Method of handling tone map interpolation and related communication device

1. A method of determining a tone allocation with a tone index, utilized in a communication device of a communication system, the method comprising:

the communication device selecting at least one base tone index from a plurality of base tone indices according to at least one relation between the tone index and the at least one base tone index; and

the communication device generating the tone allocation according to at least one base tone allocation with the at least one base tone index of a plurality of base tone allocations, and the at least one relation between the tone index and the at least one base tone index by using interpolation to interpolate the tone allocation from the at least one base tone allocation according to the at least one relation;

wherein a base tone map comprises the plurality of base tone indices and the plurality of base tone allocations;

wherein the communication device is a transmitter or a receiver in the communication system.

2. The method of claim 1 , wherein the at least one relation is at least one distance between the tone index and the at least one base tone index.

3. The method of claim 2 , wherein selecting the at least one base tone index from the plurality of base tone indices according to the at least one relation between the tone index and the at least one base tone index, comprises:

the communication device selecting the at least one base tone index which has the smallest distance from the tone index, from the plurality of base tone indices.

4. The method of claim 1 , further comprising:

the communication device selecting a first base tone index and a second base tone index from the plurality of base tone indices such that the tone index is between the first base tone index and the second base tone index; and

the communication device generating the tone allocation with the tone index according to a first base tone allocation with the first base tone index and a second base tone allocation with the second base tone index of the plurality of base tone allocations.

5. The method of claim 4 , wherein determining the first base tone index and the second base tone index from the plurality of base tone indices such that the tone index is between the first base tone index and the second base tone index, comprises:

the communication device selecting the first base tone index from the plurality of base tone indices such that the first base tone index is the largest base tone index smaller than the tone index; and

the communication device selecting the second base tone index from the plurality of base tone indices such that the second base tone index is the smallest base tone index larger than the tone index.

6. The method of claim 4 further comprising

the communication device selecting a third base tone index and a fourth base tone index from the plurality of base tone indices such that the tone index is between the third base tone index and the fourth base tone index; and

the communication device generating the tone allocation with the tone index according to the first base tone allocation, the second base tone allocation, a third base tone allocation with the third base tone index and a fourth base tone allocation with the fourth base tone index of the plurality of base tone allocations.

7. The method of claim 1 , wherein generating the tone allocation with the tone index according to the at least one base tone allocation with the at least one base tone index of the plurality of base tone allocations, comprises:

the communication device obtaining at least one contribution from the at least one base tone allocation according to the at least one relation between the tone index and the at least one base tone index; and

the communication device generating the tone allocation with the tone index according to the at least one contribution.

8. The method of claim 1 , wherein the base tone map is stored in the transmitter or the receiver.

9. The method of claim 1 , wherein the base tone map is fed back from the receiver.

10. The method of claim 1 , wherein the base tone map is indicated by an index fed back from the receiver.

11. The method of claim 1 , wherein the tone allocation and the at least one base tone allocation relate to numbers of bits allocated to the tone index and the at least one base tone index, respectively.

12. The method of claim 1 , wherein the tone index and the at least one base tone index are on a same time domain, or are on a same frequency domain.

13. The method of claim 1 , wherein the tone index and the at least one base tone index are two-dimension indices.

14. The method of claim 1 , wherein the tone index and the at least one base tone index are on a straight line.

15. A communication device of a communication system for handling a tone allocation with a tone index, the communication device comprising:

a processor for executing a program;

a memory for storing data; and

a storage device, coupled to the processor storing the program; wherein when executed by the processor, the program instructs the processor to perform the following steps:

selecting at least one base tone index from a plurality of base tone indices according to at least one relation between the tone index and the at least one base tone index; and

generating the tone allocation according to at least one base tone allocation with the at least one base tone index of a plurality of base tone allocations, and the at least one relation between the tone index and the at least one base tone index by using interpolation to interpolate the tone allocation from the at least one base tone allocation according to the at least one relation;

wherein a base tone map comprises the plurality of base tone indices and the plurality of base tone allocations.

16. The communication device of claim 15 , wherein the at least one relation is at least one distance between the tone index and the at least one base tone index.

17. The communication device of claim 16 , wherein selecting the at least one base tone index from the plurality of base tone indices according to the at least one relation between the tone index and the at least one base tone index, comprises:

selecting the at least one base tone index which has the smallest distance with the tone index, from the plurality of base tone indices.

18. The communication device of claim 15 , further comprising:

selecting a first base tone index and a second base tone index from the plurality of base tone indices such that the tone index is between the first base tone index and the second base tone index; and

generating the tone allocation with the tone index according to a first base tone allocation with the first base tone index and a second base tone allocation with the second base tone index of the plurality of base tone allocations.

19. The communication device of claim 18 , wherein determining the first base tone index and the second base tone index from the plurality of base tone indices such that the tone index is between the first base tone index and the second base tone index, comprises:

selecting the first base tone index from the plurality of base tone indices such that the first base tone index is the largest base tone index smaller than the tone index; and

selecting the second base tone index from the plurality of base tone indices such that the second base tone index is the smallest base tone index larger than the tone index.

20. The communication device of claim 18 further comprising

selecting a third base tone index and a fourth base tone index from the plurality of base tone indices such that the tone index is between the third base tone index and the fourth base tone index; and

generating the tone allocation with the tone index according to the first base tone allocation, the second base tone allocation, a third base tone allocation with the third base tone index and a fourth base tone allocation with the fourth base tone index of the plurality of base tone allocations.

21. The communication device of claim 15 , wherein generating the tone allocation with the tone index according to the at least one base tone allocation with the at least one base tone index of the plurality of base tone allocations, comprises:

obtaining at least one contribution from the at least one base tone allocation according to the at least one relation between the tone index and the at least one base tone index; and

generating the tone allocation with the tone index according to the at least one contribution.

22. The communication device of claim 15 , wherein the base tone map is stored in the communication device, or another communication device of the communication system with which the communication device communicates.

23. The communication device of claim 15 , wherein the base tone map is fed back from another communication device of the communication system.

24. The communication device of claim 15 , wherein the base tone map is indicated by an index fed back from another communication device of the communication system.

25. The communication device of claim 15 , wherein the tone allocation and the at least one base tone allocation relate to numbers of bits allocated to the tone index and the at least one base tone index, respectively.

26. The communication device of claim 15 , wherein the tone index and the at least one base tone index are on a same time domain, or are on a same frequency domain.

27. The communication device of claim 15 , wherein the tone index and the at least one base tone index are two-dimension indices.

28. The communication device of claim 15 , wherein the tone index and the at least one base tone index are on a straight line.