Imaging Transmission Line Impedance Profiles using Passband Signals and Adaptive Sequence Design

The problem of imaging transmission line impedance profiles for fault location is considered. The approach utilized makes use of a novel adaptive probing sequence. The sequence is constrained to be unimodular and trained to obtain the minimized mean square error between the channel estimate and the true channel response. To achieve a practical approach for the reconstruction process, bandlimited passband signals are also considered so that the method can be applied to real systems with a limited bandwidth. This imposes a challenge as only bandlimited information is available for profile reconstruction. Therefore a technique for exact reconstruction with bandlimited signals is also proposed. Results are provided and it is demonstrated that the use of bandlimited passband signals performs well for transmission line impedance profile reconstruction under various conditions.