Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications

In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.

Coalitional game based resource allocation in D2D-enabled V2V communication

The joint resource block(RB)allocation and power optimization problem is studied to maximize the sum-rate of the vehicle-to-vehicle(V2V)links in the device-to-device(D2D)-enabled V2V communication system,where one feasible cellular user(FCU)can share its RB with multiple V2V pairs.The problem is first formulated as a nonconvex mixed-integer nonlinear programming(MINLP)problem with constraint of the maximum interference power in the FCU links.Using the game theory,two coalition formation algorithms are proposed to accomplish V2V link partitioning and FCU selection,where the transferable utility functions are introduced to minimize the interference among the V2V links and the FCU links for the optimal RB allocation.The successive convex approximation(SCA)is used to transform the original problem into a convex one and the Lagrangian dual method is further applied to obtain the optimal transmit power of the V2V links.Finally,numerical results demonstrate the efficiency of the proposed resource allocation algorithm in terms of the system sum-rate.

MPC-based time synchronizationmethod for V2V (vehicle-tovehicle)communication

Purpose–As the strategy of 5G new infrastructure is deployed and advanced,5G-R becomes the primary technical system for future mobile communication of China’s railway.V2V communication is also an important application scenario of 5G communication systems on high-speed railways,so time synchronization between vehicles is critical for train control systems to be real-time and safe.How to improve the time synchronization performance in V2V communication is crucial to ensure the operational safety and efficiency of high-speed railways.Design/methodology/approach–This paper proposed a time synchronization method based on model predictive control(MPC)for V2V communication.Firstly,a synchronous clock for V2V communication was modeled based on the fifth generation mobile communication-railway(5G-R)system.Secondly,an observation equation was introduced according to the phase and frequency offsets between synchronous clocks of two adjacent vehicles to construct an MPC-based space model of clock states of the adjacent vehicles.Finally,the optimal clock offset was solved through multistep prediction,rolling optimization and other control methods,and time synchronization in different V2V communication scenarios based on the 5G-R system was realized through negative feedback correction.Findings–The results of simulation tests conducted with and without a repeater,respectively,show that the proposed method can realize time synchronization of V2V communication in both scenarios.Compared with other methods,the proposed method has faster convergence speed and higher synchronization precision regardless of whether there is a repeater or not.Originality/value–This paper proposed an MPC-based time synchronization method for V2V communication under 5G-R.Through the construction of MPC controllers for clocks of adjacent vehicles,time synchronization was realized for V2V communication under 5G-R by using control means such as multistep prediction,rolling optimization,and feedback correction.In view of the problems of low synchronization precision and slow convergence speed caused by packet loss with existing synchronization methods,the observer equation was introduced to estimate the clock state of the adjacent vehicles in case of packet loss,which reduces the impact of clock error caused by packet loss in the synchronization process and improves the synchronization precision of V2V communication.The research results provide some theoretical references for V2V synchronous wireless communication under 5G-R technology.

Pricing Based Power Control for Inter-Cell UAV-Assisted Vehicle-to-Vehicle Underlay Communication

The high-capacity vehicle-to-vehicle(V2 V) communication provides a promising solution to support ubiquitous media streaming and content sharing among vehicles.To extend the V2 V links to multiple cells and manage the inter-cell interference,we proposed an UAV-assisted inter-cell V2 V communication model,in which a shared UAV node is placed in the center of V2 V users.By charging the V2 V users underlay spectrum access fee,the cellular network earn profit at the cost of encountering co-channel interference from V2 V links.A Stackelberg game is formulated to model the interactions between the V2 V links and the cellular links,which are the game follower and the leader respectively.Their utility functions are maximized in terms of accessing price as well as transmit power of V2 V users and UAV relays.Simulation evaluations verify that the power-price tradeoff between V2 V network and cellular network has significant potentials to enhance their utility.

