Distributed antenna system and method for enhanced positioning

Patent metadata

Field	Value
Publication number	US-9402233-B2
Application number	US-201113992917-A
Country	US
Kind code	B2
Filing date	Dec 16, 2011
Priority date	Mar 7, 2011
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

Embodiments of a distributed antenna system (DAS) and method for enhanced positioning in a wireless network are generally described herein. In some embodiments, an enhanced Node-B (eNB) operates as part of a DAS that includes one or more nodes having the same cell ID as the eNB. The eNB is to transmit a UE-specific reference signal and configure one or more of the other nodes of the cell to transmit UE-specific reference signals that are distinguishable from each other and from the UE-specific reference signal that is transmitted by the eNB. The eNB may receive location estimate information from user equipment (UE) that is determined at least in part from the UE-specific reference signals. The eNB may also configure the nodes to perform cooperative OFDMA transmission techniques for the UEs operating in the cell.

First claim

What is claimed is:

1. An enhanced Node-B (eNB) to operate as part of a distributed antenna system (DAS) comprising one or more nodes having a same cell identifier (ID) and operating within a same cell as the eNB, the eNB arranged to:
transmit a user equipment (UE)-specific reference signal and a cell-specific reference signal;
configure one or more of the other nodes of a cell to transmit UE-specific reference signals, each of the UE-specific reference signals transmitted by each of the one or more of the other nodes being distinguishable from each of the UE-specific reference signals transmitted by each other node of the one or more of the other nodes and from the UE-specific reference signal that is transmitted by the eNB, the nodes comprising remote radio heads (RRHs); and
receive location estimate information from a UE that is determined at least in part from the UE-specific reference signals and the cell-specific reference signal, wherein each of the UE-specific reference signals comprises a channel state information reference signal (CSI-RS) and the cell-specific reference signal comprises a positioning reference signal (PRS), wherein the location estimate information comprises an initial location estimate obtained using the received PRS and a PRS received from one or more other cells, an update of the initial location estimate obtained using the received CSI-RS from the eNB and the CSI-RSs received from the RRHs of the cell, and feedback indicative of channel estimations, obtained using the CSI-RS from the eNB and the CSI-RSs from one or more of the RRHs, for use by the eNB and the RRHs for cooperative orthogonal frequency division multiple access (OFDMA) transmissions.

2. The eNB of claim 1 wherein the PRS is transmitted in a first logical portion of a wireless frame, and the CSI-RSs are transmitted in a second logical portion of the frame, and
wherein the eNB and the nodes are arranged to:
concurrently transmit data in a data portion of the wireless frame that follows the second logical portion as part of a cooperative transmission.

3. The eNB of claim 2 wherein the wireless frame is an OFDMA downlink subframe,
wherein the CSI-RSs are concurrently transmitted by the nodes and the eNB in the second logical portion, and
wherein the eNB configures the nodes to perform cooperative OFDMA transmission techniques for one or more UEs operating in the cell.

4. The eNB of claim 1 wherein the PRS is broadcast by the eNB, and
wherein each of the CSI-RSs are transmitted in a region of a physical downlink shared channel (PDSCH).

5. The eNB of claim 1 wherein the eNB is arranged to:
transmit a first CSI-RS with a first UE-specific scrambling code; and
instruct each of the RRHs to transmit a CSI-RS with different UE-specific scrambling codes.

6. The eNB of claim 5 wherein all the CSI-RSs are transmitted within same resource elements of a resource block that is concurrently transmitted by the eNB and the RRHs.

7. The eNB of claim 5 wherein the eNB is arranged to:
transmit the first CSI-RS on a first set of resource elements; and
instruct each of the RRHs to transmit an associated CSI-RS, at least in part, on a different set of resource elements of a resource block that is concurrently transmitted by the eNB and the RRHs.

8. The eNB of claim 1 wherein the eNB is arranged to:
transmit a first CSI-RS with a cell-specific scrambling code;
instruct each of the RRHs to transmit a CSI-RS with the cell-specific scrambling code; and
wherein the eNB is arranged to:
transmit the first CSI-RS on a first set of resource elements; and
instruct each of the RRHs to transmit an associated CSI-RS, at least in part, on a different set of resource elements of a resource block that is concurrently transmitted by the eNB and the RRHs.

