Dependable V2X for Cooperative Traffic
PHY and MAC Layer Exploration for Dependable Cellular-Assisted Vehicular Communications
Thesis advisor: Markus Rupp
Doctoral student: Richard Prüller
Vehicular communications is an important enabler for enhancing the safety on roads by supporting mutual awareness of vehicles, as well as, for improving the efficiency of transportation through smart traffic management by intelligent transport systems. Legacy vehicular communication systems are based on dedicated road-side infrastructure and transmission bands; however, recently the interest in cellular-assisted vehicular communications is increasing, to exploit synergies between dedicated ad-hoc transmission (mainly based on 802.11) and mobile cellular systems (5G) to enhance the dependability of vehicular connectivity. In this thesis, PHY and MAC layer signal processing methods for cellular-assisted vehicular communications will be proposed and analyzed, with specific focus on enhancing efficiency and dependability of vehicular connectivity in dense traffic scenarios.
Wireless Vehicular Connectivity for Cooperative Transport
Thesis advisor: Christoph Mecklenbräuker
Doctoral student: Mehdi Ashury
A coordinated application of advanced driver-assistance systems (ADAS) enables safer, more efficient and greener traffic among the road users. The automotive radar systems are one of the most important components of such a system. However an automotive radar system can be applied only in a LOS scenario and suffers from environmental conditions and interference. Applying a proper radar data fusion algorithm can significantly increase the estimation quality and robustness. An optimal estimation of the neighboring vehicle‘s trajectory based on the fused data with the aid of Bayesian statistics enables reliable reaction in a safety-critical situation in the road traffic. Furthermore a multi-sensor data fusion which also will be part of the research reduces the false detection rate and optimizes the driver-assistance systems efficiency.
Vehicular wireless communication using millimeter waves
Wireless Vehicular Connectivity for Cooperative Transport
Thesis advisor: Christoph Mecklenbräuker
Doctoral student: Herbert Groll
Vehicular wireless communication is gradually transitioning from utopian to ubiquitous as stakeholders commit to vehicle-to-everything (V2X) radio technologies. The increasing utilization of the sub-6 GHz frequency spectrum will make future wireless systems rely on millimeter waves for high data rate V2X services. Millimeter wave systems for V2X have to cope with a wireless propagation channel, which is directional, time-variant, time-selective, and frequency-selective. We characterize the vehicular wireless propagation channel in the millimeter wave spectrum with the goal to enhance propagation models necessary for the design of reliable wireless systems.
System Level Modeling and Optimization of Cellular Assisted V2X Communication
Thesis advisor: Markus Rupp
Doctoral student: Blanca Ramos Elbal
Vehicular communications have a wide range of applications and are quickly growing in last years. Many of them, such as road safety applications, demand low end-to-end latency which can be supported by the large bandwidth available in the millimeter-wave band. However, with growing carrier frequency the wireless network coverage degrades dramatically. Therefore we propose enhancing the vehicle-to-infrastructure link through idle vehicular users, capable to boost the signal from the base station to the users with poor quality links. Furthermore, we analyse the scenario by leveraging tools from stochastic geometry.
Grant-Free NOMA for V2X Communication
Thesis advisor: Markus Rupp
Doctoral student: Bashar Tahir
Vehicle-to-everything (V2X) communication is one of the promising paradigms for future wireless systems. By communicating with the network (V2N), infrastructure (V2I), other vehicles (V2V), and pedestrians (V2P), it can provide enhanced road safety, better management of the traffic, and broadband services on the go. However, due to the strict latency budget of safety-critical applications, the corresponding traffic shape, and the large number of vehicles, resources management becomes a challenging task, which can substantially impact the access latency and the efficiency of the resources utilization. We investigate applying the framework of grant-free non-orthogonal multiple-access (NOMA) for V2X communication. Grant-free NOMA allows the devices to access the network without a base station (BS) grant, by contesting the time-frequency resources using specially designed signatures, and advanced receivers that utilizes those signatures to resolve the non-orthogonality. We consider the operation and transceiver design of NOMA for both the uplink between the vehicles and the cellular BS, and also the direct link between the vehicles and nearby devices when there is no coordination by the BS.