c8_3.m

经典书籍《通信系统仿真原理与无线应用》chap8部分课后题仿真源代码

clear
levelx =2; %Number of D levels;
levely =2; %Number of Q levels;
m = 100;   %Number of symbols;
n = 20;    %Number of samples per symbol;
bw = 0.1;  %Filter bandwidth, 0<bw<1;
%
%
[xd,xq] = qam(levelx,levely,m,n);

lx = length(xd);
t = 0:lx-1;
nt = t/(lx-1);
nxd = xd(1,1:lx);
nxq = xq(1,1:lx);

subplot(231)
plot3(nt,nxd,nxq);
a = axis;
axis([a(1) a(2) 1.5*a(3) 1.5*a(4)]);
xlabel('Normalized Time');
ylabel('Direct');
zlabel('Quadratute');
view(45,45)

subplot(232)
plot(nt,nxd);
a = axis;
axis([a(1) a(2) 1.5*a(3) 1.5*a(4)]);
xlabel('Normalized Time');
ylabel('Direct');

subplot(233)
plot(nt,nxq);
a = axis;
axis([a(1) a(2) 1.5*a(3) 1.5*a(4)]);
xlabel('Normalized Time');
ylabel('Quadratute');

subplot(234)
plot(nxd,nxq);
a = axis;
axis([a(1) a(2) 1.5*a(3) 1.5*a(4)]);
xlabel('Direct');
ylabel('Quadratute');

subplot(235)
At = sqrt(nxd.^2+nxq.^2);
plot(nt,At);
a = axis;
axis([a(1) a(2) 1.5*a(3) 1.5*a(4)]);
xlabel('Normalized Time');
ylabel('At');

rotate3d