Distributed Adaptive Power Allocation for Wireless Relay Networks
Distributed Adaptive Power Allocation for Wireless Relay Networks
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DOI：
10.1109/twc.2007.05256
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发表时间：
2007-03
影响因子：
10.4
通讯作者：
Yonghui Li;B. Vucetic;Zhendong Zhou;M. Dohler
中科院分区：
文献类型：
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作者：
Yonghui Li;B. Vucetic;Zhendong Zhou;M. Dohler
在本文中，我们考虑一个2跳无线分集中继网络。我们探讨的源和中继之间的发送功率分配，以最大限度地提高接收信号的信噪比（SNR）在目的地。我们考虑两个中继协议，“放大和转发”（AAF）和“解码和转发”（EAF），并设计各自的功率分配的非编码和编码系统。对于一个中继节点的两跳中继系统，我们推导出一个封闭形式的功率分配解决方案，并在此基础上，我们提出了一个中继激活条件。当且仅当衰落信道系数满足该条件时，中继站将信号发送到目的地;否则，中继站将保持空闲状态。对于一个系统有一个以上的中继节点，一般封闭形式的功率分配解决方案的基础上，一个确切的SNR表达式是很难得到的，因此，我们计算的SNR上限，并得出一个次优功率分配解决方案的基础上，这个界限。仿真结果表明，对于一个中继节点的2跳分集中继信道，与等功率分配相比，自适应功率分配（阿帕）方案可获得约1 ~ 2 dB的信噪比增益。该SNR增益随着中继数目的增加而单调增加
In this paper, we consider a 2-hop wireless diversity relay network. We explore transmit power allocation among the source and relays to maximize the received signal to noise ratio (SNR) at the destination. We consider two relay protocols, "amplify and forward" (AAF) and "decode and forward" (DAF) and design the respective power allocations for both uneeded and coded systems. For a 2-hop relay system with one relay node, we derive a closed-form power allocation solution and, based on it, we propose a relay activation condition. If and only if the fading channel coefficients satisfy this condition, the relay transmits the signals to the destination; otherwise, the relay will stay in the idle state. For a system with more than one relay node, general closed-form power allocation solutions based on an exact SNR expression are difficult to derive; we hence, calculate a SNR upper bound and derive a sub-optimum power allocation solution based on this bound. The simulation results show that for a 2-hop diversity relay channel with one relay node the proposed adaptive power allocation (APA) scheme yields about 1- 2 dB SNR gains compared to the equal power allocation. This SNR gain increases monotonically as the number of relays increases