Multipath removal by online blind deconvolution in through the wall imaging
In this paper, we propose an online radar imaging scheme that recovers a sparse scene and removes the multipath ringing induced by the front wall in a Through the Wall Imaging (TWI) system without prior knowledge of the wall parameters. Our approach uses online measurements obtained from individual transmitter receiver pairs to incrementally build the primary response of targets behind the front wall and find a corresponding delay convolution operator that generates the multi path reflections available in the received signal. In order to perform online sparse imaging while removing wall clutter reflections, we developed a deconvolution extension of the Sparse Randomized Kaczmarz (SRK) algorithm that finds sparse solutions to under and over determined linear systems of equations. Our scheme allows for imaging with nonuniformly spaced antennas by building an explicit delay and sum imaging operator for each new measurement. Moreover, the active memory requirements remain small even for large scale MIMO systems since the imaging operators are only constructed for individual transmitter receiver pairs. We test our approach on a simple FDTD simulated room with internal targets and demonstrate that our method successfully eliminates multipath reflections while correctly locating the targets.
2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)