What Is MIMO?

By Andrew Tarantola on at

At today's Kindle Fire HD revealing, Jeff Bezos bragged that the Fire HD will be capable of downloading content up to 40 percent faster than either the iPad or the Nexus 7. But how will it do that, there's only so much bandwidth available, right? Wrong. And it's all thanks to the same technology that makes 4G and 802.11n so speedy.

This data transfer accelerant is known as Multiple Input/Multiple Output and employs multiple antennas at both the transmitter and receiver working in concert to improve the devices performance by transferring more data simultaneously without requiring added bandwidth or drawing additional power. A MIMO-enabled device does this by spreading the existing transmission power over multiple antennas, creating an array gain that can either transmit more bits per cycle than a SISO (single input/single output) antenna or improve the connection quality. Essentially, a MIMO system widens the broadcast "pipeline," allowing more data to flow through at a time.

MIMO was first commercially introduced in 2001 by Iospan Wireless Inc and imediately caught the attention of the Wireless communications industry. In 2005, the IEEE integrated it into the burgeoning 802.11n standard and today it can be found in 4G, 3GPP Long Term Evolution, WiMAX, and HSPA+ systems.