Locating a wireless user

• US 20040062220A1
• Filed: 09/16/2003
• Published: 04/01/2004
• Est. Priority Date: 09/06/1994
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: LaVean, Gilbert E., Bolgiano, D. Ridgely
• Granted Patent: US 8,248,988 B2
• Time in Patent Office: Days
• US Class Current: 370/334
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/082 selecting best antenna path
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04B 7/0888 with selection
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A plurality of antennas transmit a first spread spectrum signal having an associated code. The first spread spectrum signal is received at the wireless user. For each received first spread spectrum signal, a second spread spectrum signal is transmitted having an associated code having a same phase as that received first spread spectrum signal. The second spread spectrum signals are received at the plurality of antennas. A distance measurement is determined between each antenna and the wireless user based on in part a received timing of the second signals. The wireless user'"'"'s location is determined based on in part the distance determinations.

Claims

1. A method for locating a wireless user, the method comprising:

transmitting from a plurality of antennas a first spread spectrum signal having an associated code;

receiving of the first spread spectrum signals at the wireless user;

for each received first spread spectrum signal, transmitting a second spread spectrum signal having an associated code having a same phase as that received first spread spectrum signal;

receiving the second spread spectrum signals at the plurality of antennas;

determining a distance measurement between each antenna and the wireless user based on in part a received timing of the second signals; and

determining the wireless user'"'"'s location based on in part the distance determinations.

2. The method of claim 1 wherein the determining of the wireless user'"'"'s location is performed at the wireless user.

3. The method of claim 2 further comprising the antennas transmit the distance determinations to the wireless user.

4. The method of claim 3 further comprising the wireless user receiving the distance determinations.

5. A wireless communication system for geographically locating a wireless user, the system comprising:

means for transmitting from a plurality of antennas a first spread spectrum signal having an associated code;

means for receiving of the first spread spectrum signals at the wireless user;

means for each received first spread spectrum signal, for transmitting a second spread spectrum signal having an associated code having a same phase as that received first spread spectrum signal;

means for receiving the second spread spectrum signals at the plurality of antennas;

means for determining a distance measurement between each antenna and the user based on in part a received timing of the second signals; and

means for determining the wireless user'"'"'s location based on in part the distance determinations.

6. A wireless user capable of being located, the wireless user comprising:

means for receiving of first spread spectrum signals transmitted from a plurality of antennas;

means for each received first spread spectrum signal, for transmitting a second spread spectrum signal having an associated code having a same phase as that received first spread spectrum signal;

means for receiving a range determination from each of the plurality of antennas; and

means for determining a location of the wireless user using the received range determinations.