V2X-Communication Assisted Interference Minimization for Automotive Radars

With the development of automated driving vehicles, more and more vehicles will be fitted with more than one automotive radars, and the radar mutual interference will become very significant. Vehicle to everything (V2X) communication is a potential way for coordinating automotive radars and reduce the mutual interference. In this paper, we analyze the positional relation of the two radars that interfere with each other, and evaluate the mutual interference for different types of automotive radars based on Poisson point process (PPP). We also propose a centralized framework and the corresponding algorithm, which relies on V2X communication systems to allocate the spectrum resources for automotive radars to minimize the interference. The minimum spectrum resources required for zero-interference are analyzed for different cases. Simulation results validate the analysis and show that the proposed framework can achieve near-zero-interference with the minimum spectrum resources.

A Joint Power and Bandwidth Allocation Method Based on Deep Reinforcement Learning for V2V Communications in 5G

Vehicular communications have recently attracted great interest due to their potential to improve the intelligence of the transportation system.When maintaining the high reliability and low latency in the vehicle-to-vehicle(V2V)links as well as large capacity in the vehicle-to-infrastructure(V2I)links,it is essential to flexibility allocate the radio resource to satisfy the different requirements in the V2V communication.This paper proposes a new radio resources allocation system for V2V communications based on the proximal strategy optimization method.In this radio resources allocation framework,a vehicle or V2V link that is designed as an agent.And through interacting with the environment,it can learn the optimal policy based on the strategy gradient and make the decision to select the optimal sub-band and the transmitted power level.Because the proposed method can output continuous actions and multi-dimensional actions,it greatly reduces the implementation complexity of large-scale communication scenarios.The simulation results indicate that the allocation method proposed in this paper can meet the latency constraints and the requested capacity of V2V links under the premise of minimizing the interference to vehicle-to-infrastructure communications.

A Geometry-Based Stochastic Scattering Channel Model for V2V Communications in Dense Urban Street Environments

In this paper,we propose a stochastic channel model in three-dimensional(3D)space for multiple input multiple output(MIMO)vehicle-to-vehicle(V2V)communications in dense urban environments.The movement of the mobile transmitter and mobile receiver results in the V2V channel model behave temporal non-stationarity.Therefore,the time-varying parameters of the propagation paths and angles are derived to characterize such property.Using this channel model,we investigate the propagation characteristics of V2V channels in terms of the road section and moving time/directions/speeds of the transmitter and receiver.Numerical results show that the theoretical results of the propagation characteristics of the V2V channel model are very close to those of the simulation ones,which show that the proposed channel model is suitable for depicting the V2V communications in dense urban scenarios.

Integrated Sensing and Communication:Who Benefits More?

This paper compares the benefits of communication-assisted sensing and sensing-assisted communication in the context of integrated sensing and communication(ISAC).Communication-assisted sensing leverages the extensive cellular infrastructure to create a vast and cooperative sensor network,enhancing environmental perception accuracy and coverage.On the other hand,sensing-assisted communication utilizes advanced sensing technologies to improve predictive beamforming and channel estimation performance in high-frequency and highmobility scenarios,thereby increasing communication efficiency and reliability.To validate our analysis,we present an example of channel knowledge map(CKM)-assisted beam tracking.This example demonstrates the practical advantages of incorporating CKM in enhancing beam tracking accuracy.Our analysis confirms that communication-assisted sensing may offer greater development potential due to its wide coverage and cost-effectiveness in large-scale applications.

A Transmission Design in Dynamic Heterogeneous V2V Networks Through Multi-Agent Deep Reinforcement Learning

In highly dynamic and heterogeneous vehicular communication networks,it is challenging to efficiently utilize network resources and ensure demanding performance requirements of safetyrelated applications.This paper investigates machinelearning-assisted transmission design in a typical multi-user vehicle-to-vehicle(V2V)communication scenario.The transmission process proceeds sequentially along the discrete time steps,where several source nodes intend to deliver multiple different types of messages to their respective destinations within the same spectrum.Due to rapid movement of vehicles,real-time acquirement of channel knowledge and central coordination of all transmission actions are in general hard to realize.We consider applying multi-agent deep reinforcement learning(MADRL)to handle this issue.By transforming the transmission design problem into a stochastic game,a multi-agent proximal policy optimization(MAPPO)algorithm under a centralized training and decentralized execution framework is proposed such that each source decides its own transmission message type,power level,and data rate,based on local observations of the environment and feedback,to maximize its energy efficiency.Via simulations we show that our method achieves better performance over conventional methods.

