Method and device for reporting power headroom in mobile communication system for carrier aggregation

Abstract

Provided are a method and apparatus for reporting power headroom in a mobile communication system supporting carrier aggregation. A user equipment (UE) determines the maximum transmit power for each carrier and the maximum UE transmit power, and sends a power headroom report that contains power headroom for each carrier computed based on the maximum transmit power for the carrier and the maximum UE transmit power to a corresponding base station (ENB).

The invention claimed is: 
     
       1. A method of performed by a terminal operation in a wireless communication system, the method comprising:
 receiving a measurement configuration message from a first base station controlling a first cell using a first frequency band; 
 measuring a first reference signal of the first cell from the first base station; 
 measuring a second reference signal of a second cell using a second frequency band from a second base station based on the measurement configuration message; and 
 transmitting a measurement report comprising including a measurement result of the first reference signal and a measurement result of the second reference signal to the first base station, 
 wherein the measurement configuration message includes pattern first information comprising an indication of on which subframes the second reference signal is to be transmitted in, second information on a physical cell identity of the second cell, and offset third information on an offset for the second reference signal, and 
 wherein the first reference signal is transmitted in all subframes, and the second reference signal is transmitted in subframes identified based on the pattern first information included in the measurement configuration message. 
 
     
     
       2. The method of  claim 1 , wherein the first reference signal is a cell reference signal (CRS), and the second reference signal is a channel state indication reference signal (CSI-RS). 
     
     
       3. A method of operation of performed by a first base station in a wireless communication system, the method comprising:
 transmitting a measurement configuration message to a terminal; 
 transmitting a first reference signal of a first cell which is controlled by the first base station on a first frequency band to the terminal; and 
 receiving a measurement report from the terminal, 
 wherein the measurement configuration message includes pattern first information for a second reference signal of a second cell which is transmitted from a second base station using a second frequency band, second information on a physical cell identity of the second cell, and offset third information on an offset for the second reference signal, 
 wherein the pattern first information comprises an indication of indicates which subframes the second reference signal is to be transmitted in;, 
 wherein the measurement report comprises includes a measurement result of the first reference signal and a measurement result of the second reference signal, and 
 wherein the first reference signal is transmitted in all subframes, and the second reference signal is transmitted in subframes identified based on the pattern first information included in the measurement configuration message. 
 
     
     
       4. The method of  claim 3 , wherein the first reference signal is a cell reference signal (CRS), and the second reference signal is a channel state indication reference signal (CSI-RS). 
     
     
       5. A terminal in a wireless communication system, the terminal comprising:
 a transceiver configured to transmit and receive signals; and 
 a controller coupled with the transceiver and configured to control to:
 control the transceiver to receive a measurement configuration message from a first base station controlling a first cell using a first frequency band, 
 measure a first reference signal of the first cell from the first base station, 
 measure a second reference signal of a second cell using a second frequency band from a second base station based on the measurement configuration message, and 
 control the transceiver to transmit a measurement report comprisingincluding a measurement result of the first reference signal and measurement result of the second reference signal to the first base station, 
 
 wherein the measurement configuration message includes pattern first information comprising an indication of on which subframes the second reference signal is to be transmitted in, second information on a physical cell identity of the second cell, and third information on an offset information for the second reference signal, and 
 wherein the first reference signal is transmitted in all subframes, and the second reference signal is transmitted in subframes identified based on the pattern first information included in the measurement configuration message. 
 
     
     
       6. The terminal of  claim 5 , wherein the first reference signal is a cell reference signal (CRS), and the second reference signal is a channel state indication reference signal (CSI-RS). 
     
     
       7. A first base station in a wireless communication system, the first base station comprising:
 a transceiver configured to transmit and receive signals; and 
 a controller coupled with the transceiver and configured to control to:
 control the transceiver to transmit a measurement configuration message to a terminal, 
 control the transceiver to transmit a first reference signal of a first cell which is controlled by athe first base station on a first frequency band to the terminal, and 
 control the transceiver to receive a measurement report from the terminal, 
 
 wherein the measurement configuration message includes pattern first information for a second reference signal of a second cell which is transmitted from a second base station using a second frequency band, second information on a physical cell identity of the second cell, and third information on an offset information for the second reference signal, 
 wherein the pattern first information comprises an indication of indicates which subframes the second reference signal is to be transmitted in;, 
 wherein the measurement report comprises includes a measurement result of the first reference signal and a measurement result of the second reference signal, and 
 wherein the first reference signal is transmitted in all subframes, and the second reference signal is transmitted in subframes identified based on pattern the first information included in the measurement configuration message. 
 
     
     
       8. The first base station of  claim 7 , wherein the first reference signal is a cell reference signal (CRS), and the second reference signal is a channel state indication reference signal (CSI-RS).