摘要
下一代移动通信系统对更高数据传输速率的需求异常迫切。针对双向正交频分复用(orthogonal frequency division multiplexing,OFDM)中继网络,由于现有的逐载波中继策略会遭受显著的速率损失,该文提出一种多载波译码转发中继策略来改善其性能,并且通过最大化加权和速率(加权因子取决于用户数据缓冲的队列长度),建立起最优功率分配(凸)问题刻画该策略所对应的可达速率域。设计出一种基于对偶优化理论的高效算法来实现功率分配,其运算复杂度仅与子载波数目成线性关系,远远低于求解凸优化问题的传统内点法的复杂度。仿真结果表明,该多载波中继策略明显扩展了现有的逐载波中继策略的可达速率域。
Higher data rates will be needed in the next generation of mobile communication systems. This paper presents a multi-subcarrier decode-and-forward relay strategy that reduces data loss in per-subcarrier relay strategies for two-way orthogonal frequency division multiplexing （OFDM） relay networks. This paper also presents an optimal （convex） power allocation problem that characterizes the achievable rate region for the relay strategy that maximizes the weighted sum rate, where the weight factors depend on the queue lengths of the user data buffers. An efficient duality-based algorithm is developed to solve this power allocation problem. The computational complexity of this algorithm is only linear with respect to the number of subcarriers, which is much lower than that of conventional interior-point methods for solving convex optimization problems. Numerical results show that the strategy substantially enlarges the achievable rate region over existing per-subcarrier relay strategies.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第10期1503-1508,共6页
Journal of Tsinghua University(Science and Technology)
基金
国家科技重大专项(2011ZX03004-004)
国家"九七三"重点基础研究发展计划(2012CB316000)
国家自然科学基金创新研究群体项目(61021001)
国家"八六三"高技术项目(2012AA011402)
清华大学自主科研项目(2010THZ02-3)
爱立信合作项目(20123000059)
关键词
移动通信
双向中继
正交频分复用(OFDM)
功率分配
mobile communication two-way relay
orthogonal frequency division multiplexing （OFDM）
power allocation
