Estimation approach for the packet error rate of an in-vehicle wireless communications system

Modern vehicles support not only the simple broadcast radio system but also include complex head unit systems featuring WiFi, Bluetooth and cellular connectivity based on 2G/3G/4G. The evolutionary curve in car radios suggests that the upcoming 5G standard will also be included in future iterations. The requirements for ensuring high performance and robustness of the wireless communications systems in modern connected vehicles are significantly greater compared to systems from even a couple of years ago. The electrical and electronic devices in the vehicle emit electromagnetic interference (EMI) that disturbs the communications systems. The complexity of EMI immunity increases as multiple devices need to be integrated into the head unit. Furthermore, the wireless communications systems operate in similar frequency bands and thus the coexistence issue must also be taken into account. In this work, we propose a method to estimate the signal to interference ratio (SIR) from electromagnetic compatibility (EMC) radiated emission measurements. This approach enables estimation of the packet error rate (PER), which is used in the risk assessment process as applied to the vehicle environment scenario. Additionally, real-world measurements are also discussed to verify the accuracy of the estimations.