Cooperative wireless multicast: performance analysis and power/location optimization
Cooperative wireless multicast: performance analysis and power/location optimization
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DOI：
10.1109/twc.2010.06.091423
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发表时间：
2010-06
影响因子：
10.4
通讯作者：
H. V. Zhao;Weifeng Su
中科院分区：
文献类型：
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作者：
H. V. Zhao;Weifeng Su
无线网络中多媒体多播/广播应用的普及使得解决无线信道的易出错、异构和动态变化的特性变得至关重要。一个很有前途的解决方案，以对抗信道衰落是探索合作分集，用户可以帮助彼此转发数据包。本文研究了利用最大比合并器提高接收信噪比的协作组播方案，并给出了全面的性能分析。两个中继选择方案被认为是：分布式和精灵辅助合作计划。我们推导了它们的平均中断概率的近似表达式，并分析了最优功率分配和中继位置策略，证明了将总传输功率的一半分配给源可以最小化平均中断概率。我们的分析和仿真结果表明，合作组播提供更好的性能时，更多的中继帮助转发信号。协作多播有助于实现2阶分集，用户协作可以显著降低中断概率，特别是在高信噪比区域。最后，我们比较了这两种合作策略，并表明，分布式合作组播是首选，因为它实现了较低的中断概率，而不引入额外的开销控制消息。
The popularity of multimedia multicast/broadcast applications over wireless networks makes it critical to address the error-prone, heterogeneous and dynamically changing nature of wireless channels. A promising solution to combat channel fading is to explore the cooperative diversity in which users may help each other forward packets. This paper investigates cooperative multicast schemes that use a maximal ratio combiner to enhance the received signal-to-noise ratio (SNR), and provides a thorough performance analysis. Two relay selection schemes are considered: the distributed and the genie-aided cooperation schemes. We derive the closed-form formulation and the approximations of their average outage probabilities.We also analyze the optimal power allocation and relay location strategies, and show that allocating half of the total transmission power to the source minimizes the average outage probability. Our analysis and simulation results show that cooperative multicast gives better performance when more relays help forward signals. Cooperative multicast helps achieve diversity order 2, and user cooperation can significantly reduce the outage probability, especially in the high SNR region. Finally, we compare the two cooperation strategies, and show that distributed cooperative multicast is preferred since it achieves a lower outage probability without introducing extra overhead for control messages.