A Mode Selection Scheme for D2D Communication in Heterogeneous Cellular Networks

Mode selection issue is studied for Device-to-Device (D2D) communication underlaying the two-tier cellular networks (including macro cells and small cells) to guarantee the Quality of Service (QoS) requirement not only for the cellular link but also for the D2D link. Firstly the link performances are investigated for UE under D2D transmission mode and cellular transmission mode, respectively. In addition, distance bounds are derived for potential D2D links as references to select the UE transmission mode. Lastly, a mode selection scheme is proposed based on these analyses which makes the base station determine an appropriate transmission mode for transmitter with the link performance satisfying QoS requirement. Simulation results show that link performances of cellular link and D2D link can be guaranteed by the proposed scheme. In addition, compared with the existing mode selection scheme, the proposed scheme improves the link performance significantly. The average outage probability can be reduced at most 92% for communication links by the proposed scheme.