MATLAB function and hand written code output not matching?
2 views (last 30 days)
Show older comments
Dear All,
I am new to MATLAB. I am doing the following operation for QPSK modulation. One code is with in built MATLAB function for pskmod and other is hand written. I am attaching both the code please help me how to get the same output as the inbuilt MATLAB function's for hand written code.
regards,
YM
MATLAB's in built functions code:
clc
clear variable
clear all
M = 4;
b = [1,0,1,0,1,0,1,0];
%b = randi([0 1],12,1);
% check arguments
if( nargin < 2 )
M = 4; % QPSK is default
else
if( rem( log2(M), 1 ) ~= 0.0 )
error('M must be a power of two.')
end
end
% vectorise
b = b(:);
% check input length integer to be an integer multiple of M
assert( rem( length(b), M ) == 0 )
% check if b is binary
assert( sum((b ~= 0) & (b ~= 1)) == 0 )
% data symbols (binary --> integer conversion of ld(M) bits)
b2 = reshape( b, log2(M), length(b)/log2(M) ) .';
b2 = bi2de(b2, 'left-msb');
s = pskmod( b2, M, pi/M, 'gray' ); %* sqrt(2)
And this is the hand written code:
clc
clear variable
clear all
% Setting up parameters for modulation type
data = [1,0,1,0,1,0,1,0]; % generating binary data of 1000 bits with ones and zeros
%data = [1;1;0;1;1;1;1;0;0;1;1;0;0;0;0;0;1;0;0;0;0;0;0;0;0;0;0;0;0;1;0;1;0;0;0;0;0;0;0;0;0;0;1;1;1;0;0;0;1;0;0;0;0;0;1;0;1;1;0;1];
mod_type=input('Enter the modulation type[1 for BPSK,2 for QPSK,3 for 16QAM,4 for 64QAM]: ');
norm_factor=[1.0;0.7071;0.3162;0.1543]; % normalization factors, 1.0:BPSK,0.7071:QPSK,0.3162:16QAM,0.1543:64QAM
nc=[1;2;4;6]; % number of bits per subcarrier, 1:BPSK,2:QPSK,4:16QAM,6:64QAM
input_seq = data;
k=norm_factor(mod_type);
mode=nc(mod_type);
% Selecting constellation point as per modulation type
switch mode
case 1
b=k*[1 -1];
case 2
b=k*[1+1i -1+1i 1-1i -1-1i];
case 4
b=k*[1+1i 1+3i 1-1i 1-3i 3+1i 3+3i 3-1i 3-3i -1+1i -1+3i -1-1i -1-3i -3+1i -3+3i -3-1i -3-3i];
case 6
b=k*[3+3i 3+1i 3+5i 3+7i 3-3i 3-1i 3-5i 3-7i 1+3i 1+1i 1+5i 1+7i 1-3i 1-1i 1-5i 1-7i 5+3i 5+1i 5+5i 5+7i 5-3i 5-1i 5-5i 5-7i 7+3i 7+1i 7+5i 7+7i 7-3i 7-1i 7-5i 7-7i -3+3i -3+1i -3+5i -3+7i -3-3i -3-1i -3-5i -3-7i -1+3i -1+1i -1+5i -1+7i -1-3i -1-1i -1-5i -1-7i -5+3i -5+1i -5+5i -5+7i -5-3i -5-1i -5-5i -5-7i -7+3i -7+1i -7+5i -7+7i -7-3i -7-1i -7-5i -7-7i];
end
count=1;
count1=1;
for i=1:(ceil(length(input_seq)/mode))
temp=0;
for j=1:mode
temp=bitor(temp,bitshift(input_seq(count),(j-1)));
count=count+1;
if(count>length(input_seq))
break;
end
end
map_out(count1)=b(temp+1);
map_out = map_out;%* sqrt(2)
map_out = map_out(:);
count1=count1+1;
end
please help me with this. I want my hand written code's output to match to the MATLAB's in built function code's output.
0 Comments
Answers (0)
See Also
Categories
Find more on QPSK in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!