Apparatus and method for communicating two stage DCI
A two-stage DCI framework is provided in which the first stage DCI is carried by PDCCH, second stage DCI is carried by PDSCH. The first stage DCI is blind decoded. The second stage DCI is indicated by the first stage DCI and therefor no blind decoding is necessary. The size of the second stage DCI can be very flexible, can indicate scheduling information for one carrier, multiple carriers, multi transmission for one carrier. The first stage DCI can be compact in size to enhance reliability.
1 . A method in an apparatus for receiving downlink control information (DCI), the method comprising:
receiving, by the apparatus, a first stage DCI in a physical downlink control channel (PDCCH), the first stage DCI explicitly indicating a presence or absence of a second stage DCI, and the first stage DCI including at least one indicator indicating partial retransmission information, with remaining retransmission information being radio resource control (RRC) configured or predefined; and
when the first stage DCI indicates the presence of the second stage DCI, the first stage DCI explicitly indicating a scheduling information of the second stage DCI, and receiving, by the apparatus, the second stage DCI in a first physical downlink shared channel (PDSCH), wherein the first PDSCH is a physical channel without data transmission;
wherein when the first stage DCI indicates the presence of the second stage DCI, the partial retransmission information is in respect of the second stage DCI, and when the first stage DCI indicates the absence of the second stage DCI, the partial retransmission information is in respect of at least one data transmission scheduled by the first stage DCI.
2 . The method of claim 1 , the method further comprising:
when the first stage DCI indicates the absence of the second stage DCI, the first stage DCI indicating scheduling information for at least one data transmission on a physical uplink shared channel (PUSCH) or a PDSCH.
3 . The method of claim 1 , wherein:
the second stage DCI indicating scheduling information in the second stage DCI for at least one data transmission on a PUSCH and/or a PDSCH; and
fields of the first stage DCI indicating scheduling information in the first stage DCI for at least one data transmission on a PUSCH and/or a PDSCH are simplified relative to fields of the second stage DCI indicating the scheduling information in the second stage DCI.
4 . The method of claim 1 , wherein:
when the first stage DCI indicates the presence of the second stage DCI, the first stage DCI does not include multiple input multiple output (MIMO) information for the second stage DCI; and
when the first stage DCI indicates the absence of the second stage DCI, scheduling information for at least one data transmission on a PUSCH and/or a PDSCH does not include retransmission related information for the at least one data transmission.
5 . The method of claim 1 , wherein the first stage DCI has at least one of the following fields:
a field for explicitly indicating a presence or absence of the second stage DCI;
a field for indicating frequency domain resource assignment for the second stage DCI or data transmission;
a field for indicating time domain resource assignment for second stage DCI or data transmission;
a field for indicating a virtual resource block (VRB)-to-physical resource block (PRB) mapping or Frequency hopping;
an indication of modulation and coding scheme (MCS);
a field for indicating a carrier for the second stage DCI; and
a flag for differentiating between UL and DL data scheduling.
6 . The method of claim 1 , wherein the partial retransmission information comprises a subset of new data indicator (NDI), redundancy version (RV), hybrid automatic repeat request (HARQ) process number, downlink allocation index (DAI), transmit power control (TPC) for PUCCH, PUCCH resource, and HARQ-ACK timing.
7 . The method of claim 1 , wherein:
the first stage DCI is received on a first carrier, the scheduling information of the second stage DCI indicates a second carrier for the second stage DCI; and
the second stage DCI schedules resources for data transmission on one or multiple carriers.
8 . A method in a network device for transmitting downlink control information (DCI), the method comprising:
transmitting, by the network device, a first stage DCI in a physical downlink control channel (PDCCH), the first stage DCI explicitly indicating a presence or absence of a second stage DCI, and the first stage DCI including at least one indicator indicating partial retransmission information with remaining retransmission information being radio resource control (RRC) configured or predefined; and
when the first stage DCI indicates the presence of the second stage DCI, the first stage DCI explicitly indicating scheduling information of the second stage DCI, and transmitting, by the network device, the second stage DCI in a first physical downlink shared channel (PDSCH), wherein the first PDSCH is a physical channel without data transmission;
wherein when the first stage DCI indicates the presence of the second stage DCI, the partial retransmission information is in respect of the second stage DCI, and when the first stage DCI indicates the absence of the second stage DCI, the partial retransmission information is in respect of at least one data transmission scheduled by the first stage DCI.
9 . The method of claim 8 , the method further comprising:
when the first stage DCI indicates the absence of the second stage DCI, the first stage DCI indicating scheduling information for at least one data transmission on a physical uplink shared channel (PUSCH) or a PDSCH.
10 . The method of claim 8 , wherein:
the second stage DCI indicating a scheduling information in the second stage DCI for at least one data transmission on a PUSCH and/or a PDSCH; and
fields of the first stage DCI indicating scheduling information in the first stage DCI for at least one data transmission on a PUSCH and/or a PDSCH are simplified relative to fields of the second stage DCI indicating the scheduling information in the second stage DCI.
