Multiple starting positions for uplink transmission on unlicensed spectrum

1. A method of operating a wireless communication device, comprising:

identifying a plurality of candidate starting positions for an uplink, UL, transmission in an unlicensed spectrum;

selecting at least one starting position from among the plurality of candidate starting positions based on autonomous UL starting points according to an outcome of a listen-before-talk, LBT, procedure performed with respect to the unlicensed spectrum; and

determining whether a channel is obtained at a subframe/slot boundary;

in response to determining that the channel is not obtained at the subframe/slot boundary, puncturing a whole transport block, TB, and transmitting a partial subframe/slot depending on the LBT outcome.

2. The method of claim 1 , further comprising:

in response to determining that the channel is obtained at the subframe/slot boundary, transmitting the whole TB on a full subframe/slot.

3. The method of claim 1 , further comprising:

retransmitting a discarded part of the TB in a last scheduled uplink subframe/slot using a same Hybrid Automatic Repeat Request, HARQ, process ID as a punctured subframe/slot.

4. The method of claim 1 , further comprising:

retransmitting the whole TB in a last scheduled uplink subframe/slot using a same Hybrid Automatic Repeat Request, HARQ, process ID as a punctured subframe/slot.

5. The method of claim 1 , further comprising:

retransmitting autonomously a discarded part of the TB in a next subframe/slot after scheduled uplink subframe/slots.

6. The method of claim 1 , further comprising:

retransmitting autonomously the whole TB in a next subframe/slot after scheduled uplink subframe/slots.

7. The method of claim 1 , further comprising:

obtaining a UL grant from a base station, eNB; and

determining if the wireless communication device is allowed to autonomously transmit after the scheduled uplink subframe/slot based on the UL grant from the eNB.

8. The method of claim 7 , wherein the wireless communication device is allowed to autonomously transmit after the scheduled uplink subframe/slot, the method further comprising:

transmitting a discarded part of the TB, if the wireless communication device does not transmit a full first subframe/slot.

9. The method of claim 7 , wherein the wireless communication device is not allowed to autonomously transmit after the scheduled uplink subframe/slot, the method further comprising:

waiting for a full or partial subframe/slot retransmission schedule.

10. The method of claim 1 , further comprising:

obtaining a scheduling decision of X subframe/slots followed by a predetermined partial or full subframe/slot.

11. The method of claim 10 , wherein the scheduling of a partial UL subframe/slot is received by the wireless communication device in a grant indicating that the wireless communication device shall stop UL transmission in the partial UL subframe/slot at a UL ending point earlier than the last symbol.

12. The method of claim 10 , wherein the wireless communication device does not transmit a full first subframe/slot, the method further comprises:

puncturing the TB for first subframe/slot; and

retransmitting a discarded part of TB or the full TB on the predetermined subframe/slot scheduled at the end of transmission burst using same HARQ process ID as the punctured subframe/slot.

13. The method of claim 10 , wherein the wireless communication device transmits a full first subframe/slot, the method further comprising:

transmitting with a different Hybrid Automatic Repeat Request, HARQ, process ID in the predetermined subframe/slot instead of the full first subframe/slot.

14. The method of claim 10 , wherein the wireless communication device transmits on a full first subframe/slot, the method further comprising:

refraining from transmitting on the predetermined partial subframe/slot.

15. The method of claim 1 , further comprising:

scaling down a Transport Block Size, TBS, of a first subframe/slot if it is a partial subframe/slot transmission.

16. The method of claim 15 wherein scaling down the TBS of the first subframe/slot comprises determining the TBS of the first subframe/slot based on └N PRB *α┘, where α is a ratio of a transmitted partial subframe/slot to a full subframe/slot and └x┘ is a floor function.

17. The method of claim 1 , further comprising:

considering a subframe/slot after a punctured transmission in a transmission burst as a reference subframe/slot for contention window adjustment for LBT.

18. A method of operating a wireless communication device, comprising:

identifying a plurality of candidate starting positions for an uplink, UL, transmission in an unlicensed spectrum;

selecting at least one starting position from among the plurality of candidate starting positions based on a fixed UL starting point;

following a UL grant for communication; and

scaling down a Transport Block Size, TBS, for a first subframe/slot in an uplink transmission burst and for multi-subframe/slot scheduling;

wherein scaling down the TBS of the first subframe/slot comprises determining the TBS of the first subframe/slot based on └N PRB *α┘, where α is a ratio of a transmitted partial subframe/slot to a full subframe/slot and └x┘ is a floor function.

19. The method of claim 18 wherein α=1/2.

20. The method of claim 18 , further comprising:

receiving two TBS/Modulation and Coding Schemes, MCS, signaled in the UL grant, one used for a partial subframe/slot transmission and another for full subframe/slot transmissions within scheduled subframes/slots.

21. The method of claim 18 , further comprising:

scaling down the TBS of the first subframe/slot in the uplink transmission burst for a single subframe/slot scheduling.

22. A wireless communication device, comprising:

a processor; and

memory comprising instructions executable by the processor whereby the wireless communication device is operable to:

identify a plurality of candidate starting positions for an uplink, UL, transmission in an unlicensed spectrum; and

select at least one starting position from among the plurality of candidate start positions based on a fixed UL starting point;

follow a UL grant for communication; and

scale down a Transport Block Size, TBS, for a first subframe/slot in an uplink transmission burst and for multi-subframe/slot scheduling;

wherein scaling down the TBS of the first subframe/slot comprises determining the TBS of the first subframe/slot based on └N PRB *α┘, where α is a ratio of a transmitted partial subframe/slot to a full subframe/slot and └x┘ is a floor function.