Resource allocation for enhanced physical downlink control channel (EPDCCH)

Abstract

Certain aspects of the present disclosure provide techniques for systems that support DMRS-based transmissions, that may allow such systems to at least partially utilize resources in the center six RBs of subframes 0 and 5 for DMRS-based transmissions (e.g., EPDCCH), while avoiding collision with Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS) or Physical Broadcast Channel (PBCH).

What is claimed is:  
     
       1. A method for wireless communication by a User Equipment, comprising:
 determining at least one decoding candidate for Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 determining whether or not resources corresponding to the at least one EPDCCH decoding candidate can potentially collide with resources used for transmitting at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) or a Physical Broadcast Channel (PBCH) in the subframe; 
 determining validity of the at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; and 
 processing the at least one EPDCCH decoding candidate based on the determination of the potential resource collision. 
 
     
     
       2. The method of  claim 1 , further comprising:
 receiving a configuration of EPDCCH resources; and 
 determining the at least one EPDCCH decoding candidate based on the received configuration. 
 
     
     
       3. The method of  claim 2 , further comprising:
 determining the resources corresponding to the at least one EPDCCH decoding candidate based on the received configuration. 
 
     
     
       4. The method of  claim 1 , wherein determining the validity of the at least one EPDCCH decoding candidate comprises:
 declaring the at least one EPDCCH decoding candidate as a valid candidate if the resources corresponding to the at least one EPDCCH decoding candidate do not potentially collide with the resources used by the at least one of the PSS, SSS or PBCH. 
 
     
     
       5. The method of  claim 4 , wherein processing the at least one EPDCCH decoding candidate comprises:
 monitoring and decoding the at least one EPDCCH decoding candidate if the at least one EPDCCH decoding candidate is determined to be valid. 
 
     
     
       6. The method of  claim 1 , wherein determining the validity of the at least one EPDCCH decoding candidate comprises:
 declaring the at least one EPDCCH decoding candidate as an invalid candidate if the resources corresponding to the at least one EPDCCH decoding candidate potentially collide with the resources used by at least one of the PSS, SSS or PBCH. 
 
     
     
       7. The method of  claim 6 , wherein processing the at least one EPDCCH decoding candidate comprises:
 skipping monitoring the at least one EPDCCH decoding candidate if the at least one EPDCCH decoding candidate is determined to be invalid. 
 
     
     
       8. The method of  claim 1 , wherein determining if the resources corresponding to the at least one EPDCCH decoding candidate can potentially collide with resources used for transmitting at least one of the PSS, SSS or PBCH comprises:
 determining if the at least one EPDCCH decoding candidate and the at least one of the PSS, SSS or PBCH use a same resource based on a comparison of the resources corresponding to the at least one EPDCCH decoding candidate and the resources used for transmitting the at least one of the PSS, SSS or PBCH. 
 
     
     
       9. The method of  claim 1 , wherein determining if the resources corresponding to the at least one EPDCCH decoding candidate can potentially collide with resources used for transmitting at least one of the PSS, SSS or PBCH comprises:
 determining if the at least one EPDCCH decoding candidate and the at least one of the PSS, SSS or PBCH use a same physical resource block (PRB) pair, based on a comparison of a set of PRB pairs associated with EPDCCH resources and a set of PRB pairs used for transmitting at least one of the PSS, SSS or PBCH. 
 
     
     
       10. The method of  claim 1 , wherein the resources corresponding to the at least one EPDCCH decoding candidate includes at least one physical resource block (PRB) pair of a set of PRB pairs used for transmission of at least one of the PSS, SSS or PBCH such that:
 resources in the at least one PRB pair assigned to at least one of the PSS, SSS or PBCH are not assigned for EPDCCH transmission; and 
 resources in the at least one PRB pair not assigned to at least one of the PSS, SSS or PBCH are assigned for EPDCCH transmission. 
 