Secure Performance Analysis and Optimization for FD-NOMA Vehicular Communications

Vehicle-to-vehicle(V2V)communication appeals to increasing research interest as a result of its applications to provide safety information as well as infotainment services.The increasing demand of transmit rates and various requirements of quality of services(QoS)in vehicular communication scenarios call for the integration of V2V communication systems and potential techniques in the future wireless communications,such as full duplex(FD)and non-orthogonal multiple access(NOMA)which enhance spectral efficiency and provide massive connectivity.However,the large amount of data transmission and user connectivity give rise to the concern of security issues and personal privacy.In order to analyze the security performance of V2V communications,we introduce a cooperative NOMA V2V system model with an FD relay.This paper focuses on the security performance of the FD-NOMA based V2V system on the physical layer perspective.We first derive several analytical results of the ergodic secrecy capacity.Then,we propose a secrecy sum rate optimization scheme utilizing the instantaneous channel state information(CSI),which is formulated as a non-convex optimization problem.Based on the differential structure of the non-convex constraints,the original problem is approximated and solved by a series of convex optimization problems.Simulation results validate the analytical results and the effectiveness of the secrecy sum rate optimization algorithm.

Misbehavior Detection Method by Time Series Change of Vehicle Position in Vehicle-to-Everything Communication

In recent years, research has been conducted on connected vehicles (CVs) that are equipped with communication devices and can be connected to networks. CVs share their own position information and surrounding information with other vehicles using Vehicle-to-Everything (V2X) communication. CVs can recognize obstacles on non-line-of-sight (NLoS), which cannot be recognized by autonomous vehicles, and reduce travel time to a destination by cooperative driving. Therefore, CVs are expected to provide safe and efficient transportation. On the other hand, problems of security of V2X communication by CVs have been discussed. Safe and efficient transportation by CVs is on the basis of the assumption that correct vehicle information is shared. If fake vehicle information is shared, it will affect the driving of CVs. In particular, vehicle position faking has been shown that it can induce traffic congestion and accidents, which is a serious problem. In this study, we define position faking by CV as misbehavior and propose a method to detect misbehavior on the basis of changes in vehicle position time series data composed of vehicle position information. We evaluated the proposed method using four different misbehavior models. F-measure of misbehavior models that CV sends random position information detected by the proposed method is higher than one by a related method. Therefore, the proposed method is suitable for detecting misbehavior in which the position information changes over time.

Reliability Evaluation of IEEE 802.11p-Based Vehicle-to-Vehicle Communication in an Urban Expressway

IEEE 802.11p/DSRC （Dedicated Short Range Communication） is considered to be a promising wireless communication standard for enhancing transportation safety and efficiency. However, IEEE 802.11p-based Vehicle- to-Vehicle （V2V） communication is still unreliable because of the complicating factors of high vehicle speed and complex radio environments. In this paper, we performed a data-based evaluation of V2V communication reliability, using real-world measurements in a typical urban expressway in Beijing. With respect to the characteristics of the urban expressway and our experimental data, we found road slope and traffic density to be the major environmental factors having a significant impact on the V2V communication＇s Line-Of-Sight （LOS） conditions. On the basis of these two factors, we propose a fuzzy classification method for the LOS conditions, and separate the real- time communication environments into different LOS cases. For each LOS case, we quantify the metrics as received signal strength indication, packet delivery rate, and communication latency. The results reveal that the communication reliability in urban expressways is very unstable because of the changing LOS conditions. This study provides a useful reference for the IEEE 802.11 p-based cooperative systems in urban expressways.

