Mitigation of multipath in steel wall channel of ultrasonic communication system

In this paper, we analyze performance of reflected signal mitigation method for ultrasonic communication system through a steel wall channel. Pre-distortion scheme using echo cancellation pulse can be one of the solutions against the echo problem without a burden of receiver complexity. However, there are some possible exceptions which make performance of echo reduction effect worse. In this paper, therefore, we´re concerned about ununiformed path lengths of each reflection and amplitude measurement error of 1st echo. Narrow pulse test is performed for characterization of the channel and evaluation of echo cancellation method in MATLAB simulation. Simulation results show that the effect of echo cancellation can be degraded if channel model approximation is not correct. But, although this problem can be happened, the system performance of mitigation of echoes is outstandingly successful since reflections after echo cancellation are tiny compared with LOS received signal.