Method and apparatus for power savings at a user equipment
A method for a user equipment (UE) apparatus to reduce power consumption in response to an outcome of a signal reception. The outcome can indicate whether or not the UE needs to be active at a next discontinuous reception (DRX) cycle. The signal can also provide configurations of parameters for transmissions or receptions during the next DRX cycle and be used by the UE for measurements and to obtain channel state information.
1. A method for a user equipment (UE) to receive first physical downlink control channels (PDCCHs), the method comprising:
receiving:
information for groups of secondary cells (SCells) and for indexes of SCells in each group of SCells from the groups of SCells,
information for a search space set for receptions of second PDCCHs on a primary cell, outside an On-duration of any discontinuous reception (DRX) cycle on the primary cell, according to a common search space,
information for a time offset, and
the second PDCCHs starting from the time offset before a start of On-duration for a next DRX cycle, wherein a PDCCH from the second PDCCHs provides a first downlink control information (DCI) format and wherein:
the first DCI format does not schedule transmission or reception of a channel that provides data information,
the first DCI format includes a bitmap, and
bits of the bitmap have a one-to-one mapping with the groups of SCells; and
determining, based on a value of a bit of the bitmap, whether or not to receive the first PDCCHs, wherein:
the bit of the bitmap maps to a group of SCells from the groups of SCells, and
the first PDCCHs provide DCI formats that schedule receptions of physical downlink shared channels (PDSCHs) or transmissions of physical uplink shared channels (PUSCHs), on an SCell in the group of SCells.
2. The method of claim 1 , wherein the first DCI format does not schedule reception of a PDSCH or transmission of a PUSCH.
3. The method of claim 1 , wherein the PDCCH reception is on a primary cell.
4. The method of claim 1 , further comprising:
determining to receive the first PDCCHs; and
receiving:
information, by higher layer signaling, for a downlink bandwidth part (BWP) of the SCell,
the first PDCCHs, and
a PDSCH on the downlink BWP of the SCell.
5. The method of claim 1 , wherein:
the bit of the bitmap indicates a dormant state or a non-dormant state for the SCell, and
an active bandwidth part (BWP) of the SCell is a dormant BWP or a non-dormant BWP.
6. The method of claim 1 , further comprising:
receiving information for:
a first radio network temporary identifier (RNTI) that scrambles cyclic redundancy check (CRC) bits of the first DCI format, and
a second RNTI that scrambles CRC bits of the DCI formats that schedule the receptions of the PDSCHs or the transmissions of the PUSCHs.
7. A user equipment (UE) comprising:
a transceiver configured to receive:
information for groups of secondary cells (SCells) and for indexes of SCells in each group of SCells from the groups of SCells,
information for a search space set for receptions of second physical downlink control channels (PDCCHs) on a primary cell, outside an On-duration of any discontinuous reception (DRX) cycle on the primary cell, according to a common search space,
information for a time offset, and
the second PDCCHs starting from the time offset before a start of On-duration for a next DRX cycle, wherein a PDCCH from the second PDCCHs that provides a first downlink control information (DCI) format and wherein:
the first DCI format does not schedule transmission or reception of a channel that provides data information,
the first DCI format includes a bitmap, and
bits of the bitmap have a one-to-one mapping with the groups of SCells; and
a processor operably coupled to the transceiver, the processor configured to determine, based on a value of a bit of the bitmap, to instruct the transceiver whether or not to receive first PDCCHs, wherein:
the bit of the bitmap maps to a group of SCells from the groups of SCells, and
the first PDCCHs provide DCI formats that schedule receptions of physical downlink shared channels (PDSCHs) or transmissions of physical uplink shared channels (PUSCHs), on an SCell in the group of SCells.
8. The UE of claim 7 , wherein the first DCI format does not schedule reception of a PDSCH or transmission of a PUSCH.
9. The UE of claim 7 , wherein the PDCCH reception is on a primary cell.
10. The UE of claim 7 , wherein:
the processor is further configured to instruct the transceiver to receive the first PDCCHs; and
the transceiver is further configured to receive:
information, by higher layer signaling, for a downlink bandwidth part (BWP) of the SCell,
the first PDCCHs, and
a PDSCH on the downlink BWP of the SCell.
11. The UE of claim 7 , wherein:
the bit of the bitmap indicates a dormant state or a non-dormant state for the SCell, and
an active bandwidth part (BWP) of the SCell is a dormant BWP or a non-dormant BWP.
12. The UE of claim 7 , wherein:
the transceiver is further configured to receive information for:
a first radio network temporary identifier (RNTI) that scrambles cyclic redundancy check (CRC) bits of the first DCI format, and
a second RNTI that scrambles CRC bits of the DCI formats that schedule the receptions of the PDSCHs or the transmission of the PUSCHs.
13. A base station comprising:
a transceiver configured to transmit:
information for groups of secondary cells (SCells) and for indexes of SCells in each group of SCells from the groups of SCells,
information for a search space set for receptions of second physical downlink control channels (PDCCHs) on a primary cell, outside an On-duration of any discontinuous reception (DRX) cycle on the primary cell, according to a common search space,
information for a time offset, and
the second PDCCHs starting from the time offset before a start of On-duration for a next DRX cycle, wherein a PDCCH from the second PDCCHs provides a first downlink control information (DCI) format and wherein:
the first DCI format does not schedule transmission or reception of a channel that provides data information,
the first DCI format includes a bitmap, and
bits of the bitmap have a one-to-one mapping with the groups of SCells;
a processor operably coupled to the transceiver, the processor configured to determine, based on a value of a bit of the bitmap, to instruct the transceiver whether or not to transmit first PDCCHs, wherein:
the bit of the bitmap maps to a group of SCells from the groups of SCells, and
the first PDCCHs provide DCI formats that schedule transmissions of physical downlink shared channels (PDSCHs) or receptions of physical uplink shared channels (PUSCHs), on an SCell in the group of SCells.
14. The base station of claim 13 , wherein the first DCI format does not schedule transmission of a PDSCH or reception of a PUSCH.
15. The base station of claim 13 , wherein the PDCCH transmission is on a primary cell.
16. The base station of claim 13 , wherein:
the processor is further configured to instruct the transceiver to transmit the first PDCCHs; and
the transceiver is further configured to transmit:
information, by higher layer signaling, for a downlink bandwidth part (BWP) of the SCell,
the first PDCCHs, and
a PDSCH on the downlink BWP of the SCell.
17. The base station of claim 13 , wherein:
the bit of the bitmap indicates a dormant state or a non-dormant state for the SCell, and
an active bandwidth part (BWP) of the SCell is a dormant BWP or a non-dormant BWP, respectively.