Optimizing the Code Rate of Energy-Constrained Wireless Communications With HARQ

Retransmissions due to decoding errors have a big impact on the energy budget of low-power wireless communication devices, which can be reduced by using hybrid automatic repeat request (HARQ) techniques. Nevertheless, this reduction comes at the cost of extra energy consumption introduced by the added computational load. No complete analysis of the trade-off between retransmissions reduction and baseband consumption of low-power communications over fading channels has been reported so far. In this article, we study the energy efficiency achievable by HARQ schemes when the code rate of the error-correcting code is optimized. The analysis focuses on the case of simple HARQ (S-HARQ) and Chase combining (HARQ-CC), which are studied under fast-fading and blockfading scenarios with Nakagami-m fading. The retransmission statistics are analyzed and expressions for the expected number of transmission trials are derived. Using this framework, it is shown that transmission schemes with high div...

• Type: Journal
• Year: 2016
• Where: TWC
• Authors: Fernando Rosas, Richard Demo Souza, Marcelo Eduardo Pellenz, Christian Oberli, Glauber Gomes de Oliveira Brante, Marian Verhelst, Sofie Pollin
• Keywords: TWC 2016