Robustness for control channel
A method, network node and wireless device for transmitting and decoding repeated physical downlink control channel (PDCCH) messages are disclosed. According to one embodiment a method implemented in a wireless device (WD) includes receiving multiple transmissions of a PDCCH message, each of the multiple transmissions of the PDDCH message being repeated in a repetition set. The method further includes monitoring the multiple received PDCCH transmissions to obtain scheduling information for a physical uplink shared channel (PUSCH) transmission or a physical downlink shared channel (PDSCH) reception.
1. A wireless device, WD, configured to communicate with a network node, the WD comprising processing circuitry configured to:
receive multiple transmissions of a physical downlink control channel, PDCCH, message, each of the multiple transmissions of the PDCCH message being repeated in a repetition set;
monitor the multiple received PDCCH message transmissions to obtain scheduling information for one of a physical uplink shared channel, PUSCH, transmission and a physical downlink shared channel, PDSCH, reception; and
determine a scheduling offset for a PDSCH or a PUSCH based on a time location of a PDCCH candidate of the repetition set.
2. The WD of claim 1 , wherein the processing circuitry is further configured to combine the multiple received PDCCH message transmissions in the repetition set to determine the PDCCH candidate.
3. The WD of claim 1 , wherein each PDCCH message transmission is separately decodable to produce the PDCCH candidate.
4. The WD of claim 2 , wherein the WD is configured with multiple search spaces where there is a repetition association between different search spaces, and wherein the PDCCH candidate in a search space is repeated in another search space to achieve the repetition set.
5. The WD of claim 1 , wherein for a first PDCCH candidate in a first search space, the first PDCCH candidate having a first downlink control information, DCI, there is a corresponding PDCCH candidate in another search space having a same sized DCI as the first PDCCH candidate.
6. The WD of claim 5 , wherein the WD can, for each of a plurality of DCI sizes, combine PDCCH candidates from multiple search spaces to obtain PDCCH detection robustness.
7. The WD of claim 1 , wherein a search space configuration includes multiple identifiers indicating multiple PDCCH candidates, to enable a search of the PDCCH candidate based on the identifiers.
8. The WD of claim 7 , wherein the processing circuitry is further configured to count blind decodes such that a given PDCCH candidate that is repeated is counted as a single monitored PDCCH candidate.
9. The WD of claim 1 , wherein each PDCCH in the repetition set schedules a separate one of the PDSCH and the PUSCH.
10. The WD of claim 1 , wherein multiple PDCCHs schedule a same PDSCH or PUSCH to achieve a many-to-one mapping of the PDCCH to the one of the PDSCH and the PUSCH.
11. The WD of claim 1 , wherein the time location is an earliest time location at which the PDCCH candidate of the repetition set can be received.
12. A method implemented in a wireless device (WD), WD, the method comprising:
receiving multiple transmissions of a physical downlink control channel, PDCCH, message, each of the multiple transmissions of the PDCCH message being repeated in a repetition set;
monitoring the multiple received PDCCH message transmissions to obtain scheduling information for one of a physical uplink shared channel, PUSCH, transmission and a physical downlink shared channel, PDSCH, reception; and
determine a scheduling offset for a PDSCH or a PUSCH based on a time location of a PDCCH candidate of the repetition set.
13. The method of claim 12 , further comprising combining the multiple received PDCCH message transmissions in the repetition set to determine the PDCCH candidate.
14. The method of claim 12 , wherein each PDCCH message transmission is separately decodable to produce the PDCCH candidate.
15. The method of claim 13 , further comprising searching multiple search spaces where there is a repetition association between different search spaces, and wherein the PDCCH candidate in a search space is repeated in another search space to achieve the repetition set.
16. The method of claim 12 , further comprising searching for a first PDCCH candidate in a first search space, the first PDCCH candidate having a first downlink control information, DCI, there being a corresponding PDCCH candidate in another search space having a same sized DCI as the first PDCCH candidate.
17. The method of claim 16 , further comprising combining PDCCH candidates from multiple search spaces to obtain PDCCH detection robustness.
18. The method of claim 12 , further comprising searching for a PDCCH candidate based on multiple identifiers in a search space configuration, the multiple identifiers indicating multiple PDCCH candidates.
19. A network configured to communicate with a wireless device WD, the network node comprising processing circuitry configured to:
configure a physical downlink control channel, PDCCH, message for multiple transmissions; and
cause the multiple transmissions of the PDCCH message, each of the multiple transmissions of the PDCCH message being repeated in a repetition set, the multiple transmission causing the WD to monitor the multiple transmissions of the PDCCH message to obtain scheduling information for one of a physical uplink shared channel, PUSCH, transmission and a physical downlink shared channel, PDSCH, reception by the WD and determine a scheduling offset for a PDSCH or a PUSCH based on a time location of a PDCCH candidate of the repetition set.
20. The network node of claim 19 , wherein the processing circuitry is further configured to configure the PDCCH message with an identifier of at least another PDCCH that includes the same message.
21. The network node of claim 19 , wherein the processing circuitry is further configured to cause transmission of a PDCCH candidate message with a first aggregation level in a first control resource set, CORESET, and to map the PDCCH mapped to another PDCCH candidate message transmitted with a second aggregation level in a second CORESET.
22. The network node of claim 19 , wherein first and second candidate PDCCHs convey a same downlink control information.
23. The network node of claim 19 , wherein different PDCCH candidates are transmitted by different network nodes.
24. A method implemented in a network node, the network node being configured to communicate with a wireless device, WD, the method comprising:
configuring a physical downlink control channel, PDCCH, message for multiple transmissions; and
causing the multiple transmissions of the PDCCH message, each of the multiple transmissions of the PDCCH message being repeated in a repetition set, the multiple transmission causing the WD to monitor the multiple transmissions of the PDCCH message to obtain scheduling information for one of a physical uplink shared channel, PUSCH, transmission and a physical downlink shared channel, PDSCH, reception by the WD and determine a scheduling offset for a PDSCH or a PUSCH based on a time location of a PDCCH candidate of the repetition set.