Small Anechoic Chamber Channels - Estimating Channel Capacity from a Chamber Model

The development and deployment of next generation devices greatly depends on the ability to test and analyze the devices under realistic conditions. Using MIMO-OTA channels, a small anechoic chamber and with proper placement of probe antennas, testing can be conducted in a more cost-effective way for the ever emerging Wi-Fi and LTE standards developed by the 3rd Generation Partnership Project (3GPP).

Many recent and emerging standards serve to increase the adoption of MIMO technology, including IEEE 802.11n, 802.11ac and 802.11ax (Wi-Fi), Long Term Evolution (LTE) and LTE Advanced. These standards utilize multiple antennas in both the base station and the mobile device. Inherently, MIMO systems are dependent on the spatial orientation of the antennas at both ends of the links and the geometry of the antenna arrays themselves.

With small chambers being considerably more affordable and portable than traditional large anechoic chamber solutions, the result is smaller development costs for electronics manufacturers. This could serve to lower the cost of next-generation wireless devices for consumers, which could in turn assist in wider adoption of these technologies.

MIMO technologies can be tested in the near-field because the near-field OTA channel can be quantified and analyzed when the test chamber channel is repeatable. A full characterization of the wireless communications channel is critical for defining system performance limits when developing a new technology and creating test metrics for throughput testing of an existing technology.

This whitepaper, by the University of New Hampshire, provides an overview of the characterization of a near-field MIMO communications channel and propagation between the transmitter and receiver and how this is accomplished by the use of probe antennas.