NOMA Enhanced 5G Distributed Vehicle to Vehicle Communication for Connected Autonomous Vehicles

Connected autonomous vehicles (CAV) holds great potentials of improving road safety and efficiency. However ultra reliability and low latency vehicle to everything (V2X) communication service is required to fully unleash the potentials of CAV. In this paper we investigate distributed vehicle to vehicle (V2V) for CAV, which supports not only broadcast but also multicast/unicast communications. Power domain non-orthogonal multiple access (NOMA) is applied to deal with the CAV traffic patterns, which are different from those in the traditional connected vehicle applications. With NOMA the signals for long range broadcast with major power and signals for short range neighbors with small power can be superposed in one transmission. With the application of NOMA the channel load can be reduced and communication reliability and latency will be improved. The framework and operation of NOMA enhanced distributed V2V system are designed. Qualitative and quantitative benefits of the proposed scheme are analyzed. Simulation results show that the proposed scheme can achieve a gain of more than 80% on network capacity under the investigated scenarios, with large performance improvement in terms of communication throughput and reliability

Enhanced Collision Avoidance for Distributed LTE Vehicle to Vehicle Broadcast Communications

In this paper we investigate the distributed autonomous resource selection for LTE vehicle to vehicle (V2V) broadcast. The effectiveness of collision avoidance and location based resource allocation enhancements is examined. It is found that collision avoidance with multiple data resources reservation per schedule assignment (SA) is a key to improve broadcast reliability. However in the existing collision avoidance algorithm reserving multiple resources per SA can lead to many data packet collisions if a SA collision happens. We propose an enhanced collision avoidance to address this issue. The idea is to use selected data packets to disseminate the reservation of data resources and SA resources, which can provide better communication among neighbor vehicles on resource reservation and reduce data collisions. Simulation results show that the proposed collision avoidance enhancement can effectively improve SA and data transmission reliability. The network capacity in terms of supported vehicles under given V2V service requirements is largely increased by 17% at a negligible cost of added overhead

6G Cellular Networks and Connected Autonomous Vehicles

With 5G mobile communication systems been commercially rolled out, research discussions on next generation mobile systems, i.e., 6G, have started. On the other hand, vehicular technologies are also evolving rapidly, from connected vehicles as coined by V2X (vehicle to everything) to autonomous vehicles to the combination of the two, i.e., the networks of connected autonomous vehicles (CAV). How fast the evolution of these two areas will go head-in-head is of great importance, which is the focus of this paper. After a brief overview on technological evolution of V2X to CAV and 6G key technologies, this paper explores two complementary research directions, namely, 6G for CAVs versus CAVs for 6G. The former investigates how various 6G key enablers, such as THz, cell free communication and artificial intelligence (AI), can be utilized to provide CAV mission-critical services. The latter discusses how CAVs can facilitate effective deployment and operation of 6G systems. This paper attempts to investigate the interactions between the two technologies to spark more research efforts in these areas

Enhanced Collision Avoidance for Distributed LTE Vehicle to Vehicle Broadcast Communications

In this letter, we investigate the distributed autonomous resource selection for LTE vehicle to vehicle (V2V) broadcast. The effectiveness of collision avoidance and location based resource allocation enhancements is examined. It is found that collision avoidance with multiple data resources reservation per schedule assignment (SA) is a key to improve broadcast reliability. However, in the existing collision avoidance algorithm reserving multiple resources per SA can lead to many data packet collisions if a SA collision happens. We propose an enhanced collision avoidance to address this issue. The idea is to use selected data packets to disseminate the reservation of data resources and SA resources, which can provide better communication among neighbor vehicles on resource reservation and reduce data collisions. Simulation results show that the proposed collision avoidance enhancement can effectively improve SA and data transmission reliability. The network capacity in terms of supported vehicles under given V2V service requirements is largely increased by 17% at a negligible cost of added overhead

User Association and Enabling Technologies in Next Generation 5G Ultra-Dense Networks – A Review

Embedding small cells and relay nodes in a macro-cellular network is a promising method for achieving substantial gains in coverage and capacity compared to traditional macro only networks. These new types of base-stations can operate on the same wireless channel as the macro-cellular network, providing higher spatial reuse via cell splitting. However, these base-stations are deployed in an unplanned manner, can have very different transmit powers, and may not have traffic aggregation among many users. This could potentially result in much higher interference magnitude and variability. Hence, such deployments require the use of innovative cell association and inter-cell interference coordination techniques in order to realize the promised capacity and coverage gains. In this paper, we review various techniques for user association and interference mitigation which are required to meet increased data demand in next generation 5G ultra-dense networ

Performance Analysis of FD-NOMA-based Decentralized V2X Systems

In order to meet the requirements of massively connected devices, different quality of services (QoSs), various transmit rates and ultra-reliable and low latency communications (URLLC) in vehicle to everything (V2X) communications, we introduce a full duplex non-orthogonal multiple access (FD-NOMA)-based decentralized V2X system model. We then classify the V2X communications into two scenarios and give their exact capacity expressions. To solve the computation complicated problems of the involved exponential integral functions, we give the approximate closed-form expressions with arbitrary small errors. Numerical results indicate the validness of our derivations. Our analysis has that the accuracy of our approximate expressions is controlled by the division of π/2 in the urban and crowded scenario, and the truncation point T in the suburban and remote scenario. Numerical results manifest 1) Increasing the number of V2X device, NOMA power and Rician factor value yields better capacity performance. 2) Effect of FD-NOMA is determined by the FD self-interference and the channel noise. 3) FD-NOMA has better latency performance compared to other schemes