Which layer actually does HARQ level error correction?

All Answers (2) In general, HARQ is a physical layer protocol, which combines the use of forward error correction (fast, because it does not involve any retransmission) with retransmission request, when the errors are too severe for FEC to correct them.

Hybrid automatic repeat request (hybrid ARQ or HARQ) is a combination of high-rate forward error correction (FEC) and automatic repeat request (ARQ) error-control . In standard ARQ, redundant bits are added to data to be transmitted using an error-detecting (ED) code such as a cyclic redundancy check (CRC).

HARQ stands for Hybrid Automatic Repeat Request . HARQ = ARQ + FEC (Forward Error Correction)/Soft Combining. ARQ refers to Automatic Repeat Request i.e. if sender doesn’t receive Acknowledgement (ACK) before timeout, the receiver discards the bad packet and sender shall re-transmits the packet.18 Eki 2018

The eNodeB will keep transmitting the same transport block using different RV values until the UE receives an error free transport block or the total retransmission limit occurs. In LTE the total number of HARQ processes which can be initiated at any given time is 8 .