PIMD Signal Modeling Based on FTDNN

In this paper, modeling of the third-order passive intermodulation distortion (PIMD) caused by the downlink signal in the frequency division duplex (FDD) wireless communication system is developed with the Focused Time Delay Neural Network (FTDNN). PIMD is an interference signal generated due to the nonlinearity of a passive element in a wireless communication environment, and degrades the noise level of a receiver, resulting in a deterioration of communication quality. Offline learning and testing of the proposed approach are investigated with measured PIMD signals and transmitted downlink signals. As a result, it is confirmed that FTDNN structure is suitable for learning nonlinearity of the PIMD generation process.