基于CRC纠错与迭代干扰消除的星载AIS接收机

为了提升星载船舶自动识别系统（AIS）的卫星接收性能，提出了一种采用4 b循环冗余校验（CRC）纠错与迭代干扰消除算法的星载AIS接收方案。针对星载AIS系统中多路信号碰撞明显的情况，首先，通过分析星载AIS系统中CRC错误类型，采用比特反转的方式进行纠错;其次，对纠错后的序列进行AIS数据重构，采用迭代干扰消除方法消除重构信号，并将余下信号作为输入信号再次进入系统进行解调。仿真结果表明，和传统的CRC纠错系统相比，针对典型的两路信号碰撞情况，基于4 b CRC校验与迭代干扰消除的星载AIS系统能够带来1~2 dB的误码率增益，对星载AIS系统的性能提升有重要指导意义。

A satellite-borne AIS receiver based on CRC error correction and iterative interference cancellation

In order to improve the receiving performance of satellite-borne automatic identification system(AIS),this paper presents an AIS receiving scheme based on 4-bit cyclic redundancy check(CRC) error correction and iterative interference cancellation. For multi-path signal collisions of satellite-borne AIS,the CRC error types of the system are firstly analyzed and the error correction method by means of bit reversal is adopted to correct the binary sequence;then the sequence is reconstructed to the AIS signals which will be eliminated by iterative interference cancellation method and the remaining signals are input to the system as the input signal again. Simulation results show that compared with traditional non-CRC correction system,the 4-bit CRC error correction and iterative interference cancellation scheme can provide 1~2 dB gain for two collided AIS signals,which has important significance to the performance improvement of satellite-borne AIS.