基于Laurent分解的星载AIS解调算法

为了适应星载AIS（船舶自动识别系统）条件,提出了一种基于Laurent分解的单通道星载AIS信号解调算法。AIS信号可通过Laurent原理分解成若干调幅脉冲信号,该算法用其中能量最大的2个调幅脉冲信号在接收前端作近似匹配滤波处理,然后采用维特比译码算法对信息码元进行还原。结合实际工程应用,对该算法在低信噪比和混叠信号2种条件下分别进行仿真。仿真结果表明,该算法在2种情况下正确解包率均显著优于传统算法。

Demodulation Algorithm Based on Laurent Decomposition for Satellite-Based AIS Signals

A demodulation algorithm based on Laurent decomposition for single-channel satellite-based AIS （Auto-matic Identification System） signals is proposed to adapt to the conditions of satellite-based AIS systems. AIS sig-nals can be decomposed into amplitude-modulated pulse signals using Laurent theory. Signals are first processed by two filters and matched with the two signals with the highest energy in decomposition with the algorithm. Then, in-formation bits can be decoded with Viterbi algorithm. Digital simulation is respectively conducted at low SNR and with co-channel interference. Simulation results show that the ratio of correct data package demodulation with the proposed algorithm is obviously higher than traditional algorithms.