A global convergent algorithm is proposed to solve bilevel linear fractional-linear programming, which is a special class of bilevel programming. In our algorithm, replacing the lower level problem by its dual gap equ...A global convergent algorithm is proposed to solve bilevel linear fractional-linear programming, which is a special class of bilevel programming. In our algorithm, replacing the lower level problem by its dual gap equaling to zero, the bilevel linear fractional-linear programming is transformed into a traditional sin- gle level programming problem, which can be transformed into a series of linear fractional programming problem. Thus, the modi- fied convex simplex method is used to solve the infinite linear fractional programming to obtain the global convergent solution of the original bilevel linear fractional-linear programming. Finally, an example demonstrates the feasibility of the proposed algorithm.展开更多
通信感知一体化(Integrated Sensing and Communication,ISAC)系统可以将通信感知功能有机融合,以取得更高的频谱效率和硬件利用率,但传统的大规模集中式天线阵列在平面波假设下无法提供距离维增益,且其混合波束赋形设计为非凸优化问题...通信感知一体化(Integrated Sensing and Communication,ISAC)系统可以将通信感知功能有机融合,以取得更高的频谱效率和硬件利用率,但传统的大规模集中式天线阵列在平面波假设下无法提供距离维增益,且其混合波束赋形设计为非凸优化问题,仍是具有挑战性的难题。为此,提出了一种基于子阵列的混合波束赋形设计方案,在较低的硬件复杂度下通过扩展球面波区域范围提供距离维增益,以在满足感知性能约束和发射功率预算的前提下最大化通信速率。首先提出了一种基于分式规划和最优化最小化方法的算法,将非凸优化问题转化为凸问题后迭代求解得到一个联合波束赋形矩阵;进而提出一种基于流形优化和最小二乘法的算法,迭代求解后将其分解为数字/模拟波束赋形矩阵。仿真结果表明,基于子阵列的算法相较于集中式阵列能够获得更多的距离维信息和感知自由度,通信性能提升40%,且流形优化后混合波束赋形方案能够很好地逼近联合优化的数字波束赋形方案的性能。展开更多
提出同时将透射和反射可重构智能表面(Simultaneously transmitting and reflecting reconfigurable intelligent surfaces,STAR-RIS)与通信感知一体化(Integrated sensing and communication,ISAC)系统结合,以实现全空间的通信与感知...提出同时将透射和反射可重构智能表面(Simultaneously transmitting and reflecting reconfigurable intelligent surfaces,STAR-RIS)与通信感知一体化(Integrated sensing and communication,ISAC)系统结合,以实现全空间的通信与感知。同时在STAR-RIS上应用一种低成本的传感器实现了在STAR-RIS上进行目标感知,解决了雷达感知的严重路径损耗问题。基于此,本文研究了STAR-RIS辅助位于STAR-RIS两侧的多用户多输入单输出(Multi-usermulti-input single-output,MU-MISO)以及一个位于STAR-RIS透射侧的目标的ISAC系统,旨在联合优化STAR-RIS的被动波束成形矩阵和ISAC基站处的主动波束成形矩阵,以最大化用户的通信和速率,同时满足目标感知的最低信噪比要求。为了解决优化过程中的非凸问题,提出了一种基于分式规划的块坐标上升算法,将优化变量分为几个块变量交替优化。在迭代优化后续波束成形问题上,应用了连续凸逼近和半正定松弛算法。与传统的可重构智能表面相比,仿真结果验证了在ISAC系统中部署STAR-RIS的优点。同时将所提的基于分式规划的算法与基于加权最小均方误差的算法进行了对比并验证了所提算法在提高通信和速率上的优势和有效性。展开更多
基金supported by the National Natural Science Foundation of China(70771080)the Special Fund for Basic Scientific Research of Central Colleges+2 种基金China University of Geosciences(Wuhan) (CUG090113)the Research Foundation for Outstanding Young TeachersChina University of Geosciences(Wuhan)(CUGQNW0801)
文摘A global convergent algorithm is proposed to solve bilevel linear fractional-linear programming, which is a special class of bilevel programming. In our algorithm, replacing the lower level problem by its dual gap equaling to zero, the bilevel linear fractional-linear programming is transformed into a traditional sin- gle level programming problem, which can be transformed into a series of linear fractional programming problem. Thus, the modi- fied convex simplex method is used to solve the infinite linear fractional programming to obtain the global convergent solution of the original bilevel linear fractional-linear programming. Finally, an example demonstrates the feasibility of the proposed algorithm.
文摘通信感知一体化(Integrated Sensing and Communication,ISAC)系统可以将通信感知功能有机融合,以取得更高的频谱效率和硬件利用率,但传统的大规模集中式天线阵列在平面波假设下无法提供距离维增益,且其混合波束赋形设计为非凸优化问题,仍是具有挑战性的难题。为此,提出了一种基于子阵列的混合波束赋形设计方案,在较低的硬件复杂度下通过扩展球面波区域范围提供距离维增益,以在满足感知性能约束和发射功率预算的前提下最大化通信速率。首先提出了一种基于分式规划和最优化最小化方法的算法,将非凸优化问题转化为凸问题后迭代求解得到一个联合波束赋形矩阵;进而提出一种基于流形优化和最小二乘法的算法,迭代求解后将其分解为数字/模拟波束赋形矩阵。仿真结果表明,基于子阵列的算法相较于集中式阵列能够获得更多的距离维信息和感知自由度,通信性能提升40%,且流形优化后混合波束赋形方案能够很好地逼近联合优化的数字波束赋形方案的性能。
