Hi Experts.
What is the significance of reserved MCS for retransmission?
The reserved MCS doesn’t specify the code rate to be used, it just indicates the modulation order for the retransmission, then why do we use reserved MCS?
Instead we can use the non-reserved MCS indicating both code rate and modulation scheme.
38.214 for PUSCH MCS entries above 28 says:
Same is for PDSCH as well
Above is the only text I could found in spec related to reserved MCS
What is the advantage of having Reserved MCS (like 28, 29, 30, 31) for re-transmission if we already have the 27 different MCS that we can use?
The advantage is that the 3GPP has not fixed the code rate for the Reserved MCS and has left to the gNB implementation when performing retransmission.
