中继信道中基于数字喷泉编码的功率分配策略

Fountain Codes Based Power Allocation for Wireless Relay Channels

引入渐近最优喷泉码的概念,在总功率受限的前提下,讨论无线中继信道的功率分配策略。首先,针对中继缓存有限并且期望提升系统吞吐量的情况,提出合理的排队模型,并据此导出最优功率分配系数的隐式方程。然后,利用数值分析方法,给出加性高斯白噪声信道和瑞利衰落信道下最优功率分配系数的数值解。最后,通过仿真观察并总结了数字喷泉编码下,无线中继信道在可达速率和二进制信噪比方面的性能。

The paper presents the power allocation strategy under the total power constraint in wireless relay channels,based on the asymptotical optimal fountain codes.Firstly,in order to prevent the relay from accumulating too many blocks and improve the overall throughput,we derive the equation about the optimal power allocation coefficient.Then,some numerical results of the coefficient are given under the Additive White Gaussian Noise channel and Rayleigh Fading channel.By simulation,we observe and analyze the optimal power allocation coefficient variation as the total power is varying.Finally,we discuss the achievable rate and bitwise signal-to-noise ratio of wireless relay channels.