Method and apparatus for transmitting data
A data transmission method and apparatus initialize an index of a modulation and coding scheme (MCS) for transmitting data to a terminal, adjust the index of the MCS based on at least one of a hybrid automatic repeat request (HARM) feedback of the terminal and a channel quality of the terminal, and transmit the data to the terminal based on the adjusted index of the MCS.
1. A computer implemented method of transmitting data, the method comprising:
initializing an index of a modulation and coding scheme (MCS) for transmitting data to a terminal;
adjusting, by a processor, the index of the MCS based on at least one of a hybrid automatic repeat request (HARQ) feedback of the terminal and a channel quality of the terminal; and
transmitting the data to the terminal based on the adjusted index of the MCS, wherein adjusting the index of the MCS is performed by
determining an index of a first MCS based on the HARQ feedback;
determining an index of a second MCS based on the channel quality of the terminal; and
determining the index of the MCS based on the index of the first MCS and the index of the second MCS, and wherein
determining the index of the MCS based on the index of the first MCS and the index of the second MCS comprises determining the index of the MCS based on sum of a first weight predetermined for the index of the first MCS and a second weight predetermined for the index of the second MCS.
2. The method of claim 1 , further comprising:
setting a target block error ratio (BLER), wherein the adjusting comprises adjusting the index of the MCS based on the target BLER.
3. The method of claim 1 , wherein the adjusting comprises:
determining whether at least one HARQ feedback is received; and
adjusting the index of the MCS based on the at least one HARQ feedback in response to reception of the at least one HARQ feedback.
4. The method of claim 3 , wherein the adjusting of the index of the MCS based on the at least one HARQ feedback comprises adjusting the index of the MCS based on a number of consecutively received acknowledge (ACK) feedbacks.
5. The method of claim 1 , wherein the adjusting comprises:
determining whether information about the channel quality of the terminal is received; and
adjusting the index of the MCS based on information about the channel quality of the terminal in response to reception of information about the channel quality of the terminal.
6. The method of claim 1 , wherein:
the adjusting and the transmitting is performed to transmit a t-th subframe, and the initializing comprises initializing the index of the MCS by determining an index of an MCS determined to transmit a (t−1)-th subframe as the index of the MCS.
7. The method of claim 1 , wherein the adjusting and the transmitting is performed within a single transmission time interval (TTI).
8. The method of claim 1 , wherein a sum of the first weight and the second weight is 1.
9. The method of claim 1 , wherein the transmitting the data to the terminal is performed in response to reception of a scheduling request for transmitting the data.
10. The method of claim 1 , wherein the adjusting comprises:
adjusting the index of the MCS using the HARQ feedback of the terminal, based on a reception period of the channel quality of the terminal; and adjusting the index of the MCS using the HARQ feedback and the channel quality of the terminal based on the reception period of channel quality of the terminal.
11. A data transmission apparatus comprising:
a processor configured to initialize an index of a modulation and coding scheme (MCS) for transmitting data to a terminal, and to adjust the index of the MCS based on at least one of a hybrid automatic repeat request (HARQ) feedback of the terminal and a channel quality of the terminal; and
a communicator configured to transmit the data to the terminal based on the adjusted index of the MCS, wherein adjustment of the index of the MCS is performed by the processor
to determine an index of a first MCS based on the HARQ feedback;
to determine an index of a second MCS based on the channel quality of the terminal; and
to determine the index of the MCS based on the index of the first MCS and the index of the second MCS, wherein
the processor is further configured to determine the index of the MCS based on sum of a first weight predetermined for the index of the first MCS and a second weight predetermined for the index of the second MCS.
12. The data transmission apparatus of claim 11 , wherein the processor is further configured to:
set a target block error ratio (BLER), and adjust the index of the MCS based on the target BLER.
13. The data transmission apparatus of claim 11 , wherein the processor is further configured to:
determine whether at least one HARQ feedback is received, and adjust the index of the MCS based on the at least one HARQ feedback in response to reception of the at least one HARQ feedback.
14. The data transmission apparatus of claim 11 , wherein the processor is further configured to:
determine whether information about the channel quality of the terminal is received, and adjust the index of the MCS based on information about the channel quality of the terminal in response to reception of information about the channel quality of the terminal.
15. The data transmission apparatus of claim 11 , wherein the processor is further configured to:
adjust the index of the MCS using the HARQ feedback of the terminal based on a reception period associated with information about the channel quality of the terminal, and adjust the index of the MCS using the HARQ feedback and the channel quality of the terminal based on the reception period of the channel quality of the terminal.