Wireless communication method and apparatus for selecting and reselecting cells based on measurements performed using directional beams and an omni-directional beam pattern

• US 7,324,817 B2
• Filed: 12/30/2004
• Issued: 01/29/2008
• Est. Priority Date: 02/07/2004
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Iacono, Ana Lucia, Stern-Berkowitz, Janet
• Primary Examiner(s): Trost; William
• Assistant Examiner(s): Ewart; James D
• Application Number:
  US11/026,292
• Publication Number:
  US 20050176468A1
• Time in Patent Office: 1,125 Days
• Field of Search: 455/62, 455/63.4, 455/101, 455/269, 455/433, 455/435.1, 455/450, 455/464, 455/550.1, 455/525, 455/562.1, 455/575.7, 4552771-2781, 342/81, 342/154, 342/354, 342/367, 342/368, 343/757, 343/777, 343/824
• US Class Current: 455/435.1
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/0871 using different reception schemes, at least one of them being a diversity reception scheme
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 48/20 Selecting an access point

Abstract

A wireless communication method and apparatus for selecting and reselecting cells used by a wireless transmit/receive unit (WTRU) in a wireless multi-cell communication system. The WTRU includes a switched beam antenna configured to form a plurality of directional beams and an omni-directional beam pattern. The WTRU measures signals from a plurality of cells using the directional beams and the omni-directional beam pattern. The WTRU selects and registers with the cell having the strongest signal. In one embodiment, the WTRU selects a directional beam which has the strongest signal and uses it as an active beam to communicate with the selected cell. In another embodiment, the WTRU selects a cell/beam combination and registers with the selected cell using the selected beam. In yet another embodiment, the WTRU initiates a handoff to a neighboring cell that has a better signal measurement result than the selected cell.

Claims

1. In a wireless communication system including at least one wireless transmit/receive unit (WTRU) and a plurality of cells, the WTRU being configured to include a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern, a cell selection method comprising:

(a) the WTRU performing measurements on signals received from the cells using the directional beams and the omni-directional beam pattern;

(b) the WTRU selecting a cell/beam combination having the strongest signal based on the results of the measurements performed in step (a); and

(c) the WTRU registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

2. The method of claim 1 further comprising:

(d) if the selected beam is not an omni-directional beam pattern, comparing a measurement result which indicates the best directional beam/cell combination with the measurement result which indicates the best omni-directional beam pattern/cell combination.

3. The method of claim 2 wherein a directional beam is selected if the measurement result associated with the directional beam exceeds the measurement result associated with the omni-directional beam pattern by a predetermined threshold, and the omni-directional beam pattern is selected when the measurement result associated with the directional beam does not exceed the measurement result associated with the omni-directional beam pattern.

4. In a wireless communication system including at least one wireless transmit/receive unit (WTRU) and a plurality of cells, the WTRU being configured to include a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern, a cell selection method comprising:

(a) the WTRU performing measurements on signals received from the cells using the omni-directional beam pattern;

(b) the WTRU selecting a subset of the cells based on the results of the measurements performed in step (a);

(c) the WTRU performing measurements on signals received from the subset of cells using each of the directional beams;

(d) the WTRU selecting a cell/beam combination having the strongest signal based on the results of the measurements performed in step (c); and

(e) the WTRU registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

5. In a wireless communication system including a plurality of cells, a wireless transmit/receive unit (WTRU) comprising:

(a) a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern;

(b) means for performing measurements on signals received from the cells using the directional beams and the omni-directional beam pattern;

(c) means for selecting a cell/beam combination having the strongest signal based on the results of the measurements performed using either the directional beams or the omni-directional beam pattern; and

(d) means for registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

6. The WTRU of claim 5 further comprising:

(e) means for comparing a measurement result which indicates the best directional beam/cell combination with the measurement result which indicates the best omni-directional beam pattern/cell combination, if the selected beam is not an omni-directional beam pattern.

7. The WTRU of claim 6 wherein a directional beam is selected if the measurement result associated with the directional beam exceeds the measurement result associated with the omni-directional beam pattern by a predetermined threshold, and the omni-directional beam pattern is selected when the measurement result associated with the directional beam does not exceed the measurement result associated with the omni-directional beam pattern.

8. In a wireless communication system including a plurality of cells, a wireless transmit/receive unit (WTRU) comprising:

(a) a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern;

(b) means for performing measurements on signals received from the cells using the omni-directional beam pattern;

(c) means for selecting a subset of the cells based on the results of the measurements using the omni-directional beam pattern;

(d) means for performing measurements on signals received from the subset of cells using each of the directional beams;

(e) means for selecting a cell/beam combination having the strongest signal based on the results of the measurements performed using each of the directional beams; and

(f) means for registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

9. In a wireless communication system including a plurality of cells, an integrated circuit (IC) operating in conjunction with a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern, the IC comprising:

(a) means for performing measurements on signals received from the cells using the directional beams and the omni-directional beam pattern;

(b) means for selecting a cell/beam combination having the strongest signal based on the results of the measurements performed using either the directional beams or the omni-directional beam pattern; and

(c) means for registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

10. The IC of claim 9 further comprising:

(d) means for comparing a measurement result which indicates the best directional beam/cell combination with the measurement result which indicates the best omni-directional beam pattern/cell combination, if the selected beam is not an omni-directional beam pattern.

11. The IC of claim 10 wherein a directional beam is selected if the measurement result associated with the directional beam exceeds the measurement result associated with the omni-directional beam pattern by a predetermined threshold, and the omni-directional beam pattern is selected when the measurement result associated with the directional beam does not exceed the measurement result associated with the omni-directional beam pattern.

12. In a wireless communication system including a plurality of cells, an integrated circuit (IC) operating in conjunction with a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern, the IC comprising:

(a) means for performing measurements on signals received from the cells using the omni-directional beam pattern;

(b) means for selecting a subset of the cells based on the results of the measurements using the omni-directional beam pattern;

(c) means for performing measurements on signals received from the subset of cells using each of the directional beams;

(d) means for selecting a cell/beam combination having the strongest signal based on the results of the measurements performed using each of the directional beams; and

(e) means for registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

13. In a wireless communication system including at least one wireless transmit/receive unit (WTRU) and a plurality of cells, the WTRU being configured to include a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern, a cell selection method comprising:

(a) the WTRU performing measurements on signals received from the cells using the directional beams;

(b) the WTRU selecting a cell/beam combination having the strongest signal based on the results of the measurements performed in step (a); and

(c) the WTRU registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.

14. In a wireless communication system including a plurality of cells, a wireless transmit/receive unit (WTRU) comprising:

(a) a switched beam antenna for generating a plurality of directional beams and an omni-directional beam pattern;

(b) means for performing measurements on signals received from the cells using the directional beams;

(c) means for selecting a cell/beam combination having the strongest signal based on the results of the measurements performed using either directional beams; and

(d) means for registering with the selected cell using the selected beam as an active beam used for communicating with the selected cell.