### Abstract

The energy efficiency (EE) of a multi-user multi-relay system with the maximum diversity network coding (MDNC) is studied. We explicitly find the connection among the outage probability, energy consumption, and EE, and formulate the maximizing EE problem under the outage probability constraint. Relay scheduling (RS) and power allocation (PA) are applied to schedule the relay states (transmitting, sleeping, and so on) and optimize the transmitting power under the practical channel and power consumption models. Since the optimization problem is NP hard, to reduce computational complexity, the outage probability is first tightly approximated to a log-convex form. Furthermore, the EE is converted into a subtractive form based on the fractional programming. Then, a convex mixed-integer nonlinear problem is eventually obtained. With a generalized outer approximation algorithm, RS and PA are solved in an iterative manner. The Pareto-optimal curves between the EE and the target outage probability show the EE gains from PA and RS. Moreover, by comparing with the no network coding (NoNC) scenario, we conclude that with the same number of relays, MDNC can lead to EE gains. However, if RS is implemented, NoNC can outperform MDNC in terms of the EE when more relays are needed in the MDNC scheme.

Original language | English |
---|---|

Article number | 7552469 |

Pages (from-to) | 4506-4519 |

Number of pages | 14 |

Journal | IEEE Transactions on Communications |

Volume | 64 |

Issue number | 11 |

DOIs | |

Publication status | Published - Nov 1 2016 |

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### Keywords

- Energy efficiency-outage probability tradeoff
- Generalized outer approximation (GOA)
- network coding
- power allocation
- relay scheduling

### ASJC Scopus subject areas

- Electrical and Electronic Engineering

### Cite this

*IEEE Transactions on Communications*,

*64*(11), 4506-4519. [7552469]. https://doi.org/10.1109/TCOMM.2016.2602830

**Energy-Efficient Cooperative Network Coding with Joint Relay Scheduling and Power Allocation.** / Qi, Nan; Xiao, Ming; Tsiftsis, Theodoros A.; Skoglund, Mikael; Cao, Phuong L.; Li, Lixin.

Research output: Contribution to journal › Article

*IEEE Transactions on Communications*, vol. 64, no. 11, 7552469, pp. 4506-4519. https://doi.org/10.1109/TCOMM.2016.2602830

}

TY - JOUR

T1 - Energy-Efficient Cooperative Network Coding with Joint Relay Scheduling and Power Allocation

AU - Qi, Nan

AU - Xiao, Ming

AU - Tsiftsis, Theodoros A.

AU - Skoglund, Mikael

AU - Cao, Phuong L.

AU - Li, Lixin

PY - 2016/11/1

Y1 - 2016/11/1

N2 - The energy efficiency (EE) of a multi-user multi-relay system with the maximum diversity network coding (MDNC) is studied. We explicitly find the connection among the outage probability, energy consumption, and EE, and formulate the maximizing EE problem under the outage probability constraint. Relay scheduling (RS) and power allocation (PA) are applied to schedule the relay states (transmitting, sleeping, and so on) and optimize the transmitting power under the practical channel and power consumption models. Since the optimization problem is NP hard, to reduce computational complexity, the outage probability is first tightly approximated to a log-convex form. Furthermore, the EE is converted into a subtractive form based on the fractional programming. Then, a convex mixed-integer nonlinear problem is eventually obtained. With a generalized outer approximation algorithm, RS and PA are solved in an iterative manner. The Pareto-optimal curves between the EE and the target outage probability show the EE gains from PA and RS. Moreover, by comparing with the no network coding (NoNC) scenario, we conclude that with the same number of relays, MDNC can lead to EE gains. However, if RS is implemented, NoNC can outperform MDNC in terms of the EE when more relays are needed in the MDNC scheme.

AB - The energy efficiency (EE) of a multi-user multi-relay system with the maximum diversity network coding (MDNC) is studied. We explicitly find the connection among the outage probability, energy consumption, and EE, and formulate the maximizing EE problem under the outage probability constraint. Relay scheduling (RS) and power allocation (PA) are applied to schedule the relay states (transmitting, sleeping, and so on) and optimize the transmitting power under the practical channel and power consumption models. Since the optimization problem is NP hard, to reduce computational complexity, the outage probability is first tightly approximated to a log-convex form. Furthermore, the EE is converted into a subtractive form based on the fractional programming. Then, a convex mixed-integer nonlinear problem is eventually obtained. With a generalized outer approximation algorithm, RS and PA are solved in an iterative manner. The Pareto-optimal curves between the EE and the target outage probability show the EE gains from PA and RS. Moreover, by comparing with the no network coding (NoNC) scenario, we conclude that with the same number of relays, MDNC can lead to EE gains. However, if RS is implemented, NoNC can outperform MDNC in terms of the EE when more relays are needed in the MDNC scheme.

KW - Energy efficiency-outage probability tradeoff

KW - Generalized outer approximation (GOA)

KW - network coding

KW - power allocation

KW - relay scheduling

UR - http://www.scopus.com/inward/record.url?scp=84999740124&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84999740124&partnerID=8YFLogxK

U2 - 10.1109/TCOMM.2016.2602830

DO - 10.1109/TCOMM.2016.2602830

M3 - Article

AN - SCOPUS:84999740124

VL - 64

SP - 4506

EP - 4519

JO - IEEE Transactions on Communications

JF - IEEE Transactions on Communications

SN - 0096-1965

IS - 11

M1 - 7552469

ER -