Interacting multiple model-based ETUKF for efficient state estimation of connected vehicles with V2V communication

Accurate prediction of the motion state of the connected vehicles,especially the preceding vehicle(PV),would effectively improve the decision-making and path planning of intelligent vehicles.The evolution of vehicle-tovehicle(V2V)communication technology makes it possible to exchange data between vehicles.However,since V2V communication has a transmission interval,which will result in the host vehicle not receiving information from the PV within the time interval.Furthermore,V2V communication is a time-triggered system that may occupy more communication bandwidth than required.On the other hand,traditional estimation methods of the PV state based on individual models are usually not applicable to a wide range of driving conditions.To address these issues,an event-triggered unscented Kalman filter(ETUKF)is first employed to estimate the PV state to strike a balance between estimation accuracy and communication cost.Then,an interactive multi-model(IMM)approach is combined with ETUKF to form IMMETUKF to further improve the estimation accuracy and applicability.Finally,simulation experiments under different driving conditions are implemented to verify the effectiveness of IMMETUKF.The test results indicated that the IMMETUKF has high estimation accuracy even when the communication rate is reduced to 14.84%and the proposed algorithm is highly adaptable to different driving conditions.

Simulation and Analysis on Overtaking Safety Assistance System Based on Vehicle-to-Vehicle Communication

Because of the complexity and variability of an intelligent vehicle’s driving environment,it is difficult for the application of the vehicular sensors to meet the needs of the surrounding environment information entirely.Vehicle-to-vehicle(V2V)communication technology is used by target vehicles to exchange information,and obtain the driving condition and driving intention of the front driver.To obtain environmental information outside the range of vehicular sensors in advance,in this paper,a vehicle overtaking assistance system is proposed based on V2V communication.The data,including the speed,position,direction angle and steering angle obtained using V2V communication,were preliminarily processed.Then,combined with an overtaking safety distance model,the vehicle parameters,driver’s driving intention and vehicle status information were entered into an overtaking security assistance system to determine the overtaking conditions.Fuzzy theory was used to control the parameters of the overtaking safety distance model.Finally,the overtaking safety assistance system was established and the proposed algorithm was tested using PreScan/MATLAB cooperative simulation software.The results showed that the proposed overtaking safety algorithm effectively provided a warning according to environmental change and the driver’s intention,which assisted the driver to overtake and avoid the occurrence of accidents,which improved the safety performance of the vehicle.

Secure Model to Generate Path Map for Vehicles in Unusual Road Incidents Using Association Rule Based Mining in VANET

Logical behavioral arrangements are a class of conventional arrangements to illustrate the happening of incidents in an appropriate and structured approach in vehicular ad hoc network （VANET）. These incidents are characterized as a list of path segments that are passed through by the vehicles for the duration of their journeys from a pre-decided local source to a local destination in a structured manner. A set of proper description illustrating the paths traversed by the vehicles as logical behavioral arrangements is describedin this paper. The data gathering scheme based on secure authentication to gather the data from the vehicles is proposed in this paper. This proposed data gathering scheme based on secure authentication is compared with the existing data gathering schemes by using veins framework and the results of analysis reflect that the proposed scheme outperforms among others. The data collected from the vehicles by the proposed data gathering scheme is stored at distributed road side units （RSUs）. From these collected paths, the common and frequent paths opted by the vehicles in a certain region are determined by using frequent arrangement mining approach. An estimation model is used to decidethe next path and the whole path map opted by the vehicles in unusual situations like accident, jams, or a particular time of day. The proposed scheme will helpthe society in reducing the waiting time in vent of emergency or normal working days.

