System and method for determining a search space in carrier aggregation in LTE-A

Abstract

Systems, methods, and software can be used to process a control channel at a user agent (UA) within a wireless communication system. In some aspects, the method includes identifying one carrier as an anchor carrier and at least one other another carrier as a non-anchor carrier; for each carrier: determining a location of a UA specific search space including one or more control channel candidates for the carrier based on a linear congruential random number; and attempting to decode each of the control channel candidates in the UA specific search space to identify at least one of an uplink or a downlink grant associated with the carrier and receiving information indicating a first number of control channel candidates for a first aggregation level for the anchor carrier and a second number of control channel candidates for the first aggregation level for the non-anchor carrier, wherein the first number of control channel candidates is different from the second number of control channel candidates.

What is claimed is: 
     
       1. A non-transitory computer readable medium for processing a control channel at a user agent (UA) within a wireless communication system, the computer readable medium storing instructions to cause a processor to perform operations comprising:
 identifying one carrier as an anchor carrier and at least one other another carrier as a non-anchor carrier, the anchor carrier and the at least one non-anchor carrier compatible with Long Term Evolution (LTE) carrier aggregation operations; 
 receiving information indicating a first number of control channel candidates for a first aggregation level for the anchor carrier and a second number of control channel candidates for the first aggregation level for the non-anchor carrier, wherein the first number of control channel candidates is different from the second number of control channel candidates; and 
 for each carrier:
 based on the received information, determining a location of a UA specific search space including one or more control channel candidates for the carrier based on a linear congruential random number and a carrier index of the carrier, wherein each control channel candidate comprises at least one control channel element (CCE); and 
 attempting to decode each of the one or more control channel candidates in the UA specific search space to identify at least one of an uplink or a downlink grant associated with the carrier. 
 
 
     
     
       2. The non-transitory computer readable medium of  claim 1 , wherein the linear congruential random number is based on the carrier index. 
     
     
       3. The non-transitory computer readable medium of  claim 1 , the instructions further comprising where a control channel candidate is successfully decoded, using the grant to facilitate communication. 
     
     
       4. A non-transitory computer readable medium for processing a control channel at an access device within a wireless communication system for transmission to a user agent, the computer readable medium storing instructions to cause a processor to perform operations comprising:
 identifying one carrier as an anchor carrier and at least one other another carrier as a non-anchor carrier, the anchor carrier and the at least one non-anchor carrier compatible with Long Term Evolution (LTE) carrier aggregation operations; and 
 transmitting information indicating a first number of control channel candidates for a first aggregation level for the anchor carrier and a second number of control channel candidates for the first aggregation level for the non-anchor carrier, wherein the first number of control channel candidates is different from the second number of control channel candidates; and  
 for each carrier:
 based on the information, determining a location of a UA specific search space including one or more control channel candidates for the carrier based on a linear congruential random number and a carrier index of the carrier, wherein each control channel candidate comprises at least one control channel element (CCE); and 
 transmitting at least one of an uplink grant or a downlink grant to a UA using at least one of the one or more control channel candidates. 
 
 
     
     
       5. The computer readable medium of  claim 4 , wherein the linear congruential random number is based on the carrier index. 
     
     
       6. An access device for processing a control channel within a wireless communication system for transmission to a user agent, the access device comprising:
 a linear congruential random number generator; 
 one or more processors; and 
 a memory coupled to one or more processors and storing programming instructions for execution by the one or more processors configured to:
 identify one carrier as an anchor carrier and at least one other another carrier as a non-anchor carrier, the anchor carrier and the at least one non-anchor carrier compatible with Long Term Evolution (LTE) carrier aggregation operations; and 
 transmit information indicating a first number of control channel candidates for a first aggregation level for the anchor carrier and a second number of control channel candidates for the first aggregation level for the non-anchor carrier, wherein the first number of control channel candidates is different from the second number of control channel candidates; and  
 for each carrier:
 based on the information, determine a location of a UA specific search space including one or more control channel candidates for the carrier based on a linear congruential random number and a carrier index of the carrier, wherein each control channel candidate comprises at least one control channel element (CCE); and 
 transmit at least one of an uplink grant or a downlink grant to a UA using at least one of the one or more control channel candidates. 
 
 
 
     
     
       7. The access device of  claim 6 , wherein the linear congruential random number is based on the carrier index. 
     
     
       8. A method for processing a control channel at a user agent (UA) within a wireless communication system, the method comprising:
 identifying one carrier as an anchor carrier and at least one other another carrier as a non-anchor carrier, the anchor carrier and the at least one non-anchor carrier compatible with Long Term Evolution (LTE) carrier aggregation operations; 
 receiving information indicating a first number of control channel candidates for a first aggregation level for the anchor carrier and a second number of control channel candidates for the first aggregation level for the non-anchor carrier, wherein the first number of control channel candidates is different from the second number of control channel candidates; and 
 for each carrier:
 based on the received information, determining a location of a UA specific search space including one or more control channel candidates for the carrier based on a linear congruential random number and a carrier index of the carrier, wherein each control channel candidate comprises at least one control channel element (CCE); and 
 attempting to decode each of the one or more control channel candidates in the UA specific search space to identify at least one of an uplink or a downlink grant associated with the carrier. 
 
 
     
     
       9. An apparatus for processing a control channel at a user agent (UA) within a wireless communication system, the apparatus comprising:
 a linear congruential random number generator; 
 a processor; and  
 a processor that is programmed to perform the steps of a memory coupled to the processor and storing programming instructions for execution by the processor to:
 identifyingidentify one carrier as an anchor carrier and at least one otheranother carrier as a non-anchor carrier, the anchor carrier and the at least one non-anchor carrier compatible with Long Term Evolution (LTE) carrier aggregation operations; and 
 receive information indicating a first number of control channel candidates for a first aggregation level for the anchor carrier and a second number of control channel candidates for the first aggregation level for the non-anchor carrier, wherein the first number of control channel candidates is different from the second number of control channel candidates; and  
 for each carrier:
 determiningbased on the received information, determine a location of a UA specific search space including one or more control channel candidates for the carrier based on a carrier index of the carrier and a linear congruential random number generated by the linear congruential random number generator, wherein each control channel candidate comprises at least one control channel element (CCE); and 
 
 
 attemptingattempt to decode each of the one or more control channel candidates in the UA specific search space to identify at least one of an uplink or a downlink grant associated with the carrier.