Method and apparatus for positioning pilot in an OFDMA mobile communication system

1. A method for positioning a pilot in a transmitter for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the method comprising:

identifying, by a block assignment determiner, whether a consecutive block or a single block is assigned in a frequency axis or a time axis;

determining, by a pilot tone pattern generator, a pilot pattern in the block by applying a predetermined rule according to a result of the identifying; and

positioning, by a pilot tone inserter, pilots in the block based on the determined pilot pattern,

wherein the predetermined rule defines that a pilot pattern of at least one of a plurality of blocks comprising the consecutive block is different from that of the single block.

2. The method of claim 1 , further comprising:

determining a Pilot-to-Data Ratio (PDR) according to the result of the identifying result.

3. The method of claim 1 , wherein when a consecutive block is assigned in the frequency axis, the predetermined rule comprises:

determining an interval between pilots in the frequency axis as a number that can be obtained by dividing a number of frequency tones in one block, positioning pilots in all blocks at the determined pilot interval, and positioning pilot symbols in frequency tones of an end of a last block.

4. The method of claim 1 , wherein when a consecutive block is assigned in the frequency axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block in a start block and an end block, and positioning pilot symbols at a regular interval in a mid-block.

5. The method of claim 1 , wherein when a single block is assigned, the predetermined rule comprises:

positioning pilot symbols in a frequency domain at an irregular interval to transmit the pilot symbols over frequency tones located at a top and a bottom of one block.

6. The method of claim 1 , wherein when a consecutive block is assigned in the time axis, the predetermined rule comprises:

using a pilot pattern of a single block for a start block and an end block, and performing decimation on mid-blocks except for the start block and the end block in the time axis, for pilot positioning.

7. A method for estimating a pilot in a receiver for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the method comprising:

identifying, by a block assignment determiner, whether an assigned block is a consecutive block or a single block in a frequency axis or a time axis;

determining, by a pilot tone pattern recognizer, a pilot pattern in the block to which a predetermined rule is applied according to a result of the identifying; and

extracting, by a pilot tone extractor, pilots using the determined pilot pattern,

wherein the predetermined rule defines that a pilot pattern of at least one of blocks comprising the consecutive block is different from that of the single block.

8. The method of claim 7 , further comprising:

recognizing a Pilot-to-Data Ratio (PDR) according to the result of the identifying result.

9. The method of claim 7 , wherein when the assigned block is a consecutive block in the frequency axis, the predetermined rule comprises:

determining an interval between pilots in the frequency axis as a number that can be obtained by dividing a number of frequency tones in one block, positioning pilots in all blocks at the determined pilot interval, and positioning pilot symbols in frequency tones of an end of a last block.

10. The method of claim 7 , wherein when the assigned block is a consecutive block in the frequency axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block in a start block and an end block, and positioning pilot symbols at a regular interval in a mid-block.

11. The method of claim 7 , wherein when the assigned block is a single block, the predetermined rule comprises:

positioning pilot symbols in a frequency domain at an irregular interval to transmit the pilot symbols over frequency tones located at a top and a bottom of one block.

12. The method of claim 7 , wherein when the assigned block is a consecutive block in the time axis, the predetermined rule comprises:

using a pilot pattern of a single block for a start block and an end block, and performing decimation on mid-blocks except for the start block and the end block in the time axis, for pilot positioning.

13. An apparatus for positioning a pilot in a transmitter for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the apparatus comprising:

a block assignment determiner for determining whether a consecutive block or a single block is assigned in a frequency axis or a time axis;

a pilot tone pattern generator for determining a pilot pattern in the block by applying a predetermined rule according to a determination result of the block assignment determiner; and

a pilot tone inserter for positioning pilots in the block based on the determined pilot pattern,

wherein the predetermined rule defines that a pilot pattern of at least one of a plurality of blocks comprising the consecutive block is different from that of the single block.

14. The apparatus of claim 13 , further comprising a pilot tone Pilot-to-Data Ratio (PDR) generator for determining a PDR according to the determination result of the block assignment determiner.

15. The apparatus of claim 13 , wherein when a consecutive block is assigned in the frequency axis, the predetermined rule comprises:

determining an interval between pilots in the frequency axis as a number that can be obtained by dividing a number of frequency tones in one block, positioning pilots in all blocks at the determined pilot interval, and positioning pilot symbols in frequency tones of an end of a last block.

16. The apparatus of claim 13 , wherein when a consecutive block is assigned in the frequency axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block in a start block and an end block, and positioning pilot symbols at a regular interval in a mid-block.

