针对多用户多目标通感服务的全空间覆盖问题,研究了有源同时传输和反射可重构智能表面(Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface,STAR-RIS)辅助的通信感知一体化(Integrated Sensing and Commun...针对多用户多目标通感服务的全空间覆盖问题,研究了有源同时传输和反射可重构智能表面(Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface,STAR-RIS)辅助的通信感知一体化(Integrated Sensing and Communication,ISAC)系统。不同于已有研究工作,本方案建模优化了有源STAR-RIS的幅度参数。在满足各通信用户的信干噪比、各感知目标的照射波束增益以及有源STAR-RIS的硬件约束等条件下,以系统总功率最小化为准则,建模ISAC基站发射波束赋形矢量和有源STAR-RIS相移/幅度等关键参数的联合优化设计问题。为快速解决该复杂的非凸联合优化设计问题,首先将其分解为ISAC基站发射波束赋形设计、有源STAR-RIS元件相移参数设计和幅度参数优化这3个子问题,然后采取块坐标下降策略,迭代求解获取最优解。仿真结果显示,相比于已有方案,本方案提出的联合优化设计算法有效降低了系统总功率30%,能取得复杂度和通信感知性能的良好折中。展开更多
The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-inpu...The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-input multiple-output(MIMO)communication system with a STAR-RIS,a base station(BS),an eavesdropper,and multiple users,the system security rate is studied.A joint design of the power allocation at the transmitter and phase shift matrices for reflection and transmission at the STAR-RIS is conducted,in order to maximize the worst achievable security data rate(ASDR).Since the problem is nonconvex and hence challenging,a particle swarm optimization(PSO)based algorithm is developed to tackle the problem.Both the cases of continuous and discrete phase shift matrices at the STAR-RIS are considered.Simulation results demonstrate the effectiveness of the proposed algorithm and shows the benefits of using STAR-RIS in MIMO mutliuser systems.展开更多
为解决车辆与基站之间通信链路受阻和通信可靠性问题,本文研究同时传输和反射可重构智能表面(Simultaneous Transmitting and Reflecting Reconfigurable Intelligent Surfaces, STAR-RIS)辅助的车辆通信,考虑速率分割多址接入(Rate-Spl...为解决车辆与基站之间通信链路受阻和通信可靠性问题,本文研究同时传输和反射可重构智能表面(Simultaneous Transmitting and Reflecting Reconfigurable Intelligent Surfaces, STAR-RIS)辅助的车辆通信,考虑速率分割多址接入(Rate-Splitting Multiple Access, RSMA),并结合混合自动重传(Hybrid Automatic Repeat reQuest, HARQ)技术,分析系统性能。通过信道近似分布推导HARQ传输协议下车辆用户的中断概率,根据中断概率表达式进一步分析吞吐量和能量效率,推导出吞吐量和能量效率的闭式表达式。最后,借助MATLAB平台进行数值模拟,验证了理论分析的正确性。结果表明,通过对比不同STAR-RIS元件个数、基站发射功率和HARQ最大重传次数下的系统性能,发现采用HARQ的系统性能优于不采用HARQ的系统,且分配更多功率的车辆用户性能更优。To solve the problems of communication link obstruction and communication reliability between vehicles and base stations, this paper studies vehicle communication assisted by Simultaneous Transmitting and Reflecting Reconfigurable Intelligent Surfaces (STAR-RIS), considers Rate Splitting Multiple Access (RSMA) and combines Hybrid Automatic Repeat reQuest (HARQ) technology to analyze system performance. The outage probability of vehicle users under the HARQ transmission protocol is deduced from channel approximation distribution, throughput and energy efficiency are further analyzed based on the outage probability expression, and closed-form expressions for throughput and energy efficiency are derived. Finally, numerical simulations are conducted using the MATLAB platform to verify the correctness of the theoretical analysis. The results show that by comparing the system performance under different numbers of STAR-RIS elements, base station transmission power, and maximum HARQ retransmission times, it is found that the system performance using HARQ is better than that without HARQ, and the performance of vehicle users who allocate more power is better.展开更多
The simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)is regarded as a promising paradigm for enhancing the connectivity and reliability of non-orthogonal multiple access(NOMA)netw...The simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)is regarded as a promising paradigm for enhancing the connectivity and reliability of non-orthogonal multiple access(NOMA)networks.However,the transmission of STAR-RIS enhanced NOMA networks performance is severely limited due to the inter-user interference(IUI)on multi-user detections.To mitigate this drawback,we propose a generalized quadrature spatial modulation(GQSM)aided STAR-RIS in conjunction with the NOMA scheme,termed STARRIS-NOMA-GQSM,to improve the performance of the corresponding NGMA network.By STAR-RISNOMA-GQSM,the information bits for all users in transmission and reflection zones are transmitted via orthogonal signal domains to eliminate the IUI so as to greatly improve the system performance.The lowcomplexity detection and upper-bounded bit error rate(BER)of STAR-RIS-NOMA-GQSM are both studied to evaluate its feasibility and performance.Moreover,by further utilizing index modulation(IM),we propose an enhanced STAR-RIS-NOMA-GQSM scheme,termed E-STAR-RIS-NOMA-GQSM,to enhance the transmission rate by dynamically adjusting reflection patterns in both transmission and reflection zones.Simulation results show that the proposed original and enhanced scheme significantly outperform the conventional STAR-RIS-NOMA and also confirm the precision of the theoretical analysis of the upper-bounded BER.展开更多
A simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)aided integrated sensing and communication(ISAC)dual-secure communication system is studied in this paper.The sensed target and le...A simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)aided integrated sensing and communication(ISAC)dual-secure communication system is studied in this paper.The sensed target and legitimate users(LUs)are situated on the opposite sides of the STAR-RIS,and the energy splitting and time switching protocols are applied in the STAR-RIS,respectively.The long-term average security rate for LUs is maximized by the joint design of the base station(BS)transmit beamforming and receive filter,along with the STAR-RIS transmitting and reflecting coefficients,under guarantying the echo signal-to-noise ratio thresholds and rate constraints for the LUs.Since the channel information changes over time,conventional convex optimization techniques cannot provide the optimal performance for the system,and result in excessively high computational complexity in the exploration of the long-term gains for the system.Taking continuity control decisions into account,the deep deterministic policy gradient and soft actor-critic algorithms based on off-policy are applied to address the complex non-convex problem.Simulation results comprehensively evaluate the performance of the proposed two reinforcement learning algorithms and demonstrate that STAR-RIS is remarkably better than the two benchmarks in the ISAC system.展开更多
A simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)assisted multiuser near-field wideband communication system is investigated,in which a robust deep reinforcement learning(DRL)ba...A simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)assisted multiuser near-field wideband communication system is investigated,in which a robust deep reinforcement learning(DRL)based algorithm is proposed to enhance the users’achievable rate by jointly optimizing the active beamforming at the base station(BS)and passive beamforming at the STAR-RIS.To mitigate the beam split issue,the delay-phase hybrid precoding structure is introduced to facilitate wideband beamforming.Considering the coupled nature of the STARRIS phase-shift model,the passive beamforming design is formulated as a problem of hybrid continuous and discrete phase-shift control,and the proposed algorithm controls the high-dimensional continuous action through hybrid action mapping.Additionally,to address the issue of biased estimation encountered by existing DRL algorithms,a softmax operator is introduced into the algorithm to mitigate this bias.Simulation results illustrate that the proposed algorithm outperforms existing algorithms and overcomes the issues of overestimation and underestimation.展开更多
文摘针对多用户多目标通感服务的全空间覆盖问题,研究了有源同时传输和反射可重构智能表面(Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface,STAR-RIS)辅助的通信感知一体化(Integrated Sensing and Communication,ISAC)系统。不同于已有研究工作,本方案建模优化了有源STAR-RIS的幅度参数。在满足各通信用户的信干噪比、各感知目标的照射波束增益以及有源STAR-RIS的硬件约束等条件下,以系统总功率最小化为准则,建模ISAC基站发射波束赋形矢量和有源STAR-RIS相移/幅度等关键参数的联合优化设计问题。为快速解决该复杂的非凸联合优化设计问题,首先将其分解为ISAC基站发射波束赋形设计、有源STAR-RIS元件相移参数设计和幅度参数优化这3个子问题,然后采取块坐标下降策略,迭代求解获取最优解。仿真结果显示,相比于已有方案,本方案提出的联合优化设计算法有效降低了系统总功率30%,能取得复杂度和通信感知性能的良好折中。
文摘The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-input multiple-output(MIMO)communication system with a STAR-RIS,a base station(BS),an eavesdropper,and multiple users,the system security rate is studied.A joint design of the power allocation at the transmitter and phase shift matrices for reflection and transmission at the STAR-RIS is conducted,in order to maximize the worst achievable security data rate(ASDR).Since the problem is nonconvex and hence challenging,a particle swarm optimization(PSO)based algorithm is developed to tackle the problem.Both the cases of continuous and discrete phase shift matrices at the STAR-RIS are considered.Simulation results demonstrate the effectiveness of the proposed algorithm and shows the benefits of using STAR-RIS in MIMO mutliuser systems.
