一种高动态低信噪比环境下基于多样本点串行快速傅里叶变换的信号捕获方法  

A Signal Acquisition Method Based on Multi-Sample Serial Fast Fourier Transform in High Dynamic and Low SNR Environment

作　　者：陈延涛 董彬虹[1] 李昊 蔡沅沅 CHEN Yantao;DONG Binhong;LI Hao;CAI Yuanyuan(National Key Laboratory of Communication,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]电子科技大学通信抗干扰技术国家级重点实验室,成都611731

出　　处：《电子与信息学报》2021年第6期1691-1697,共7页Journal of Electronics & Information Technology

基　　金：基础加强计划(017-JCJQ-ZD-041);基础科研计划(JCKY2016204A603)。

摘　　要：高超音速技术是未来空间飞行器的发展趋势,同时对通信平台在超高动态、低信噪比环境下的快速捕获能力也提出了新的挑战。针对经典捕获算法受频偏影响的局限性,该文提出一种基于信号多样本点串行快速傅里叶变换的信号捕获算法(MS-FFT),所提算法通过串行执行多个样本点的FFT,采用非相干合并后的峰值搜索得到捕获结果,在不增加复杂度的条件下,避免了频偏对捕获性能的影响。通过对峰值信噪比(PSNR)理论公式的推导,证明了MS-FFT的频偏适应范围取决于采样率,随着数模转换器件采样能力的不断提升,具有比经典算法更大的频偏适应范围。最后,通过仿真验证了上述理论推导的正确性,证明了所提算法更加适合超高动态环境的应用场景。Hypersonic technology is the development trend of space vehicles in the future.It also poses new challenges for the fast acquire capability of communication platforms in ultra-high dynamic and low signal-tonoise ratio environments.To overcome the limitation of the classic acquisition algorithm affected by frequency offset,a signal acquisition algorithm based on Multi-sample Serial Fast Fourier Transform(MS-FFT)is proposed.The proposed algorithm serially executes the FFT of multiple samples and runs the peak searching after non-coherent combining to obtain the acquire result.Without increasing the complexity,the influence of frequency offset on the acquisition performance is avoided.By deriving the theoretical formula of the Peak Signal-to-Noise Ratio(PSNR),it is proved that the frequency offset adaptation range of MS-FFT depends on the sampling rate and can be larger than the classical algorithm with the continuous improvement of the sampling capability of digital-analog conversion devices.Finally,the correctness of the above theoretical derivation is verified by simulation,and it is proved that the proposed algorithm is more suitable for the application scenarios of ultra-high dynamic environment.

关 键 词：信号捕获 高动态 低信噪比 多样本点串行FFT 

分 类 号：TN911.7[电子电信—通信与信息系统]