wednesday_fudu_xiangwei.m

微波视距信道的仿真

close all;
                                            
f_c=4;                                            
                                      
N_point=2000;                                     
B=10;                                             
                                                  
T=1/B                                             
time_1 = (linspace (0, N_path, N_point));         
x_min=0;
x_max=max(time_1);
y_min=0;
y_max=1;                                         
                 
figure;                  
xlabel('时间');ylabel('振幅');
title('信道冲激响应')
grid on;   
hold on
 
    a_0=exp(-j*2*pi*f_c*T);                                             
    a_1=exp(-j*2*pi*f_c*2*T);
    a_2=exp(-j*2*pi*f_c*3*T);
    
    signal_0=[zeros(1,N_point/2-1) 1 zeros(1,N_point/2)];
    signal_1=[zeros(1,N_point/2) 1 zeros(1,N_point/2-1)];
    signal_2=[zeros(1,N_point/2+1) 1 zeros(1,N_point/2-2)];
    signal_3=[zeros(1,N_point/2+2) 1 zeros(1,N_point/2-3)];
    
    signal_99=signal_0+0.86*a_0*signal_1+0.2*2*a_1*signal_2+0.1*3*a_2*signal_3                                   
                               
    signal_out=abs(signal_99) 

plot (time_1,signal_out,'r')                                                   
axis([1.99 2.01 y_min y_max]) 

figure;
xlabel('频率');ylabel('振幅');
title('信道冲激响应幅频特性');
grid on;                                                                   
hold on;
 
 signal_a=fft(signal_99); 
 signal_out=abs(signal_a);
y_max=max(signal_out);

plot (time_1,signal_out,'r')                                                   
axis([0 4 y_min  y_max]) 
hold off;
 
figure;
xlabel('频率');ylabel('相位');
title('信道冲激响应相频特性');
grid on;                                                                   
hold on;
 

 signal_a=angle(signal_99);
signal_out=fftshift(angle(signal_99))
 
plot (time_1,signal_out,'r')                                                   
axis([-0.01 0.01 -pi  pi/2]) 
hold off