瑞利信道的感知通信概率融合系统性能分析  

Performance Analysis of Sensing and Communication Probability Fusion System for Rayleigh Channels

作　　者：许欢 徐大专[1] 鞠美玉 XU Huan;XU Dazhuan;JU Meiyu(College of Electronic and Information Engineering,Nanjing University of Aeronautics&Astronautics,Nanjing 211106,China)

机构地区：[1]南京航空航天大学电子信息工程学院,南京211106

出　　处：《数据采集与处理》2025年第2期446-455,共10页Journal of Data Acquisition and Processing

基　　金：国家自然科学基金(62271254)。

摘　　要：本文给出了瑞利衰落信道感知通信一体化(Integrated sensing and communication,ISAC)系统模型,提出感知通信一体化概率融合(Probability fusion after integrated sensing and communication,PF‐ISAC)方法,推导出PF‐ISAC信道模型。从理论上证明,当感知信噪比(Signal to noise ratio,SNR)趋于无穷时,ISAC模型将退化为理想信道状态信息(Channel state information,CSI)的场景;当感知SNR趋于零时,ISAC模型将退化为CSI未知的场景。给出了PF‐ISAC系统的互信息与SNR的变化关系,随着SNR的增加,互信息从CSI未知时的信道容量逐渐逼近于理想CSI的容量。本文提出最大后验概率融合(Probability fusion after maximum a posteriori,PF‐MAP)检测方法、最大似然概率融合(Probability fusion after maximum likelihood,PF‐ML)检测方法,并与最小均方误差(Minimum mean square error,MMSE)估计‐MMSE检测(MMSE‐MMSE)方法进行比较,结果表明PF‐MAP在中低SNR时与MMSE‐MMSE性能相当,而在高SNR时,PF‐MAP优于MMSE‐MMSE;用熵误差(Entropy error,EE)评价PF‐ISAC系统的误差性能,结果表明MMSE‐MMSE、PF‐MAP、PF‐ML与理论性能极限EE均有较大差距。最后,给出感知和通信两阶段功率分配方案,当总功率给定时,感知和通信两阶段等功率分配,性能接近最佳。This article presents a Rayleigh fading channel model of integrated sensing and communication(ISAC),proposes a method of probability fusion after integrated sensing and communication(PF‐ISAC),and derives the PF‐ISAC channel model.It is theoretically proved that when the sensing signal to noise ratio(SNR)approaches infinity,the ISAC model degenerats into an ideal channel state information(CSI)scenario,and when the sensing SNR approaches zero,the ISAC model degenerats into a scenario where CSI is unknown.The relationship between mutual information and SNR of the PF‐ISAC system is given.As the SNR increases,the channel capacity of the mutual information gradually approaches the capacity of the ideal CSI when the CSI is unknown.This article proposes a probability fusion after maximum a posterior(PF‐MAP)detection method and a probability fusion after maximum likelihood(PF‐ML)detection method,and compares them with the minimum mean square error(MMSE)estimation‐MMSE detection method(MMSE‐MMSE).The results show that PF‐MAP performs similarly to MMSE‐MMSE at low to medium SNRs,while PF‐MAP outperforms MMSE‐MMSE at high SNRs.We evaluate the error performance of the PF‐ISAC system using entropy error(EE).Results show that MMSE‐MMSE,PF‐MAP,PF‐ML have significant gaps from the theoretical optimal performance EE.Finally,a scheme for power allocation in ISAC system is proposed.When the total power is given,the performance of two‐stage equal power allocation in ISAC system is close to optimal.

关 键 词：瑞利衰落信道 概率融合 互信息 信道估计 功率分配 

分 类 号：TN911[电子电信—通信与信息系统]