基于OFDM信号的联合环境感知和数据解调方法  

Joint Environmental Sensing and Data Demodulation Using OFDM Signals

作　　者：余昭逸 梁天豪 张霆廷 YU Zhaoyi;LIANG Tianhao;ZHANG Tingting(School of Electronics and Information Engineering,Harbin Institute of Technology,Shenzhen,Guangdong 518055,China)

机构地区：[1]哈尔滨工业大学(深圳)电子与信息工程学院,广东深圳518055

出　　处：《信号处理》2023年第6期1006-1015,共10页Journal of Signal Processing

基　　金：国家自然科学基金“基于数据包预测控制框架的智能车辆协同调度机理研究”(62171160)。

摘　　要：在下一代无线通信网络中,通信感知一体化(Integrated Sensing and Communications, ISAC)通过频谱共享、硬件共享、信号共享等方式实现感知与通信的融合,从而在进行信息传递的同时,感知环境中的物体的方位角度、距离、速度等信息。为进一步提高资源利用率和一体化系统集成度,一体化信号设计和信号处理成为了ISAC的主要任务之一。作为信号处理中的一项基本流程,信道估计是高速数据传输和波束成形的先决条件,也是环境感知和参数估计的基础,因此准确的信道估计结果对感知和数据传输都至关重要。本文针对基于正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)信号在动态场景下的高导频开销问题,设计并实现了一种高效的时变信道估计与解调方案,并将其运用到通信感知一体化系统中。首先,本文设计了一种无导频的OFDM信号作为ISAC信号,仅依靠较短的前导码获取合适的初始信道估计值;接着提出了联合时变信道估计与数据解调的迭代算法,旨在利用数据辅助信道估计;最后,为了进一步提高动态场景下的信道估计精度,本文提出了一种鲁棒的基于卡尔曼滤波技术的数据辅助的时变信道跟踪算法。仿真表明本文设计的联合信号处理算法能在降低导频开销的同时,仅仅使用几次迭代就能显著提升时变信道估计和数据解调性能;本文还通过蒙特卡洛实验统计了所提方案的最大有效频谱效率,结果表明本文所提方法相比较传统能提高在高动态场景下的效率、鲁棒性和实用性;最后,本文还通过数值实验验证在多径环境中的目标感知功能,表明了本文的一体化信号适用于感知通信一体化系统,且本文设计的算法能提升通信和感知性能。In next-generation wireless communication networks,the Integrated Sensing and Communications(ISAC)are regarded as a paradigm shift for improving resource utilization.ISAC achieves the integration of sensing and communication through spectrum sharing,hardware sharing,and signal sharing,so as to obtain the orientation,distance,speed,and other state information of target objects while conducting the information transmission.Recently,with the development of communication technologies,ISAC holds great potential in many spectrum and cost limited scenarios by realizing dual/multiple functions besides communication,such as autonomous vehicles networking,collaborative sensing,etc.In order to further improve resource utilization and system integration,integrated waveform design and signal processing becomes one of the main tasks of ISAC.As a fundamental process of signal processing,channel estimation is regarded as a basic ISAC process,which is prerequisite for beamforming,precoding and high-quality data transmission,as well as a mathematical basis for environment sensing and parameter estimation.Therefore,accurate channel estimation plays an important role for both data transition and environmental sensing.However,a large number of polit is required in OFDM-based system to estimate the channel,which results in a low spectrum efficiency,especially in dynamic scenarios.In order to solve this problem,an efficient joint channel sensing and data demodulation scheme based on OFDM signals is designed and implemented in this paper.First,an OFDM-based ISAC signal without periodic pilots is designed,after that,an iterative algorithm for joint channel estimation and data detection is proposed,reconstructing the sensing signal using data.Finally,in order to further improve the channel estimation accuracy in high dynamic scenarios,a data-assisted time-varying channel tracking algorithm based on Kalman filtering technique is designed.Simulation results show that the proposed algorithm can improve the performance of channel estimation a

关 键 词：通信感知一体化 一体化信号设计 数据辅助的信道估计 时变信道跟踪 

分 类 号：TN911.7[电子电信—通信与信息系统]