AF-OFDM非对称通信双向中继系统能效优化

针对具有非对称通信需求的单中继协同放大转发正交频分复用(amplify forward orthogonal frequency division multiplexing,AF-OFDM)双向中继系统,提出一种中继能效优化策略。在AF-OFDM双向非对称中继通信系统中,子载波有两种工作模式:单向中继传输和双向中继传输。以系统能效为优化目标,构建联合中继传输模式选择、功率分配和比特加载组合优化模型;采用结构近似优化算法,首先固定子载波分配集合,优化单向中继传输和双向中继传输的功率分配,将原优化问题分解为两个子优化问题求解,然后优化子载波分配集合,利用子载波配对形成的线性结构搜索双向中继传输的最佳子载波数,避免穷举搜索造成的大运算量。仿真结果表明,该能效优化策略能有效提高AF-OFDM双向非对称中继通信系统的能量效率。

Energy-efficiency optimization strategy for AF-OFDM two-way relaying system with asymmetric traffic

The energy-efficiency optimization strategy is studied for the amplify forward orthogonal frequency division multiplexing (AF-OFDM) two-way relaying system with asymmetric traffic demand. Subcarrier has two working modes: one-way relaying transmission and two-way relaying transmission. Taking the system energy-efficiency as the optimization objective, a combination optimization model of joint relaying transmission mode selection, power allocation and bit loading is structured. Firstly, fix the subcarrier allocation set, decompose the original optimization problem into two suboptimization problems, optimize power allocation of the one-way relaying transmission and two-way relaying transmission. Then, the optimal subcarrier number of the two-way relaying transmission is searched by using the linear structure formed by the subcarrier pairing, and optimize the subcarrier allocation set. Simulation results show that the proposed strategy can improve the energy-efficiency of the AF-OFDM two-way relaying system with asymmetric traffic.