Energy Aware Evaluation of LTE Hybrid-ARQ and Modulation/Coding Schemes

Mobile internet devices are among the fastest growing markets in consumer electronics. A big issue with these devices is the low battery capacity that requires the user to recharge the device regularly. This paper aims to reduce the energy consumption of LTE modems used in future devices. For this, the LTE HARQ process is modeled as a Markov chain and a simple generic model for energy consumption is introduced that divides energy consumption in a static and a dynamic part. Using these and the results of link-level simulations it is found that throughput maximization will also maximize the energy efficiency if the static energy consumption dominates. However, if the energy consumption also contains a dynamic part, the energy efficiency will severely degrade unless another optimization approach is used.