Generate Complex White Gaussian Noise in MATLAB In the followinf code I am trying to generate a Complex Gaussian Noise:
n_3 = sqrt(0.1)*randn(1,K);
n_4 = sqrt(0.1)*randn(1,K);
beta_NLoS = (n_3+1i*n_4); % CN(0,0.1)

Does my code do as intended?
If you want a Circular Complex Gaussian Noise (Independent):

vComplexNoise = sqrt(noiseVar / 2) * (randn(1, numSamples) + (1i * randn(1, numSamples)))


For correlated noise you'll need to define the Co Variance Matrix and use Cholesky Decomposition.

Update

Following @Stanley Pawlukiewicz advise, run the following code:

numSamples = 100000;
noiseVar   = 4;

mA = sqrt(noiseVar / 2) * (randn(numSamples, 1) + (1i * randn(numSamples, 1)));

var(mA)


You should see result which is very close to noiseVar on the screen.