Table design for 256 quadrature amplitude modulation

1. A method of determining a modulation coding scheme in a wireless network, the method comprising:

receiving a channel quality indicator (CQI) index, wherein the CQI index comprises a four-bit value associated with a channel quality of a wireless signal;

identifying an entry in a CQI table based on the CQI index, wherein the CQI table comprises:

a first contiguous plurality of table entries associated with low SINR, each entry of the first contiguous plurality based on a first sampling grid; and

a second contiguous plurality of table entries associated with medium SINR, each entry of the second contiguous plurality based on a second sampling grid, the second sampling grid having a smaller spacing than the first sampling grid; and

a third contiguous plurality of table entries associated with high SINR, each entry of the third contiguous plurality based on a third sampling grid, the second sampling grid having a smaller spacing than the third sampling grid; and

determining a modulation coding scheme based on the identified entry in the CQI table; and

encoding a transport block according to the determined modulation coding scheme.

2. The method of claim 1 , wherein:

the first sampling grid comprises a grid spacing of approximately 3 dB;

the second sampling grid comprises a grid spacing of approximately 2 dB; and

the third sampling grid comprises a grid spacing of approximately 2.5 dB.

3. The method of claim 1 , wherein:

the first contiguous plurality of table entries comprises Quadrature Phase Shift Keying (QPSK) entries;

the second contiguous plurality of table entries comprises 16 Quadrature Amplitude Modulation (16QAM) entries; and

the third contiguous plurality of table entries comprises 64 Quadrature Amplitude Modulation (64QAM) entries and 256 Quadrature Amplitude Modulation (256QAM) entries.

4. The method of claim 1 , wherein:

the first contiguous plurality of table entries comprises four entries;

the second contiguous plurality of table entries comprises three entries; and

the third contiguous plurality of table entries comprises eight entries.

5. The method of claim 1 , wherein the third contiguous plurality of table entries comprises four 64QAM entries and four 256QAM entries.

6. A radio network node in a wireless network comprising a processor operable to:

receive a channel quality indicator (CQI) index, wherein the CQI index comprises a four-bit value associated with a channel quality of a wireless signal;

identify an entry in a CQI table based on the CQI index, wherein the CQI table comprises:

a first contiguous plurality of table entries associated with low SINR, each entry based on a first sampling grid;

a second contiguous plurality of table entries associated with medium SINR, each entry based on a second sampling grid; and

a third contiguous plurality of table entries associated with high SINR, each entry based on a third sampling grid;

determine a modulation coding scheme based on the identified entry in the CQI table; and

encode a transport block according to the determined modulation coding scheme.

7. The radio network node of claim 6 , wherein:

the first sampling grid comprises a grid spacing of approximately 3 dB;

the second sampling grid comprises a grid spacing of approximately 2 dB; and

the third sampling grid comprises a grid spacing of approximately 2.5 dB.

8. The radio network node of claim 6 , wherein:

the first contiguous plurality of table entries comprises Quadrature Phase Shift Keying (QPSK) entries;

the second contiguous plurality of table entries comprises 16 Quadrature Amplitude Modulation (16QAM) entries; and

the third contiguous plurality of table entries comprises 64 Quadrature Amplitude Modulation (64QAM) entries and 256 Quadrature Amplitude Modulation (256QAM) entries.

9. The radio network node of claim 6 , wherein:

the first contiguous plurality of table entries comprises four entries;

the second contiguous plurality of table entries comprises three entries; and

the third contiguous plurality of table entries comprises eight entries.

10. The radio network node of claim 6 , wherein the third contiguous plurality of table entries comprises four 64QAM entries and four 256QAM entries.

11. A method of determining a modulation coding scheme (MCS) index in a wireless network, the method comprising:

receiving a channel quality indicator (CQI) index, wherein the CQI index comprises a four-bit value associated with a channel quality of a wireless signal;

determining an MCS and a transport block size (TBS) based at least in part on the received CQI index;

identifying an entry in an MCS table based on the determined MCS, wherein the MCS table comprises:

a first contiguous plurality of table entries associated with low SINR, each entry of the first contiguous plurality based on a first sampling grid; and

a second contiguous plurality of table entries associated with medium SINR, each entry of the second contiguous plurality based on a second sampling grid, the second sampling grid having a smaller spacing than the first sampling grid; and

a third contiguous plurality of table entries associated with high SINR, each entry of the third contiguous plurality based on a third sampling grid, the second sampling grid having a smaller spacing than the third sampling grid; and

determining an MCS index, wherein the MCS index comprises a five-bit value associated with the identified entry in the MCS table.

12. The method of claim 11 , wherein:

the first contiguous plurality of table entries comprises Quadrature Phase Shift Keying (QPSK) entries;

the second contiguous plurality of table entries comprises 16 Quadrature Amplitude Modulation (16QAM) entries; and

the third contiguous plurality of table entries comprises 64 Quadrature Amplitude Modulation (64QAM) entries and 256 Quadrature Amplitude Modulation (256QAM) entries.