11 . The method of claim 8 , wherein:
when the first stage DCI indicates the presence of the second stage DCI, the first stage DCI does not include multiple input multiple output (MIMO) information for the second stage DCI; and
when the first stage DCI indicates the absence of the second stage DCI, scheduling information for at least one data transmission on a PUSCH and/or a PDSCH does not include retransmission related information for the at least one data transmission.
12 . The method of claim 8 , wherein the first stage DCI has at least one of the following fields:
a field for explicitly indicating a presence or absence of the second stage DCI;
a field for indicating frequency domain resource assignment for the second stage DCI or data transmission;
a field for indicating time domain resource assignment for the second stage DCI or data transmission;
a field for indicating a virtual resource block (VRB)-to-physical resource block (PRB) mapping or frequency hopping;
an indication of modulation and coding scheme (MCS);
a field for indicating a carrier for the second stage DCI; and
a flag for differentiating between UL and DL data scheduling.
13 . The method of claim 8 , wherein the partial retransmission information comprises a subset of new data indicator (NDI), redundancy version (RV), hybrid automatic repeat request (HARQ) process number, downlink allocation index (DAI), transmit power control (TPC) for PUCCH, PUCCH resource, and HARQ-ACK timing.
14 . An apparatus comprising:
at least one processor; and
a memory storing processor-executable instructions that, when executed, cause the at least one processor to:
receive a first stage DCI in a physical downlink control channel (PDCCH), the first stage DCI explicitly indicating a presence or absence of a second stage DCI, and the first stage DCI including at least one indicator indicating partial retransmission information, with remaining retransmission information being radio resource control (RRC) configured or predefined; and
when the first stage DCI indicates the presence of the second stage DCI, the first stage DCI explicitly indicating scheduling information of the second stage DCI, and receive the second stage DCI in a first physical downlink shared channel (PDSCH), wherein the first PDSCH is a physical channel without data transmission;
wherein when the first stage DCI indicates the presence of the second stage DCI, the partial retransmission information is in respect of the second stage DCI, and when the first stage DCI indicates the absence of the second stage DCI, the partial retransmission information is in respect of at least one data transmission scheduled by the first stage DCI.
15 . The apparatus of claim 14 , wherein when the first stage DCI indicates the absence of the second stage DCI, the first stage DCI indicating scheduling information for at least one data transmission on a physical uplink shared channel (PUSCH) or a PDSCH.
16 . The apparatus of claim 14 , wherein the first stage DCI has at least one of the following fields:
a field for explicitly indicating a presence or absence of the second stage DCI;
a field for indicating frequency domain resource assignment for the second stage DCI or data transmission;
a field for indicating time domain resource assignment for the second stage DCI or data transmission;
a field for indicating a virtual resource block (VRB)-to-physical resource block (PRB) mapping or Frequency hopping;
an indication of modulation and coding scheme (MCS);
a field for indicating a carrier for the second stage DCI; and
a flag for differentiating between UL and DL data scheduling.
17 . The apparatus of claim 14 , wherein the partial retransmission information comprises a subset of new data indicator (NDI), redundancy version (RV), hybrid automatic repeat request (HARQ) process number, downlink allocation index (DAI), transmit power control (TPC) for PUCCH, PUCCH resource, and HARQ-ACK timing.
18 . A network device comprising:
at least one processor; and
a memory storing processor-executable instructions that, when executed, cause the at least one processor to:
transmit a first stage DCI in a physical downlink control channel (PDCCH), the first stage DCI explicitly indicating a presence or absence of a second stage DCI, and the first stage DCI including at least one indicator indicating partial retransmission information, with remaining retransmission information being radio resource control (RRC) configured or predefined; and
when the first stage DCI indicates the presence of the second stage DCI, the first stage DCI explicitly indicating scheduling information of the second stage DCI, and transmit the second stage DCI in a first physical downlink shared channel (PDSCH), wherein the first PDSCH is a physical channel without data transmission;
wherein when the first stage DCI indicates the presence of the second stage DCI, the partial retransmission information is in respect of the second stage DCI, and when the first stage DCI indicates the absence of the second stage DCI, the partial retransmission information is in respect of at least one data transmission scheduled by the first stage DCI.
19 . The network device of claim 18 , wherein when the first stage DCI indicates the absence of the second stage DCI, the first stage DCI indicating scheduling information for at least one data transmission on a physical uplink shared channel (PUSCH) or a PDSCH.
20 . The network device of claim 18 , wherein the first stage DCI has at least one of the following fields:
a field for explicitly indicating a presence or absence of the second stage DCI;
a field for indicating frequency domain resource assignment for the second stage DCI or data transmission;
a field for indicating time domain resource assignment for the second stage DCI or data transmission;
a field for indicating a virtual resource block (VRB)-to-physical resource block (PRB) mapping or frequency hopping;
an indication of modulation and coding scheme (MCS);
a field for indicating a carrier for the second stage DCI; and
a flag for differentiating between UL and DL data scheduling.