Efficient power utilization for enhanced component carriers
Methods, systems, and devices for wireless communication are described. A user equipment (UE) may monitor a narrowband (e.g., a single carrier, anchor carrier, etc.) for a control message that includes a grant for downlink data transmissions. The narrowband containing the control message may be a portion of a system bandwidth. The UE may then monitor a wideband (e.g., all or multiple carriers of the system bandwidth) for data according to the control message. Monitoring the wideband may include additional or alternate circuitry being powered (e.g., receiver circuit switching) to enable reception on an increased range of frequency spectrum. In some examples, a gap or narrowband data transmission may be scheduled between the control message and the grant to allow grant processing and receiver circuitry switching at the UE. In some cases, the control message and data transmission may be received in the same or different transmission time intervals (TTIs).
1. A method for wireless communication, comprising:
monitoring a first bandwidth of downlink resources at a wireless device, the first bandwidth associated with a first subcarrier spacing;
receiving a control message that includes a grant indicating a second bandwidth of downlink resources associated with a data transmission, the second bandwidth associated with a second subcarrier spacing different than the first subcarrier spacing;
determining to monitor the second bandwidth based at least in part on receiving the grant that indicates the second bandwidth; and
monitoring the second bandwidth for the data transmission during a transmission time interval (TTI) based at least in part on determining to monitor the second bandwidth, wherein a time gap exists between the control message and the data transmission.
2. The method of claim 1 , wherein the time gap allows the wireless device to switch from monitoring the first bandwidth to monitoring the second bandwidth, and wherein the time gap does not include any transmissions to the wireless device.
3. The method of claim 1 , wherein the time gap allows the wireless device to prepare receiver circuitry to switch from receiving in the first bandwidth to receiving in the second bandwidth.
4. The method of claim 1 , wherein the second bandwidth comprises a subset of frequencies on a same cell as the first bandwidth.
5. The method of claim 1 , wherein the first bandwidth and the second bandwidth at least partially overlap.
6. The method of claim 5 , wherein:
the second bandwidth comprises a wideband;
the first bandwidth comprises a narrowband portion of the wideband; and
the first bandwidth is a portion of the second bandwidth.
7. The method of claim 1 , wherein:
the second bandwidth comprises a first wideband;
the first bandwidth comprises a narrowband portion of a second wideband; and
the first bandwidth is not overlapping with the second bandwidth.
8. The method of claim 1 , further comprising:
decoding the control message during the time gap; and
preparing to switch from monitoring the first bandwidth with a receiver of the wireless device to monitoring the second bandwidth with the receiver.
9. The method of claim 1 , wherein:
monitoring the first bandwidth comprises monitoring the first bandwidth with a narrowband receiver circuit of a receiver of the wireless device; and
monitoring the second bandwidth comprises monitoring the second bandwidth with a wideband receiver circuit of the receiver.
10. The method of claim 1 , wherein:
the first bandwidth comprises an anchor carrier; and
the second bandwidth comprises one or more carriers.
11. The method of claim 1 , further comprising:
receiving the data transmission in the second bandwidth during a second part of the TTI, wherein the grant is received in a first part of the TTI before the second part of the TTI.
12. The method of claim 11 , further comprising:
processing the grant during the first part of the TTI and prior to receiving the data transmission.
13. The method of claim 11 , further comprising:
receiving, based at least in part on the grant, a first portion of the data transmission in the first bandwidth during the first part of the TTI prior to switching to monitoring the second bandwidth in the second part of the TTI.
14. The method of claim 13 , further comprising:
receiving an indication of a duration to receive the first portion of the data transmission in one or both of the grant, or a radio resource control message, or a message broadcast to a plurality of wireless devices.
15. The method of claim 1 , further comprising:
receiving the data transmission in the second bandwidth during the TTI, wherein the grant is received in a previous TTI.
16. The method of claim 15 , further comprising:
receiving, in the first bandwidth during the TTI, the control message that includes the grant of downlink data transmission resources of a second TTI, wherein the second TTI follows the TTI.
