低信噪比环境下Link-11解调方法研究

摘要

In modern information warfare, Link-11 scout and demodulation shows great military signiifcance. In order to improve performance of Link-11 demodulation in low Signal Noise Ratio condition, the key technologies of Link-11 demodulation are researched. To solve the problem that low FFT resolution, the carry wave product method which realizes frame synchronization is improved. This new method improves frequency measure performance. To solve the problem of phase spectrum error, the phase spectrum method which realizes parallel multi-tone demodulation is improved. Otherwise, base of the two new methods, a demodulation system of Link-11 is designed. The environment noise leads to demodulation error. The theory analysis and simulation results shows the methods which researched in this paper could hold Link-11 demodulation precision in low Signal Noise Ratio condition.%现代信息化战争中，对Link-11信号的侦收解调具有重要军事意义。为了提高低信噪比环境下Link-11信号解调性能，文章对Link-11解调中的关键技术进行了研究，首先改进了实现Link-11帧同步的载波相乘法，解决信号采样序列较短造成FFT分辨率低的问题，提高测频的时效性和精确性，然后改进并行多音频解调的相位谱方法，解决FFT采样点少造成相位谱偏差较大的问题，并基于改进的新方法设计了Link-11解调系统。文章还对环境噪声引起的解调误差进行了分析，仿真结果表明文章研究的方法能在低信噪比环境下较好地保持Link-11的解调精度。