Transmission time interval (tti) bundling for control channels in long term evolution (lte)

Abstract

Certain aspects of the present disclosure propose techniques for transmission time interval (TTI) bundling for control channels (e.g., physical downlink control channel (PDCCH) and enhanced PDCCH) in long term evolution (LTE). According to certain aspects a method is provided for wireless communications. The method may be performed, for example, by a user equipment (UE). The method generally includes determining a first set of possible decoding candidates for the downlink control channel in a first subframe of the bundle of subframes and a second set of possible decoding candidates for the downlink control channel in a second subframe in the bundle of subframes, wherein the first set of possible decoding candidates and the second set of possible decoding candidates are different and processing the bundle of subframes based, at least in part, on the determination.

What is claimed is: 
     
         1 . A method of processing a downlink control channel sent as a bundled transmission over a bundle of subframes, comprising:
 determining how to perform rate matching for the downlink control channel in different subframes of the bundle of subframes; and   processing the bundle of subframes based, at least in part, on the determination.   
     
     
         2 . The method of  claim 1 , wherein the processing comprises performing rate matching separately for each subframe in the bundle of subframes. 
     
     
         3 . The method of  claim 1 , wherein the processing comprises performing rate matching jointly for each subframe in the bundle of subframes. 
     
     
         4 . The method of  claim 3 , wherein performing the rate matching jointly for each subframe in the bundle of subframes includes performing rate matching of a first subframe in the bundle of subframes based on a rate matching of a second subframe in the bundle of subframes. 
     
     
         5 . The method of  claim 3 , wherein performing the rate matching jointly for each subframe in the bundle of subframes includes performing rate matching for the bundle of subframes treating all resources across the bundled of subframes as a whole. 
     
     
         6 . The method of  claim 1 , wherein the bundle of subframes comprises a transmission time interval (TTI) bundle of subframes, the TTI bundle of subframes including a plurality of consecutive subframes in which a transmission on the downlink control channel is configured to be repeated with an aggregation level in each of the plurality of consecutive subframes. 
     
     
         7 . The method of  claim 6 , wherein the repetitions of the transmission on the downlink control channel have a same hybrid automatic repeat request (HARQ) process number. 
     
     
         8 . The method of  claim 1 , wherein the downlink control channel comprises a type of physical downlink control channel (PDCCH). 
     
     
         9 . An apparatus for processing a downlink control channel sent as a bundled transmission over a bundle of subframes, comprising:
 at least one processor; and   memory coupled to the at least one processor, the memory comprising code executable by the at least one processor to cause the apparatus to:
 determine how to perform rate matching for the downlink control channel in different subframes of the bundle of subframes; and 
 process the bundle of subframes based, at least in part, on the determination. 
   
     
     
         10 . The apparatus of  claim 9 , wherein the code executable by the at least one processor to cause the apparatus to process the bundle of subframes based, at least in part, on the determination comprises code executable by the at least one processor to cause the apparatus to perform rate matching separately for each subframe in the bundle of subframes. 
     
     
         11 . The apparatus of  claim 9 , wherein the code executable by the at least one processor to cause the apparatus to process the bundle of subframes based, at least in part, on the determination comprises code executable by the at least one processor to cause the apparatus to perform rate matching jointly for each subframe in the bundle of subframes. 
     
     
         12 . The apparatus of  claim 11 , wherein the code executable by the at least one processor to cause the apparatus to perform the rate matching jointly for each subframe in the bundle of subframes includes code executable by the at least one processor to cause the apparatus to perform rate matching of a first subframe in the bundle of subframes based on a rate matching of a second subframe in the bundle of subframes. 
     
     
         13 . The apparatus of  claim 11 , wherein the code executable by the at least one processor to cause the apparatus to perform the rate matching jointly for each subframe in the bundle of subframes includes code executable by the at least one processor to cause the apparatus to perform rate matching for the bundle of subframes treating all resources across the bundled of subframes as a whole. 
     
