Please Solve the Error...if the run the below code..i got one error ..but logically code correct..the error is Matrix dimensions is not match

function [bit_stream ]=msk_demod( signal_ip,f,Tb)
%msk_demod program for minimum shift keying demodulation
% %   Detailed explanation goes here
clc;clear all;close all;
s1=0;s2=0;s3=0;s4=0; 
d1=0;d2=0;d3=0;d4=0;
bit_odd=0;bit_even=0;
data1=[0 0];
data2=[0 1];
data3=[1 0];
data4=[1 1];
% data=input('Enter the data size 8 bits {Ex:- format [1 1 1 1 0 0 1 0]} ');
% Tb=input('Enter Bit period time from 0 to 1 {Ex:- 0.1}');
% f=input('Enter frequency in Hz from 0 t0 80 {Ex:-7}');
data=[1 0 0 1 1 1 0 0];
Tb=0.1;
f=7;
signal_ip=msk_mod(data,f,Tb,1);
s1=msk_mod(data1,f,Tb,1);
s2=msk_mod(data2,f,Tb,1);
s3=msk_mod(data3,f,Tb,1);
s4=msk_mod(data4,f,Tb,1);
l=length(signal_ip);
n_samp=l/1000;
ind=1;
samp=signal_ip;
for i=1:n_samp
    d1=samp(:,(i-1)*1000+1:(i*l)/4).*s1;
    d2=samp(:,(i-1)*1000+1:(i*l)/4).*s2;
    d3=samp(:,(i-1)*1000+1:(i*l)/4).*s3;
    d4=samp(:,(i-1)*1000+1:(i*l)/4).*s4;
    d11=0;d22=0;d33=0;d44=0;
 for k=1:1000
        if (d1(1,k)>0)
            d11=d11+1;
        end
        if (d2(1,k)>0)
            d22=d22+1;
        end
        if (d3(1,k)>0)
            d33=d33+1;
        end
        if (d4(1,k)>0)
            d44=d44+1;
        end
    end
    if (d11 > d22) && (d11 > d33) &&(d11 > d44)
        bit_odd=0;
        bit_even=0;
    end
     if (d22 > d11) && (d22 > d33) &&(d22 > d44)
        bit_odd=0;
        bit_even=1;
     end
     if (d33 > d22) && (d33 > d11) &&(d33 > d44)
        bit_odd=1;
        bit_even=0;
     end
     if (d44 > d22) && (d44 > d33) &&(d44 > d11)
        bit_odd=1;
        bit_even=1;
     end
     bit_stream(1,ind)=bit_odd;
     bit_stream(1,ind+1)=bit_even;
     ind=ind+2;  
end
bit_stream
end

[Walter Roberson]

Apparently we need msk_mod to test this out.

[suresh tadikonda]

that is ok, that i alredy there..that modulation code is also k...i want demodulation code and in that i got that error..please run and tell me solution

[Walter Roberson]

I did run. The output was

>> msk_demod
Undefined function or variable 'msk_mod'.
Error in msk_demod (line 18)
signal_ip=msk_mod(data,f,Tb,1);

To get any further I would need to have the code for msk_mod

[suresh tadikonda]

K i put modulation code also..please solve my error

function [ signal ] = msk_mod(bit_stream,f,Tb,Eb)
t=0.001 : .001 : 1;
bit_stream=[1 0 0 1 0 0 1 1];
Eb=1;
nn=length(bit_stream);
amp=sqrt(2*Eb);

Tb=0.001;
f=30;
if (mod(nn,2)~=0)
    bit_stream(1,nn+1)=0;
    nn=nn+1;
end
N=length(bit_stream);
m_i=zeros(1,N/2); 
m_q=zeros(1,N/2);
a=1;
for i=1:1:N/2
    if (bit_stream(1,a)==0)
        m_i(1,i)=-1;
    else
        m_i(1,i)=1;
    end
    a=a+1;
      if (bit_stream(1,a)==0)
        m_q(1,i)=-1;
    else
        m_q(1,i)=1;
    end
    a=a+1;
end
Smsk=zeros(N/2,1000);

for loop =1:N/2
    Smsk(loop,:)=(amp*(m_i(1,loop)*sin(2*pi*t/(4*Tb))).*cos(2*pi*f*t)) + (amp*(m_q(1,loop)*cos(2*pi*(t/(4*Tb)))).*sin(2*pi*f*t));
end
signal=column_to_row(Smsk);
end

[suresh tadikonda]

And i also got one more error while executing one by one line of demodulation of MSK

 d1=samp(i,(i-1)*1000+1:(i*l)/4).*s1;

[Walter Roberson]

Undefined function or variable 'column_to_row'.
Error in msk_mod (line 37)
  signal=column_to_row(Smsk);
Error in msk_demod (line 18)
signal_ip=msk_mod(data,f,Tb,1);

[suresh tadikonda]

k i will send column_to_row code

function [ output_matrix ] =column_to_row( input_matrix )
% Converts a column matrix to row matrix
% Ex: [1 2 3 4; 2 3 4 5; 9 8 7 6]
% will be converted to [1 2 3 4 2 3 4 5 9 8 7 6]

[a,b]=size(input_matrix);
count=-b;
for i=1:a
    count=count+b;
    for j=1:b
        op(count+j)=input_matrix(i,j);
    end
end
output_matrix=op;
end

[sloppydisk]

You could use

   reshape(a', 1, numel(a))

instead of your column_to_row function