Quality, Reliability, Security and Robustness in Heterogeneous Networks. 7th International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2010, and Dedicated Short Range Communications Workshop, DSRC 2010, Houston, TX, USA, November 17-19, 2010, Revised Selected Papers

Research Article

Optimal Channel Pairing and Power Allocation for Multi-channel Multi-hop Relay Networks

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  • @INPROCEEDINGS{10.1007/978-3-642-29222-4_10,
        author={Mahdi Hajiaghayi and Min Dong and Ben Liang},
        title={Optimal Channel Pairing and Power Allocation for Multi-channel Multi-hop Relay Networks},
        proceedings={Quality, Reliability, Security and Robustness in Heterogeneous Networks. 7th International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2010, and Dedicated Short Range Communications Workshop, DSRC 2010, Houston, TX, USA, November 17-19, 2010, Revised Selected Papers},
        proceedings_a={QSHINE},
        year={2012},
        month={10},
        keywords={},
        doi={10.1007/978-3-642-29222-4_10}
    }
    
  • Mahdi Hajiaghayi
    Min Dong
    Ben Liang
    Year: 2012
    Optimal Channel Pairing and Power Allocation for Multi-channel Multi-hop Relay Networks
    QSHINE
    Springer
    DOI: 10.1007/978-3-642-29222-4_10
Mahdi Hajiaghayi1,*, Min Dong2,*, Ben Liang1,*
  • 1: University of Toronto
  • 2: University of Ontario Institute of Technology
*Contact email: mahdih@comm.utoronto.ca, min.dong@uoit.ca, liang@comm.utoronto.ca

Abstract

We study the problem of channel pairing and power allocation in a multi-channel, multi-hop relay network to enhance the end-to-end data rate. OFDM-based relays are used as an illustrative example, and the amplify-and-forward and decode-and-forward relaying strategies are considered. Given fixed power allocation to the OFDM subcarriers, we observe that a sorted-SNR subcarrier pairing strategy is data-rate optimal, where each relay pairs its incoming and outgoing subcarriers by their SNR order. For the joint optimization of subcarrier pairing and power allocation, we show that it is optimal to separately consider the two subproblems, for both individual and total power constraints. This separation principle significantly reduces the computational complexity in finding the jointly optimal solution. We further establish the equivalence between sorting SNRs and sorting channel gains in the jointly optimal solution, which allows simple implementation of optimal subcarrier pairing at the relays. Simulation results are presented to demonstrate the performance gain of the jointly optimal solution over some suboptimal alternatives.