Random reuse based control channels

• US 8,761,032 B2
• Filed: 06/27/2008
• Issued: 06/24/2014
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lin, Dexu, Gorokhov, Alexei, Khandekar, Aamod, Palanki, Ravi
• Primary Examiner(s): Russell, Wanda Z
• Application Number:
  US12/163,818
• Publication Number:
  US 20090129268A1
• Time in Patent Office: 2,188 Days
• Field of Search: 370/252, 370/310, 370/522, 455/452.2
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0004 applied to control information
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Systems and methodologies are described that facilitate wireless network transmitters blanking or reducing power on portions of bandwidth reserved for control information transmission. This mitigates interference from disparate transmitters. Furthermore, the control information portion can be divided into a plurality of OFDM tiles that are reusable by transmitters for transmitting the control information. In this regard, interference between transmitters is additionally mitigated as the transmitters can multiplex the control information over a plurality of tiles increasing the chance that at least a portion of the tiles are not interfered. The control information can be decoded by the receivers from the portion of tiles with a low probability of interference.

Claims

1. A method that facilitates communicating control information in wireless networks, comprising:

receiving, at a communications apparatus, control information from a transmitting apparatus, the control information being received over one or more tiles that are a portion of a reserved control segment that is dedicated for transmitting the control information, wherein a tile comprises a set of tones that includes at least one pilot signal and the control information is multiplexed over a plurality of tiles to thereby increase the probability that at least a portion of the tiles are not interfered;

determining, at the communications apparatus, respective levels of interference affecting respective transmissions on the one or more tiles, wherein the respective level of interference affecting transmission on a tile is determined based at least in part on interference affecting transmission of the at least one pilot signal included in the tile; and

weighting, at the communications apparatus, the tiles for channel estimation for subsequent data decoding with a low probability of interference based at least in part on the respective levels of interference, wherein assignment of respective weights is dependent on the respectively associated levels of interference, such that the higher the level of interference, the lower the associated weight and vice versa, and such that a first tile is given less weight for the channel estimation than a second tile if the first tile has a higher level of interference than the second tile.

2. The method of claim 1, further comprising determining the one or more tiles based at least in part on a random or pseudo-random function utilized by a transmitter.

3. The method of claim 2, the random or pseudo-random function is specific to the transmitter.

4. The method of claim 1, further comprising estimating a frequency response from the one or more tiles.

5. The method of claim 4, further comprising decoding the control information from the one or more tiles based at least in part on the frequency response.

6. The method of claim 4, the frequency response is estimated based at least in part on a subset of the one or more tiles with a level of interference less than a threshold interference.

7. The method of claim 1, the one or more tiles comprise one or more contiguous tones of one or more contiguous OFDM symbols.

8. The method of claim 6, the control information is randomly multiplexed as one or more encoded modulation symbols over the one or more tiles.

9. The method of claim 1, wherein during the reserved control segment, multiple transmitting apparatuses blank or reduce power for non-control information.

10. The method of claim 1, wherein the respective level of interference for a tile is determined based only on the at least one pilot signal included in the tile.

11. A wireless communications apparatus, comprising:

at least one processor configured to determine a level of interference affecting transmission on one or more control information tiles received from a transmitting apparatus over a reserved control segment and weight the control information tiles for channel estimation for subsequent data decoding with a low probability of interference based at least in part on the level of interference, wherein the control information tiles are a portion of the reserved control segment and multiplexed over a plurality of tiles to thereby increase the probability that at least a portion of the tiles are not interfered, wherein assignment of a weight is dependent on the associated level of interference, such that the higher the level of interference, the lower the associated weight and vice versa, and such that a first control information tile is given less weight for the channel estimation than a second control information tile if the first control information tile has a higher level of interference than the second control information tile, wherein a control information tile comprises a set of tones that includes at least one pilot signal, and wherein the level of interference affecting transmission on a control information tile is determined based at least in part on interference affecting transmission of the at least one pilot signal included in the control information tile; and

a memory coupled to the at least one processor.

