伪码调相连续波雷达的脉压主旁瓣比数学分析

Mathematical Analysis of Main-to-Sidelobe Ratio After the Pulse Compression in Pseudorandom Code Phase Modulation Continuous Wave Radar

研究了伪码(m序列)调相连续波雷达的脉压主旁瓣比随目标多普勒频率变化的关系,并推导了其数学表达式。由于m序列调相连续波雷达在非目标距离门上的脉冲压缩是一种"宽带输入窄带输出的过程",那么脉压旁瓣实部和虚部分别近似服从正态分布,由此可计算出脉压后峰值旁瓣实部和虚部的值,然后给出了脉压输出主旁瓣比的数学表达式。仿真结果表明:当m序列的周期长度p≥31时,由脉压主旁瓣比数学表达式计算得到的数据与仿真得到的数据能很好地吻合。

The relation between main-to-sidelobe ratio and Doppler frequency after the pulse compression in pseudorandom code （m-sequence） phase modulation continuous wave （CW） radar was studied, and the mathematical expression of main-to-sidelobe ratio after the pulse compression was deduced. Since the pulse compression with the non-target range gate in m-sequence phase modulation CW radar is a ＂wide-band input, narrow-band output process＂, the sidelobe＇s real part and imaginary part after the pulse compression approximately obey normal distribution, respectively. Thus, the peak sidelobe＇s real part and imaginary part after the pulse compression were calculated. Then the mathematical expression of the main-to-sidelobe ratio after the pulse compression was deduced. Simulation result indicates that the data calculated by the mathematical expression of the main-to-sidelobe ratio is close to the data attained by the simulation at the period length of m-sequence of p≥31.