Page 281 - Kaleidoscope Academic Conference Proceedings 2024

Innovation and Digital Transformation for a Sustainable World

L
h h  +
x +
y = ( rl H sr h sl H )  i i  , i (3) 10 RIS-NOMA
l
i l = AF-Relay NOMA
The signal to interference plus noise ratio of the vehicle 8
after decoding the signal can be written as 6

h h  H  h  + 2 Maximum Achievable Rate (Mbps/Hz)
SINR = rl sr l sl l (4)
l L 2 4
 ( rl H sr h sl H ) + i +  2
h h 
i l = + 1 2
The achievable rate can be calculated using the Shannon’s
theorem [17] and can be given by 0
0 5 10 15 20 25 30
= log 2 (1 SINR l ) SNR(dB)
+

Figure 3- Maximum achievable rate versus SNR
 
 h h  H  h  + 2 
= log 1  2 rl sr l sl l  + (5) x 1   n =  1 1  r n −  1 (9)
 L H H 2 2 
h h 
  ( rl sr h sl ) + i +  
 i l = + 1  Where is the amplification coefficient of , [ − 1] is
1
1 1
the signal obtained in the ( − 1) ℎ symbol period.
The throughput of the above system can be calculated as Similarly, for 2 the transmitted symbol in ( −
1) ℎ symbol period is [ − 1] . If the additive white
2
L
+
 =  log 2 (1 SINR l ) (6) Gaussian noise (AWGN) is assumed to be added in the
1
received signal with zero mean and variance as . The
2
l= 1
signal [ − 1] can be expressed as
1
  H 2   
1]
L
=  log 1  2 L h h  rl sr  l h  + sl l  + (7) r 1 n −  1 = h sR 1   1 Ps 1 [n − +  2 Ps 2 [n − 1]
H
l= 1   h h  h H ) + 2 +  2 
 ( rl sr sl i 
1] 
 i l = + 1  + h R 1 2 R x 2 [n− + 1 [n− 1] (10)
2.2. AF relay assisted NOMA V2V model at destination vehicle , the received signal in ℎ symbol

duration is given by
A unique two-path successive relay system based on NOMA
has been demonstrated in Fig. 2. A source vehicle , a y [ ] n = h x [ ] n  [ ] n
+

destination vehicle , and two AF mode relays make up the d V 1 R d 1 d

system. The channel gain between source vehicle and the

1] 
1] 
h
1] h
first relay is given by ℎ 1 , between and as ℎ 2 , =  1 h 1 R d  sR 1 [ x n − + R 2 1 R x 2 [n − + 1 [n − + d [n  ] (11)

1
2
between first relay to second as ℎ , between second relay
1 2
to first as ℎ , between and destination vehicle as
1]
1]
2 1 1 Where [ x n − =  1 Ps 1 [n − +  2 Ps 2 [n − 1] and [ ] is

ℎ 1 and between and as ℎ 2 . AWGN with mean zero and variance . In equation 11, The

2
2
term  h h [ x n− 1] is the message component and
Using NOMA, the vehicle transmits the superimposed 1 sR 1 R d
1

signal which can be written as follows:  1 h h 2 1 x 2 [n − 1] is the interference noise from and
2
1 R d R R
needs to be suppressed. The signal received at the destination
2
2 
S =  Ps +  Ps =  Ps (8) in the ( + 1) ℎ symbol duration can be given as

1 1 2 i i
i= 1
1] 
y d V [n+ = 2 sR 2 R d [ ] n +  2 R 1 2 R h x 1 [ ] n
h h x
h
2 R d
Where and are the transmitted signals with their 1
2
1
variances equals to one. is the power allocation coefficient, +  h  [ ] n  [n+ 1] (12)
+

such that ∑ 2 =1 = 1 and is the transmit power. 2 2 R 2 d

Once the superimposed signal is transmitted from the source, Where is the amplification factor of .
2
2
the forwarded signal from in the ℎ slot can be given as
1
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