System and method for link adaptation for low cost user equipments

Abstract

Methods and apparatus are provided to perform link adaptation for transmissions from a base station to a user equipment (UE) capable of receiving only in a part of a system bandwidth. Mechanisms are provided for determining and mapping a range of channel quality information (CQI) values and for measuring, deriving, and providing channel state information (CSI) reports.

What is claimed is: 
     
         1 . A user equipment (UE), comprising:
 a transceiver configured to receive a physical downlink control channel (PDCCH) according to one or more numbers of repetitions; and   a processor configured to determine a number of repetitions for a PDCCH reception, wherein the transceiver is further configured to transmit an indication for the number of repetitions.   
     
     
         2 . The UE of  claim 1 , wherein the number of repetitions is from a predetermined set of numbers of repetitions. 
     
     
         3 . The UE of  claim 1 , wherein:
 the transceiver is further configured to receive a configuration for a subset of numbers of repetitions from a predetermined set of numbers of repetitions; and   the processor is further configured to determine the number of repetitions from the subset of numbers of repetitions.   
     
     
         4 . The UE of  claim 1 , wherein the PDCCH reception is within a sub-band of a downlink bandwidth. 
     
     
         5 . The UE of  claim 4 , wherein the PDCCH reception is within a set of resource blocks of the sub-band. 
     
     
         6 . The UE of  claim 1 , wherein:
 a PDCCH includes a downlink control information (DCI) format scheduling a reception of a physical downlink shared channel (PDSCH), and   the DCI format includes a field indicating a sub-band, from a set of sub-bands of a downlink bandwidth, for the PDSCH reception.   
     
     
         7 . The UE of  claim 1 , wherein:
 the processor is further configured to determine a channel quality indicator (CQI) for a reception of a physical downlink shared channel (PDSCH); and   the transceiver is further configured to transmit the CQI.   
     
     
         8 . A base station, comprising:
 a transceiver configured to:
 transmit a physical downlink control channel (PDCCH) according to one or more numbers of repetitions; and 
 receive an indication for a number of repetitions. 
   
     
     
         9 . The base station of  claim 8 , wherein the number of repetitions is from a predetermined set of numbers of repetitions. 
     
     
         10 . The base station of  claim 8 , wherein:
 the transceiver is further configured to transmit a configuration for a subset of numbers of repetitions from a predetermined set of numbers of repetitions, and   the indication is for a number of repetitions from the subset of numbers of repetitions.   
     
     
         11 . The base station of  claim 8 , wherein the PDCCH transmission is within a sub-band of a downlink bandwidth. 
     
     
         12 . The base station of  claim 11 , wherein the PDCCH transmission is within a set of resource blocks of the sub-band. 
     
     
         13 . The base station of  claim 11 , wherein:
 a PDCCH includes a downlink control information (DCI) format scheduling a transmission of a physical downlink shared channel (PDSCH), and   the DCI format includes a field indicating a sub-band, from a set of sub-bands of a downlink bandwidth, for the PDSCH transmission.   
     
     
         14 . The base station of  claim 8 , wherein the transceiver is further configured to receive a channel quality indicator (CQI) for a transmission of a physical downlink shared channel. 
     
     
         15 . A method for receiving a physical downlink control channel (PDCCH), the method comprising:
 receiving a physical downlink control channel (PDCCH) according to one or more numbers of repetitions;   determining a number of repetitions for a PDCCH reception; and   transmitting an indication for the number of repetitions.   
     
     
         16 . The method of  claim 15 , wherein the number of repetitions is from a predetermined set of numbers of repetitions. 
     
     
         17 . The method of  claim 15 , wherein the PDCCH reception is within a sub-band of a downlink bandwidth. 
     
     
         18 . The method of  claim 17 , wherein the PDCCH reception is within a set of resource blocks of the sub-band. 
     
     
         19 . The method of  claim 15 , wherein:
 a PDCCH includes a downlink control information (DCI) format scheduling a reception of a physical downlink shared channel (PDSCH), and   the DCI format includes a field indicating a sub-band, from a set of sub-bands of a downlink bandwidth, for the PDSCH reception.   
     
     
         20 . The method of  claim 15 , further comprising:
 determining a channel quality indicator (CQI) for a reception of a physical downlink shared channel (PDSCH); and   transmitting the CQI.