Paulraj, a professor emeritus in the department of electrical engineering at Stanford University, joins a select group of IT pioneers such as Tim Berners-Lee (world wide web), Vint Cerf (internet), Larry Page (Google), Marty Hellman (public key cryptography) and Martin Cooper (cell phone).
His invention in the field of telecom, known as MIMO (multiple input/multiple output), is the backbone of high-speed wireless communication. The Marconi Prize is considered equivalent to the Nobel as Nobel prizes are not awarded to engineers.
In an interview, Prof Paulraj told Johnson T A about his award and its significance.
Can you explain the basics of MIMO technology for which you have been awarded the Marconi Prize?
MIMO antenna technology multiplies the frequency spectrum, which is of course an extremely limited resource. MIMO requires the use of multiple antennas at the transmitter and receiver and special coding for transmit and decoding for receive. A 3×3 antenna MIMO radio common today triples the value of the radio spectrum; and this expansion will be much higher in a few years. MIMO works by creating parallel channels proportional to the number of antenna pairs. The details get very complicated and thousands of researchers work in this area. There are many eminent researchers in MIMO in India, including IISc-Bangalore.
When you invented MIMO in 1991, you faced significant push back — why? Did you believe it would become the cornerstone of future communication?
There are many reasons for the skepticism, the highest encoding practical for digital modulation in 1991 was around 4 QAM and even doubling that would have been huge. I claimed that 1 million QAM system is possible and this, not surprisingly, was hard to believe. Incidentally, today’s MIMO-based 802.11ac WiFi chip support 16 million-QAM! It took 20 years.
I was quite sure MIMO will work and be transformative, but faced with so much skepticism, I put it aside for 3-4 years before going back to work on it and also to build a company to develop a product.
You have been a vocal critic of India being a laggard in the area of high technology innovation. Is this a cause for serious concern?
It is indeed serious for a variety of reasons — national security, high cost of imports (high technology imports by India in 2014 will easily exceed $200 billion) and the sheer waste of the talent we have in our country who have the potential to create such technologies. However, entering high technology is hard. We are still a country with large amounts of poor people. If we can reduce such imports, perhaps we can build a fairer society.
Of course, we have an IT services industry with giants like Infosys and WIPRO.
What about our rocket to the Mars or the cryogenic engine — is that not high technology?
These are good achievements by good people. However, I am not sure they solve the pressing economic problems of our people. Also, these technologies were mastered in the West decades ago. To succeed in mass market high tech today, we have to innovate at the cutting edge level, not just play catch up.
You were a part of the Indian scientific establishment at one time. How conducive is it to innovation?
There are some outstanding people and some real achievements. However, if we are doing things right, we will not be almost totally dependent on high technology imports today — 67 years since Independence. Also, looking at the technology we use every day — civil jet planes, cell phones, laptops, advanced instruments — where inside them are the major innovative ideas that have come from India?
You were a champion of the WiMAX technology which seems to have lost out to LTE — what happened?
Both LTE and WiMAX use nearly identical technologies. The main difference was on the radio spectrum plans — WiMAX focused on wideband higher frequency bands while LTE built its technology around standard cellular lower frequency bands. The spectrum choices by WiMAX were not a good idea, in hindsight.
What professional links do you have with India?
I am in India often — conferences, committee work and some teaching. My companies always had R&D groups in India. Of course I have lots of close family here.