13. The method of claim 11 , wherein:

the first contiguous plurality of table entries comprises five entries;

the second contiguous plurality of table entries comprises seven entries; and

the third contiguous plurality of table entries comprises seventeen entries.

14. The method of claim 11 , wherein the third contiguous plurality of table entries comprises nine 64QAM entries and eight 256QAM entries.

15. A radio network node in a wireless network, the radio network node comprising a processor operable to:

receive a channel quality indicator (CQI) index, wherein the CQI index comprises a four-bit value associated with a channel quality of a wireless signal;

determine an MCS and a transport block size (TBS) based at least in part on the received CQI index;

identify an entry in an MCS table based on the determined MCS, wherein the MCS table comprises:

a first contiguous plurality of table entries associated with low SINR, each entry of the first contiguous plurality based on a first sampling grid; and

a second contiguous plurality of table entries associated with medium SINR, each entry of the second contiguous plurality based on a second sampling grid, the second sampling grid having a smaller spacing than the first sampling grid; and

a third contiguous plurality of table entries associated with high SINR, each entry of the third contiguous plurality based on a third sampling grid, the second sampling grid having a smaller spacing than the third sampling grid; and

determine an MCS index, wherein the MCS index comprises a five-bit value associated with the identified entry in the MCS table.

16. The radio network node of claim 15 , wherein:

the first contiguous plurality of table entries comprises Quadrature Phase Shift Keying (QPSK) entries;

the second contiguous plurality of table entries comprises 16 Quadrature Amplitude Modulation (16QAM) entries; and

the third contiguous plurality of table entries comprises 64 Quadrature Amplitude Modulation (64QAM) entries and 256 Quadrature Amplitude Modulation (256QAM) entries.

17. The radio network node of claim 15 , wherein:

the first contiguous plurality of table entries comprises five entries;

the second contiguous plurality of table entries comprises seven entries; and

the third contiguous plurality of table entries comprises seventeen entries.

18. The wireless network element of claim 15 , wherein the third contiguous plurality of table entries comprises nine 64QAM entries and eight 256QAM entries.

19. A method of determining a modulation coding scheme (MCS) in a wireless network, the method comprising:

receiving an MCS index, wherein the MCS index comprises a five-bit value associated with an entry in an MCS table;

identifying an entry in the MCS table based on the received MCS index, wherein the MCS table comprises:

a first contiguous plurality of table entries associated with low SINR, each entry of the first contiguous plurality based on a first sampling grid; and

a second contiguous plurality of table entries associated with medium SINR, each entry of the second contiguous plurality based on a second sampling grid, the second sampling grid having a smaller spacing than the first sampling grid; and

a third contiguous plurality of table entries associated with high SINR, each entry of the third contiguous plurality based on a third sampling grid, the second sampling grid having a smaller spacing than the third sampling grid; and

determining an MCS based on the identified entry in the MCS table.

20. The method of claim 19 , wherein:

the first contiguous plurality of table entries comprises Quadrature Phase Shift Keying (QPSK) entries;

the second contiguous plurality of table entries comprises 16 Quadrature Amplitude Modulation (16QAM) entries; and

the third contiguous plurality of table entries comprises 64 Quadrature Amplitude Modulation (64QAM) entries and 256 Quadrature Amplitude Modulation (256QAM) entries.

21. The method of claim 19 , wherein:

the first contiguous plurality of table entries comprises five entries;

the second contiguous plurality of table entries comprises seven entries; and

the third contiguous plurality of table entries comprises seventeen entries.

22. The method of claim 19 , wherein the third contiguous plurality of table entries comprises nine 64QAM entries and eight 256QAM entries.

23. A wireless device in a wireless network, the wireless device comprising a processor operable to:

receive an MCS index, wherein the MCS index comprises a five-bit value associated with an entry in an MCS table;

identify an entry in the MCS table based on the received MCS index, wherein the MCS table comprises:

a first contiguous plurality of table entries associated with low SINR, each entry of the first contiguous plurality based on a first sampling grid; and

a second contiguous plurality of table entries associated with medium SINR, each entry of the second contiguous plurality based on a second sampling grid, the second sampling grid having a smaller spacing than the first sampling grid; and

a third contiguous plurality of table entries associated with high SINR, each entry of the third contiguous plurality based on a third sampling grid, the second sampling grid having a smaller spacing than the third sampling grid; and

determine an MCS based on the identified entry in the MCS table.

24. The wireless device of claim 23 , wherein:

the first contiguous plurality of table entries comprises Quadrature Phase Shift Keying (QPSK) entries;

the second contiguous plurality of table entries comprises 16 Quadrature Amplitude Modulation (16QAM) entries; and

the third contiguous plurality of table entries comprises 64 Quadrature Amplitude Modulation (64QAM) entries and 256 Quadrature Amplitude Modulation (256QAM) entries.

25. The wireless device of claim 23 , wherein:

the first contiguous plurality of table entries comprises five entries;

the second contiguous plurality of table entries comprises seven entries; and

the third contiguous plurality of table entries comprises seventeen entries.

26. The wireless device of claim 23 , wherein the third contiguous plurality of table entries comprises nine 64QAM entries and eight 256QAM entries.