BASE TRANSCEIVER STATION AND ASSOCIATED METHOD FOR COMMUNICATION BETWEEN BASE TRANSCEIVER STATION AND USER EQUIPMENTS

• US 20120264469A1
• Filed: 05/28/2010
• Published: 10/18/2012
• Est. Priority Date: 06/15/2009
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Dartois, Luc, Betrencourt, Samuel
• Granted Patent: US 9,083,398 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity

Abstract

The invention relates to a base transceiver station (BTS) for communicating with a plurality of user equipments (UE1, UE2, UE3, UE4, UE5) divided in at least two groups, said base station comprises: an antenna element arrangement generating at least two shifted static beams (Bi, Bo) with respective down tilts for reaching the user equipments (UE1, UE2, UE3, UE4, UE5) a processing unit (25) connected to said transceiver chains (9) and having means for performing at least two linear complex combinations of up-link digital signals—means for receiving said up-link signals and for selecting per user equipment the appropriate beam based on the quality of said up-link signals in the beam flows (Fi,FO).

Claims

1. Base transceiver station (BTS) for communicating with a plurality of user equipments (UE1,UE2,UE3,UE4,UE5) divided in at least two groups, said base station comprises:

an antenna element arrangement generating at least two shifted static beams (Bi₅Bo) with respective down tilts for reaching the user equipments (UE1,UE2,UE3,UE4,UE5) and comprising;

a plurality of antenna elements (7) respectively connected to transceiver processing chains (9) for exchanging communication signals between the base transceiver station (BTS) and the user equipments (UE1,UE2,UE3,UE4,UE5),

a processing unit (25) connected to said transceiver chains (9) and having means for performing at least two linear complex combinations of digital signals between said antenna elements (7) and the base transceiver station for the same spectrum resources, and processing beam flows (Fi,Fo) respectively associated to said generated beams (Bi,Bo), with up-link signals received from user equipments (UE1,UE2,UE3,UE4,UE5), —

means for receiving said up-link signals and for selecting per user equipment the appropriate beam based on the quality of said up-link signals in the beam flows (Fi,Fo).

2. Base transceiver station according to claim 1, wherein said antenna element arrangement is adapted to generate an inner beam (Bi) and an outer beam (Bo), wherein the inner beam (Bi) reaches user equipments located close to said antenna element arrangement, and the outer beam (Bo) reaches user equipments located far from said antenna element arrangement.

3. Base transceiver station according to claim 1, wherein the processing unit (25) comprises means for applying complex antenna weights to said antenna elements, so that said antenna element arrangement generates beams in predefined elevation direction.

4. Base transceiver station according to claim 1, comprising means for comparing the carrier to interference ratio (C/I) between up-link signals received per beam for the same spectrum resources with a predetermined threshold, to determine the appropriate beam to be used.

5. Base transceiver station according to claim 1, comprising means to isolate said up-link signals received per beam.

6. Base transceiver station according to claim 1, configured to identify the appropriate beam for the down-link transmission based on the appropriate beam determined for up-link transmission.

7. Base transceiver station according to claim 6, comprising a feedback channel monitoring the quality of the down-link signal to validate said beam selected for down-link transmission.

8. Base transceiver station according to claim 6, comprising means for identifying the appropriate down-link resources used per beam to be used and reused in each beam.

9. Base transceiver station according to claim 1, wherein said processing unit (25) comprises means for directing beam flows (Fi₅Fo) with down-link signals to respective beams bound to user equipments (UE1,UE2,UE3,UE4,UE5) using respective beams.

10. Method for communication between a base transceiver station and a plurality of user equipments divided in at least two groups, wherein said base station comprises:

an antenna element arrangement generating at least two shifted static beams (Bi,Bo) with respective down tilts for reaching the user equipments (UE1,UE2,UE3,UE4,UE5) and comprising;

a plurality of antenna elements (7) respectively connected to transceiver processing chains (9) for exchanging communication signals between the base transceiver station (BTS) and the user equipments (UE1,UE2,UE3,UE4,UE5),

a processing unit (25) connected to said transceiver chains (9) and having means for performing at least two linear complex combinations of digital signals between said antenna elements (7) and the base transceiver station for the same spectrum resources, said method comprising following steps;

—

process beam flows (Fi₅Fo) respectively associated to said generated beams (Bi,Bo), with up-link signals received from user equipments (UE1,UE2,UE3,UE4,UE5),

receive said up-link signals and

select per user equipment the appropriate beam based on the quality of said up-link signals in the beam flows (Fi₅Fo).

11. Method according to claim 10, comprising further following steps:

for each beam flow (Fi,Fo) per user, compare the carrier to interference ratio (C/I) between up-link signals received per beam for the same spectrum resources with a predetermined threshold, —

if said ratio (C/I) meets or exceeds said threshold, select the beam with the highest power level at user equipment location and assign said user equipment to the selected beam,

otherwise combine said beams flows using a maximum ratio combining (MRC).

12. Method according to claim 10, comprising processing step such as multi-user detection (MUD), interference cancellation (IC) or direct 16QAM demodulation/modulation.

13. Method according to claim 10, comprising further processing:

identify the appropriate beam for the down-link transmission based on the appropriate beam determined for up-link transmission,

monitoring the quality of the down-link signal to validate said beam selected for down-link transmission.