Channel Characterization at 77 GHz for Vehicular Communication

With the rapid development of modern communication technologies, a well understanding of the channel is essential. Therefore, in this paper, the channel characteristic for mm Waves is investigated. Modern intelligent transportation systems require higher data rates and, therefore, more bandwidth. Thus, higher frequencies, which can provide these needs, get more and more in focus in the context of 5G , As part of our current research, the proposed work aims to give a deeper understanding of the channel characteristics and wave propagation at 77 GHz, especially for automotive use cases like platooning or intersection assistant. Typical traffic scenarios, starting with a rural street and proceeding with a highway scenario, were reconstructed using the commercial simulator WinProp. Furthermore, the scenarios were evaluated by including additional obstacles, like vehicles and traffic signs. Time-varying environments with driving vehicles with either line-of-sight (LOS) as well as non-LOS (NLOS) connections were investigated. The results reveal significant changes in the channel impulse response for one time step, when a new reflection path gets available. This is especially relevant in the NLOS case, since the scattering and reflection paths can have more than 25 dB difference in receiving amplitude. Overall, the antenna alignment and the environment had a strong influence. Thus, it could be shown that scatters like traffics signs cause power fading in the LOS connection, whereas they have benefits in the NLOS case, by enabling communication at all. In future research, the channel models will be further addressed and expanded to design a link that is capable of communicating safety-relevant information and hold the high demands on latency.