A step beyond MIMO: Media-based Wireless

Amir K. Khandani
khandani@uwaterloo.ca, 519-8851211x35324

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Abstract
Global mobile data has doubled every year over the last five years. By the end of 2012, the number of mobile-connected devices will exceed the number of people on earth, with over 100 million smartphone users using over 1 GB per month. By 2016, mobile network connection speeds will increase 9-fold, aggregate smartphone traffic will be 50 times greater than it is today, and mobile video will increase 25-fold [Cisco Global Mobile Data Traffic Forecast]. Real breakthroughs are desperately needed to keep up with this phenomenal growth. In spite of this urgent need, breakthroughs, particularly those that could be readily applied to product development, have been scarce and far in between. Multiple-Input Multiple-Output (MIMO) antenna systems, developed in parallel by AT&T and Bell Labs in late 90’s, resulted in a significant increase in throughput of wireless networks and soon found its way in many wireless products. After MIMO, a more recent breakthrough, namely Interference Alignment (IA) was introduced by my group in 2006. IA has attracted significant attention, however, in spite of extensive efforts by industry and academia, its practical implementation remains challenging.

This presentation introduces a novel approach to wireless communications which can be readily used in practice and offers huge performance gains with respect to traditional MIMO, at the same time offering a lower complexity. The key idea is based on embedding the information to be transmitted in the dynamics of the transmission media (channel), thereby called media-based wireless, in contrast to the traditional systems which are based on embedding the information in the RF source to be transmitted over the given (fixed/static) channel. In particular, using a single transmit and K receive antennas, savings in energy in the range of tens of dBs with respect to a KxK traditional MIMO are reported. This gain is due to:
  1. Additive information over receive antennas. This is similar to KxK MIMO, with the advantage of using a single transmit antenna.
  2. Harvesting of wireless energy over multiple receive antennas while (unlike traditional MIMO) keeping the corresponding additive noise components independent.
  3. Having an inherent diversity which improves with the transmission rate. This feature essentially converts a static Raleigh fading channel into an Additive White Gaussian Noise (AWGN) channel with a signal energy equal to the received energy averaged over fading statistics. This is unlike MIMO where diversity over a static fading channel can be improved only by increasing the number of antennas and this is achieved at the cost of a reduction in MIMO spectral efficiency (i.e., multiplexing gain)






Presentation (Powerpoint with sound and PDF) 

Presentation-Powerpoint (Please run in full-screen mode for sound) - (April 25, 2012)
Presentation-PDF - (April 25, 2012)

Videos


Media-based Wireless - (August 10, 2012)
Right-click to download