Power Allocation Strategies for Fixed-Gain Half-Duplex Amplify-and-Forward Relaying in Nakagami-m Fading
Power Allocation Strategies for Fixed-Gain Half-Duplex Amplify-and-Forward Relaying in Nakagami-m Fading
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DOI：
10.1109/twc.2013.120113.121944
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发表时间：
2012-11
影响因子：
10.4
通讯作者：
Ammar Zafar;R. Radaydeh;Yunfei Chen;Mohamed-Slim Alouini
中科院分区：
文献类型：
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作者：
Ammar Zafar;R. Radaydeh;Yunfei Chen;Mohamed-Slim Alouini
本文研究了采用多中继器的固定增益放大转发中继网的功率分配策略。我们考虑了两个中继网的优化问题：1)最大化端到端信噪比(SNR)；2)在保持端到端信噪比超过阈值的情况下最小化总功率消耗。我们针对全参与(AP)中继和选择性中继这两种中继协议以及向中继反馈的两种情况，即完全和有限两种情况，研究了这两个问题。我们证明了对于所有协议和反馈情况，信噪比最大化问题是凹的，而功率最小化问题是凸的。在完全反馈的情况下，我们得到了这两个问题的闭式表达式，并利用有限反馈的凸规划进行了求解。数值结果表明，对于这两个优化问题，在中继器具有完全反馈的好处。然而，它们也表明，只对继电器进行有限的反馈可以减少反馈开销，而性能只会有很小的下降。
In this paper, we study power allocation strategies for a fixed-gain amplify-and-forward relay network employing multiple relays. We consider two optimization problems for the relay network: 1) maximizing the end-to-end signal-to-noise ratio (SNR) and 2) minimizing the total power consumption while maintaining the end-to-end SNR over a threshold value. We investigate these two problems for two relaying protocols of all-participate (AP) relaying and selective relaying and two cases of feedback to the relays, namely full and limited. We show that the SNR maximization problem is concave and that the power minimization problem is convex for all protocols and feedback cases considered. We obtain closed-form expressions for the two problems in the case of full feedback and solve the problems through convex programming for limited feedback. Numerical results show the benefit of having full feedback at the relays for both optimization problems. However, they also show that feedback overhead can be reduced by having only limited feedback to the relays with only a small degradation in performance.