Downlink hybrid automatic repeat request feedback for narrowband Internet of Things devices
Techniques for transmitting hybrid automatic repeat request (HARQ) feedback by narrowband Internet-of-Things (NB-IoT) devices are provided. NB-IoT user equipment (UE) can transmit HARQ feedback in response to a narrowband physical downlink shared channel (NPDSCH) received over a downlink (DL). NB-IoT UEs can transmit the responsive HARQ feedback over a narrowband physical uplink shared channel (NPUSCH) or a narrowband physical uplink control channel (NPUCCH). Options for defining the physical structures of the NPUCCH and NPUSCH and user multiplexing on the uplink (UL) are provided. Determination of an UL resource allocation by determining resources in time, frequency, and the code domain for the HARQ feedback transmissions are also provided. Higher level signaling and/or indications provided in downlink control information (DCI) can be used to determine the time, frequency, or code domain resources.
1. A narrowband Internet of Things (NB-IoT) user equipment (UE), comprising:
a memory; and
baseband circuitry coupled to the memory, the baseband circuitry to:
decode an indication contained in received downlink control information (DCI), the indication to indicate an offset between a last frame of a narrowband physical downlink shared channel (NPDSCH) and a first slot for inclusion of hybrid automatic repeat request (HARQ) feedback;
determine an uplink (UL) resource allocation for the HARQ feedback based on the indication for inclusion on a narrowband physical uplink shared channel (NPUSCH) or a narrowband physical uplink control channel (NPUCCH); and
encode the HARQ feedback for inclusion on one of the NPUSCH or NPUCCH.
2. The NB-IoT UE of claim 1 , the indication to indicate one or more of a time domain resource, a number of repetitions, a frequency domain resource, or a cyclic shift.
3. The NB-IoT UE of claim 2 , the indication to indicate a starting time for transmission of the HARQ feedback.
4. The NB-IoT UE of claim 2 , the indication to specify a predetermined set of UL time domain resources designated for inclusion of the HARQ feedback.
5. The NB-IoT UE of claim 2 , the indication to indicate use of a single redundancy version (RV) for repetitions of the HARQ feedback.
6. The NB-IoT UE of claim 2 , the indication to indicate a number of subcarriers for the UL resource allocation.
7. The NB-IoT UE of claim 6 , the indication to indicate a location of the subcarriers for the UL resource allocation.
8. The NB-IoT UE of claim 7 , the indication to indicate one or more predefined subcarriers for the UL resource allocation.
9. The NB-IoT UE of claim 7 , the indication to indicate a predefined subcarrier spacing for the UL resource allocation.
10. The NB-IoT UE of claim 7 , the indication to indicate a single subcarrier for the UL resource allocation based on a two-bit field.
11. The NB-IoT UE of claim 7 , the indication to indicate one of a first edge, a second edge, or a center for the location of the subcarriers within an operating bandwidth.
12. The NB-IoT UE of claim 7 , the indication to indicate an offset for determining one or more subcarriers.
13. The NB-IoT UE of claim 2 , the indication to indicate a modulation scheme for encoding the HARQ feedback.
14. The NB-IoT UE of claim 2 , the HARQ feedback included in the NPUCCH and the UL resource allocation to comprise a single subcarrier.
15. The NB-IoT UE of claim 14 , the HARQ feedback encoded by multiplexing with reference signals.
16. The NB-IoT UE of claim 15 , the HARQ feedback encoded by binary phase shift keying (BPSK).
17. A narrowband Internet of Things (NB-IoT) user equipment (UE), comprising:
a memory; and
baseband circuitry coupled to the memory, the baseband circuitry to:
decode an indication contained in received downlink control information (DCI), the indication to indicate one or more of a time domain resource, a number of repetitions, a frequency domain resource or a cyclic shift;
determine an uplink (UL) resource allocation for hybrid automatic repeat request (HARQ) feedback based on the indication for inclusion on a narrowband physical uplink shared channel (NPUSCH) or a narrowband physical uplink control channel (NPUCCH); and
encode the HARQ feedback for inclusion on one of the NPUSCH or NPUCCH, the HARQ feedback included in the NPUCCH and the UL resource allocation to comprise a single subcarrier, and the HARQ feedback included in the NPUCCH and the UL resource allocation to comprise guard subcarriers positioned at edges of the NB-IoT physical resource block (NB-IoT PRB).
18. At least one non-transitory computer-readable storage medium comprising a set of wireless communication instructions that, in response to being executed on a computing device, cause the computing device to:
decode an indication contained in received downlink control information (DCI), the indication to indicate an offset between a last frame of a narrowband physical downlink shared channel (NPDSCH) and a first slot for inclusion of hybrid automatic repeat request (HARQ) feedback;
determine an uplink (UL) resource allocation for the HARQ feedback based on the indication for inclusion on a narrowband physical uplink shared channel (NPUSCH) or a narrowband physical uplink control channel (NPUCCH); and
encode the HARQ feedback for inclusion on one of the NPUSCH or NPUCCH.
19. The at least one computer-readable storage medium of claim 18 , comprising wireless communication instructions that, in response to being executed on the computing device, cause the computing device to determine one or more of a time domain resource, a number of repetitions, a frequency domain resource, or a cyclic shift.
20. The at least one computer-readable storage medium of claim 19 comprising wireless communication instructions that, in response to being executed on the computing device, cause the computing device to determine a first slot for inclusion of the HARQ feedback.
21. The at least one computer-readable storage medium of claim 18 , comprising wireless communication instructions that, in response to being executed on the computing device, cause the computing device to determine a number of subcarriers for the UL resource allocation and a location of the subcarriers for the UL resource allocation.
22. A narrowband Internet of Things (NB-IoT) user equipment (UE), comprising:
a memory;
radio frequency (RF) circuitry, the RF circuitry to receive downlink control information (DCI);
baseband circuitry coupled to the memory and coupled to the RF circuitry, the baseband circuitry to:
decode an indication contained in the received downlink control information (DCI), the indication to indicate an offset between a last frame of a narrowband physical downlink shared channel (NPDSCH) and a first slot for inclusion of hybrid automatic repeat request (HARQ) feedback;
determine an uplink (UL) resource allocation for the HARQ feedback for inclusion on a narrowband physical uplink shared channel (NPUSCH) or a narrowband physical uplink control channel (NPUCCH) based on the indication; and
encode the HARQ feedback for inclusion on one of the NPUSCH or NPUCCH; and
the RF circuitry to transmit the HARQ feedback on one of the NPUSCH or NPUCCH.