Method and apparatus for reporting a measurement in a wireless communication system

• US 9,491,652 B2
• Filed: 07/26/2012
• Issued: 11/08/2016
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Seo, Inkwon, Seo, Hanbyul, Kim, Kijun, Kim, Hakseong
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Daya, Tejis
• Application Number:
  US14/234,920
• Publication Number:
  US 20140192672A1
• Time in Patent Office: 1,566 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports

Abstract

The present invention relates to a method for reporting a measurement by a terminal, comprising the steps of: measuring the magnitude of a signal from a first transmission point; and measuring the magnitude of a signal from a second transmission point. The measurements of the magnitudes of the signals from each transmission point are performed using a channel state information reference signal.

Claims

1. A method for performing measurement reporting at a User Equipment (UE) in a wireless communication system, the method comprising:

receiving, from a serving cell, a neighboring cell list;

measuring channel state information (CSI) using a first CSI-reference signal (CSI-RS) from the serving cell;

reporting a result of the CSI measurement to the serving cell;

measuring radio resource management (RRM) using a second CSI-RS from a neighboring cell;

reporting a result of the RRM measurement to the serving cell; and

transmitting a random access preamble to a neighboring cell based on an equation min{Pcmax, PRTP+PLc}, where Pcmax is maximum transmission power allowed to the UE, PRTP is preamble received target power, and PLc is pathloss determined based on a result of the RRM measurement of the second CSI-RS,

wherein the first CSI-RS and the second CSI-RS belong to a specific CSI-RS configuration and are transmitted with different CSI-RS antenna port numbers of the specific CSI-RS configuration by the serving cell and the neighboring cell respectively, and

wherein the serving cell and the neighboring cell are distinguished from each other by the different CSI-RS antenna port numbers, the different CSI-RS antenna port numbers being signaled by the neighbor cell list.

2. The method according to claim 1, wherein the serving cell and the neighboring cell perform cooperative transmission for the UE.

3. The method according to claim 1, wherein the second CSI-RS signal is transmitted from a first transmission point of the neighboring cell.

4. The method according to claim 3, further comprising:

receiving a third CSI-RS signal from a second transmission point of the neighboring cell,

wherein the UE recognizes each of the transmission points that transmit the second CSI-RS and the third CSI-RS respectively using at least one of CSI-RS subframe configurations, CSI-RS configurations, and CSI-RS antenna ports.

5. The method according to claim 1, further comprising:

receiving information about an antenna port used for transmitting for the first CSI-RS from the serving cell.

6. The method according to claim 1, further comprising:

receiving a CSI-RS subframe configuration used for transmitting the first CSI-RS from the serving cell.

7. The method according to claim 1, wherein the RRM measurement includes a reference signal received strength (RSRP) of the second CSI-RS.

8. The method according to claim 1, wherein a magnitude of the second CSI-RS is measured by calculating a linear average of power of resource elements carrying the second CSI-RS, total reception power, and a number of resource blocks in a corresponding bandwidth, used for measuring the total reception power.

9. A User Equipment (UE) for performing measurement reporting in a wireless communication system, the UE comprising:

a transmitter; and

a processor operatively connected to the transmitter and configured to;

receive, from a serving cell, a neighboring cell list,

measure channel state information (CSI) using a first CSI-reference signal (CSI-RS) from the serving cell,

report a result of the CSI measurement to the serving cell,

measure radio resource management (RRM) using a second CSI-RS from a neighboring cell,

report a result of the RRM measurement to the serving cell, and

transmit a random access preamble to a neighboring cell based on an equation min{Pcmax, PRTP+PLc}, where Pcmax is maximum transmission power allowed to the UE, PRTP is preamble received target power, and PLc is pathloss determined based on a result of the RRM measurement of the second CSI-RS,

wherein the first CSI-RS and the second CSI-RS belong to a specific CSI-RS configuration and are transmitted with different CSI-RS antenna port numbers of the specific CSI-RS configuration by the serving cell and the neighboring cell respectively, and

wherein the serving cell and the neighboring cell are distinguished from each other by the different CSI-RS antenna port numbers, the different CSI-RS antenna port numbers being signaled by the neighbor cell list.