Algorithm 2 Transmit beamforming design at the base station (BS) for all time slots.

Input:S, ${\mathbf{h}}_{\mathrm{U}}^{\left[n,t\right]}$, ${\mathbf{h}}_{\mathrm{E}}^{\left[e,t\right]},{\mathcal{N}}_t\forall n,\forall e,\forall t$

Output:${\mathbf{V}}_t\forall t$

for $t=1:T$ do

${\mathbf{H}}_{\mathrm{C},t}={\left[{\mathbf{h}}_{\mathrm{C}}^{\left[n_t^{\left[1\right]},t\right]T},{\mathbf{h}}_{\mathrm{C}}^{\left[n_t^{\left[2\right]},t\right]T},\cdots ,{\mathbf{h}}_{\mathrm{C}}^{\left[n_t^{\left[S\right]},t\right]T}\right]}^T$

${\mathbf{H}}_{\mathrm{E},t}={\left[{\mathbf{h}}_{\mathrm{E}}^{\left[1,t\right]T},{\mathbf{h}}_{\mathrm{E}}^{\left[2,t\right]T},\cdots ,{\mathbf{h}}_{\mathrm{E}}^{\left[E,t\right]T}\right]}^T$

${\mathbf{B}}_t={\mathrm{Eig}}_S\left({\left({\mathbf{I}}_M+\rho {\mathbf{H}}_{\mathrm{E},t}^H{\mathbf{H}}_{\mathrm{E},t}\right)}^{-1}\left({\mathbf{I}}_M+\rho {\mathbf{H}}_{\mathrm{C},t}^H{\mathbf{H}}_{\mathrm{C},t}\right)\right)$

if $S>1$ then

${\mathbf{Z}}_t={\left({\mathbf{H}}_{\mathrm{C},t}{\mathbf{B}}_t\right)}^{-1}$

${\mathbf{V}}_t={\mathbf{B}}_t{\mathbf{Z}}_t$

else

${\mathbf{V}}_t={\mathbf{B}}_t$

end if

All column vectors of ${\mathbf{V}}_t$ are normalized to the unit norm.

end for