Outage capacity optimisation for cognitive radio networks with cooperative communications
Outage capacity optimisation for cognitive radio networks with cooperative communications
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DOI：
10.1049/iet-com.2011.0343
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发表时间：
2012-07
期刊：
影响因子：
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通讯作者：
Renchao Xie;F. Yu;Hong Ji
中科院分区：
文献类型：
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作者：
Renchao Xie;F. Yu;Hong Ji
具有协作通信功能的认知无线电网络可以有效提高频谱效率和数据速率。在该网络场景下，存在三种可能的传输模式：直接传输、多跳传输和协作通信。为了优化系统性能，需要仔细考虑三个问题：是否需要中继、使用哪个中继、选择哪个信道以及使用哪种传输模式。因此，在本研究中，作者共同解决这三个问题，以优化协作通信认知无线电网络的中断容量。他们特别强调不完善的信道感知情况。在这些设置和约束下，作者将中继确定、传输信道和相应传输模式选择的问题表述为最大化中断容量作为离散优化问题。然后提出一种离散随机优化算法，最大化中断容量，自适应地确定中继并选择最佳的传输信道和传输模式。该算法收敛速度快，计算复杂度低。此外，还考虑了时变无线电环境场景，结果表明该算法对时变无线电环境具有良好的跟踪能力。最后，给出了仿真结果来证明所提出方案的性能。
Cognitive radio networks with cooperative communications can effectively improve spectrum efficiency and data rate. Under this network scenario, there are three possible transmission modes: direct transmission, multi-hop transmission and cooperative communication. To optimise the system performance, three issues should be carefully considered: whether or not and which relay is needed, which channel is selected and which transmission mode is used. Therefore in this study, the authors solve these three problems jointly to optimise the outage capacity for cognitive radio networks with cooperative communications. Particularly, they emphasise on the imperfect channel sensing situation. Under these setup and the constraints, the authors formulate the problem of relay determination, transmission channel and corresponding transmission mode selection to maximise the outage capacity as a discrete optimisation problem. Then a discrete stochastic optimisation algorithm is proposed to maximise the outage capacity to adaptively determine relay and select the optimal transmission channel and transmission mode. The proposed algorithm has fast convergence rate and low computation complexity. Moreover, the time-varying radio environment scenario is also considered, and they show that the proposed algorithm has good tracking capability for time-varying radio environment. Finally, simulation results are presented to demonstrate the performance of proposed scheme.