Rate and Outage Trade-Offs for OFDMA Based Device to Device Communication Frameworks

This paper presents the rate and outage tradeoffs for orthogonal frequency division multiple access-based device-to-device (D2D) communication frameworks, wherein multiple D2D users coexist with the cellular users in the same cell. Analytical expressions for outage probability for three D2D frameworks, namely underlay, overlay, and cooperative D2D (C-D2D) have been derived. Specifically, for underlay framework, a minimum value of angle θ (an angle between a cellular link and D2D interference link) is derived, for which the target rate and outage probability constraint of both cellular and D2D users are satisfied. For overlay and C-D2D frameworks, an optimal subcarrier sharing scheme is proposed, which not only helps the cellular users to achieve the target quality-of-service but also helps the D2D users to communicate with each other. In addition to above, benefits involved in employing one framework over other have also been investigated. Our results show that for a higher outage probability constraint of the cellular user, the C-D2D framework outperforms the underlay and overlay frameworks.