fsk_fm_2s.m

％ 新波动方程 FM_2s ％ 不考虑路径衰落和界面损耗

% 新波动方程 FM_2s
% 不考虑路径衰落和界面损耗
clear
clc
% ******************
% 定义两个基带信号的相关参量
w = 2*pi;
t = 0:5/29:5;
theta = -pi:2*pi/29:pi;
L = 5;
Ref = 3;
k =2*pi*1.5;

% 随机数对图形结果影响较大。注意设置 
    rd =  randint(1,10);
% pl = 1:-0.2/259:0.8;   % PL->path loss
% PL = meshgrid(pl);
% IL = 0.6;               % IL->interface loss
for i = 1:length(theta)
    
%     初始数据和波形
    x = 0:10*cos(theta(i))/259:10*cos(theta(i));
    y = 0:10*sin(theta(i))/259:10*sin(theta(i));
    [x,y] = meshgrid(x,y);
    theta1 = sqrt(x.^2+(y-L/2).^2);
    theta2 = sqrt(x.^2+(y+L/2).^2);

    s_a1 = cos(w*t(10)-k*theta1);
    s_a2 = cos(w*t(10)-2*k*theta2); 
    s_b1 = cos(w*t(10)-k*theta1);
    s_b2 = cos(w*t(10)-2*k*theta2); 
% FSK modulation
        for m = 1:10
            M=(m-1)*26+1:(m*26); 
              srandom = (rd(m)*4+Ref)*ones(260,26);
                if srandom == Ref*ones(260,26)
                    s1(:,M) = s_a1(:,M).*srandom;
                else 
                    s1(:,M) = s_a2(:,M).*srandom;
                end
        end
       
         for m = 1:10
            M=(m-1)*26+1:(m*26); 

                if srandom == Ref*ones(260,26)
                    s1_image(:,M) = s_b1(:,M).*srandom;
                else 
                    s1_image(:,M) = s_b2(:,M).*srandom;
                end
         end
% FM modulation
Fs = 120;
Fc = 20;
dev = 1;
s1_up = fmmod(s1,Fc,Fs,dev); 
s1_up_image = fmmod(s1_image,Fc,Fs,dev);

% 叠加
s_add = s1_up+s1_up_image;
% 作图
mesh(x,y,s_add);
hold on 
view(0,90)
colormap gray
end