Big Wave of the Intelligent Connected Vehicles

Internet of things is deemed as the one of the great revolution after the age of Industrial Revolution.With the development of the communication technology,more and more entities are connected to the communication network and become one of the elements in the network.Over recent decades,in the area of intelligent transportation,pedestrian and transport infrastructure are connected to the communication network to improve the driving safety and traffic efficiency which is known as the ICV(Intelligent Connected Vehicle).This paper summarizes the global ICV progresses in the past decades and the latest activities of ICV in China,and introduces various aspects regarding the recent development of the ICV,including industry development,spectrum and standard,at the same time.

A 3D Geometry-Based Scattering Model for Vehicleto-Vehicle Wideband MIMO Relay-Based Cooperative Channels

In this paper, a three-dimensional(3D) geometry- based stochastic scattering model(GBSSM) for wideband multi-input multi-output(MIMO) vehicle-to-vehicle(V2V) relay-based cooperative fading channel based on geometrical three-cylinder is proposed. Non-line-of-sight(NLOS) propagation condition is assumed in amplify-and-forward(AF) cooperative networks from the source mobile station(S) to the destination mobile station(D) via the mobile relay station(R). We extend the proposed narrowband model to wideband and also introduce the carrier frequency and bandwidth into the model. To avoid complicated procedure in deriving the analytical expressions of the channel parameters and functions, the channel is realized first. By using the realized channel matrix, the channel properties are further investigated.

Design of hexagon microstrip antenna for vehicle-to-vehicle communication

Considering the shortcomings of the existing vehicle-to-vehicle（V2V） communication antennas, this paper proposes a regular hexagon broadband microstrip antenna. By loading shorting pins and etching V-shape slots with different size at each angle of the regular hexagon patch, it realizes impedance matching and obtains better impedance bandwidth. The simulated results show that the relative bandwidth of this antenna reaches 35.55%, covers the frequency band of 4.74 GHz to 6.79 GHz. The antenna acquires an omni-directional radiation pattern in the horizontal plane whose out of roundness is less than 0.5 d B. In addition, the antenna is manufactured and tested, whose tested results are basically consistent with simulated results. Because the height of antenna is 3 mm, it is easy to be hidden on roof of a vehicle for V2 V communication.

Review of the Security Issues in Vehicular Ad Hoc Networks (VANET)

There is a significant increase in the rates of vehicle accidents in countries around the world and also the casualties involved ever year. New technologies have been explored relating to the Vehicular Ad Hoc Network (VANET) due to the increase in vehicular traffic/congestions around us. Vehicular communication is very important as technology has evolved. The research of VANET and development of proposed systems and implementation would increase safety among road users and improve the comfort for the corresponding passengers, drivers and also other road users, and a great improvement in the traffic efficiency would be achieved. This research paper investigates the current and existing security issues associated with the VANET and exposes any slack amongst them in order to lighten possible problem domains in this field.

A Multi-Mode Public Transportation System Using Vehicular to Network Architecture

The number of accidents in the campus of Suranaree University of Technology(SUT)has increased due to increasing number of personal vehicles.In this paper,we focus on the development of public transportation system using Intelligent Transportation System(ITS)along with the limitation of personal vehicles using sharing economy model.The SUT Smart Transit is utilized as a major public transportation system,while MoreSai@SUT(electric motorcycle services)is a minor public transportation system in this work.They are called Multi-Mode Transportation system as a combination.Moreover,a Vehicle toNetwork(V2N)is used for developing theMulti-Mode Transportation system in the campus.Due to equipping vehicles with On Board Unit(OBU)and 4G LTE modules,the real time speed and locations are transmitted to the cloud.The data is then applied in the proposed mathematical model for the estimation of Estimated Time of Arrival(ETA).In terms of vehicle classifications and counts,we deployed CCTV cameras,and the recorded videos are analyzed by using You Only Look Once(YOLO)algorithm.The simulation and measurement results of SUT Smart Transit and MoreSai@SUT before the covid-19 pandemic are discussed.Contrary to the existing researches,the proposed system is implemented in the real environment.The final results unveil the attractiveness and satisfaction of users.Also,due to the proposed system,the CO_(2) gas gets reduced when Multi-Mode Transportation is implemented practically in the campus.