Method and procedures for downlink physical channels to reduce latency in an lte advanced system

Abstract

A wireless transmit/receive unit (WTRU) may receive, in a higher layer message, a configuration for a short transmission time interval (sTTI) physical downlink control channel (sPDCCH). The WTRU may monitor, on a condition that a sPDCCH is configured, a subset of PDCCH candidates of one or more aggregation levels. The WTRU may monitor, on a condition that the sPDCCH is not configured, the PDCCH candidates.

1 . A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
 receiving, in a higher layer message, a configuration for a short transmission time interval (sTTI) physical downlink control channel (sPDCCH);   monitoring, on a condition that a sPDCCH is configured, a subset of PDCCH candidates of one or more aggregation levels; and   monitoring, on a condition that the sPDCCH is not configured, the PDCCH candidates.   
     
     
         2 . The method of  claim 1  further comprising receiving a physical hybrid-ARQ indicator channel (PHICH) on a known sPDCCH resource that indicates presence of a configured sTTI resource. 
     
     
         3 . (canceled) 
     
     
         4 . The method of  claim 1 , wherein a configuration of sTTI resources is received in a sTTI indicator. 
     
     
         5 . The method of  claim 4 , wherein the sTTI indicator is based on a set of physical hybrid-ARQ indicator channel (PHICH) resources. 
     
     
         6 . A wireless transmit/receive unit (WTRU) comprising:
 a processor;   a receiver; and
 wherein the receiver is configured to receive, in a higher layer message, a configuration for a short transmission time interval (sTTI) physical downlink control channel (sPDCCH); 
 the processor is configured to monitor, on a condition that a sPDCCH is configured, a subset of PDCCH candidates of one or more aggregation levels; and 
 the processor is further configured to monitor, on a condition that the sPDCCH is not configured, the PDCCH candidates. 
   
     
     
         7 . The WTRU of  claim 6 , wherein a physical hybrid-ARQ indicator channel (PHICH) is received on a known sPDCCH resource that indicates presence of a configured sTTI resource. 
     
     
         8 . (canceled) 
     
     
         9 . The WTRU of  claim 6 , wherein a configuration of sTTI resources is received in a sTTI indicator. 
     
     
         10 . The WTRU of  claim 9 , wherein the sTTI indicator is based on a set of physical hybrid-ARQ indicator channel (PHICH) resources. 
     
     
         11 - 15 . (canceled)