Invention: Faster wireless technology
Indian-American inventor Arogyaswami Paulraj and a team of researchers at Stanford University are the pioneers behind MIMO, a novel idea that dramatically improves the performance of cellular networks and wireless modems. The innovation enables higher rates of data transmission for digital LTE and Wi-Fi, and significantly expands signal coverage. Without MIMO, the availability of the high-speed internet as we know it today, whether in rural or urban areas, would likely not be possible.
The ingenuity of Paulraj and his
team's invention is that it overcomes a fundamental limitation of the wireless
spectrum, namely that bandwidth is finite. Paulraj first began working on
solving this problem nearly 25 years ago and turned to the idea of spatial
multiplexing - adding more antennas to deliver more information on the same channel.
Along the way the electrical engineering professor approached two of his
post-doctoral students - David Gesbert and Robert Heath - to assist him in
technical development. The seeds for a method known as MIMO, or "multiple
input, multiple output", were sown.
Paulraj's idea was to incorporate the space between antennae and receivers as part of the overall transferal equation - thinking about how buildings, ceilings, trees and any other objects influenced radio signals - and create a phenomenon called multipath propagation. By exploiting this, along with clever modulation techniques, he was able to incorporate at least two antennae and two receivers into wireless or Wi-Fi transmission. Instead of receiving two scrabbled signals, the receivers are able to recognise each individual signal thanks in part to the slightly different path it takes.
Societal benefit
Without Paulraj's pioneering innovation, the increases in connectivity speed to which millions of people around the world have grown accustomed may not have been possible. MIMO is a key reason behind the increase in data transmission speeds by a factor of several hundred times between 2001 and 2006. And it continues to be employed in the next generations of wireless data standards.
Mobile phone networks, for instance, may never have evolved significantly past their analogue forebears. Fewer cutting-edge technology start-ups would have emerged. Mobile Cloud Computing would certainly be impossible. And, the digital era, ushered in by higher and higher bit rates, would have hit a wall.
Economic benefit
"Multiple input, multiple output" functionality is such a central pillar of modern telecommunications that it is used in all new wireless systems. MIMO is essential for current 4G LTE networks and its importance will not diminish when 5G networks are rolled out in 2020. In 2015, network operators were spending EUR 5.1 billion (USD 5.6 billion) each quarter to provide customers with 4G LTE connectivity. By the time 5G coverage is introduced, it will already have attracted investment of EUR 4.6 billion, according to estimates. That amount is then likely to rise in subsequent years.
The economic success of Paulraj's innovation is attributable to the fact that the invention became a standard-essential patent. This led to others in the field contributing to the development of the standard as well.
However, the immediate economic impact of those areas of MIMO for which Paulraj holds patents is perhaps most apparent in the two start-ups he founded. In 1999, Paulraj, Gesbert and Heath founded Iospan Wireless to develop a specific type of MIMO product. The company was eventually acquired by Intel. In 2004, Paulraj co-founded a second company, Beceem Communications, which became a market leader in 4G wireless chip sets before its acquisition by Broadcom Corp. in 2010 for EUR 287 million (USD 316 million).
