Polar Codes for Multiple Access Channels

  • Speaker:
    Edmund Yeh
  • Event Date:
    Wednesday December 11th, 2013
  • Time:
    10:30AM
  • Location:
    366 WVH

Abstract

Achieving the fundamental capacity limits of communication channels with low complexity coding schemes has been a major challenge for over 60 years. Recently, a revolutionary coding construction, called Polar coding, has been shown to provably achieve the “symmetric capacity” of binary-input, memoryless single-user channels. The underlying principle of the technique is to convert repeated uses of a given single-user channel to single uses of a set of extremal channels, whereby almost every channel in the set is either almost perfect, or almost useless.

The latter phenomenon is referred to as polarization.

Whereas a number of practical coding constructions (e.g. Turbo codes and Low Density Parity Check codes) can empirically approach the capacity of single-user communication channels, there is still a lack of good practical coding schemes for multi-user communication channels. In this talk, we extend the polar coding method to two-user multiple-access communication channels. We have shown that if the two users use the channel combining and splitting construction, the resulting multiple-access channels will polarize to one of five possible extremals, on each of which uncoded transmission is optimal. Our coding technique can achieve some of the optimal transmission rate pairs obtained with uniformly distributed inputs. The encoding and decoding complexity of the code is O(n log n) with n being the block length, and the block error probability is roughly O(2^{-sqrt{n}}). Our construction is one of the first low-complexity coding schemes which have been proved to achieve capacity in multi-user communication networks.

 Joint work with Eren Sasoglu (UC Berkeley) and Emre Telatar (EPFL)

Brief Biography

Edmund Yeh received his B.S. in Electrical Engineering with Distinction from Stanford University in 1994, his M.Phil in Engineering from the University of Cambridge in 1995, and his Ph.D. in Electrical Engineering and Computer Science from MIT under Professor Robert Gallager in 2001.

Since July 2011, he has been Associate Professor of Electrical and Computer Engineering at Northeastern University. Previously, he was Assistant and Associate Professor of Electrical Engineering, Computer Science, and Statistics at Yale University.  He has held visiting positions at MIT, Princeton, University of California at Berkeley, Swiss Federal Institute of Technology Lausanne (EPFL), and Technical University of Munich.

 

Professor Yeh is the recipient of the Alexander von Humboldt Research Fellowship, the Army Research Office Young Investigator Award, the Winston Churchill Scholarship, the National Science Foundation and Office of Naval Research Graduate Fellowships, the Barry M. Goldwater Scholarship, the Frederick Emmons Terman Engineering Scholastic Award, and the President’s Award for Academic Excellence (Stanford University).

He is a Senior Member of the IEEE, a member of Phi Beta Kappa and Tau Beta Pi. He received the Best Paper Award at the IEEE International Conference on Ubiquitous and Future Networks (ICUFN), Phuket, Thailand, July 2012.  Professor Yeh serves as the Secretary of the Board of Governors of the IEEE Information Theory Society.

 Host: Guevara Noubir