Compared with common near space satellite Telemetry,Telecommand,and Communication(TT&C),deep space TT&C presents a more challenging environment such as long distance,very low Signal to Noise Ratio(SNR).How to ...Compared with common near space satellite Telemetry,Telecommand,and Communication(TT&C),deep space TT&C presents a more challenging environment such as long distance,very low Signal to Noise Ratio(SNR).How to acquire main carrier exactly becomes a hot focus for deep space communications.Already there emerged some main carrier acquisition algorithms,but they all require high SNR and small modulation index.In this paper,we develop a new acquire algorithm.First we use the spectral energy center algorithm to shorten the original sequence,filter out some noise and make the spectral more symmetric.Then we adopt the spectral symmetry algorithm to make full use of the whole spectrum information,and utilize FFT to reduce computation complexity.Simulation results show that our algorithm can acquire main carrier successfully under large modulation index and get good performance with low Carrier to Noise Ratio(CNR).展开更多
针对正交时频空(Orthogonal Time Frequency Space,OTFS)调制系统采用矩形窗函数时,信道矩阵结构复杂导致的鲁棒性差的问题,提出了一种基于时域处理和酉近似消息传递的检测算法。该算法首先添加循环前缀,将时域信道转换为分块对角矩阵;...针对正交时频空(Orthogonal Time Frequency Space,OTFS)调制系统采用矩形窗函数时,信道矩阵结构复杂导致的鲁棒性差的问题,提出了一种基于时域处理和酉近似消息传递的检测算法。该算法首先添加循环前缀,将时域信道转换为分块对角矩阵;然后应用酉变换和近似消息传递建立迭代检测算法。仿真结果表明,所提检测算法能够在不增加复杂度的条件下有效提升检测精度和鲁棒性,特别是存在信道编码的条件下表现出2 dB的性能增益,使得该算法更适用于杂散多径、高速移动等环境,具有较高的应用价值。展开更多
基金Supported by the National Natural Science Foundation of China (No. 61032003 and No. 61021001)
文摘Compared with common near space satellite Telemetry,Telecommand,and Communication(TT&C),deep space TT&C presents a more challenging environment such as long distance,very low Signal to Noise Ratio(SNR).How to acquire main carrier exactly becomes a hot focus for deep space communications.Already there emerged some main carrier acquisition algorithms,but they all require high SNR and small modulation index.In this paper,we develop a new acquire algorithm.First we use the spectral energy center algorithm to shorten the original sequence,filter out some noise and make the spectral more symmetric.Then we adopt the spectral symmetry algorithm to make full use of the whole spectrum information,and utilize FFT to reduce computation complexity.Simulation results show that our algorithm can acquire main carrier successfully under large modulation index and get good performance with low Carrier to Noise Ratio(CNR).
文摘针对正交时频空(Orthogonal Time Frequency Space,OTFS)调制系统采用矩形窗函数时,信道矩阵结构复杂导致的鲁棒性差的问题,提出了一种基于时域处理和酉近似消息传递的检测算法。该算法首先添加循环前缀,将时域信道转换为分块对角矩阵;然后应用酉变换和近似消息传递建立迭代检测算法。仿真结果表明,所提检测算法能够在不增加复杂度的条件下有效提升检测精度和鲁棒性,特别是存在信道编码的条件下表现出2 dB的性能增益,使得该算法更适用于杂散多径、高速移动等环境,具有较高的应用价值。
