摘要
研究了多相码雷达信号的识别算法,建立了基于似然函数的多相码信号分类准则,并给出具体的实现步骤。首先估计接收信号的载频、幅度和码元宽度;然后利用多相码信号的时宽和码元宽度已知的条件下可以确定相位调制规律的特点,构造本地参考信号;接着构造假设检验,把对数似然函数的输出与门限进行比较,如果输出大于且只大于某一种多相码信号的门限,则判接收信号为该多相码信号,否则判为未知信号。仿真表明该算法可以在低信噪比条件下对多相码信号进行识别。
The recognition algorithm of the polyphase-coded radar signals is discussed in this paper. Polyphase-coded radar signal classification rules based on likelihood function are derived and the implementation steps of the rules are presented. First, carrier frequency, amplitude and code period of the received signal are estimated. When the pulse width and the code period are of prior knowledge, the phase modulation of the polyphase-coded signals can be determined. Therefore the local reference signals are generated. Now a hypothesis testing can be established. The output of the log-likelihood function was compared with the thresholds. If the output is greater than unity and only bigger than one of the thresholds of the polyphase-coded radar signals, the type of the received signal would be identical with that of the reference signal, which generates the maximum output. Otherwise, it is an unknown signal. The simulation results show that this method can recognize the polyphase-coded signals at low signal-to-noise ratio.
出处
《现代雷达》
CSCD
北大核心
2009年第12期43-48,共6页
Modern Radar
基金
中国博士后基金资助(20080441050)
关键词
多相码
识别
似然函数
假设检验
polyphase-coded
recognition
likelihood function
hypothesis testing
