I need to confirm if spreading signal by using walsh code in MATLAB is right or no,
Suppose I'm using QAM modulation, so I need to spread the signal over walsh code, is the below step is right:
M = 4; alphabit = modem.qammod('M', M ) ; %QAM modulation mod = transpose(modulate( alphabit , (0:M-1))); avg = mod'*mod / M ; % average power of constellation points mod = mod / sqrt(avg); % to make E[x^t x ] = 1 H = hadamard(4); % The walsh code generation H_use = H(:,2); %using the second column for spreading. S_coded = kron(mod,H_use); % Spread the modulated data mod over the walsh code
My question is about the last step, is that right how we spread the modulated signal? ..