     
         14 . The apparatus of  claim 9 , wherein the bundle of subframes comprises a transmission time interval (TTI) bundle of subframes, the TTI bundle of subframes including a plurality of consecutive subframes in which a transmission on the downlink control channel is configured to be repeated with an aggregation level in each of the plurality of consecutive subframes. 
     
     
         15 . The apparatus of  claim 14 , wherein the repetitions of the transmission on the downlink control channel have a same hybrid automatic repeat request (HARD) process number. 
     
     
         16 . The apparatus of  claim 9 , wherein the downlink control channel comprises a type of physical downlink control channel (PDCCH). 
     
     
         17 . An apparatus for processing a downlink control channel sent as a bundled transmission over a bundle of subframes, comprising:
 means for determining how to perform rate matching for the downlink control channel in different subframes of the bundle of subframes; and   means for processing the bundle of subframes based, at least in part, on the determination.   
     
     
         18 . The apparatus of  claim 17 , wherein the means for processing comprises means for performing rate matching separately for each subframe in the bundle of subframes. 
     
     
         19 . The apparatus of  claim 17 , wherein the means for processing comprises means for performing rate matching jointly for each subframe in the bundle of subframes. 
     
     
         20 . The apparatus of  claim 19 , wherein means for performing the rate matching jointly for each subframe in the bundle of subframes includes means for performing rate matching of a first subframe in the bundle of subframes based on a rate matching of a second subframe in the bundle of subframes. 
     
     
         21 . The apparatus of  claim 19 , wherein means for performing the rate matching jointly for each subframe in the bundle of subframes includes means for performing rate matching for the bundle of subframes treating all resources across the bundled of subframes as a whole. 
     
     
         22 . The apparatus of  claim 17 , wherein the bundle of subframes comprises a transmission time interval (TTI) bundle of subframes, the TTI bundle of subframes including a plurality of consecutive subframes in which a transmission on the downlink control channel is configured to be repeated with an aggregation level in each of the plurality of consecutive subframes. 
     
     
         23 . The apparatus of  claim 22 , wherein the repetitions of the transmission on the downlink control channel have a same hybrid automatic repeat request (HARD) process number. 
     
     
         24 . The apparatus of  claim 17 , wherein the downlink control channel comprises a type of physical downlink control channel (PDCCH). 
     
     
         25 . A computer readable medium for an apparatus to process a downlink control channel sent as a bundled transmission over a bundle of subframes, comprising:
 code executable by at least one processor to cause the apparatus to:
 determine how to perform rate matching for the downlink control channel in different subframes of the bundle of subframes; and 
 process the bundle of subframes based, at least in part, on the determination. 
   
     
     
         26 . The computer readable medium of  claim 25 , wherein the code executable by the at least one processor to cause the apparatus to process comprises code executable by the at least one processor to cause the apparatus to perform rate matching separately for each subframe in the bundle of subframes. 
     
     
         27 . The computer readable medium of  claim 25 , wherein the code executable by the at least one processor to cause the apparatus to process comprises code executable by the at least one processor to cause the apparatus to perform rate matching jointly for each subframe in the bundle of subframes. 
     
     
         28 . The computer readable medium of  claim 27 , wherein he code executable by the at least one processor to cause the apparatus to perform the rate matching jointly for each subframe in the bundle of subframes includes he code executable by the at least one processor to cause the apparatus to perform rate matching of a first subframe in the bundle of subframes based on a rate matching of a second subframe in the bundle of subframes. 
     
     
         29 . The computer readable medium of  claim 27 , wherein he code executable by the at least one processor to cause the apparatus to perform the rate matching jointly for each subframe in the bundle of subframes includes he code executable by the at least one processor to cause the apparatus to perform rate matching for the bundle of subframes treating all resources across the bundled of subframes as a whole. 
     
     
         30 . The computer readable medium of  claim 25 , wherein the bundle of subframes comprises a transmission time interval (TTI) bundle of subframes, the TTI bundle of subframes including a plurality of consecutive subframes in which a transmission on the downlink control channel is configured to be repeated with an aggregation level in each of the plurality of consecutive subframes.