17. The apparatus of claim 13 , wherein when a single block is assigned, the predetermined rule comprises:

positioning pilot symbols in a frequency domain at an irregular interval to transmit the pilot symbols over frequency tones located at a top and a bottom of one block.

18. The apparatus of claim 13 , wherein when a consecutive block is assigned in the time axis, the predetermined rule comprises:

using a pilot pattern of a single block for a start block and an end block, and performing decimation on mid-blocks except for the start block and the end block in the time axis, for pilot positioning.

19. An apparatus for estimating a pilot in a receiver for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the apparatus comprising:

a block assignment determiner for identifying whether an assigned block is a consecutive block or a single block in a frequency axis or a time axis;

a pilot tone pattern recognizer for determining a pilot pattern in the block to which a predetermined rule is applied according to a result of the identifying; and

a pilot tone extractor for extracting pilots using the determined pilot pattern,

wherein the predetermined rule defines that a pilot pattern of at least one of blocks comprising the consecutive block is different from that of the single block.

20. The apparatus of claim 19 , further comprising a pilot tone Pilot-to-Data Ratio (PDR) recognizer for recognizing a PDR according to the result of the identifying.

21. The apparatus of claim 20 , wherein when the assigned block is a consecutive block in the time axis, the predetermined rule comprises:

using a pilot pattern of a single block for a start block and an end block, and performing decimation on mid-blocks except for the start block and the end block in the time axis, for pilot positioning.

22. The apparatus of claim 19 , wherein when the assigned block is a consecutive block in the frequency axis, the predetermined rule comprises:

determining an interval between pilots in the frequency axis as a number that can be obtained by dividing a number of frequency tones in one block, positioning pilots in all blocks at the determined pilot interval, and positioning pilot symbols in frequency tones of an end of a last block.

23. The apparatus of claim 19 , wherein when the assigned block is a consecutive block in the frequency axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block in a start block and an end block, and positioning pilot symbols at a regular interval in a mid-block.

24. The apparatus of claim 19 , wherein when the assigned block is a single block, the predetermined rule comprises:

positioning pilot symbols in a frequency domain at an irregular interval to transmit the pilot symbols over frequency tones located at a top and a bottom of one block.

25. A method for positioning a pilot in a transmitter for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the method comprising:

identifying, by a block assignment determiner, whether a consecutive block or a single block is assigned in a frequency axis or a time axis;

determining, by a pilot tone pattern generator, a pilot pattern in the block by applying a predetermined rule according to a result of the identifying; and

positioning, by a pilot tone inserter, pilots in the block based on the determined pilot pattern,

wherein when a consecutive block is assigned in the frequency axis or the time axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block for all blocks, and decreasing a Pilot-to-Data Ratio (PDR) for mid-blocks in the frequency axis or the time axis for pilot positioning.

26. A method for estimating a pilot in a receiver for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the method comprising:

identifying, by a block assignment determiner, whether an assigned block is a consecutive block or a single block in a frequency axis or a time axis;

determining, by a pilot tone pattern recognizer, a pilot pattern in the block to which a predetermined rule is applied according to a result of the identifying; and

extracting, by a pilot tone extractor, pilots using the determined pilot pattern,

wherein when the assigned block is a consecutive block in the frequency axis or the time axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block for all blocks, and decreasing a Pilot-to-Data Ratio (PDR) for mid-blocks in the frequency axis or time axis for pilot positioning.

27. An apparatus for positioning a pilot in a transmitter for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the apparatus comprising:

a block assignment determiner for determining whether a consecutive block or a single block is assigned in a frequency axis or a time axis;

a pilot tone pattern generator for determining a pilot pattern in the block by applying a predetermined rule according to a determination result of the block assignment determiner; and

a pilot tone inserter for positioning pilots in the block based on the determined pilot pattern,

wherein when a consecutive block is assigned in the frequency axis or time axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block for all blocks, and decreasing a Pilot-to-Data Ratio (PDR) for mid-blocks in the frequency axis or the time axis for pilot positioning.

28. An apparatus for estimating a pilot in a receiver for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system, the apparatus comprising:

a block assignment determiner for identifying whether an assigned block is a consecutive block or a single block in a frequency axis or a time axis;

a pilot tone pattern recognizer for determining a pilot pattern in the block to which a predetermined rule is applied according to a result of the identifying; and

a pilot tone extractor for extracting pilots using the determined pilot pattern,

wherein when the assigned block is a consecutive block in the frequency axis or time axis, the predetermined rule comprises:

maintaining a pilot pattern used for a single block for all blocks, and decreasing a PDR for mid-blocks in the frequency axis or time axis for pilot positioning.