% setup.m
% setup
disp(' '), disp('------------------------------------------------------------')
disp('Simulation Setup')
% OFDM Setup -----------------------------------------------------------
fft_size = 128 % should be a power of 2 for fast computation
% more points = more time domain samples (smoother & more cycles)
num_carriers = 32 % should be <= fft_size/4
% number of carriers used for each data chunk
% new var - denotes even spacing or variations of carriers among fft points
input_type = 2;
% 1 = test input
test_input_type = 1;
% 1 = bit specified (binary)
binary_data = [0 1 0 1 0 1 0 1];
% 2 = random data stream (samples in the range of 0-255)
num_symbols = 9;
% 3 = sinusoidal
frequency = 2;
num_samples = 50;
% 2 = external file input
file_name = 'shortest.wav'; % Name of input file
file_input_type = 3;
% 1 = binary (not implemented)
% 2 = text % Demo file: 'text.txt'
% 3 = sound % Demo files: 'shortest.wav' & 'shorter.wav'
% 4 = image (not implemented)
% QAM Setup ------------------------------------------------------------
do_QAM = 1; % (1=on, 0=off)
QAM_periods = 10; % defines the number of periods per QAM Symbos (1=2*pi)
% Channel Simulation Parameters --------------------------------------------
channel_on = 1; % 1=on, 0=off
clip_level = 1.0; % 0.0 - 1.0 (0-100%)
% Max magnitude of the signal is 'clip_level' times the full magnitude of the signal
noise_level = 0.0; % 0.0 - 1.0 (0-100%)
% Magnitude of noise is 'noise_level' times the magnitude of the signal
% Multipath Channel Simulation
% Good defaults when fft_size = 128 and num_carriers = 32:
% d1=6; a1=0.30; d2=10; a2=0.25
d1 = 6; % delay in units
a1 = 0.32; % attenuation factor - multipath signal is x% of size or original signal
d2 = 10; % delay for second multipath signal
a2 = 0.28; % attenuation factor for second multipath signal
% ****************** TEST INPUT SETUP - DO NOT MODIFY **************************
if input_type == 1
if test_input_type == 1
%specify BINARY input bit-by-bit
data_in = binary_data;
end
if test_input_type == 2
%random input defined by parameters
num_levels = 255; %number of possible levels of a symbol
%must be integer between 1-255
data_samples = round(rand(1,num_symbols)*(num_levels-1));
data_in = zeros(1,8*length(data_samples));
for i = 1:length(data_samples)
data_in(1 + (i-1)*8:(i-1)*8 + 8) = eight2bin(data_samples(i));
end
end
if test_input_type == 3
%data stream represents sine wave samples
t = linspace(0,1,num_symbols); %evenly space number of samples
%take 8-bit samples of sine wave
data_samples = round(127.5*sin(frequency*2*pi*t) +127.5);
data_in = zeros(1,8*length(data_samples));
for i = 1:length(data_samples)
data_in(1 + (i-1)*8:(i-1)*8 + 8) = eight2bin(data_samples(i));
end
end
end
already_made_noise = 0; % initialization (don't change)