Automated Measurements Setup for Investigating Space-Temporal Characteristics of Indoor Wireless Channels

Abstract

An automated hardware-software system for probing and measuring the spatiotemporal characteristics of short-range multipath radio channels in indoor environments is presented. Using ultra-wideband channel sounding in a test room of approximately 6 × 7 m square, the frequency and impulse responses of the wire-less channel as well as their spatial correlation functions were measured. Measurements were performed in the 2.0…3.0 and 5.3…6.3 GHz frequency bands under line-of-sight (LoS) and non-line-of-sight (NLoS) conditions at 1680 spatial observation points uniformly distributed over a 1200 × 1200 mm area. The measured frequency re-sponses revealed frequency-selective fading with depths of up to 30 dB. The measured impulse responses identified a dominant line-of-sight component with a delay of 8…10 ns and numerous reflections with delays of up to 40 ns, consistent with the geometry of the test room. Three-dimensional spatial correlation maps of the channel characteristics were constructed; the transition from LoS to NLoS conditions resulted in a 15–25 % reduction in the spatial correlation coefficient.