When we get ACK or NACK to inform transmitter, how much is the Latency?

Hello everyone.
I have a question regarding for HARQ.
When we get ACK or NACK to inform transmitter, how much is the Latency?
As I know the latency for HARQ in 4G is 25% latency of the system.
Like for example, you have a slot duration assume it 0.5 ms which is latency of this one slot. And in 4G is 25% of latency in HARQ, so you multiply 0.5x0.25= 0.125.
Therefore, you have total latency with HARQ is 0.5+0.125=0.625 ms per slot
In 5G, is same latency of 25% in the HARQ?
For either ACK or NACK to inform transmitter.

Check here:

Source: https://www.etsi.org/deliver/etsi_tr/125900_125999/125912/09.00.00_60/tr_125912v090000p.pdf
Page 45

I see for retransmission is 30%.
For PDSCH can be used this?

This is LTE right?
For 5G is the same as LTE or not?

Normally it should be less for 5G.

In 5G, the slot offset for the ACK/NACK of PDSCH is defined by K1 parameter.
In FDD LTE, it is fixed and always happens at n+4, where n is the PDSCH subframe no.
In LTE TDD config 2, the ACK/NACK is always sent at subframe no n for PDSCH Subframe no (n-4), (n-6), (n-7) and (n-8).
There is a concept of multiplexing and bundling in LTE TDD.

And, the K1 parameter where I will find it and how to calculate it?

I can see DL to UL ACK IE in RRC connection reconfiguration which will tell slot offset.
Between DL packet TX and UL ACK.

You will see in RRC Reconfiguration Message for Sgnb addition in NSA.

But, I am simulating mimo-ofdm as physical layer with harq I am using low mac layer.

There would be a Timing indicator bit in DCI.
Which points towards a table in the DL to UL ACK IE to find out K1.
You need to know that table.
For dci 1_1 that is.
For dci 1_0, the table values are fixed.

But, I am not simulating control channel.
I am just focusing on user data channel.

But how is User data being transmitted on Pdsch without Pdcch?

So you mean for different DCI formats I have different K1 table values?

Yes. Fallback one is predefined. The other ones are user defined.

In matlab simulation there is like fixed pdcch.

Ok. But that fixed pdcch might be sending some fixed dci with a fixed format?
Trying to understand…

Do you mean for dci 1_1 we define the table? And others like user defined?
Not getting you when you said fallback predefined and user defined…


1_0 is fallback. So fixed table for it. The other one user defined.

User defined means we define them?

So if we can get that DCI format, we can get the K1 table? (From the timing indicator field inside DCI)

Yup, in the dl to ul ack IE.