|
η
|
The energy conversion efficiency
|
|
E
D
|
The maximum transmission power of UE1, UE2, and UE3.
|
|
E
C
|
The circuit power of UE1,UE2, and UE3.
|
|
E
R
|
The transmit power of R
|
|
|X|2, r
X
, and P
L
X
|
The channel power gain, the distance, and the path loss model for the link from UE1 to R, respectively.
|
|
|Y|2, r
Y
, and P
L
Y
|
The channel power gain, the distance, and the path loss model for the link from R to UE2, respectively.
|
|
|Z|2, r
Z
, and P
L
Z
|
The channel power gain, the distance, and the path loss model for the link from R to UE3, respectively.
|
|
|W|2, r
W
, and P
L
W
|
The channel power gain, the distance, and the path loss model for the link from UE2 to UE3, respectively.
|
|
Ω
k
|
The exponential parameters corresponding to |k|2, k∈[X,Y,Z,W].
|
|
α
1
T
|
Time switching (TS) fraction used for EH from UE1 to R
|
|
α
2
T
|
TS fraction used for IT from EU1 to R
|
|
(T−α
1
T−α
2
T)
|
TS used for IT from R to UE2 and UE3
|
|
β
E
D
|
Power spitting (PS) fraction used for EH at R
|
|
(1−β)E
D
|
Information transmission (IT) from UE1 to R in PS protocol
|
|
λ
|
The power allocation at R used to transmit signals to UE2
|
|
(1−λ)
|
The power allocation at R used to transmit signals to UE3
|
|
κ
|
The aggregate level of hardware impairments
|
|
H
I
1
|
The distortion noise caused by HWIs in the communication between UE1 and R with variance, H
I
1∼C
N(0,κ
E
D
P
L
X
|X|2)
|
|
H
I
2, H
I
3, and H
I
4
|
The distortion noise HWIs from R to UE2, R to UE3, and between UE2 and UE3 with variance H
I
2∼CN(0,κ
λ
E
R
P
L
Y
|Y|2), H
I
3∼CN(0,κ(1−λ)E
R
P
L
Z
|Z|2), and H
I
4∼CN(0,κ
E
D
P
L
W
|W|2), respectively.
|
|
n
0
|
The additive white Gaussian noise (AWGN) at UEs and R with mean power, Ω
0,
|
|
F
x
, f
x
|
The cumulative distribution function (CDF)/the probability density function (PDF) of the RV x is \({F_x}(z) = Pr(x<z)=1 - {e^{-\frac {z}{{{\Omega _x}}}}}\), \({f_x}(z) = Pr(x<z)={\frac {z}{{{\Omega _x}}}}{e^{-\frac {z}{{{\Omega _x}}}}}\), respectively, in which Ω
x
is the mean of the exponential RV x.
|
|
Pr{.}
|
The probability distribution function.
|
|
K
n
{.}
|
The n order modified Bessel function of the second kind with the last equality
|
|
\(\mathbb {E}\left \{ {.} \right \}\)
|
The expectation operator.
|
|
\(\gamma _{i}^{AF}\), \(\gamma _{i}^{DF}\)
|
The signal-to-noise-plus-distortion ratio (SNDR) at UEi for AF scheme and DF scheme, respectively
|
|
Γ
D
|
The SNDR threshold
|
