Research On Resource Allocation Based On Cooperative Technology In Cognitive Radio Networks

Cognitive radio(CR) technology, an effective solution to the problem of radio spectrum scarcity, has causing great concerns in the world. CR technology is a new type of intelligent spectrum sharing techniques [1-2], which allows the primary users (PUs) and secondary users (SUs) to share the same spectrum and makes the secondary network detect and use the spectrum holes so as to greatly improve the spectral efficiency. In addition, cooperative relaying technique using diversity of radio users can further enhance efficient use of spectrum, also has become another hot research topic in cognitive radio system recently.In cognitive radio networks, system can make real-time detection of the current spectrum environment and adaptively adjust its transmission power, modulation method and carrier frequency, so as to effectively complete the communication process. But how to control the transmit power and allocate the sensing spectrums reasonably in the process so that the cognitive radio transmission system can achieve the optimized target in certain index, which is the important issues in cognitive radio collaborative communication process to address the resource allocation imbalance problem more effectively. This paper studies the following two questions:First, the problem of spectrum allocation in the cognitive radio secondary network for the spectrum access phase is studied. Based on the joint consideration of collaborate spectrum sensing and dynamic spectrum access in cognitive OFDMA network a fairness scheduling scheme is proposed. Simulation results show that compared to traditional spectrum access scheduling methods, this approach not only reached the system goal of maximizing network throughput, but also ensures the all users' perception of fairness.Second, the problem of power control and spectrum allocation in the cognitive radio secondary network over the collaborative communication links is studied. In order to making the communication throughput of the system up to the maximum under the interference requirement of the primary system, we propose a joint optimization of power allocation and channel allocation scheme. Simulation results show that, compared to a separate power distribution or distribution channel under the program can effectively improve the cognitive radio system end to end transmission performance.