Method of Diagnosing Abnormalities in Bidirectional Communication Channel by Using Adaptive Decision Feedback Equalizer

Nowadays, as autonomous cars become widely used, it will be even more crucial to maintain their self-diagnosis functions to ensure the reliability of the vehicles. The importance of in-vehicle communication will increase as well, resulting in more frequent maintenance. Moreover, the configuration of autonomous driving systems, which include in-vehicle cables, are becoming increasingly complicated, and replacing all abnormal components for maintenance can be costly and time consuming. In this paper, we propose a new method of diagnosing abnormalities in the communication channel by using the tap information of adaptive DFE (Decision Feedback Equalizer). The method detects the reflected signal and calculates its delay from the abnormal point by superimposing the reflected signal to the transmitted signal in a bidirectional communication channel. We used a simulation to verify that the DFE reacts to the superimposed signal and corresponds to the delay of the reflected signal. The proposed method enables the diagnosis of abnormalities with a resolution of 0.17 m in 1 Gbps bidirectional communication. Thus, by simply replacing the abnormal component, maintenance costs can be reduced.