     
     
       11. The method of  claim 1 , wherein the at least one EPDCCH decoding candidate is based on a demodulation reference signal (DMRS), and the resources corresponding to the at least one EPDCCH decoding candidate comprise resources used by the DMRS. 
     
     
       12. The method of  claim 11 , wherein in a subframe comprising of two slots, the DMRS is located in at least one symbol not occupied by at least one of the PSS or SSS in a same slot as the at least one of the PSS or SSS. 
     
     
       13. The method of  claim 11 , wherein the DMRS is located only in symbols not occupied by at least one of the PSS or SSS. 
     
     
       14. The method of  claim 11 , wherein the DMRS is located at least in one symbol originally occupied by at least one of PSS or SSS of a legacy type. 
     
     
       15. The method of  claim 1 , wherein the at least one EPDCCH decoding candidate scheduling a transmission on a first carrier is transmitted on a second carrier different from the first carrier. 
     
     
       16. The method of  claim 1 , wherein the resources corresponding to the at least one EPDCCH decoding candidate includes at least one Physical Resource Block Pair. 
     
     
       17. The method of  claim 1 , wherein the resources used for transmitting the at least one of the PSS, SSS or PBCH includes at least one Physical Resource Block Pair. 
     
     
       18. An apparatus for wireless communication, comprising:
 means for determining at least one decoding candidate for Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 means for determining whether or not resources corresponding to the at least one EPDCCH decoding candidate can potentially collide with resources used for transmitting at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) or a Physical Broadcast Channel (PBCH) in the subframe; 
 means for determining validity of the at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; and 
 means for processing the at least one EPDCCH decoding candidate based on the determination of potential resource collision. 
 
     
     
       19. The apparatus of  claim 18 , wherein the means for determining the validity of the at least one EPDCCH decoding candidate is configured to:
 declare the at least one EPDCCH decoding candidate as a valid candidate if the resources corresponding to the at least one EPCDDH decoding candidate do not potentially collide with the resources used by the at least one of the PSS, SSS or PBCH. 
 
     
     
       20. The apparatus of  claim 19 , wherein the means for processing the at least one EPDCCH decoding candidate is configured to:
 monitor and decode the at least one EPDCCH decoding candidate if the at least one EPDCCH decoding candidate is determined to be valid. 
 
     
     
       21. The apparatus of  claim 18 , wherein the means for determining the validity of the at least one EPDCCH decoding candidate is configured to:
 declare the at least one EPDCCH decoding candidate as an invalid candidate if the resources corresponding to the at least one EPDCCH decoding candidate potentially collide with the resources used by the at least one of the PSS, SSS or PBCH. 
 
     
     
       22. The apparatus of  claim 21 , wherein the means for processing the at least one EPDCCH decoding candidate is configured to:
 skip monitoring the at least one EPDCCH decoding candidate if the at least one EPDCCH decoding candidate is determined to be invalid. 
 
     
     
       23. The apparatus of  claim 18 , wherein the at least one EPDCCH decoding candidate is based on a demodulation reference signal (DMRS), and the resources corresponding to the at least one EPDCCH decoding candidate comprise resources used by the DMRS. 
     
     
       24. The apparatus of  claim 23 , wherein in a subframe comprising of two slots, the DMRS is located in at least one symbol not occupied by at least one of the PSS or SSS in a same slot as the at least one of the PSS or SSS. 
     
     
       25. The apparatus of  claim 23 , wherein the DMRS is located only in symbols not occupied by at least one of the PSS or SSS. 
     
     
       26. The apparatus of  claim 23 , wherein the DMRS is located at least in one symbol originally occupied by at least one of PSS or SSS of a legacy type. 
     
     
       27. The apparatus of  claim 18 , wherein the at least one EPDCCH decoding candidate scheduling a transmission on a first carrier is transmitted on a second carrier different from the first carrier. 
     
