QoS Driven Multi-user Video Streaming in Cellular CRNs: The Case of Multiple Channel Access

We tackle the challenging problem of streaming multi-user videos over the downlink of a cellular Cognitive Radio Network (CRN), where each Cognitive User (CU) can sense and access multiple channels at a time. Spectrum sensing, channel assignment, and power allocation strategies are jointly optimized to maximize the Quality of Service (QoS) for the CUs. We show that the formulated Mixed Integer NonLinear Programming (MINLP) problem can be decomposed into two sub-problems without sacrificing optimality: SP1 for the optimal spectrum sensing strategy, and SP2 for optimal channel assignment and power allocation. We show that SP1 can be optimally solved and then develop a Column Generation (CG) based algorithm to solve SP2 iteratively in a distributed manner. We also develop a heuristic algorithm for spectrum sensing with greatly reduced requirement on CU hardware, but with a highly competitive sensing performance. We analyze the proposed algorithms with respect to complexity and derive a performance upper bound. The proposed algorithms are validated with extensive simulations.