I] to obtain the typical values of $\sigma_\chi$ for and links) whose spatial correlation model is described in [@Ngo17 (54)-(55)].

The channel vector ${\boldsymbol}{h}_{mk} \in \mathbb{C}^{N \times 1}$ between $k$ and $m$ will be modelled as the sum of the contributions of $C_{mk}$ scattering clusters, each contributing $P_{mk}$ propagation paths as $${\boldsymbol}{h}_{mk}=\sum_{c=1}^{C_{mk}}\sum_{p=1}^{P_{mk}} \alpha_{mk,cp} {\boldsymbol}{a}\left(\theta_{mk,cp},\phi_{mk,cp}\right),$$ where $\alpha_{mk,cp}$ is the complex small-scale fading gain on the $p$th path of cluster $c$, and ${\boldsymbol}{a}\left(\theta_{mk,cp},\phi_{mk,cp}\right)$ represents the normalized array response vector at the azimuth and elevation angles $\theta_{mk,cp}$ and $\phi_{mk,cp}$, respectively. These angles, as stated by Akdeniz *et al.* in [@Akdeniz14 Section III.E] can be generated as wrapped Gaussians around the cluster central angles with standard deviation given by the angular spreads for the cluster. The azimuth cluster central angles are uniformly distributed in the range $[-\pi,\pi]$ and the elevation cluster central angles are set to the elevation angle. Moreover, the cluster angular spreads are exponentially distributed with a mean equal to $1/\lambda_{\gls{rms}}$ that depends on the carrier frequency and on whether we are considering the azimuth or elevation directions (see [@Akdeniz14 Table I]). The number of clusters is distributed as a random variable of the form $$C_{mk} \sim \max\left\{\text{Poisson}(\sigma_C),1\right\},$$ where $\sigma_C$ is set 