| dc.description.abstract |
A promising technology for vehicular ad-Hoc Networks (VANETs) is Millimeter-
wave (mmWave). mmWave is, however, susceptible to path loss and fading, which
degrades system performance. Error-free data between Vehicle to Vehicle (V2V)
and Vehicle to Infrastructure (V2I) in the context of fading and mobility of vehicles
calls for in-depth research.
In addition to the above-mentioned limitations, challenging issues degrading
the reliability of VANET are the problems of high penetration loss and blocking.
To establish effective communication in mmWave networks in context of vehicles, a
detailed understanding of the VANET communication channel is necessary, which
differs significantly from those explored at frequencies lower than 6 GHz. When
a vehicle’s speed exceeds 50 km/h, Doppler shifts can have adverse affects on the
reliability of V2V communication. The transmission becomes impossible in VANET
because of the increasing mobility of the nodes.
This research presents three tractable channel models for VANET in which
system performance degradation due to error is addressed. The operating frequency
is 60 GHz. In the first model, concatenated Bose-Chaudhuri-Hocquenghem (BCH)
and Alamouti Space-Time Block Coding (ASTBC) and coding are used. The two Bit
Error Rate (BER) closed-form approximations, one for BCH in Rayleigh fading and
the other for BCH with ASTBC, are obtained. Signal to Noise Ratio (SNR) and code
rate are included in these expressions, which can be used to create VANET systems.
The findings demonstrate that the BER obtained by concatenating ASTBC and
BCH is 10"5 thus outperforming the traditional BER obtained by ASTBC expression.
The code rate (127,36), (127,64) and (255,251) are used to evaluate the performance
of the proposed expressions.
The second model is designing a comprehensive tractable model for VANET
over millimeter waves that combines Reed Solomon (RS) coding with Space-Time
Block Coding (STBC). The closed-form approximations for BER of RS in the Addi
tive White Gaussian Noise (AWGN) channel and Rayleigh fading are derived. The
performance of RS closed-form expressions is compared with previous BER com
putation approaches. The results shows that the BER lies between 10'7 to 10'6.
Furthermore, the model’s performance has been compared with the current VANET
communication systems, specifically the IEEE 802.11bd and 3GPP V2X communi
cation systems. Results are comparable with V2X NR and demonstrate that our
suggested approach works better than IEEE 802.11bd. As metrics for performance,
throughput, Packet Error Rate (PER) and Packet Reception Ratio (PRR) are em
ployed. The model has also been evaluated with vehicles moving at faster velocities.
Further, the simulation and numerical findings show that the AWGN approxima
tion for STBC-RS model outperforms Reed Solomon - Mary Phase Shift Keying
(RS-MPSK) traditional system i.e. the achieving the BER of 1CT7. These derived
expressions can be adopted in designing various VANET architectures targeting re
liability in the network. The path loss and fading are reduced since the directivity
of the transmitter has increased using beamforming.
The analytical and numerical results are compared, demonstrating the accuracy
of our closed-form expressions. In the third model, the impact of the Doppler
shift using BCH and RS coding is also analyzed in VANET communication. Since
Orthogonal Frequency Division Multiplexing (OFDM), which is highly susceptible
to Doppler shift, is used by the IEEE 802.lip PHY layer. It is seen that the results
of the suggested model surpass those of earlier models, including 802.lip.
Considering there exhibits a strong dependence of 5G/6G communication on
both the molecular composition of the medium and the transmission distance. The
closed-form expressions of BER are simulated in the Terahertz (THz) channel. A
detailed analysis of relative humidity dependency on code rate is conducted. Further,
the relation between code rate and relative humidity is analyzed. The results are
analyzed at different code rates. Moreover, we have compared our results with the
performance of existing ASTBC technique in the THz channel. The results depict
that the proposed model surpasses the behavior of the ASTBC equation in THz.
The findings presented here are expected to pave the way for ultra-reliable vehicular
communication networks |
en_US |