文摘为解决车辆与基站之间通信链路受阻和通信可靠性问题,本文研究同时传输和反射可重构智能表面(Simultaneous Transmitting and Reflecting Reconfigurable Intelligent Surfaces, STAR-RIS)辅助的车辆通信,考虑速率分割多址接入(Rate-Splitting Multiple Access, RSMA),并结合混合自动重传(Hybrid Automatic Repeat reQuest, HARQ)技术,分析系统性能。通过信道近似分布推导HARQ传输协议下车辆用户的中断概率,根据中断概率表达式进一步分析吞吐量和能量效率,推导出吞吐量和能量效率的闭式表达式。最后,借助MATLAB平台进行数值模拟,验证了理论分析的正确性。结果表明,通过对比不同STAR-RIS元件个数、基站发射功率和HARQ最大重传次数下的系统性能,发现采用HARQ的系统性能优于不采用HARQ的系统,且分配更多功率的车辆用户性能更优。To solve the problems of communication link obstruction and communication reliability between vehicles and base stations, this paper studies vehicle communication assisted by Simultaneous Transmitting and Reflecting Reconfigurable Intelligent Surfaces (STAR-RIS), considers Rate Splitting Multiple Access (RSMA) and combines Hybrid Automatic Repeat reQuest (HARQ) technology to analyze system performance. The outage probability of vehicle users under the HARQ transmission protocol is deduced from channel approximation distribution, throughput and energy efficiency are further analyzed based on the outage probability expression, and closed-form expressions for throughput and energy efficiency are derived. Finally, numerical simulations are conducted using the MATLAB platform to verify the correctness of the theoretical analysis. The results show that by comparing the system performance under different numbers of STAR-RIS elements, base station transmission power, and maximum HARQ retransmission times, it is found that the system performance using HARQ is better than that without HARQ, and the performance of vehicle users who allocate more power is better.
基金supported in part by Guangdong Basic and Applied Basic Research Foundation under Grants 2023A1515030118 and 2024A1515010012in part by the Guangzhou Science and Technology Project under Grant 2023A03J0110+3 种基金in part by Guangzhou Basic Research Program Municipal School(College)Joint Funding Project under Grant 2025A03J3119in part by National Natural Science Foundation of China under Grant 62173101in part by the Key Discipline Project of Guangzhou Education Bureau under Grant 202255467in part by the Key Laboratory of on-Chip Communication and Sensor Chip of Guangdong Higher Education Institutes under Grant 2023KSYS002。
文摘The simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)is regarded as a promising paradigm for enhancing the connectivity and reliability of non-orthogonal multiple access(NOMA)networks.However,the transmission of STAR-RIS enhanced NOMA networks performance is severely limited due to the inter-user interference(IUI)on multi-user detections.To mitigate this drawback,we propose a generalized quadrature spatial modulation(GQSM)aided STAR-RIS in conjunction with the NOMA scheme,termed STARRIS-NOMA-GQSM,to improve the performance of the corresponding NGMA network.By STAR-RISNOMA-GQSM,the information bits for all users in transmission and reflection zones are transmitted via orthogonal signal domains to eliminate the IUI so as to greatly improve the system performance.The lowcomplexity detection and upper-bounded bit error rate(BER)of STAR-RIS-NOMA-GQSM are both studied to evaluate its feasibility and performance.Moreover,by further utilizing index modulation(IM),we propose an enhanced STAR-RIS-NOMA-GQSM scheme,termed E-STAR-RIS-NOMA-GQSM,to enhance the transmission rate by dynamically adjusting reflection patterns in both transmission and reflection zones.Simulation results show that the proposed original and enhanced scheme significantly outperform the conventional STAR-RIS-NOMA and also confirm the precision of the theoretical analysis of the upper-bounded BER.
文摘A simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)aided integrated sensing and communication(ISAC)dual-secure communication system is studied in this paper.The sensed target and legitimate users(LUs)are situated on the opposite sides of the STAR-RIS,and the energy splitting and time switching protocols are applied in the STAR-RIS,respectively.The long-term average security rate for LUs is maximized by the joint design of the base station(BS)transmit beamforming and receive filter,along with the STAR-RIS transmitting and reflecting coefficients,under guarantying the echo signal-to-noise ratio thresholds and rate constraints for the LUs.Since the channel information changes over time,conventional convex optimization techniques cannot provide the optimal performance for the system,and result in excessively high computational complexity in the exploration of the long-term gains for the system.Taking continuity control decisions into account,the deep deterministic policy gradient and soft actor-critic algorithms based on off-policy are applied to address the complex non-convex problem.Simulation results comprehensively evaluate the performance of the proposed two reinforcement learning algorithms and demonstrate that STAR-RIS is remarkably better than the two benchmarks in the ISAC system.
基金Project supported by the National Natural Science Foundation of China(Nos.62101205 and 62101308)the Key Research and Development Program of Hubei Province,China(No.2023BAB061)。
文摘A simultaneously transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)assisted multiuser near-field wideband communication system is investigated,in which a robust deep reinforcement learning(DRL)based algorithm is proposed to enhance the users’achievable rate by jointly optimizing the active beamforming at the base station(BS)and passive beamforming at the STAR-RIS.To mitigate the beam split issue,the delay-phase hybrid precoding structure is introduced to facilitate wideband beamforming.Considering the coupled nature of the STARRIS phase-shift model,the passive beamforming design is formulated as a problem of hybrid continuous and discrete phase-shift control,and the proposed algorithm controls the high-dimensional continuous action through hybrid action mapping.Additionally,to address the issue of biased estimation encountered by existing DRL algorithms,a softmax operator is introduced into the algorithm to mitigate this bias.Simulation results illustrate that the proposed algorithm outperforms existing algorithms and overcomes the issues of overestimation and underestimation.
