5G/NR - MiniSlot Home : www.sharetechnote.com
You may heard of MiniSlot in various 5G/NR related white papers and presentations even before 5G/NR 3GPP technical specification roll out. However, I still don't find any formal term 'MiniSlot' in 3GPP TS spec as of now (Jan 2019). It implies that 'MiniSlot' would not be the formal term even if it is possible to implement it.
Based on the white papers and presentations that I saw (Ref  for example), they define 'MiniSlot' as a slot that carries PDSCH or PUSCH with only a few symbol length(e.g, 2 symbols, 4 symbols etc) as illustrated below.
How to implement MiniSlot ?
As of now(Jan 2019), I don't see any explicit description on MiniSlot implemenations in 3GPP spec. Probably we may see some when eMTC or URLLC related specification is fully specified even if they would not use the term 'MiniSlot'.
One possible implementation can be illustrated as follows.
Transmit a DCI that schedule PDSCH with 2 or 4 symbols (using SLIV). In most of white papers, they show that DCI(PDSCH) symbol is directly followed by PDSCH. Also most of white paper illustrates that the DCI and PDSCH is located in the same slot (i.e, K0 = 0). But I think it is possible to schedule PDSCH in such way that DCI and PDSCH is not in the same slot(i.e, K0 is not Zero).
Like DL Minislot (PDSCH MiniSlot), we can transmit UL minislot(PUSCH minislot) in similar way as shown below.
Transmit a DCI that schedule PUSCH with 2 or 4 symbols (using SLIV). In most of white papers, they show that DCI(PUSCH) symbol is directly followed by PUSCH, but in practice it is likely to put one or more symbol gaps between DCI and PUSCH because switching between DL(DCI/PDCCH) and UL(PUSCH) without any guard period would be very challenging.
Also most of white paper illustrates that the DCI and PUSCH is located in the same slot (i.e, K2 = 0). But I think it is possible to schedule PDSCH in such way that DCI and PUSCH is not in the same slot(i.e, K2 is not Zero).