A Practical Distance Measurement Improvement Technique for a SFCW-based Health Monitoring Radar

A technique in improving the distance measurement of an indoor Stepped-Frequency Continuous Wave (SFCW) radar is proposed and presented in this work. The main objective of this SFCW radar is to enable a non-invasive way in measuring the location of patients in a home environment without the need for a worn geo-locating tag. The theoretical and practical operation principle of the radar setup is first explained. Due to its operation in an indoor environment using a two-antenna setup, reflections, multipath, backscattering and cross-coupling are expected to affect its localization estimation. Thus a compensation technique based on Inverse Fast Fourier Transform (IFFT) is used to overcome this limitation. Practical measurements conducted in a 5 x 5 m(2) room have successfully proven that the approach is able to compensate for practical multipath from walls, furniture and metallic shelves, yielding a distinct improved measurement technique in localizing a person in a real indoor environment.