17. The method of claim 1 , further comprising:
receiving a radio resource control (RRC) message comprising an indication of the time gap, wherein monitoring the second bandwidth for the data transmission is based at least in part on receiving the RRC message comprising the indication of the time gap.
18. A method for wireless communication, comprising:
determining to transmit a data transmission via a second bandwidth of downlink resources that is associated with a second subcarrier spacing different than the first subcarrier spacing;
transmitting, in a first bandwidth of downlink resources that is associated with a first subcarrier spacing, a control message that includes a grant for a wireless device indicating the second bandwidth of downlink resources based at least in part on determining to transmit the data transmission via the second bandwidth of downlink resources;
scheduling a time gap between the control message and the data transmission based at least in part on the control message; and
transmitting, in the second bandwidth, the data transmission during a transmission time interval (TTI) based at least in part on the time gap.
19. The method of claim 18 , wherein the time gap allows time for the wireless device to switch from monitoring the first bandwidth to monitoring the second bandwidth, and wherein the time gap does not include any transmissions to the wireless device.
20. The method of claim 18 , wherein the time gap allows time for the wireless device to prepare receiver circuitry to switch from receiving in the first bandwidth to receiving in the second bandwidth.
21. The method of claim 18 , wherein the first bandwidth and the second bandwidth at least partially overlap.
22. The method of claim 21 , wherein:
the second bandwidth comprises a wideband;
the first bandwidth comprises a narrowband portion of the wideband; and
the first bandwidth is a portion of the second bandwidth.
23. The method of claim 18 , wherein:
the first bandwidth comprises an anchor carrier; and
the second bandwidth comprises one or more carriers.
24. The method of claim 18 , further comprising:
transmitting the data transmission in the second bandwidth during a second part of the TTI, wherein the grant is transmitted in a first part of the TTI before the second part of the TTI.
25. The method of claim 24 , further comprising:
transmitting, based at least in part on the grant, a first portion of the data transmission in the first bandwidth during the first part of the TTI prior to transmitting a second portion of the data transmission in the second bandwidth in the second part of the TTI.
26. The method of claim 18 , further comprising:
transmitting the data transmission in the second bandwidth during the TTI, wherein the grant is transmitted in a previous TTI.
27. The method of claim 18 , further comprising:
transmitting a radio resource control (RRC) message comprising an indication of the time gap, wherein transmitting the data transmission is based at least in part on transmitting the RRC message comprising the indication of the time gap.
28. An apparatus for wireless communication, in a system comprising:
a processor;
memory coupled with the processor; and
instructions stored in the memory, the instructions being executable by the processor to:
monitor a first bandwidth of downlink resources at a wireless device, the first bandwidth associated with a first subcarrier spacing;
receive a control message that includes a grant indicating a second bandwidth of downlink resources associated with a data transmission, the second bandwidth associated with a second subcarrier spacing different than the first subcarrier spacing;
determine to monitor the second bandwidth based at least in part on receiving the grant that indicates the second bandwidth; and
monitor the second bandwidth for the data transmission during a transmission time interval (TTI) based at least in part on determining to monitor second bandwidth, wherein a time gap exists between the control message and the data transmission.
29. An apparatus for wireless communication, in a system comprising:
a processor;
memory coupled with the processor; and
instructions stored in the memory, the instructions being executable by the processor to:
determine to transmit a data transmission via a second bandwidth of downlink resources that is associated with a second subcarrier spacing different than the first subcarrier spacing;
transmit, in a first bandwidth of downlink resources that is associated with a first subcarrier spacing, a control message that includes a grant for a wireless device indicating the second bandwidth of downlink resources based at least in part on determining to transmit the data transmission via the second bandwidth of downlink resources;
schedule a time gap between the control message and the data transmission based at least in part on the control message; and
transmit, in the second bandwidth, the data transmission during a transmission time interval (TTI) based at least in part on the time gap.