N	$N\ge 1$	Number of devices
$R_1$, $R_2$		Coupled relays
$d_{R_1}$, $d_{R_2}$		Distances from BS to relays
$\mathcal{R}$	$\mathcal{R}=\left\{R_1,R_2\right\}$	Set of relays
$D_n$	$n\in N$	Devices
$d_n$	$n\in N$	Distances from relay $R_1$ to devices
$v_n$	$n\in N$	Distances from relay $R_2$ to devices
$A_0$, $A_1$, $A_2$	$A_0>1$, $A_1>1$, $A_2>1$	Number of antennas on BS, $R_1$ and $R_2$, respectively
$\omega$		Path-loss exponent factor
${\mathbf{H}}_0$, ${\mathbf{G}}_0$		Pre-coding channel matrices from BS to $R_1$ and $R_2$
$h_0^{\left(a_0,a_1\right)}$, $g_0^{\left(a_0,a_1\right)}$	$a_0\in A_0$, $a_1\in A_1$	Channels from BS to $R_1$ and $R_2$
${\mathbf{H}}_n$, ${\mathbf{G}}_n$		Pre-coding channel matrices from $R_1$ and $R_2$ to devices
$\theta$	$\theta =\left\{odd,even\right\}$	binary value
$T^{\left(\theta \right)}$	$\theta =\left\{odd,even\right\}$	Odd/even transmission block
$h_n^{\left(a_0,a_1\right)}$, $g_n^{\left(a_0,a_1\right)}$	$n\in N$,$a_0\in A_0$, $a_1\in A_1$	Channels from relays $R_1$ and $R_2$ to devices
$T_1^{\left(\theta \right)}$,$T_2^{\left(\theta \right)}$		First/second time slot in odd/even transmission block
$\lambda$	$0\le \lambda \le 1$	Power splitting factor
$\eta$	$0\le \eta \le 1$	Collect factor
$P_S$,$P_{\mathcal{R}}$		Power domain on BS and relays
${\rho }_S$,${\rho }_{\mathcal{R}}$		SNR on BS and relays
${\alpha }_i$	$i\in N$, ${\displaystyle \sum _i}{\alpha }_i=1$, ${\alpha }_1<\dots <{\alpha }_N$	PA factors for devices
$x_i$	$i\in N$	Data of devices
$n_{{ }_{\mathcal{R}}}$, $n_n$,	$n\in N$	AWGN at relays and devices
${\mathbf{Y}}_{\mathcal{R}}^{\left(T_1^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $\mathcal{R}=\left\{R_1,R_2\right\}$	Received signals at relays
${\mathbf{Y}}_n^{\left(T_2^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $n\in N$	Received signals at devices
$R_i^{*}$	$i\in N$	Devices’ data rate thresholds
${\gamma }_i^{*}$	$i\in N$	SINR thresholds
${\gamma }_{\mathcal{R}-x_i}^{\left(T_1^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $\mathcal{R}=\left\{R_1,R_2\right\}$, $i\in N$	SINRs at relays decode symbol $x_i$
${\gamma }_{n-x_i}^{\left(T_2^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $n\in N$, $i\in n$	SINRs at devices decode symbol $x_i$
${\mathbf{R}}_{\mathcal{R}-x_i}^{\left(T_1^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $\mathcal{R}=\left\{R_1,R_2\right\}$, $i\in N$	Relays’ instantaneous bit-rate thresholds
${\mathbf{R}}_{n-x_i}^{\left(T_2^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $n\in N$, $i\in n$	Devices’ instantaneous bit-rate thresholds
$E_{\mathcal{R}}^{\left(T_1^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $\mathcal{R}=\left\{R_1,R_2\right\}$	EH at relay $R_1$ or $R_2$ in odd/even transmission block
$O{P}_{\mathcal{R}}^{\left(T_1^{\left(\theta \right)}\right)}$	$\theta =\left\{odd,even\right\}$, $\mathcal{R}=\left\{R_1,R_2\right\}$	OP at relays
$O{P}_n^{\left(\theta \right)}$	$\theta =\left\{odd,even\right\}$, $n\in N$	OP at devices
$T{P}_{ }^{\left(\theta \right)}$	$\theta =\left\{odd,even\right\}$	System throughput in odd/even transmission block
$E{E}_{ }^{\left(\theta \right)}$	$\theta =\left\{odd,even\right\}$	Energy efficiency in odd/even transmission block