Techniques for downlink control channel location indication in wireless communications
Methods, systems, and devices for wireless communications are described that provide for a location indicator transmission that may indicate a location of control channel resources that are to be monitored by a user equipment (UE) for control channel transmissions. A UE may receive the location indicator, and monitor the indicated control channel resources to receive downlink control information with an allocation of shared channel resources for the UE. The location indicator may include one or more parameters that allow a UE to receive the control channel transmissions according to a single decoding hypothesis. The location indicator may include one or more of a valid period of the location of the control channel transmissions, an interval at which control channel transmissions may be transmitted, an aggregation level used for the control channel transmissions, an index that identifies a first control channel element of the control channel transmissions, or combinations thereof.
1. A method for wireless communication, comprising:
receiving, at a user equipment (UE), a location indicator transmission based at least in part on monitoring a set of resources specific to the location indicator transmission, the location indicator transmission having a location indicator that identifies downlink control channel resources that are to be monitored by the UE for downlink control information transmissions, wherein the receiving the location indicator transmission comprises identifying a search space of downlink transmission resources that are configured for transmission of the location indicator transmission, searching the search space for the location indicator transmission, and decoding the location indicator transmission responsive to the searching;
monitoring the downlink control channel resources based at least in part on the received location indicator;
receiving downlink control information on the downlink control channel resources based at least in part on the monitoring;
identifying, based at least in part on the downlink control information, downlink shared channel resources that have been allocated for shared channel transmissions to the UE; and
receiving the shared channel transmissions via the downlink shared channel resources.
2. The method of claim 1 , wherein the receiving the location indicator transmission comprises receiving a physical location indicator channel (PLICH) transmission that includes the location indicator.
3. The method of claim 2 , wherein the PLICH transmission and a first instance of the downlink control channel resources to be monitored are in a same radio frame.
4. The method of claim 2 , wherein the location indicator includes one or more of a valid period for the location indicator, an interval at which the downlink control channel resources are to be monitored, an aggregation level of the downlink control information transmitted using the downlink control channel resources, an index of a first control channel element of the downlink control channel resources, or any combination thereof.
5. The method of claim 4 , wherein the valid period corresponds to a number of radio frame intervals during which the UE is to monitor the identified downlink control channel resources, and wherein the UE monitors for a second PLICH transmission responsive to an expiration of the valid period.
6. The method of claim 1 , wherein the search space includes a common search space for multiple UEs and a UE-specific search space.
7. The method of claim 1 , wherein the searching comprises blindly decoding a plurality of decoding hypotheses within the search space.
8. The method of claim 1 , wherein the shared channel transmissions are transmissions of a first service that has a lower latency than a second service, and wherein the search space corresponds to a subset of a control channel search space associated with the second service.
9. The method of claim 8 , wherein the first service is an ultra-reliable low latency (URLLC) service and the second service is an enhanced mobile broadband (eMBB) service.
10. The method of claim 8 , wherein a coding rate of the location indicator transmission is lower than a coding rate of control channel transmissions of the second service that are transmitted in the control channel search space associated with the second service.
11. A method for wireless communication, comprising:
establishing a connection with a user equipment (UE);
configuring a search space of downlink transmission resources for transmission of a location indicator transmission;
transmitting the location indicator transmission to the (UE) in a set of resources specific to the location indicator transmission, the location indicator transmission including a location indicator that identifies downlink control channel resources that are to be monitored by the UE for downlink control information transmissions;
transmitting downlink control information to the UE using the identified downlink control channel resources, the downlink control information indicating downlink shared channel resources that have been allocated for shared channel transmissions to the UE; and
transmitting the shared channel transmissions to the UE via the downlink shared channel resources.
12. The method of claim 11 , wherein the transmitting the location indicator transmission comprises transmitting a PLICH transmission that includes the location indicator.
13. The method of claim 12 , wherein the PLICH transmission and a first instance of the downlink control channel resources that are to be monitored are in a same radio frame.
