Mitigation of wireless transmit/receive unit (WTRU) to WTRU interference using multiple antennas or beams

• US 7,835,700 B2
• Filed: 12/07/2009
• Issued: 11/16/2010
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zeira, Eldad
• Primary Examiner(s): Nguyen; Duc
• Assistant Examiner(s): Rego; Dominic E
• Application Number:
  US12/632,420
• Publication Number:
  US 20100081396A1
• Time in Patent Office: 344 Days
• Field of Search: 455/562.1, 455/63.1, 455/114.1, 455/278.1, 455/296, 455/67.13, 455/135, 455/161.3, 455/277.2, 455/13.3, 455/25, 455/63.4, 455/82, 455/575.7, 370/310, 370/328, 370/330, 370/332
• US Class Current: 455/63.1
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Multiple antenna elements of a WTRU are used to form an adaptive antenna beam pattern for receiving signals in the downlink direction. The WTRU utilizes the formed antenna beam to form a transmission antenna beam for transmitting signals in the uplink direction. In an alternate embodiment, the multiple antenna elements are used to form a plurality of fixed, predetermined antenna beams. The WTRU then selects and switches to the one of the predetermined beams that yields the best downlink reception signals. The WTRU utilizes the selected beam pattern to transmit signals in the uplink direction. In an alternate embodiment, the WTRU receives spectral arrangement information and utilizing this information to avoid transmitting in the direction of spectrally adjacent WRTUs.

Claims

1. A method of reducing wireless transmit/receive unit (WTRU) to WTRU interference in wireless communications, the method comprising:

transmitting from a first WTRU on a first uplink frequency;

receiving at the first WTRU on a first downlink frequency;

receiving at the first WTRU, information relating to a spectral arrangement of a signal environment of the first WTRU, wherein the information includes a second uplink frequency used by another WTRU; and

monitoring the second uplink frequency to determine the location of the other WTRU;

selecting a transmit beam pattern such that the transmissions from the first WTRU are in a direction other than the direction of the other WTRU.

2. The method of claim 1, wherein monitoring the second uplink frequency comprises identifying a high energy signal received on the second uplink frequency.

3. The method of claim 1, wherein the transmit beam pattern is selected from a predetermined set of transmit beams.

4. The method of claim 1 further comprising applying antenna weights to a plurality of antenna elements to produce the transmit beam pattern.

5. The method of claim 1, wherein the transmit beam pattern directs a null toward the other WTRU.

6. The method of claim 1, wherein the information relating to the spectral arrangement of the signal environment includes information relating to another WTRU that has an uplink frequency that is spectrally adjacent to the downlink frequency of the WTRU.

7. A wireless transmit/receive unit (WTRU) configured to reduce WTRU to WTRU interference in wireless communications, comprising:

a receiver configured to receive data transmissions and information relating to the spectral arrangement of the WTRU environment, including a frequency on which another WTRU is transmitting;

a signal processor configured to process a signal received on the frequency on which the other WTRU is transmitting and determine a direction of the other WTRU;

a signal weighting unit configured to calculate antenna weights based on the signal received on the frequency on which the other WTRU is transmitting;

an adaptive antenna array; and

a transmitter configured to transmit data in a transmit beam pattern in a direction other than the direction of the other WTRU.

8. The WTRU of claim 7, wherein the direction of the other WTRU is determined based on identifying a high energy signal received on the frequency on which the other WTRU is transmitting.

9. The WTRU of claim 7, wherein the transmit beam pattern is selected from a predetermined set of transmit beams.

10. The WTRU of claim 7 further comprising applying antenna weights to a plurality of antenna elements to produce the transmit beam pattern.

11. The WTRU of claim 7, wherein the transmit beam pattern directs a null toward the other WTRU.

12. The WTRU of claim 7, wherein the WTRU transmits a beam pattern in a direction other than the direction of the other WTRU on a condition that the other WTRU is transmitting on an uplink frequency that is spectrally adjacent to the downlink frequency of the WTRU.