p2_2.m

A function to find necessary angle

clc
clear all
close all
M = 16; % Size of signal constellation
k = log2(M); % Number of bits per symbol
n = 3e4; % Number of bits to process
nsamp = 1; % Oversampling rate
x = randint(n,1);
% Plot first 40 bits in a stem plot.
stem(x(1:40),'filled');
title('Random Bits');
xlabel('Bit Index'); ylabel('Binary Value');
%% Bit-to-Symbol Mapping
% Convert the bits in x into k-bit symbols.
xsym = bi2de(reshape(x,k,length(x)/k).','left-msb')


%% Stem Plot of Symbols 
% Plot first 10 symbols in a stem plot.
figure; % Create new figure window.
stem(xsym(1:10));
title('Random Symbols');
xlabel('Symbol Index'); ylabel('Integer Value');
%% Modulation
y = modulate(modem.qpskmod(M),xsym); % Modulate using 16-QAM.
%% Transmitted Signal
ytx = y;

%% Channel
% Send signal over an AWGN channel.
for i=1:30
snr = i;
ynoisy = awgn(ytx,snr,'measured');

%% Received Signal
yrx = ynoisy;

zsym = demodulate(modem.qamdemod(M),yrx);

z = de2bi(zsym,'left-msb'); % Convert integers to bits.
% Convert z from a matrix to a vector.
z = reshape(z.',prod(size(z)),1);
%% BER Computation
% Compare x and z to obtain the number of errors and
% the bit error rate.
[number_of_errors,bit_error_rate] = biterr(x,z)
m(i)=bit_error_rate;
end
i=[1:30];
plot(i,m);