Blind detection of the number of sources with gerschgorin radii

Let us assume the following MIMO model:
Y(k)=HX(k)+Y(k)
This file can detect the number of sources, i.e the size of the vector X(k) from the received signal Y(k). The noise is assumed spatially white and the number of receivers must be strictly greater than the number of sources. For algorithm details, dee reference [WYC95] H.T. Wu, J.F. Yang, and F.K Chen. Source number estimators using transformed gerschgorin radii. IEEE Transactions on Signal Processing, 43(6):1325-1333, 1995.