UU interface enhancement for NR V2X
A method and apparatus for performing sidelink communications in a wireless transmit receive unit (WTRU) using Long Term Evolution (LTE) and New Radio (NR) technologies is described herein. A WTRU receives downlink control information (DCI) on a physical downlink control channel (PDCCH) from a gNodeB (gNB), wherein the DCI is associated with a cyclic redundancy check (CRC). The a determination is made as to whether the DCI is for an LTE or NR technology sidelink transmission. On a condition that the DCI is for NR technology, the WTRU determines which transmit modulation and coding scheme (MCS) table to apply based on the masking of at least some of the bits in the CRC. Then the WTRU transmits sidelink data on resources indicated by the DCI using the determined MCS table. The WTRU may also receive HARQ feedback on resources indicated by the DCI for HARQ feedback.
1. A method performed by a wireless transmit receive unit (WTRU) configured to perform sidelink (SL) communications using Long Term Evolution (LTE) and New Radio (NR) technologies, the method comprising:
receiving a downlink control information (DCI) on a physical downlink control channel (PDCCH) transmission from a base station, wherein the DCI is associated with a cyclic redundancy check (CRC) that is scrambled using a radio network temporary identifier (RNTI), wherein the DCI indicates resources for a LTE sidelink transmission when the CRC is scrambled using a first RNTI, and the DCI indicates resources for an NR sidelink transmission when the CRC is scrambled using a second RNTI; and
transmitting SL data using the resources indicated by the DCI.
2. The method of claim 1 , wherein the DCI includes a sidelink transmission grant for both data transmissions and HARQ feedback transmissions.
3. The method of claim 1 , wherein the second RNTI is a sidelink V2X RNTI (SL-V-RNTI).
4. The method of claim 1 , wherein the second RNTI is a sidelink semi persistent (SL-SPS) V2X RNTI (SPS-SL-RNTI).
5. The method of claim 1 , wherein the DCI has either a first format or a second format based on whether the CRC is scrambled using the first RNTI or the second RNTI.
6. The method of claim 5 , wherein the first format and the second format have a same payload size.
7. A wireless transmit receive unit (WTRU) configured to perform sidelink (SL) communications using Long Term Evolution (LTE) and New Radio (NR) technologies, the WTRU comprising:
a receiver configured to receive a downlink control information (DCI) on a physical downlink control channel (PDCCH) transmission from a base station, wherein the DCI is associated with a cyclic redundancy check (CRC) that is scrambled using a radio network temporary identifier (RNTI), wherein the DCI indicates resources for a LTE sidelink transmission when the CRC is scrambled using a first RNTI, and the DCI indicates resources for an NR sidelink when the CRC is scrambled using a second RNTI; and
a transmitter configured to transmit sidelink data on the resources indicated by the DCI.
8. The WTRU of claim 7 , wherein the DCI includes a sidelink transmission grant for both data transmissions and HARQ feedback transmissions.
9. The WTRU of claim 7 , wherein the second RNTI is a sidelink V2X RNTI (SL-V-RNTI).
10. The method of claim 1 , wherein the second RNTI is a sidelink semi persistent (SL-SPS) V2X RNTI (SPS-SL-RNTI).
11. The WTRU of claim 7 , wherein the DCI has either a first format or a second format based on whether the CRC is scrambled using the first RNTI or the second RNTI.
12. The WTRU of claim 9 , wherein the first format and the second format have a same payload size.