Hybrid Automatic Repeat Request in LTE


Wireless communication systems are continuing to grow and evolve amidst high performance, expectations and requirements. Therefore the 3GPP has considered LTE to ensure future competitions. Obtaining accurate channel quality is not feasible due to various errors. These errors tend to degrade the system throughput. The Hybrid ARQ (HARQ) comes into use in such situations to provide fast re-transmission and lowering the error rate in the physical link. A HARQ mechanism allows one to mend the errors using techniques such as Incremental Redundancy and Chase Combining along with certain protocols depending on the timing and modulation selection. In this paper, the various HARQ schemes will be discussed. To save the radio resources, the number of HARQ retransmission in the downlink may be limited. Therefore adequate result using an algorithm proposed in an earlier research work has been provided in this paper to make more efficient utilization of the radio link. This paper also focuses on the performance of HARQ schemes in the OFDMA downlink operation. The throughput and PER of these schemes are compared based on the buffering memory available.

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@inproceedings{Mizan2013HybridAR, title={Hybrid Automatic Repeat Request in LTE}, author={Chowdhury Mizan and Mahmood Taher}, year={2013} }