Hi, as I am new in Matlab, so I need your help. I want to replace the following inverse matrix (X'*X)^-1 with its expectation value: E{(X'*X)^-1} = E{|1/Xk|^2}I X'*X and (X'*X)^-1 is a diagonal matrix. Could anyone give me an Idea how to write it in matlab this expectation value. The elements of a matrix X are composed by QPSK symbols, or 16-QAM, or 64-QAM. Assume for now QPSK. Assuming the same signal constellation on all tones and equal probability on all constellation points. Thanks in advande.