Toward Investigation of the Multi-Gig Data Transmission up to 5 Gbps in Vehicle and Corresponding EMC Interferences

Abstract

This article focuses on the automotive Ethernet Multi-Gig data communication (data rates up to 5 Gbps) and the corresponding EMC issues. As an entry into the topic, both the existing (100BASE-T1, 1000BASE-T1) and the future (NBASE-T1) automotive Ethernet standards are described in detail. Three important aspects of the NGAUOT (Multi-Gigabit Automotive Ethernet Study) are pointed out. First, the bandwidth requirements concerning the selected pulse amplitude modulation level (PAM-N) and the transmitted data rate are mentioned. Second, the appropriate cables (as the medium) are compared. Finally, the different types of operation modes and their advantages are described in detail. The structure of the Multi-Gig Ethernet physical layer (PHY) is briefly discussed. In this work, the use of Field Programmable Gate Array (FPGA) as a dummy gigabit automotive PHY is proposed. From author's point of view, this is the first time that the FPGAs are used for characterizing the EMC issues of automotive Multi-Gig Ethernet links. For this purpose, laboratory and vehicle measurements are carried out. In the laboratory, the influence of different data rates (2.5 Gbps, 5 Gbps) and cable lengths (2m, 6m, 15m) on the signal quality in terms of bit error rate (statistical eye diagram) is examined and evaluated. For the vehicle measurements, the FPGA boards were configured as transmitter and receiver separately. The emission of shielded twisted pair (STP) cable carrying data rates in gigabit range (2.5 Gbps, 5 Gbps) over various frequency bands in vehicle is measured.