Hybrid automatic repeat request protocols: Turbo-Codes against Cyclic Binary low-density parity-check codes

Hybrid ARQ is defined as the joint use of a retransmission protocol ARQ and forward error coding (FEC) at the transmitter and/or receiver. We will focus on the HARQ-type-II protocols, namely type-II-CC (Chase Combining) characterized by a storage and combination of erroneous packets, and the type-II-IR (Incremental Redundancy) which provides an Incremental Redundancy strategy that helps to increase the throughput. These two strategies are used by the new mobile communications networks. The HARQ transmission performance depends especially on the selected retransmission protocol (ARQ), and on the model of the forward error correction code (FEC). In this paper, we propose a comparison of the HARQ protocols using two different FEC Codes, in the first hand we use the Turbo Codes, referring to 4G LTE networks, in the other hand we propose a new transmission scheme using a Cyclic Binary LDPC Code with a higher coderate. This study will allow us to reach an optimized transmission scheme based on a combination of coding and retransmission (HARQ), in order to provide higher average throughputs and reliable radio transmissions over all the SNR values.