IRS辅助的全双工通感一体化波束成形设计

IRS-assisted full-duplex ISAC system beamforming design

为了解决传统通感一体化(integrated sensing and communication,ISAC)场景中通信和感知系统收发信号的切换频率差异以及通信易受障碍物阻挡的问题,将全双工(full-duplex,FD)技术和智能反射面(intelligent reflecting surface,IRS)引入ISAC系统,研究ISAC场景下IRS辅助的FD波束成形设计。基于IRS相移约束、基站接收波束成形约束、基站最大发射功率约束、上行用户最大发射功率约束、雷达感知阈值约束,建立了上下行用户和速率最大化波束成形优化问题。利用交替优化、连续凸逼近、半正定松弛、变量替换、半正定规划将原非凸优化问题转换成凸优化问题进行求解。仿真结果表明,在所考虑的通信性能指标下,所提方案相比对应的半双工和随机IRS方案分别提升了89.02%和70.15%。

To address the issues of frequency switching differences between communication and sensing systems in traditional integrated sensing and communication(ISAC)scenarios,as well as the susceptibility of communication to obstruction by obstacles,the integration of full-duplex(FD)technology and intelligent reflecting surface(IRS)into the ISAC system was studied.The design of FD beamforming assisted by IRS in the ISAC scenario was investigated.An optimization problem for maximizing the user rates of uplink and downlink beamforming was formulated,considering constraints on IRS phase shift,base station receiving beamforming,the maximum transmission power of the base station,the maximum transmission power of uplink users,and the radar sensing threshold.The original nonconvex problem was solved by being transformed into a convex optimization problem through the use of alternating optimization,continuous convex approximation,semi-definite relaxation,variable substitution,and semi-definite programming.Simulation results show that the proposed scheme resulted in an 89.02%enhancement under the communication performance indicators considered compared to the corresponding half-duplex scheme and a 70.15%improvement over the random IRS scheme.