Method and apparatus for collision mitigation and complexity reduction for NOMA
A method and apparatus for performing autonomous transmission for performing collision mitigation and complexity reduction for non-orthogonal multiple access (NOMA) transmissions are disclosed. A wireless transmit/receive unit (WTRU) may receive a configuration with multiple SRs and associated preamble subsets, randomly select a preamble subset and select a SR configuration according to the randomly selected preamble subset based on the received configuration. The WTRU may transmit an SR associated with the selected preamble subset. Next the WTRU may select a preamble from the selected preamble subset, and transmit the selected preamble with a data transmission. Each SR associated with preamble subsets may be distinguished by time and frequency resources, sequence index value, or PUCCH index value.
1. A wireless/transmit receive unit (WTRU) comprising:
a receiver configured to receive configuration information that includes multiple SRs and associated demodulation reference signal (DMRS) subsets;
a processor configured to randomly select a DMRS subset and select a SR configuration according to the randomly selected DMRS subset based on the received configuration information;
a transmitter configured to transmit an SR associated with the selected DMRS subset;
the processor further configured to select a DMRS from the selected DMRS subset;
the processor further configured to autonomously determine a transmission type, wherein the transmission type is either grant-based or grant-free; and
the transmitter further configured to transmit the selected DMRS with a data transmission.
2. The WTRU of claim 1 wherein each SR associated with DMRS subsets is distinguished by time and frequency resources.
3. The WTRU of claim 1 wherein each SR associated with DMRS subsets is distinguished by a sequence index value.
4. The WTRU of claim 1 wherein each SR associated with DMRS subsets is distinguished by a PUCCH index value.
5. A method of performing a data transmission, the method comprising:
receiving configuration information that includes multiple SRs and associated demodulation reference signal (DMRS) subsets;
randomly selecting a DMRS subset and selecting a SR configuration according to the randomly selected DMRS subset based on the received configuration information;
autonomously determining a transmission type, wherein the transmission type is either grant-based or grant-free;
transmitting an SR associated with the selected DMRS subset;
selecting a DMRS from the selected DMRS subset; and
transmitting the selected DMRS with a data transmission.
6. The method of claim 5 wherein each SR associated with DMRS subsets is distinguished by time and frequency resources.
7. The method of claim 5 wherein each SR associated with DMRS subsets is distinguished by a sequence index value.
8. The method of claim 5 wherein each SR associated with DMRS subsets is distinguished by a PUCCH index value.