Verification of wireless communication performance and robustness for automotive applications

Abstract: Today's test methods used for verifying the performance and robustness of automotive applications using wireless communication are often based on fieldtrails, which are time consuming, costly, and not repeatable. Therefore, there is an urgent need for new verification methods that can be performed in lab environment, where the realistic radio propagation environment can be emulated. The telecom industry is using standardized over-the-air (OTA) test methods for verification of their products, e.g., smartphones. In these OTA test methods, different standardized channel models are emulated to reflect different user scenarios, e.g., walking in a city or driving on a highway. One topic in this thesis has been to see if it possible to scale up the used OTA verification methods for smartphones, to a setup where the device under test(DUT) is a car. Detailed studies have been performed on the OTA mutliprobesetup inside an anechoic chamber, using a complete car as the DUT. The measurements were performed on a single-input single-output (SISO) system at5.9 GHz, a frequency band used for vehicle-to-vehicle (V2V) communication.The conclusions we present are that the repeatability is under control for a SISO system and that the desired channel can be emulated. For multiple-input multiple-output (MIMO) systems further research is needed. Emulation of a V2V channel in the OTA test setups requires deep knowledge of the characteristics of the V2V channel, e.g., it could be gathered through measurement based nalysis. In the other research topic, measurement campaigns have been preformed using IEEE 802.11p transceivers (standard for V2V communication) installed in several vehicles, both cars and trucks, a unique campaign in that sense. For the communication links cross all vehicles, estimation of the joint shadowing effects have been possible to make. A cross-correlation model of the large scale fading process is presented for a V2V scenario on a highway. In addition, improved path loss models for both highway and urban scenarios is presented, which consider antenna pattern and other vehicles obstructing the communication.