Experimental characterization of NLOS broadband millimeter wave links

This study investigates the potential use of microwave scatterers (MS) for data transmission relay in order to extend the signal coverage over shadowed remote places where lineof-sight (LOS) transmission is not present. Series of indoor NLOS-CW (non-LOS continuous wave) measurements over the 29-30 GHz band were conducted at the intersection of two hallways in presence of two metallic cylinders of different diameters, a right angle standing metallic corner, and a flat surface metallic reflector. Results indicate that for systems operating at a short range of tens of meters, MS provides an alternative to LOS systems, cables or the use of repeaters. It was also found that some types of MS yield better signal coverage while others deflect the signal destructively. Hence, the received signal strength depends strongly on the MS's shape, size and surface roughness.