The radio spectrum of communication systems is largely occupied by wideband technologies, and thus, efficient usage of spectrum is a crucial requirement from regulators' and service providers' perspectives. Cognitive communication has been proposed as a potential solution to resolve the spectrum scarcity problem. Cognitive radio schemes can be jointly applied with cooperative communications to improve the performance under both overlay and underlay strategies as the two main cognitive strategies supported by multiple relays. This combination significantly improves the reliability and capacity of data communication. In this paper, two QoS parameters, namely, the effective capacity and outage probability, have been thoroughly analyzed in a Nakagami‐m fading channel that is the typical channel condition often considered in the transmission of communication systems. Closed‐form expressions are obtained for effective capacity and outage probability in both underlay and overlay strategies. Simulation results verify the effectiveness of the mathematical modelling of the proposed QoS parameters.

中文翻译：

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Nakagamim和瑞利衰落信道中多中继认知通信系统的有效容量和中断概率评估

通信系统的无线电频谱在很大程度上被宽带技术所占据，因此，从监管机构和服务提供商的角度来看，频谱的有效利用是至关重要的要求。已经提出认知通信作为解决频谱短缺问题的潜在解决方案。认知无线电方案可以与协作通信一起应用，以提高作为覆盖多个中继的两种主要认知策略的覆盖策略和底层策略的性能。这种结合大大提高了数据通信的可靠性和容量。在本文中，两个QoS参数，即有效容量和中断概率，已经在Nakagamim衰落信道中进行了彻底分析，这是通信系统传输中经常考虑的典型信道条件。在底层策略和叠加策略中均可获得有效容量和中断概率的闭式表达式。仿真结果验证了所提出的QoS参数的数学建模的有效性。