Immunity of Automotive Power Line Communication Systems

Power line communication (PLC) could not be established in automotive environments till now due to concerns with the unavoidable electromagnetic disturbances in the vehicle supply nets. Conducted broad band switching noise and field coupled narrow band noise can disturb the communication and prevent higher data rates. The continuously increasing size of the communication cable harnesses in vehicles is very difficult to handle, and PLC could reduce the complexity of the harness. This paper presents an approach to estimate the theoretical limits of PLC in the presence of noise in automobiles. Signal power and bit error rates are computed and discussed, based on electromagnetic compatibility-standards and PLC-parameter sets from older investigations' noise levels. Commonly used automotive immunity tests are applied to analyze the signal to noise ratio of the PLC in a simulation environment. Therefore, immunity test setup models are introduced in order to analyze the noise injection and coupling characteristics to the PLC receiver. A virtual direct power injection (DPI) test is carried out with narrow band noise and transient pulse injection. For method validation, BCI measurements of a real PLC transceiver were carried out and failure behavior was compared to DPI simulation results. Immunity improvement for single carrier modulation in PLC is proposed. Finally, an analysis of the immunity to pulses is performed and results are discussed.