Multi-length ZT DFT-s-OFDM transmission

1. A method performed by a network device, the method comprising:

selecting, by the network device, an allocation of frequency resources for transmission, wherein the allocated frequency resources include a plurality of sub-bands;

assigning, by the network device, one or more of the plurality of sub-bands to each of a plurality of wireless transmit/receive units (WTRUs);

assigning, by the network device, a zero head length and a zero tail length to each of the assigned one or more of the plurality of sub-bands based on one or more patterns;

generating, by the network device, a multi-length zero tail (ZT) discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-s-OFDM) signal for the assigned one or more of the plurality of sub-bands with a zero head based on the assigned zero head length and a zero tail based on the assigned zero tail length; and

transmitting, by the network device, the multi-length ZT DFT-s OFDM signal.

2. The method of claim 1 , wherein the one or more patterns include increasing or decreasing the zero head length and the zero tail length between adjacent sub-bands.

3. The method of claim 1 , wherein:

the assigning of the one or more of the plurality of sub-bands to each of the plurality of WTRUs includes assigning adjacent sub-bands to WTRUs with a same channel delay profile.

4. The method of claim 1 , wherein:

the assigning the zero head length and the zero tail length to each of the assigned one or more of the plurality of sub-bands is repeated at each time slot, within an allocated time period, such that the assigned zero head length and the assigned zero tail length to a first assigned sub-band in a first time slot is different than in a second time slot immediately following the first time slot.

5. The method of claim 1 , further comprising:

applying, by the network device, a pre-known sequence with a correlation property to a first generated ZT DFT-s OFDM signal for transmission so that a receiving WTRU may determine the zero head length and the zero tail length.

6. The method of claim 1 , wherein:

the generating the multi-length ZT DFT-s OFDM signal includes inserting zeros into a time domain to generate a zeroed-out portion of the multi-length ZT DFT-s OFDM signal.

7. The method of claim 6 further comprising:

inserting, by the network device, ultra-reliable low-latency data into the zeroed-out portion of the multi-length ZT DFT-s OFDM signal.

8. The method of claim 6 , wherein one or more measurements are performed during the zeroed-out portion of the multi-length ZT DFT-s OFDM signal.

9. A network device comprising:

a transceiver coupled to a processor and at least one antenna; and

the processor is configured to:

select an allocation of frequency resources for transmission, wherein the allocated frequency resources include a plurality of sub-bands;

assign one or more of the plurality of sub-bands to each of a plurality of wireless transmit/receive units (WTRUs);

assign a zero head length and a zero tail length to each of the assigned one or more of the plurality of sub-bands based on one or more patterns; and

generate a multi-length zero tail (ZT) discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-s-OFDM) signal for the assigned one or more of the plurality of sub-bands with a zero head based on the assigned zero head length and a zero tail based on the assigned zero tail length;

the transceiver configured to transmit the multi-length ZT DFT-s OFDM signal.

10. The network device of claim 9 , wherein the one or more patterns include increasing or decreasing the zero head length and the zero tail length between adjacent sub-bands.

11. The network device of claim 9 , wherein:

the processor is configured to assign the one or more of the plurality of sub-bands to each of the plurality of WTRUs includes assigning adjacent sub-bands to WTRUs with a same channel delay profile.

12. The network device of claim 9 , wherein:

the processor is further configured to assign the zero head length and the zero tail length to each of the assigned one or more of the plurality of sub-bands is repeated at each time slot, within an allocated time period, such that the assigned zero head length and the assigned zero tail length to a first assigned sub-band in a first time slot is different than in a second time slot immediately following the first time slot.

13. The network device of claim 9 , wherein:

the processor is configured to apply a pre-known sequence with a correlation property to a first generated ZT DFT-s OFDM signal for transmission so that a receiving WTRU may determine the zero head length and the zero tail length.

14. The network device of claim 9 , wherein:

the processor is further configured to generate the multi-length ZT DFT-s OFDM signal by inserting zeros into a time domain to generate a zeroed-out portion of the multi-length ZT DFT-s OFDM signal.

15. The network device of claim 14 , wherein:

the processor is configured to insert ultra-reliable low-latency data into the zeroed-out portion of the multi-length ZT DFT-s OFDM signal.

16. The network device of claim 14 , wherein one or more measurements are performed during the zeroed-out portion of the multi-length ZT DFT-s OFDM signal.

17. A wireless transmit/receive unit (WTRU) comprising:

a transceiver coupled to a processor and at least one antenna;

the transceiver and the processor are configured to receive a multi-length zero tail (ZT) discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-s-OFDM) signal; and

wherein the multi-length ZT DFT-s-OFDM signal is composed of one or more of a plurality of sub-bands assigned to the WTRU and is composed of a zero head and a zero tail for each of the assigned one or more of the plurality of sub-bands based on one or more patterns.

18. The WTRU of claim 17 , wherein the one or more patterns include increasing or decreasing the length between adjacent sub-bands.