Method for transmitting coMP feedback information in wireless communication system and terminal apparatus
Disclosed are a method for transmitting CoMP feedback information in a wireless communication system and a terminal apparatus using the same. Measured values of adjacent cells for performing a CoMP operation can be generated by using measured values defined in an existing LTE system. Consequently, the present invention doesn't need to define new measured values in a LTE-Advanced system.
1. A method of transmitting CoMP feedback information at a user equipment (UE) performing CoMP (Coordinated Multi-Point) operations in a wireless communication system, the method comprising:
measuring a signal intensity of a serving cell and one or more neighboring cells among CoMP cells performing the CoMP operations for the UE by using a reference signal received from the CoMP cells;
measuring interference from one or more non-CoMP cells that do not perform the CoMP operations for the UE;
generating a first channel quality information (CQI) regarding the serving cell and a second CQI regarding the neighboring cells among the CoMP cells based on the measured signal intensity and interference; and
transmitting the generated first and second channel quality information to the serving cell,
wherein the first CQI is generated based on the signal intensity of the serving cell and a time-average of the signal intensity of the neighboring cells among the CoMP cells plus the interference from the non-CoMP cells, and
the second CQI is generated based on the signal intensity of the neighboring cells and the time-average of the signal intensity of the neighboring cells among the CoMP cells plus the interference from the non-CoMP cells.
2. The method of claim 1 , wherein the signal intensity or the interference is expressed as any one of SINR (Signal to Interference plus Noise Ratio), CINR (Carrier to Interference plus Noise Ratio), RSRP (Reference Signal Received Power), and RSRQ (Reference Signal Received Quality).
3. The method of claim 1 , wherein the first and the second channel quality information is expressed as Equation A shown below:
CQI
i
=
S
i
V
,
[
Equation
A
]
where S i indicates signal intensity of cell i, cell i performing the CoMP operations, V indicates a time-averaged value of a sum of noise and interference from the non-CoMP cells and the CoMP cells excluding the serving cell.
4. A user equipment (UE) apparatus for transmitting CoMP feedback information in order to perform CoMP (Coordinated Multi-Point) operations in a wireless communication system, the user equipment apparatus comprises:
a measurement module configured to measure a signal intensity of a serving cell and one or more neighboring cells among CoMP cells performing the CoMP operations for the UE, by using a reference signal received from the CoMP cells and to measure interference from one or more non-CoMP cells that do not perform the CoMP operations for the UE;
a generation module configured to generate first channel quality information (CQI) regarding the serving cell and second channel quality information (CQI) regarding the neighboring cells, based on the measured signal intensity and the interference; and
a transmission module configured to transmit the first and the second channel quality information to the serving cell,
wherein the first CQI is generated based on the signal intensity of the serving cell and a time-average of the signal intensity of the neighboring cells among the CoMP cells plus the interference from the non-CoMP cells, and
the second CQI is generated based on the signal intensity of the neighboring cells and the time-average of the signal intensity of the neighboring cells among the CoMP cells plus the interference from the non-CoMP cells.
5. The user equipment apparatus of claim 4 , wherein the single intensity and the interference is expressed as any one of SINR (Signal to Interference plus Noise Ratio), CINR (Carrier to Interference plus Noise Ratio), RSRP (Reference Signal Received Power), and RSRQ (Reference Signal Received Quality).
6. The user equipment apparatus of claim 4 , wherein the first and the second channel quality information is expressed as Equation A shown below:
CQI
i
=
S
i
V
,
[
Equation
A
]
where S i indicates intensity of a signal received from cell i, cell i performing the CoMP operations, V indicates an average value of a sum of noise and interference power levels measured from the remaining cells excluding the serving cell, the average value of the sum being accumulated for a predetermined time period.
7. A method of generating Channel Quality Information values at a base station (BS) performing CoMP (Coordinated Multi-Point) operations in a wireless communication system, comprising:
receiving a channel quality information value respective to each cell performing the CoMP operations from a user equipment (UE); and
generating at least one channel quality information value, among a channel quality information value corresponding to a first CoMP operation scheme and a channel quality information value corresponding to a second CoMP operation scheme, by using the received channel quality information value respective to each cell,
wherein the received channel quality information is generated by using the measured intensity or interference levels values of the signals corresponding to each cell performing the CoMP operations and an average value of a sum of the signal intensity or interference level values of each cell that does not perform the CoMP operations, the average value of the sum being accumulated for a predetermined time period,
wherein, among the generated channel quality information values, the channel quality information value corresponding to the first CoMP operation scheme, the first CoMP operation scheme being operated by using a Coordinated Beamforming scheme, is expressed by using Equation B shown below:
CQI
=
Q
A
1
-
Q
B
-
Q
C
,
[
Equation
B
]
where A indicates a serving cell performing CoMP operations, B and C respectively indicate neighboring cells performing the CoMP operations, and where Q A , Q B , and Q C respectively indicate channel quality information values of serving cell A, neighboring cell B, and neighboring cell C that perform the CoMP operations,
wherein the Q A , Q B , and Q C are transmitted from the user equipment.
8. The method of claim 7 , wherein, among the generated channel quality information values, the channel quality information value corresponding to the second CoMP operation method, the second CoMP operation scheme being operated by using a Joint Processing scheme, is expressed by using Equation C shown below:
CQI
=
(
Q
A
+
Q
B
+
Q
C
1
-
Q
B
-
Q
C
)
2
.
[
Equation
C
]
9. A base station (BS) apparatus performing CoMP (Coordinated Multi-Point) operations for generating Channel Quality Information values in a wireless communication system, the base station apparatus comprises:
a reception module configured to receive a channel quality information value respective to each cell performing the CoMP operations from a user equipment; and
a generation module configured to generate at least one channel quality information value, among a channel quality information value corresponding to a first CoMP operation scheme and a channel quality information value corresponding to a second CoMP operation scheme, by using the received channel quality information value respective to each cell,
wherein the received channel quality information is generated by using the measured intensity or interference level values of the signals corresponding to each cell performing the CoMP operations, an average value of a sum of the signal intensity or interference level values of each cell that does not perform the CoMP operations, the average value of the sum being accumulated for a predetermined time period,
wherein, among the generated channel quality information values, the channel quality information value corresponding to the first CoMP operation scheme, the first CoMP operation scheme being operated by using a Coordinated Beamforming method, is expressed by using Equation D shown below:
CQI
=
Q
A
1
-
Q
B
-
Q
C
,
[
Equation
D
]
where A indicates a serving cell performing CoMP operations, B and C respectively indicate neighboring cells performing the CoMP operations, and where Q A , Q B , and Q C respectively indicate channel quality information values of serving cell A, neighboring cell B, and neighboring cell C, each cell performing the CoMP operations,
wherein the Q A , Q B , and Q C are transmitted from the user equipment.
10. The base station apparatus of claim 9 , wherein, among the generated channel quality information values, the channel quality information value corresponding to the second CoMP operation scheme, the second CoMP operation scheme being operated by using a Joint Processing scheme, is expressed by using Equation E shown below:
CQI
=
(
Q
A
+
Q
B
+
Q
C
1
-
Q
B
-
Q
C
)
2
.
[
Equation
E
]