In this paper, we investigate the outage performance of dual-hop multiuser multi-relay cognitive radio networks under spectrum sharing constraints. Using an efficient relay-destination selection scheme, the exact and asymptotic closed-form expressions for the outage probability are derived. From these expressions it is indicated that the achieved diversity order is only determined by the number of secondary user (SU) relays and destinations, and equals to M+N (where M and N are the number of destination nodes and relay nodes, respectively). Further, we find that the coding gain of the SU network will be affected by the interference threshold $bar I$ at the primary user (PU) receiver. Specifically, as the increases of the interference threshold, the coding gain of the considered network approaches to that of the multiuser multi-relay system in the non-cognitive network. Finally, our study is corroborated by representative numerical examples.
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机译:在本文中,我们研究了在频谱共享约束下双跳多用户多中继认知无线电网络的中断性能。使用有效的中继目的地选择方案,可以得出中断概率的精确和渐近闭式表达式。从这些表达式可以看出,实现的分集顺序仅由辅助用户(SU)中继和目的地的数量确定,并且等于M + N(其中M和N分别是目的地节点和中继节点的数量) 。此外,我们发现SU网络的编码增益将受到主要用户(PU)接收器的干扰阈值$ bar I $的影响。具体地,随着干扰阈值的增加,所考虑的网络的编码增益接近非认知网络中的多用户多中继系统的编码增益。最后,我们的研究得到了具有代表性的数值实例的证实。
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