Corrections to “Secrecy Outage Analysis for Distributed Antenna Systems in Heterogeneous Cellular Networks”
Ming Yang Sun, Yulong Zou, Jia Zhu · IEEE Access · 2018
In[1], the calculation of(8)was erroneous. To be specific, as shown in(8)of[1], the average transmit power of a specially-designed signal${x_{m} = - {{\sqrt {P_{S}} {h_{Sm}}h_{Am}^{*}{x_{S}}}}/{{{{\left |{ {{h_{Am}}} }\right |}^{2}}}}}$was obtained as\begin{equation*}{P_{m} = \frac {{\sigma _{Sm}^{2}}}{{\sigma _{Am}^{2}}}}P_{S},\end{equation*}where$\sigma _{Sm}^{2} = E(|{h_{Sm}}{|^{2}})$and$\sigma _{Am}^{2} = E(|{h_{Am}}{|^{2}})$. This calculation was obtained by mistaking an expectation of$1/|h_{Am}|^{2}$for$E(1/|h_{Am}|^{2})=1/E(|h_{Am}|^{2})= 1/\sigma _{Am}^{2}$, which is erroneous to be corrected. Actually, considering that$|h_{Am}|^{2}$is an exponentially distributed random variable with a mean of$\sigma ^{2}_{Am}$, the expectation of$1/|h_{Am}|^{2}$tends toward infinity, rather than$1/\sigma _{Am}^{2}$.