Hi ganesh,
In LTE there is two kind of data transmission . one is adaptive tx and another one is non-adaptive tx.
adaptive TX :
adaptive transmission means in case of Re-transmission ENB will select different resource or different mcs for the same TB. say example END had sent 1500 bytes of data with 15Rb and mcs of 28. If that TB is nack means ENB can select different MCS for the same TB based on UE channel condition.
Non-adaptive Tx:
In this case ENB wont select different resource or MCS for the re-transmission. ENB will use the same RB's and MCS which is used in the new Transmission.
This applicable in both UL & DL data transmission.
Happy Learning :)