12. The wireless communications apparatus of claim 11, the one or more control information tiles comprise one or more tones over one or more OFDM symbols.

13. The wireless communications apparatus of claim 12, the control information tiles are partially interfered by one or more disparate control information tiles received from a disparate device over at least a portion of the control information tiles.

14. The wireless communications apparatus of claim 11, the one or more control information tiles are randomly positioned in the reserved control segment.

15. The wireless communications apparatus of claim 14, the random positioning is specific to a transmitter of the one or more control information tiles.

16. The wireless communications apparatus of claim 14, the one or more control information tiles are contiguous in time or frequency over the reserved control segment.

17. A wireless communications apparatus that facilitates communicating control information in wireless networks, comprising:

means for determining respective levels of interference affecting respective transmissions on one or more tiles received from a transmitting apparatus over a reserved control segment that is dedicated for transmitting control information, wherein the one or more tiles are a portion of the reserved control segment and multiplexed over a plurality of tiles to thereby increase the probability that at least a portion of the tiles are not interfered, wherein a tile comprises a set of tones that includes at least one pilot signal, and wherein the respective level of interference affecting transmission on a tile is determined based at least in part on interference affecting transmission of the at least one pilot signal included in the tile; and

means for weighting the tiles for channel estimation for subsequent data decoding with a low probability of interference based at least in part on the respective levels of interference, wherein assignment of respective weights is dependent on the respectively associated levels of interference, such that the higher the level of interference, the lower the associated weight and vice versa, and such that a first tile is given less weight for the channel estimation than a second tile if the first tile has a higher level of interference than the second tile.

18. The wireless communications apparatus of claim 17, further comprising means for determining the one or more tiles based at least in part on a random or pseudo-random function utilized by a transmitter.

19. The wireless communications apparatus of claim 18, the random or pseudorandom function is specific to the transmitter.

20. The wireless communications apparatus of claim 18, further comprising means for transmitting a control information transmission scheme to the transmitter, control information is multiplexed over the one or more tiles according to the scheme.

21. The wireless communications apparatus of claim 17, further comprising means for estimating one or more control channels from the one or more tiles, control information is decoded based at least in part on the estimated control channels.

22. A computer program product, comprising:

a non-transitory computer-readable medium comprising;

code for causing at least one computer to receive control information from a transmitting apparatus, the control information being received over one or more tiles that are a portion of a reserved control segment that is dedicated for transmitting the control information and multiplexed over a plurality of tiles to thereby increase the probability that at least a portion of the tiles are not interfered, wherein a tile comprises a set of tones that includes at least one pilot signal;

code for causing the at least one computer to determine respective levels of interference affecting respective transmissions on the one or more tiles, wherein the respective level of interference affecting transmission on a tile is determined based at least in part on interference affecting transmission of the at least one pilot signal included in the tile; and

code for causing the at least one computer to weight the tiles for channel estimation for subsequent data decoding with a low probability of interference based at least in part on the respective levels of interference, wherein assignment of respective weights is dependent on the respectively associated levels of interference, such that the higher the level of interference, the lower the associated weight and vice versa, and such that a first tile is given less weight for the channel estimation than a second tile if the first tile has a higher level of interference than the second tile.

23. A wireless communication apparatus, comprising:

a processor configured to;

determine respective levels of interference affecting respective transmissions on one or more tiles received from a transmitting apparatus over a reserved control segment that is dedicated for transmitting control information, wherein the one or more tiles are a portion of the reserved control segment, wherein a tile comprises a set of tones that includes at least one pilot signal, and wherein the respective level of interference affecting transmission on a tile is determined based at least in part on interference affecting transmission of the at least one pilot signal included in the tile; and

weight the tiles for channel estimation for subsequent data decoding based at least in part on the respective levels of interference, wherein assignment of respective weights is dependent on the respectively associated levels of interference, such that the higher the level of interference, the lower the associated weight and vice versa, and such that a first tile is given less weight for the channel estimation than a second tile if the first tile has a higher level of interference than the second tile; and

a memory coupled to the processor.