Method and apparatus for wireless communication using modulation, coding schemes, and channel quality indicators

1. A wireless communication method comprising:

receiving, through a wireless channel, table indication information indicating one of first and second Modulation and Coding Scheme (MCS) tables, each of the first and second MCS tables supporting up to 256 Quadrature Amplitude Modulation (QAM), the second MCS table including a same number of MCS indices as the first MCS table and including less MCS indices corresponding to 256 QAM than the first MCS table; and

identifying one of the first and second MCS tables at a signal-to-noise ratio (SNR) according to the received table indication information to recognize a demodulation scheme for data to be received through the wireless channel,

wherein the second MCS table includes at least one MCS index corresponding to lower modulation order and providing higher throughput than at least one corresponding MCS index included in the first MCS table, and

the table indication information is determined by detecting respective maximum throughputs with respect to MCS indices of the first MCS table and with respect to MCS indices of the second MCS table at the SNR.

2. The wireless communication method of claim 1 , wherein the at least one MCS index corresponds to 256 QAM in the first MCS table and corresponds to 64 QAM in the second MCS table.

3. The wireless communication method of claim 2 , wherein

each of the first and second MCS tables comprises MCS indices 0 to 31 that are expressed in 5 bits,

the first MCS table comprises MCS indices 20 to 27 corresponding to 256 QAM, and

the second MCS table comprises MCS indices 20 to 23 corresponding to 64 QAM.

4. The wireless communication method of claim 1 , further comprising:

transmitting, through the wireless channel, table support information indicating availability of the second MCS table.

5. The wireless communication method of claim 1 , wherein the table indication information comprises a Control Format Indicator (CFI) received through a Physical Control Format Indicator Channel (PCFICH).

6. The wireless communication method of claim 1 , further comprising:

identifying one of first and second Channel Quality Indicator (CQI) tables according to the table indication information, the first and second Channel Quality Indicator (CQI) tables being tables corresponding to the first and second MCS tables, respectively

wherein the second CQI table comprises a same number of CQI indices as the first CQI table, and the second CQI table comprises less CQI indices corresponding to 256 QAM than the first CQI table.

7. The wireless communication method of claim 6 , wherein at least some of CQI indices corresponding to 256 QAM in the first CQI table correspond to 64 QAM in the second CQI table.

8. The wireless communication method of claim 7 , wherein the first and second CQI tables comprise CQI indices 0 to 15 expressed in 4 bits, respectively,

the first CQI table comprises a CQI index 12 corresponding to 256 QAM, and

the second CQI table comprises a CQI index 12 corresponding to 64 QAM.

9. The wireless communication method of claim 1 , further comprising:

calculating a code rate of data received through the wireless channel; and

identifying one of first and second Channel Quality Indicator (CQI) tables corresponding to the first and second MCS tables, respectively, according to the calculated code rate,

wherein the second CQI table comprises a same number of CQI indices as the first CQI table, and the second CQI table comprises less CQI indices corresponding to 256 QAM than the first CQI table.

10. A wireless communication method comprising:

transmitting, through a wireless channel, downward support information indicating availability of downward indication information;

receiving, through the wireless channel, the downward indication information;

identifying an MCS table supporting up to 256 QAM in response to the downward indication information;

receiving an MCS index through the wireless channel;

detecting a maximum throughput provided by the received MCS index at a signal-to-noise ratio (SNR), while gradually increasing or decreasing the SNR; and

recognizing a demodulation scheme of data received through the wireless channel, based on the identified MCS table and the received MCS index and in consideration of the detecting maximum throughput, the recognizing comprising selectively recognizing 64 QAM, which provides higher throughput than 256 QAM with respect to the received MCS index, as the demodulation scheme in response to the identified MCS table, the downward indication information, and the received MCS index corresponding to 256 QAM.

11. The wireless communication method of claim 10 , wherein

the identified MCS table comprises MCS indices 0 to 31 expressed in 5 bits, among which MCS indices 20 to 27 correspond to 256 QAM, and

the recognizing comprises recognizing 256 QAM or 64 QAM as the demodulation scheme in response to the identified MCS table, the downward indication information, and the received MCS index being one of the MCS indices 20 to 23 .

12. The wireless communication method of claim 11 , further comprising:

receiving, through the wireless channel, the downward indication information indicating recognition of 64 QAM,

wherein the recognizing comprises recognizing 64 QAM from the MCS indices 20 to 23 based on the downward indication information.

13. The wireless communication method of claim 12 , wherein the downward indication information comprises a Control Format Indicator (CFI) received through a Physical Control Format Indicator Channel (PCFICH).