QoE-Aware Cross-Layer Adaptation for D2D Video Communication in Cooperative Cognitive Radio Networks

In this article, a cross-layer parameter optimization is considered for H.264 scalable video transmission in cognitive radio enabled device-to-device networks. Adaptive modulation and coding is considered at the physical layer along with video layer aware automatic repeat request (VLA-ARQ) at the link layer. The VLA-ARQ scheme is aware of video characteristics. Scalable video coding (SVC) based video streaming is carried out at the application layer. A novel cognitive radio network frame structure is proposed accommodating cooperative spectrum sensing (CSS), relaying primary user’s (PU) transmission, and secondary users’ (SU) opportunistic transmission to maximize quality of experience (QoE) and to minimize total power consumption. In SVC-based video streaming, successful reception of a particular video layer is dependent upon the successful reception of its higher layers, which influences the eventual QoE at the user end. A set of optimal values of CSS time duration, sensing decision threshold, cooperation, and transmission power control are obtained under the constraints of detection reliability, PU spectrum efficiency, and SU power budget. Extensive simulation results with respect to the system parameters show the efficacy of the proposed system. The numerical results demonstrate that the proposed technique offers more than 14% gain in overall utility with the proposed CSS and cross-layer parameter optimization strategy.