Indeed, the best explanation of the concept around PDCCH scheduling I have seen anywhere, including the '5G bible' "5G New Radio In Bullets". Thank you for your effort!
I didnt understand Interleaving and REG Bundle. Why is this neccessary when we already already know CCE is made of 6 REs? and Why is interleaving and cyclic shift used ?
As you mentioned , In 4G, on every slot, some 1 are 2 are symbols are reserved for PDCCH and remaining symbols are for data transmission..in that reserved symbols if we don't transmit PDCCH,the unused symbols can't be used for data transmission.. Coming to 5G , CORESET concept was introduced for PDCCH transmission My query is like Can't we transmit PDCCH without CORESET? In 5G, we can use that unused symbols in the PDCCH for data transmission purpose... Can we do in this way like ..without having that CORESET for PDCCH transmission,can we use that unused symbols in the PDCCH for data transmission purpose? How that CORESET will be placed in time and frequency grid? Is there any triggering condition or when the PDCCH data is available it will also be available at that time?
UE search for PDCCH in all CORESET configured. If CORESET concept is absent, then UE has to search for PDCCH on a larger search space. CORESET is introduced to reduce the search space for UEs. Time-frequency location of CORESET is informed by BS to UE via RRC messages 1:25 .
Pros: 1) BS doesn't need to explicitly tell the location of PDCCH. 2) No dedicated resources for PDCCH, hence no resource wastage [0:49]. Cons: 1) Higher computational complexity (hence higher power consumption) for UE's blind decoding.
