Channel Capacity Limits of Cognitive Radio in Asymmetric Fading Environments
Channel Capacity Limits of Cognitive Radio in Asymmetric Fading Environments
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DOI：
10.1109/icc.2008.760
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发表时间：
2008-05
期刊：
影响因子：
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通讯作者：
H. Suraweera;Jason H. Gao;Peter J. Smith;M. Shafi;M. Faulkner
中科院分区：
文献类型：
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作者：
H. Suraweera;Jason H. Gao;Peter J. Smith;M. Shafi;M. Faulkner
认知无线电技术是一种创新的无线电设计理念，旨在通过在动态变化的环境中利用未使用的频谱来提高频谱利用率。通过扩展以前的结果，我们调查的容量增益与这种动态频谱的方法在非对称衰落信道。更具体地说，我们允许次级到初级和次级到次级用户信道经历瑞利或莱斯衰落，具有任意链路功率。为了计算容量，我们推导了瑞利变量和莱斯变量的比值分布。对称衰落的情况下相比，我们的研究结果表明，在平均和峰值接收功率约束下的容量行为的几个有趣的功能。最后，研究了非对称衰落下多主用户对系统容量的影响。
Cognitive radio technology is an innovative radio design concept which aims to increase spectrum utilization by exploiting unused spectrum in dynamically changing environments. By extending previous results, we investigate the capacity gains achievable with this dynamic spectrum approach in asymmetric fading channels. More specifically, we allow the secondary-to- primary and secondary-to-secondary user channels to undergo Rayleigh or Rician fading, with arbitrary link power. In order to compute the capacity, we derive the distributions of ratios of Rayleigh and Rician variables. Compared to the symmetric fading scenario, our results indicate several interesting features of the capacity behaviour under both average and peak received power constraints. Finally, the impact of multiple primary users on the capacity under asymmetric fading has also been studied.