How does a UE or gNB decide which DCI format to use i.e. fallback (0_0/1_0) or complete format (0_1/1_1)

5G NR
1

How does a UE or gNB decide which DCI format to use i.e. fallback (0_0/1_0) or complete format (0_1/1_1) in DL or UL respectively?

Does it depend on the poor channel condition i.e. when channel conditions are bad, use the minimum number of options and go with fallback format?

1 Like
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I have samE question:

How does the gNB decide DCI format in PDCCH?

Whether it should use 0_0 or 0_1
And
1_0 or 1_1

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Until UE is not dedicated configured,… fallback dci is used.

Or in case when UE need to do reconfigure and network is not sure at the exact time when UE applied the reconfig, in this case also fallback DCI is used.

4

Yes, also good complementary reading here: ShareTechNote - DCI