Information in DCI that indicates if the scheduled PDSCH is Old or New

Specs & Protocol Testing
,
1

Hi Experts.

When UE doesn’t decode PDSCH correctly it sends a NACK.

Then gNB sends DCI again for scheduling a retransmit.

Does anyone know if there is an information in DCI that indicates if the PDSCH scheduled is Old or New?

Admin note: this post was updated with image below.

Information in DCI that indicates if the scheduled PDSCH is Old or New
Information in DCI that indicates if the scheduled PDSCH is Old or New987×614 99.9 KB

2

NDI bit toggled if new tx.

1 Like
3

Is that for both UL and DL?

4

Yes, for both.

1 Like
5

Yes. RV - Redundancy Version

I think this one is for PUSCH.

6

That’s my understanding as well…

How exactly?

7

This is a field in DCI.

I think it’s sent like 0 2 1 3

0 for tx

Rest for retx

8

So through this field UE can know if PDSCH is new or no?

9

Yup, correct.

10

Information in DCI that indicates if the scheduled PDSCH is Old or New
Information in DCI that indicates if the scheduled PDSCH is Old or New987×614 99.9 KB

1 Like
11

Makes sense…
Because 4 RV values and up to 8 TX possible.

12

Infact 16 in 5G.

2 Likes
13

So it’s both NDI and RV?

14

Yes, correct.

1 Like
15

What does 16 indicate here?

16

I think he’s mentioning HARQ process.