     
       28. An apparatus for wireless communication, comprising:
 at least one processor configured to:
 determine at least one decoding candidate for Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 determine whether or not resources corresponding to the at least one EPDCCH decoding candidate can potentially collide with resources used for transmitting at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) or a Physical Broadcast Channel (PBCH) in the subframe; 
 determine validity of the at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; and 
 process the at least one EPDCCH decoding candidate based on the determination of potential resource collision; and 
 
 a memory coupled to the at least one processor. 
 
     
     
       29. A computer program product for wireless communication, comprising:
 a non-transitory computer-readable medium comprising code for:
 determining at least one decoding candidate for Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 determining whether or not resources corresponding to the at least one EPDCCH decoding candidate can potentially collide with resources used for transmitting at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) or a Physical Broadcast Channel (PBCH) in the subframe; 
 determining validity of the at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; and 
 processing the at least one EPDCCH decoding candidate based on the determination of potential resource collision. 
 
 
     
     
       30. A method for wireless communications by a Base Station (BS), comprising:
 determining potential collision conditions for each of a set of decoding candidates for transmitting Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 determining validity of at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; 
 selecting the at least one EPDCCH decoding candidate from the set based on the validity determination; and 
 transmitting an EPDCCH on the selected EPDCCH decoding candidate. 
 
     
     
       31. The method of  claim 30 , wherein the selecting comprises selecting the at least one EPDCCH decoding candidate if the at least one EPDCCH decoding candidate is determined to be valid, wherein the at least one EPDCCH decoding candidate is declared as a valid candidate if resources corresponding to the candidate do not collide with resources used for transmitting at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) or a Physical Broadcast Channel (PBCH) in the subframe. 
     
     
       32. The method of  claim 31 , wherein the determining the potential collision conditions comprises:
 determining if the at least one EPDCCH decoding candidate and the at least one of the PSS, SSS or PBCH use a same resource based on a comparison of the resources corresponding to the EPDCCH decoding candidate and the resources used for transmitting the at least one of the PSS, SSS or PBCH. 
 
     
     
       33. The method of  claim 31 , wherein the determining the potential collision conditions comprises:
 determining if the at least one EPDCCH decoding candidate and the at least one of the PSS, SSS or PBCH use a same physical resource block (PRB) pair, based on a comparison of a set of PRB pairs associated with EPDCCH resources and a set of PRB pairs used for transmitting at least one of the PSS, SSS or PBCH. 
 
     
     
       34. The method of  claim 31 , wherein the resources corresponding to the at least one EPDCCH decoding candidate includes at least one physical resource block (PRB) pair of a set of PRB pairs used for transmission of at least one of the PSS, SSS or PBCH such that:
 resources in the at least one PRB pair assigned to at least one of the PSS, SSS or PBCH are not assigned for EPDCCH transmission; and 
 resources in the at least one PRB pair not assigned to at least one of the PSS, SSS or PBCH are assigned for EPDCCH transmission. 
 
     
     
       35. The method of  claim 30 , wherein the at least one EPDCCH decoding candidate is based on a demodulation reference signal (DMRS), and resources corresponding to the at least one EPDCCH decoding candidate comprise resources used by the DMRS. 
     
     
       36. The method of  claim 35 , wherein in a subframe comprising of two slots, the DMRS is located in at least one symbol not occupied by at least one of Primary Synchronization Signal (PSS) or Secondary Synchronization Signal (SSS) in a same slot as the at least one of the PSS or SSS. 
     
     
       37. The method of  claim 35 , wherein the DMRS is located only in symbols not occupied by at least one of Primary Synchronization Signal (PSS) or Secondary Synchronization Signal (SSS). 
     
     
       38. The method of  claim 35 , wherein the DMRS is located at least in one symbol originally occupied by at least one of Primary Synchronization Signal (PSS) or Secondary Synchronization Signal (SSS) of a legacy type. 
     
     
       39. The method of  claim 30 , wherein resources corresponding to each EPDCCH decoding candidate includes at least one Physical Resource Block Pair. 
     
     
       40. The method of  claim 30 , wherein resources used for transmitting at least one of the PSS, SSS or PBCH includes at least one Physical Resource Block Pair. 
     
