Small Terminal MIMO Channels with User Interaction

This paper gives an overview of results obtained from measurements of different types of multiple-input multiple-output (MIMO) channels. For the indoor case measurements were made at 5.8 GHz from access points (APs) to mobile stations (MSs) at different places in a large open office type room. These measurements led to the so-called room electromagnetics theory, allowing simple modeling of the channel. Also channels between realistic AP arrays and multiple realistic MS terminal arrays are measured including users. The correlation between all channels is found to be low. Outdoor measurements at 2.4 GHz were made in a cellular scenario in an urban environment with a phantom user holding a mobile device in browsing position. These measurements show that MIMO techniques are beneficial even for small handheld devices. Finally, vehicle to vehicle (VTV) highway measurements at 3.5 GHz allow an investigation of the potentials for communication between cars approaching as well as in convoy and from inside and outside the car.