大气激光通信系统中空时网格码的研究

Research on Space-time Trellis Coding in Atmospheric Laser Communication Systems

针对大气激光通信中具有单极性、单脉冲特性的多进制脉冲位置调制(M-PPM)信号无法计算实际接收信号与估计信号间欧氏距离的问题,提出了一种适用于M-PPM的空时网格码译码方法。该方法利用实际接收信号与估计信号间的差值信息进行分支度量的计算和存活路径的选择。仿真结果表明,论文所提出的译码方法能够有效地将空时网格码应用于大气激光通信系统。

In order to solve the problem that the unipolar and monopulse Multiple pulse position modulation （M-PPM） signal cannot obtain the Euclidean distance between the actual received signal and the estimated signal, the paper proposes a space-time trellis code decoding algorithm suitable for M-PPM. The new algorithm uses the difference information between the actual received signal and the estimated signal to calculate the branch metric and select the survival path. Numerical simulation results further con-firm that the novel decoding algorithm shows an excellent performance for atmospheric laser communicatioin systems that adopt space-time trellis coding.