     
       41. An apparatus for wireless communications, comprising:
 means for determining potential collision conditions for each of a set of decoding candidates for transmitting Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 means for determining validity of at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; 
 means for selecting the at least one EPDCCH decoding candidate from the set based on the validity determination; and 
 means for transmitting an EPDCCH on the selected EPDCCH decoding candidate. 
 
     
     
       42. The apparatus of  claim 41 , wherein the means for selecting is configured to select the at least one EPDCCH decoding candidate if the at least one EPDCCH decoding candidate is determined to be valid, wherein the at least one EPDCCH decoding candidate is declared as a valid candidate if resources corresponding to the candidate do not collide with resources used for transmitting at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) or a Physical Broadcast Channel (PBCH) in the subframe. 
     
     
       43. The apparatus of  claim 42 , wherein the means for determining the potential collision conditions is configured to:
 determine if the at least one EPDCCH decoding candidate and the at least one of the PSS, SSS or PBCH use a same resource based on a comparison of the resources corresponding to the EPDCCH decoding candidate and the resources used for transmitting at least one of the PSS, SSS or PBCH. 
 
     
     
       44. The apparatus of  claim 42 , wherein the means for determining the potential collision conditions is configured to:
 determine if the at least one EPDCCH decoding candidate and the at least one of the PSS, SSS or PBCH use a same physical resource block (PRB) pair, based on a comparison of a set of PRB pairs associated with EPDCCH resources and a set of PRB pairs used for transmitting at least one of the PSS, SSS or PBCH. 
 
     
     
       45. The apparatus of  claim 42 , wherein the resources corresponding to the at least one EPDCCH decoding candidate includes at least one physical resource block (PRB) pair of a set of PRB pairs used for transmission of at least one of the PSS, SSS or PBCH such that:
 resources in the at least one PRB pair assigned to at least one of the PSS, SSS or PBCH are not assigned for EPDCCH transmission; and 
 resources in the at least one PRB pair not assigned to at least one of the PSS, SSS or PBCH are assigned for EPDCCH transmission. 
 
     
     
       46. The apparatus of  claim 41 , wherein the at least one EPDCCH decoding candidate is based on a demodulation reference signal (DMRS), and resources corresponding to the at least one EPDCCH decoding candidate comprise resources used by the DMRS. 
     
     
       47. The apparatus of  claim 46 , wherein in a subframe comprising of two slots, the DMRS is located in at least one symbol not occupied by at least one of Primary Synchronization Signal (PSS) or Secondary Synchronization Signal (SSS) in a same slot as the at least one of the PSS or SSS. 
     
     
       48. The apparatus of  claim 46 , wherein the DMRS is located only in symbols not occupied by at least one of Primary Synchronization Signal (PSS) or Secondary Synchronization Signal (SSS). 
     
     
       49. The apparatus of  claim 46 , wherein the DMRS is located at least in one symbol originally occupied by at least one of Primary Synchronization Signal (PSS) or Secondary Synchronization Signal (SSS) of a legacy type. 
     
     
       50. An apparatus for wireless communications, comprising:
 at least one processor configured to:
 determine potential collision conditions for each of a set of decoding candidates for transmitting Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 determine validity of at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; 
 select the at least one EPDCCH decoding candidate from the set based on the validity determination; and 
 transmit an EPDCCH on the selected EPDCCH decoding candidate; and 
 
 a memory coupled to the at least one processor. 
 
     
     
       51. A computer program product for wireless communications, comprising:
 a non-transitory computer-readable medium comprising code for:
 determining potential collision conditions for each of a set of decoding candidates for transmitting Enhanced Physical Downlink Control Channel (EPDCCH) in a subframe; 
 determining validity of at least one EPDCCH decoding candidate based, at least in part, on the determination of the potential resource collision; 
 selecting the at least one EPDCCH decoding candidate from the set based on the validity determination; and 
 transmitting an EPDCCH on the selected EPDCCH decoding candidate.