Cross-Layer Resource Allocation for Video Streaming over OFDMA Cognitive Radio Networks with Imperfect Cross-Link CSI

In this paper, novel cross-layer radio resource allocation (RRA) algorithm is proposed in the context of Orthogonal frequency division multiple access (OFDMA)-based cognitive radio (CR) video application systems. User video quality and channel awareness are incorporated in the design, to exploit joint optimization of rate and power for secondary receivers (SRs), subject to minimum SR video quality and primary receiver (PR) interference threshold constraints. Firstly, the relationship between PR interference margin and power limits at the secondary transmitter (ST) is analytically derived. Then, to provide PRs with satisfactory quality of service (QoS), we propose a new probabilistic approach to mitigate the total imposed interference of the ST on PRs, considering imperfect ST to PR channel state information (CSI). The effect of PR interference limit violation probability, interference threshold, and error variance of imperfect CSI are evaluated using computer simulations. Results indicate that significant improvement in SR total video quality is achieved through our proposed algorithm over other state-of-the-art Non-Quality-Aware (NQA) designs in the literature. The enhanced performance was obtained whilst guaranteeing SR minimum quality and PR prescribed QoS constraints.