beams.

7. The invention according to claim 5 further comprising a controller operatively associated with the receiver 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.

8. The invention according to claim 7 wherein:

the transmitter 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;

the receiver is configured to receive data sets of beam identifying information data and WTRU received signal strength data with respect to a predetermined number, not less than three, of network station transmitted beams.

9. The invention according to claim 7 wherein

the receiver 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.

10. The invention according to claim 9 wherein:

the transmitter 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;

the receiver is configured to receive data sets of beam identifying information data and WTRU received signal strength data with respect to a predetermined number, not less than three, of network station transmitted beams.

11. 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 WTRU comprising:

a receiver configured to receive directional beams including beam identifying information transmitted by a network station and to measure the strength of the received beams;

a memory operatively associated with the receiver for storing the beam identifying information and received signal strength for a plurality of beams; and

a transmitter operatively associated with the memory and configure to transmit to the network sets of collected beam identifying information data and received signal strength data for a plurality of beams; and

the memory configured to store and the transmitter 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.