The previous examples would show you the most of the cases for scheduling regular slots (By regular slot, I mean those slots that can be fully allocated for user data(e.g, PDSCH, PUSCH) and control information (e.g, DCI, UCI)). You cannot apply TDD UL/DL Configuration Common with Pattern 1 only since there are multiple DL/UL switching pointsīut if you break this 10 slots into two 5 slots, you can apply tdd-ul-dl-ConfigCommon using the two patterns (i.e, Pattern 1 and Pattern 2) NOTE : If you want, you can even apply tdd-ul-dl-ConfigCommon to this kind of pattern if this 10 slot scheduling repeats. But if we assume that this 10 slot scheduling repeats then you can take the 10 slots as a pattern. If you define the length of the pattern to be 5 slots, there is no pattern. NOTE : Even in this case, you may apply some pattern if you try hard. In terms of UCI transmission as well, I mapped one UCI in the same way as above and mapped another I put the first 5 slots in the same pattern as in example 01 and in the second 5 slots I put 2 PDSCH at the beginning and 2 PUSCH slots at the end and put UCI slot in the middle. In this example, I just try to break the pattern to show you that the scheduling can be done in any arbitray way. NOTE : If the UCI slot structure is like Case 1,3,4 of the 4 cases shown here, this pattern May (orĬonfigured as tdd-UL-DL-ConfigCommon in Rrc. Like a previous example, the UCI slot can be scheduled as in a case out of 4 cases shown here. This example also shows a scheduling with a specific pattern(5 slot pattern) where the first 3 slots are scheduled for PDSCH and the 4th slot is scheduled for PUSCH and the last (5th slot) is reserved for UCI. The difference from the previous example is that UCI for some PDSCH within a period is mapped to the UCI slot in next period. In terms of overall slot configuration, the pattern in this example is same as the pattern in previous example. NOTE : When scheduling happens with a certain repeating pattern like this, Network May (or May Not) configure tdd-UL-DL-ConfigCommon in Rrc. Looking further into UCI slot, it can be scheduled as in a case out of 4 cases shown here. Ack/Nack for all the PDSCH within the 5 slot span is conveyed by the single UCI in the fifth slot. Each period spans 5 slots in which the first 4 slot is scheduled for PDSCH and the fifth slot is reserved for UCI. In this example, the scheduling is done in periodic fashion. These are only a few examples, there can be almost infinite number of different way of scheduling method. In this section, I will show you some of the examples of the scheduling you may see in live network situation or test setups for high throughput. Process (individual HARQ processes) are running in interleaving fashion and it can minimize the number of not-used slots. So in most of real situation, multiples of those individual If only the single cycle (single HARQ) is used, there would be a lot of slots being idle(i.e, not scheduled) because almost always there are some slots not scheduling between PDSCH and UCI, and between DCI and PUSCH. The scheduling procedure describe in previous section is for the scheduling in single cycle (i.e, single HARQ process). This is interpreted as 'retransmittion request' on UE side. Network just send the same UL Grant(DCI) with NDI value NOT toggled. There is no special mechanism (e.g, specialĭCI for retransmission). Then next question would be How Network can request retransmit ?. Then what would happen Network failed to recieve / decode PUSCH ? In that case, Network request UE to retransmit PUSCH. NOTE : As you see here, there is no ACK/NACK report for PUSCH. Ii) After K2 slot after the DCI slot, UE transmit PUSCH. I) Network send UL Grant(DCI 0_0 or DCI 0_1). Uplink scheduling is relatively simple comparing the downlink scheduling explained in previous section. ![]() In this illustration, I just presented only 4 different cases but there can be more cases. NOTE : The above illustration shows several typical forms of the UCI slot (the slot carrying the UCI). ![]() The slot carrying the UCI can be utilized in various different form which can be examplified as Case 1,2,3,4 as shown below). The UCI can be carried by PUCCH or PUSCH depending on situations. Iii) After k1 slots after the PDSCH is transmitted, UE transmit Ack/Nack via UCI. Ii) After K0 slots after the DCI, PDSCH is transmitted (K0 can be any value from 0 through 32, but as of Sep 2021, only K0 = 0 seems to be supported). I) NW (Network) send DCI for PDSCH (PDSCH Grant) This process can be illustrated as follows, the process can be summarized as follows. Now let's look into a typical downlink scheduling (i.e, PDSCH scheduling).
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