Experimental characterization of the MIMO wireless channel: data acquisition and analysis

TLDR

Accurate knowledge of wireless channel spatial characteristics is essential for detailed performance assessment of space‑time coding algorithms in realistic channels. This paper presents an experimental measurement platform that provides the narrowband channel transfer matrix for wireless communication scenarios. The platform employs linear antenna arrays of up to ten elements at transmit and receive to directly measure key MIMO parameters in an indoor 2.45 GHz environment, and analyzes the transfer matrix data to reveal statistical distributions and temporal and spatial correlation. The results demonstrate that antenna polarization, directivity, and array size significantly influence channel capacity, and that multipath richness and path loss jointly determine capacity.

Abstract

Detailed performance assessment of space-time coding algorithms in realistic channels is critically dependent upon accurate knowledge of the wireless channel spatial characteristics. This paper presents an experimental measurement platform capable of providing the narrowband channel transfer matrix for wireless communications scenarios. The system is used to directly measure key multiple-input-multiple-output parameters in an indoor environment at 2.45 GHz. Linear antenna arrays of different sizes and construction with up to ten elements at transmit and receive are utilized in the measurement campaign. This data is analyzed to reveal channel properties such as transfer matrix element statistical distributions and temporal and spatial correlation. Additionally, the impact of parameters such as antenna element polarization, directivity, and array size on channel capacity are highlighted. The paper concludes with a discussion of the relationship between multipath richness and path loss, as well as their joint role in determining channel capacity.