Propagation prediction model and performance analysis of RFID system under metallic container production circumstance

Radio-wave attenuation negatively affects RF communications in a RFID system. In order to ensure the reliability of RFID system, one must predict the radio-wave path-loss accurately before detailed design. However, it is infeasible to estimate the path-loss for the container RFID systems using the conventional path-loss models such as the Okumura model, two-ray model and so on. This paper firstly focuses on studying the radio propagation mechanism in the container RFID system, analyzing the radio-wave diffraction in the container metallic environment and establishing a mathematic model to estimate the path-loss between the readers and tags. A test in a real container working area was conducted and it was found that the actual measuring results are consistent with the corresponding computing results according to the established path-loss model. The model is further used to analyze some performances of the container RFID system. A group of curves are obtained to show the relationships among the identification distance, the sending power and the BER (bit error rate). The paper is concluded that the TE polarization mode cannot be applied to a container RFID system and the attenuation caused by multi-path propagation will dramatically reduce the recognition reliability of a container RFID system.