% 新波動方程 ASK_like_FM,不考慮pathloss and interface loss
clear all;
clc ;
% ******************
% 定義兩個基帶信號的相關參量
L = 5;
w = 2*pi;
t = 0:6/29:6;
Ref =0;
x = 0:10/2599:10;
y = 0:10/2599:10;
k =2*pi*3;
% 路徑衰落和界面損耗設置
% PL = 1:-0.2/2599:0.8;   % PL->path loss
% IL = 0.6;               % IL->interface loss
% *******************
for i = 1:length(t)
%     隨機數
     rd =  randint(1,10);
% 基帶信號
    theta1 = sqrt(x.^2+(y-L/2).^2);
    theta2 = sqrt(x.^2+(y+L/2).^2);
    s_a1 = cos(w*t(i)-k*theta1);
    s_a2 = cos(w*t(i)-3*k*theta2); 
    s_b1 = cos(w*t(i)-k*theta1);
    s_b2 = cos(w*t(i)-3*k*theta2); 

        % 信號s1
        for m = 1:10
            M=(m-1)*260+1:(m*260); 
              srand(M) = (rd(m)*2+Ref)*ones(1,260);
                if srand(:,M) ~= Ref
                    s1(M) = s_a1(M).*2;% 低頻對應“1”
                else 
                    s1(M) = s_a2(M).*2;% 高頻對應“0”
                end
        end
        % 信號s1_image
        for m = 1:10
            M=(m-1)*260+1:(m*260); 
              srandom(M) = (rd(m)*2+Ref)*ones(1,260);
                if srandom(:,M) ~= Ref
                    s1_image(M) = s_b1(M).*2;
                else 
                    s1_image(M) = s_b2(M).*2;
                end
        end

% 調制
Fs = 200;
Fc = 20;
dev = 1;
s1_up = fmmod(s1,Fc,Fs,dev); 
s1_image_up = fmmod(s1_image,Fc,Fs,dev);

% 疊加
s_add = s1_up+s1_image_up;

% 作圖
figure(2)

subplot(311),plot(x,s1_image);
axis([0 10 -3 3])
xlabel('(a) Distance')
ylabel('Amplitude')
subplot(312),plot(x,s1_up);
axis([0 10 -2 2])
xlabel('(b) Distance')
ylabel('Amplitude')
subplot(313),plot(x,s_add);
axis([0 10 -3 3])
xlabel('(c) Distance')
ylabel('Amplitude')
hold on
end