9. The eNB of claim 1 wherein the eNB is arranged to provide a location service (LCS) to the UE based on the updated location estimate information.

10. The eNB of claim 1 wherein the eNB is arranged to request one or more neighboring eNBs to apply PDSCH muting to CSI-RS subcarriers when the UE is unable to accurately update its initial location estimate using the CSI-RSs.

11. The eNB of claim 1 wherein the eNB is arranged to
use the feedback indicative of channel estimates for multiple-input multiple-output (MIMO) beamforming for configuring a cooperative transmission to the mobile station; and
use the location estimate information to provide a location-based service to the mobile station.

12. User Equipment (UE) arranged for receipt of cooperative orthogonal frequency division multiple access (OFDMA) transmissions from an enhanced Node-B (eNB) and one or more remote radio heads (RRHs) of a cell,
wherein the UE is arranged to:
receive a UE-specific reference signal from the eNB, a cell-specific reference signal comprising a channel state information reference signal (CSI-RS) from a current cell and a cell-specific reference signal comprising a positioning reference signal (PRS) from one or more neighbor cells;
receive UE-specific reference signals from one or more of the RRHs, each of the UE-specific reference signals from each of the one or more of the RRHs being distinguishable from each of the UE-specific reference signals from each other RRH of the one or more of the RRHs and from the UE-specific reference signal received from the eNB;
generate a location estimate at least in part from the UE-specific reference signals;
determine an initial location estimate from the cell-specific reference signal;
update the location estimate using the UE-specific reference signals;
perform channel estimations using the CSI-RS from the eNB and the CSI-RSs from each of the RRHs;
report an updated location estimate to the eNB; and
provide feedback to the eNB indicative of the channel estimations for use by the eNB and the RRHs for cooperative OFDMA transmissions.

13. A method performed by an enhanced Node-B (eNB) arranged to operate as part of a distributed antenna system (DAS) comprising one or more nodes having a same cell identifier (ID) and operating within a same cell as the eNB, the method comprising:
transmitting a user equipment (UE)-specific reference signal and a cell-specific reference signal comprising a positioning reference signal (PRS);
configuring one or more of the other nodes of a cell to transmit UE-specific reference signals comprising a channel state information reference signal (CSI-RS), each of the UE-specific reference signals transmitted by each of the one or more of the other nodes of the cell being distinguishable from each of the UE-specific reference signals transmitted by each other node of the one or more of the other nodes of the cell and from the UE-specific reference signal that is transmitted by the eNB, the nodes comprising remote radio heads (RRHs); and
receiving location estimate information from a UE that is determined at least in part from the UE-specific reference signals and the cell-specific reference signal, the location estimate information comprising an initial location estimate obtained using the received PRS and a PRS received from of one or more other cells, an update of the initial location estimate obtained using the received CSI-RS from the eNB and the CSI-RSs received from the RRHs of the cell, and feedback indicative of channel estimations, obtained using the CSI-RS from the eNB and the CSI-RSs from one or more of the RRHs, for use by the eNB and the RRHs for cooperative OFDMA transmissions.

14. The method of claim 13 wherein:
the PRS is transmitted in a first logical portion of a wireless frame, and the CSI-RSs are transmitted in a second logic

Assignees

• Davydov Alexei
• Maltsev Alexander
• Etemad Kamran
• Morozov Gregory
• Sergeyev Vadim
• Intel Corp

Inventors

• Davydov Alexei
• Maltsev Alexander
• Etemad Kamran
• Morozov Gregory
• Sergeyev Vadim

Classifications

• H04W72/52

  based on load · CPC title

• H04W72/51

  based on terminal or device properties · CPC title

• H04B7/2656 Primary

  for structure of frame, burst · CPC title

• H04W88/08

  Access point devices · CPC title

• H04W4/70 Primary

  Services for machine-to-machine communication [M2M] or machine type communication [MTC] · CPC title