METHOD AND APPARATUS FOR TRANSCEIVING SIGNALS IN A DISTRIBUTED ANTENNA SYSTEM

• US 20130077580A1
• Filed: 01/21/2011
• Published: 03/28/2013
• Est. Priority Date: 01/25/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kang, Ji Won, Ihm, Bin Chul, Chun, Jin Young
• Granted Patent: US 8,867,446 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

The present invention relates to a terminal which receives signals from a base station, and to a method in which the terminal receives signals from the base station in a distributed antenna system (DAS). The terminal receives, from the base station having a plurality of antennas, control information on one or more active transmission antennas allocated to the terminal, from among the plurality of antennas, and receives signals from the base station via said one or more active transmission antennas.

Claims

1. A method of receiving a signal, which is received from a base station by a user equipment in a distributed antenna system (DAS), the method comprising the steps of:

1) receiving control information on at least one effective transmitting antenna allocated to the user equipment among a plurality of antennas from the base station including the plurality of antennas; and

2) receiving the signal via the at least one effective transmitting antenna from the base station.

2. The method of claim 1, wherein the control information comprises at least one selected from the group consisting of information on the number of the at least one effective transmitting antenna, index information of the at least one effective transmitting antenna and received signal strength information for each of the plurality of antennas.

3. The method of claim 2, further comprising the step of mapping at least one PAI to logical antenna indexes (LAI) according to a predetermined mapping rule.

4. The method of claim 3, wherein the predetermined mapping rule configures the LAI with an index of the effective transmitting antenna in performance order according to a power gain for each effective transmitting antenna.

5. The method of claim 1, wherein the control information comprises at least one selected from the group consisting of information on one or more pilot pattern indexes (PPI) supportive of the user equipment and information on PPI having an interference influence on the user equipment.

6. The method of claim 1, further comprising the step of transmitting feedback information including antenna related information used for a transmission of a downlink signal based on the downlink signal received from the base station by the user equipment to the base station before the step 1), wherein the control information is determined by the base station based on the feedback information.

7. The method of claim 6, wherein the feedback information comprises at least one selected from the group consisting of a received signal strength for each of the plurality of antennas, a received signal strength for at least one antenna selected from the plurality of antennas by the user equipment, information on the number and/or indexes of antennas meeting a predetermined selection reference, and candidate PPI meeting a predetermined selection reference.

8. The method of claim 7, wherein the information on the indexes of antennas fed back by the user equipment is transmitted via a bitmap.

9. The method of claim 7, wherein the predetermined selection reference comprises whether a received signal strength of the downlink signal received via a portion of the plurality of antennas is equal to or greater than a reference value.

10. The method of claim 9, wherein information on the reference value is received from the base station.

11. The method of claim 6, wherein the feedback information comprises preferred pilot pattern indexes (PPPI) requested by the user equipment and wherein the PPPI comprises at least one PPI in which a received signal strength or a channel gain of a channel estimated via a common pilot transmitted from the base station meets a value equal to or greater than a predetermined reference value.

12. The method of claim 11, wherein the PPPI is transmitted via a bit map.

13. The method of claim 11, wherein the feedback information further comprises at least one selected from the group consisting of channel state information estimated from each PPI included in the PPPI, a preferred order of at least one PPI included in the PPPI, a specific number of most preferred PPIs among the at least one PPI included in the PPPI, and channel state information on the specific number of the most preferred PPIs.

14. The method of claim 13, wherein the specific number of the most preferred PPI corresponds to one selected from the group consisting of system configuration parameter information, indication information determined and transmitted by the base station, and information arbitrarily determined by the user equipment.

15. The method of claim 7, wherein the control information comprises at least one selected from the group consisting of information on specific pilot pattern indexes (PPI) supportive of the user equipment, an index set (excluded PPI:

e-PPI) supposed to be excluded from the candidate PPI or the PPPI fed back from the user equipment, and an index agreement indicator indicating whether PPI equal to the candidate PPI or the PPPI fed back from the user equipment is used.

16. The method of claim 15, wherein if the index agreement indicator is set to indicate the information indicating that the PPI equal to the candidate PPI or the PPPI fed back from the user equipment is used, the control information does not comprise information on the specific PPI and the e-PPI.

17. The method of claim 15, further comprising the step of mapping the specific PPI to LAI by a predetermined mapping rule.

18. The method of claim 17, wherein the predetermined mapping rule comprises configuring the LAI in performance order according to power gain for each of the PPI.

19. The method of claim 4, further comprising the steps of:

estimating channel related information based on the LAI; and

transmitting the channel related information to the base station by feedback.

20. The method of claim 4, further comprising the step of transmitting information on the predetermined mapping rule to the base station.

21. The method of claim 1, wherein the control information is independently configured for each user equipment belonging to the DAS and wherein the control information is determined independently in accordance with at least one of a location of the user equipment and a frequency band used by the user equipment.

22. The method of claim 1, further comprising the step of receiving indication information indicating that the system supports at least one of the DAS and a centralized antenna system from the base station when the user equipment enters a cell area in which the base station provides a service.

23. The method of claim 22, wherein the indication information is transmitted via cell ID.

24. A user equipment in a distributed antenna system (DAS), comprising:

a receiving module configured to receive a signal;

a processor configured to generate a feedback information on a distributed antenna of a base station used for a downlink transmission based on a downlink signal received from the base station including a plurality of antennas spaced apart from a predetermined distance via the receiving module; and

a transmitting module configured to transmit the feedback information to the base station,

wherein the processor is configured to receive control information on at least one effective transmitting antenna to be used for a communication with the user equipment among the plurality of antennas from the base station via the receiving module.