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| clear;
close all;
clc;
L = 1:1000;
N = 16;
v = 40 / 3.6;
f_c = 800e6;
C = physconst('lightspeed');
R = 9600;
ramda = C / f_c;
T = 1 / R;
FDT = v * f_c / C * T;
theta = zeros([N, 1]);
for n = 1 : N
if(n == 1)
theta(n) = rand() * 2 * pi / 16;
else
theta(n) = theta(n - 1) + rand() * 2 * pi / 16;
end
end
phi = rand([N, 1]) * 2 * pi;
alpha = 2 * pi * FDT * cos(theta);
k = 1 : 1000;
Fk = exp(1j * ((alpha * k) + phi));
Fk = sum(Fk, 1) / sqrt(N);
Fk = 20 * log10(abs(Fk));
figure(1);
plot(Fk);
xlabel('k'), ylabel('F(k)/dB');
X = 1 : 100;
Y = 1 : 100;
F = zeros(100, 100);
for x = X
for y = Y
F(x, y) = abs(sum(exp(1j * ((y / 100 * cos(theta) - x / 100 * sin(theta)) * 2 * pi / ramda + phi))) / sqrt(N));
end
end
figure(2);
mesh(F);
xlabel('x'), ylabel('y'), zlabel('F(x, y)');
snr_in_db = 0 : 20;
M = 1e6;
data = zeros([M, 1]);
for i = 1 : M
temp = rand();
if(temp > 0.5)
data(i) = 1;
else
data(i) = 0;
end
end
signal = zeros([M, 1]);
for i = 1 : M
signal(i) = 2 * data(i) - 1;
end
pf = zeros([length(snr_in_db), 1]);
for i = 1 : length(snr_in_db)
numoferr = 0;
k = 1 : M;
Fk = exp(1j * ((alpha * k) + phi));
Fk = sum(Fk, 1) / sqrt(N);
rk = awgn(signal .* Fk', snr_in_db(i));
dk = real(rk .* conj(Fk'));
for k = 1 : M
if (dk(k) > 0)
a_cd = 1;
else
a_cd = 0;
end
if (a_cd ~= data(k))
numoferr = numoferr + 1;
end
end
pf(i) = numoferr / M;
end
pa = zeros([length(snr_in_db), 1]);
for i = 1 : length(snr_in_db)
numoferr = 0;
snr = power(10, snr_in_db(i) / 10);
rk = signal + wgn(length(signal), 1, 10 * log10(1 / 2 / snr));
dk = rk;
for k = 1 : M
if (dk(k) > 0)
a_cd = 1;
else
a_cd = 0;
end
if (a_cd ~= data(k))
numoferr = numoferr + 1;
end
end
pa(i) = numoferr / M;
end
figure(3);
semilogy(snr_in_db, [pf, pa]);
grid on;
xlabel('SNR'), ylabel('BER');
|
