中文说明：
1．步进频率信号的压缩实验。编写Matlab程序，得到类似如下两图的结果。步进频率信号参数：（1）载频f0 = 5.321GHz, N=21（子脉冲的个数）, F = 20MHz （频率步进值）, 合成带宽B = 400MHz，（2）载频f0 = 5.321GHz, N=81（子脉冲的个数）, F = 5MHz（频率步进值） , 合成带宽B = 400MHz。目标参数：四个分别位于995，1000，1001和1005米处, 其反射系数为1, 1.5, 2.25, 3.375
English Description：
1. Compression experiment of step frequency signal. Write matlab program and get the results similar to the following two figures. Step frequency signal parameters: (1) carrier frequency f0 = 5.321ghz, n = 21 (number of sub pulses), f = 20MHz (frequency step value), synthetic bandwidth B = 400MHz, (2) carrier frequency f0 = 5.321ghz, n = 81 (number of sub pulses), f = 5MHz (frequency step value), synthetic bandwidth B = 400MHz. Target parameters: four are located at 99510001001 and 1005m respectively, and their reflection coefficients are 1, 1.5, 2.25 and 3.375