Adaptive impedance matching for Vehicular Power Line Communication systems

The growing number of electronic devices inside vehicles has motivated research and development activities in Vehicular Power Line Communication (VPLC) systems. Advantages of the VPLC approach include reduced complexity and cost of the wiring harness. Among the design challenges of VPLC systems is the problem of impedance matching. The access impedance at the modem port is a time varying quantity which also depends on the location of the VPLC modem. Impedance mismatch degrades the signal-to-noise ratio (SNR) and thus the signal integrity. Given the variable nature of the access impedance, a fixed matching circuit will be inefficient. A potential solution to cope with the access impedance variability is an adaptive impedance matching system which is the subject of this work. Here we have designed an adaptive impedance matching system. The system is simulated and its performance is evaluated under extreme changes in access impedance.