14. The method of claim 12 , wherein the location indicator includes one or more of a valid period for the location indicator, an interval at which the downlink control channel resources are to be monitored by the UE, an aggregation level of the downlink control information transmitted using the downlink control channel resources, an index of a first control channel element of the downlink control channel resources, or any combination thereof.
15. The method of claim 14 , wherein the valid period corresponds to a number of radio frame intervals during which the UE is to monitor the identified downlink control channel resources, and wherein the UE monitors for a second PLICH transmission responsive to an expiration of the valid period.
16. The method of claim 11 , wherein the search space includes a common search space for multiple UEs and a UE-specific search space.
17. The method of claim 11 , wherein the shared channel transmissions are transmissions of a first service that has a lower latency than a second service, and wherein the search space corresponds to a subset of a control channel search space associated with the second service.
18. The method of claim 17 , wherein the first service is an URLLC service and the second service is an eMBB service.
19. The method of claim 17 , wherein a coding rate of the location indicator transmission is lower than a coding rate of control channel transmissions of the second service that are transmitted in the control channel search space associated with the second service.
20. A user equipment (UE), comprising:
means for receiving, at the UE, a location indicator transmission based at least in part on monitoring a set of resources specific to the location indicator transmission, the location indicator transmission having a location indicator that identifies downlink control channel resources that are to be monitored by the UE for downlink control information transmissions, wherein the means for receiving the location indicator transmission comprise means for identifying a search space of downlink transmission resources that are configured for transmission of the location indicator transmission, means for searching the search space for the location indicator transmission, and means for decoding the location indicator transmission responsive to the searching;
means for monitoring the downlink control channel resources based at least in part on the received location indicator;
means for receiving downlink control information on the downlink control channel resources based at least in part on the monitoring;
means for identifying, based at least in part on the downlink control information, downlink shared channel resources that have been allocated for shared channel transmissions to the UE; and
means for receiving the shared channel transmissions via the downlink shared channel resources.
21. The UE of claim 20 , wherein the means for receiving the location indicator transmission receives a physical location indicator channel (PLICH) transmission that includes the location indicator.
22. The UE of claim 21 , wherein the PLICH transmission and a first instance of the downlink control channel resources to be monitored are in a same radio frame.
23. The UE of claim 21 , wherein the location indicator includes one or more of a valid period for the location indicator, an interval at which the downlink control channel resources are to be monitored, an aggregation level of the downlink control information transmitted using the downlink control channel resources, an index of a first control channel element of the downlink control channel resources, or any combination thereof.
24. The UE of claim 23 , wherein the valid period corresponds to a number of radio frame intervals during which the UE is to monitor the identified downlink control channel resources, and wherein the UE monitors for a second PLICH transmission responsive to an expiration of the valid period.
25. A network entity, comprising:
means for establishing a connection with a user equipment (UE);
means for configuring a search space of downlink transmission resources for transmission of a location indicator transmission;
means for transmitting the location indicator transmission to the UE in a set of resources specific to the location indicator transmission, the location indicator transmission including a location indicator that identifies downlink control channel resources that are to be monitored by the UE for downlink control information transmissions;
means for transmitting downlink control information to the UE using the identified downlink control channel resources, the downlink control information indicating downlink shared channel resources that have been allocated for shared channel transmissions to the UE; and
means for transmitting the shared channel transmissions to the UE via the downlink shared channel resources.
26. The network entity of claim 25 , wherein the means for transmitting the location indicator transmission transmits a PLICH transmission that includes the location indicator.
27. The network entity of claim 26 , wherein the PLICH transmission and a first instance of the downlink control channel resources that are to be monitored are in a same radio frame.
28. The network entity of claim 26 , wherein the location indicator includes one or more of a valid period for the location indicator, an interval at which the downlink control channel resources are to be monitored by the UE, an aggregation level of the downlink control information transmitted using the downlink control channel resources, an index of a first control channel element of the downlink control channel resources, or any combination thereof.