# Green Communication via Power-optimized HARQ Protocols Artikel i vetenskaplig tidskrift, 2014

Recently, efficient use of energy has become an essential research topic for green communication. This paper studies the effect of optimal power controllers on the performance of delay-sensitive communication setups utilizing hybrid automatic repeat request (HARQ). The results are obtained for repetition time diversity (RTD) and incremental redundancy (INR) HARQ protocols. In all cases, the optimal power allocation, minimizing the outage-limited average transmission power, is obtained under both continuous and bursting communication models. Also, we investigate the system throughput in different conditions. The results indicate that the power efficiency is increased substantially, if adaptive power allocation is utilized. For instance, assume Rayleigh-fading channel, a maximum of two (re)transmission rounds with rates $\{1,\frac{1}{2}\}$ nats-per-channel-use and an outage probability constraint ${10}^{-3}$. Then, compared to uniform power allocation, optimal power allocation in RTD reduces the average power by 9 and 11 dB in the bursting and continuous communication models, respectively. In INR, these values are obtained to be 8 and 9 dB, respectively.

hybrid automatic repeat request

feedback

Green communication

outage probability

## Författare

#### Behrooz Makki

Chalmers, Signaler och system, Kommunikations- och antennsystem, Kommunikationssystem

#### Alexandre Graell i Amat

Chalmers, Signaler och system, Kommunikations- och antennsystem, Kommunikationssystem

#### Thomas Eriksson

Chalmers, Signaler och system, Kommunikations- och antennsystem, Kommunikationssystem

#### IEEE Transactions on Vehicular Technology

0018-9545 (ISSN)

Vol. 63 1 161-177 6566132

#### Styrkeområden

Informations- och kommunikationsteknik

#### Ämneskategorier

Telekommunikation

Signalbehandling

#### DOI

10.1109/TVT.2013.2274287

2017-10-08