面对高速移动场景的OTFS系统导频设计方法  

Pilot Design Method for OTFS System in High-Speed Mobile Scenarios

作　　者：李一兵[1] 汤云鹤 简鑫 孙骞 陈浩 LI Yibing;TANG Yunhe;JIAN Xin;SUN Qian;CHEN Hao(College of Information and Communication Engineering,Harbin Engineering University,Harbin 150001,China;Wuhan Maritime Communication Research Institute,Wuhan 430010,China)

机构地区：[1]哈尔滨工程大学信息与通信工程学院,哈尔滨150001 [2]武汉船舶通信研究所,武汉430010

出　　处：《电子与信息学报》2025年第2期490-497,共8页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(52271311);中国船舶集团有限公司第七二二所2022年创新基金(2022J-4)。

摘　　要：正交时频空(Orthogonal Time Frequency Space,OTFS)系统由于在面对高速移动通信场景下的时频双色散信道时的优异性能受到了广泛关注。为了准确获取信道状态信息,采用基于压缩感知的信道估计方法,并辅以特殊的导频序列完成信道估计。该文针对导频优化问题,提出了一种基于改进遗传算法的OTFS导频序列优化方法,该方法以互相关最小化为优化目标,采用遗传算法进行寻优,并能够自适应调整交叉和变异概率,在较少的迭代次数下即可实现比传统伪随机序列更优的互相关性,能够有效提高信道估计的准确性。此外,考虑到目标函数的计算量较大,该文分析了互相关的计算过程,并对其中的冗余计算进行了化简,与直接计算字典集的互相关值相比大大提高了算法的优化效率。Objective Orthogonal Time Frequency Space(OTFS)have attracted significant attention in recent years due to excellent performance in high-speed mobile communication scenarios characterized by time-frequency doubleselective channels.Accurate and efficient channel state information acquisition is critical for these systems.To address this,a channel estimation method based on compressed sensing is employed,using specialized pilot sequences.The performance of such channel estimation algorithms based on compressed sensing and the crosscorrelation properties of the dictionary sets generated by these pilot sequences.which vary depending on the sequence design.This study addresses the pilot design problem in OTFS communication systems,proposing an optimization method to identify pilot sequences that enhance channel estimation accuracy effectively.Methods A pilot-assisted channel estimation algorithm based on compressed sensing is employed to estimate the delay and Doppler channel state information in OTFS systems for high-speed mobile scenarios.To improve channel estimation accuracy in the Delay-Doppler domain and achieve better performance than traditional pseudo-random sequences,this study proposes a pilot sequence optimization method using an Improved Genetic Algorithm(IGA).The algorithm takes the cross-correlation among dictionary set columns as the optimization goal,leveraging the GA's strong integer optimization capabilities to search for optimal pilot sequences.An adaptive adjustment strategy for crossover and mutation probabilities is also introduced to enhance the algorithm's convergence and efficiency.Additionally,to address the high computational complexity of the fitness function,the study analyzes the expressions for calculating cross-correlation among dictionary set columns and simplifies redundant calculations,thereby improving the overall optimization efficiency.Results and Discussions This study investigates the channel estimation performance of OTFS systems using different pilot sequences.The simulation

关 键 词：正交时频空(OTFS) 压缩感知 导频优化 遗传算法 

分 类 号：TN929.5[电子电信—通信与信息系统]