Page 279 - Kaleidoscope Academic Conference Proceedings 2024

PERFORMANCE EVALUATION OF STAR-RIS AND AF RELAY IN NOMA-ENABLED
V2V NETWORKS FOR 6G

1
1
Abhinav Kumar Singh ; Bikash Chandra Sahana
1 National Institute of Technology, Patna, India-800005

ABSTRACT rate in a MIMO system, whether it is single-user or multiuser
system [11].
In this paper the performance analysis of simultaneously
transmitting and reflecting-reconfigurable intelligent The primary drawback of RISs, even though they can
surface (STAR-RIS) aided non-orthogonal multiple access enhance the quality of end-to-end channel, the equivalent
(NOMA) for vehicle-to-vehicle (V2V) communication has value of the reflected channel from vehicle to RIS and RIS
been done along with the Amplify and Forward (AF) relay to vehicle is lower than the direct channel linking the
aided NOMA for V2V communication. The NOMA transmitter vehicle and the receiver vehicle, as the channel
cooperative system uses two amplify-and-forward (AF) gain of reflected signal is the product of the RIS-user channel
relays. The RIS NOMA uses the intelligent surface with N and the vehicle to RIS channel. If a relay node is used in
element single structure. The achievable rate and its closed place of the RIS which is having the forwarding capabilities,
form approximations for both STAR-RIS framework and AF the above-mentioned limitation can be addressed, but the
relaying systems have been calculated. The simulation was relay will require more energy and complexity. Comparing
done at high and low signal to interference noise ratio (SNR), STAR-RIS and relay-aided systems, the authors in [12]
the obtained results suggest that the STAR-RIS V2V model demonstrate that the RIS-aided system can achieve up to
outperforms the AF relay V2V NOMA model at high SNR. three times more energy efficiency than using an angular
amplify-and-forward (AF) relaying system with multiple
Keywords – AF relay, NOMA, STAR-RIS, V2V antennas. This significant gain results from the fact that, as
compared to a relay, a RIS uses relatively low power to
1. INTRODUCTION forward the reflected signal. AF relay usually has a lower
latency than RIS since it does not need the extensive
In V2V wireless communication systems, scattering, delays, processing needed to dynamically modify reflections. In
reflections, and diffractions all have an impact on wave situations where the channel conditions are largely stable or
propagation [1]. The attenuated, delayed, random and change slowly, an AF relay may be appropriate. Because of
multiple copies of the transmitted signal make up the its dynamic reflection characteristics, RIS may be more
received signal a complex process to realize, as a result, these advantageous in channels that change quickly. The authors
characteristics affects the coverage probability, attainable of [13] demonstrate that for any value of N, a RIS-assisted
rate, and energy efficiency [2]. The performance in such system is unable to produce a SNR greater than a decode-
scenario can be enhanced by giving the propagation medium and-forward (DF) relay-assisted MIMO system.
some degree of reconfigurability, this can be achieved by
using a RIS, RIS has been recognized as a fundamental In 6G V2V communication Simultaneously Transmitting
element in 6G wireless communications technology. To be and Reflecting RIS (STAR-RIS) and AF relay are two
more precise, RIS is a cost-effective planar array with a high popular technologies that are being used, in this work, a
number of reflecting elements that can be reconfigured using STAR-RIS aided V2V network using NOMA and an AF
a programmable controller to improve the wireless relay aided V2V network with NOMA has been proposed, to
propagation environment. [3]-[5]. An RIS can increase study the effectiveness and ambiguities in both models, a
energy and communication system efficiency [6, 7], reduce closed form expression of achievable rates have been
inter-cell interference [8], improve secrecy rate [9], and calculated. A comparative study has been carried out
expand millimeter wave communications coverage [10]. thoroughly to evaluate the throughput and sum rate of each
Furthermore, it has the potential to greatly enhance the sum model. An investigation has been carried out by varying the

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