【摘要】 该文将各分布式天线簇内的天线单元相关性纳入考虑,且在仅可获得包含发送端大尺度信道状态信息和发送天线单元相关特性的慢变信道统计特性的条件下,研究多小区分布式天线系统(distributed antenna system,DAS)的高能效协同传输问题,通过小区间协同优化输入协方差矩阵,使系统能效最大化。该优化问题为复杂的非凸问题,故难以求解。通过连续Taylor展开方法,使原问题转化成系列拟凸分式规划子问题,然后通过分式规划方法将其进一步转化成易处理的等价凸问题。据此,提供一种原优化问题的迭代法求解方案。仿真结果验证:相比已有方案,该方案改善了系统的能效水平。更多还原

【Abstract】 The energy efficiency of coordinated transmissions in multi-cell distributed antenna systems(DAS)was analyzed with a focus on the antenna element correlation within each distributed antenna cluster to maximize the system energy efficiency through inter-cell coordinated optimization of the input covariance matrices.The system uses only the slowly varying channel statistics including the large-scale channel state information at the transmitter and the transmit antenna element correlation characteristics. The optimization problem is non-convex and,therefore,is hard to solve.The method of successive Taylor expansions was used to recast the problem into a succession of quasi-convex fractional optimization sub-problems,which were then further converted to tractable equivalent convex forms via the fractional programming approach.An iterative scheme was then used to address the original optimization problem.Simulations show that this scheme provides improved system energy efficiencies compared to existing schemes.更多还原