Simple and Accurate Error Probability Evaluation of Multiple-Input–Multiple-Output Systems Using Optimum Linear Combining

This correspondence motivates simple and accurate evaluation of the error probability of multiantenna multiple-input-multiple-output (MIMO) systems using optimum linear combining (OLC). Using both the first- and second-order statistics of the eigenvalues involved, we propose an Order-2 approximation approach (i.e., Gamma-approximation), which approximates the related eigenvalues as independent gamma-distributed random variables. Our analysis shows that the proposed Order-2 approximation results in simple formulas that are convenient to evaluate. The performance examples show that the error probability evaluated using the derived formulas is accurate and usually indistinguishable from that obtained by simulations.