ANANT SAHAI Electrical Engineering and Computer Sciences Assistant Professor sahai@eecs.berkeley.edu Official website
Research For prospective students Bio Teaching My Students	267 Cory Hall UC Berkeley 94720-1770 Sp08 Office Hours: Tue 3:30-4:30pm and Thu 9-10AM in 267 Cory

Announcements:

5/1/08: No office hours due to the EECS Faculty retreat. Please make an appointment by email.

Full current publication list (updated 02/08) now available.

Information for the ISIT 2007 tutorial attendees is available here. The full presentation set of my slides is also available online here for your perusal. The tutorial mostly supersedes the earlier slides on noiseless feedback, side-information, and delay, and its sequel on how to get gains from noisy or otherwise limited feedback. The material in this other one that interprets some of the results in the control context is different.

I am in the process of posting current preprints onto the arXiv.org preprint server.

Information for the DySPAN05 tutorial attendees is available here.

My areas of interest are communications, control, and signal processing. Within that range, my focus is on the communications theory side, particularly in the areas of wireless and information theory. Within information theory, my main interest is in developing the conceptual tools needed to understand feedback, interaction, delay, reliability, and complexity. To that end, I am interested in control and dynamical systems as they provide well understood mathematical models that do not mesh with the classical notions from information theory. They also tell us why delay is important. On the wireless communication side, I am interested in power consumption and how multi-scale heterogenous wireless systems can coexist peacefully. Cognitive radio is of particular interest.

My research sits within the Wireless Foundations center, where we study the fundamental basis for the wireless technologies of the future. The following pages give more details about some of my research interests, with links to additional publications, some representative talk slides, etc.

• All publications categorized by importance
• UNI: Understanding Networks and Information
• RASP: Robust and Adaptive Signal Processing for cognitive radio

Some recent research results: (descriptions can be found here and here.

• P. Grover and A. Sahai, "A vector version of Witsenhausen's counterexample: Towards the convergence of control, communication and computation," Submitted to the 2008 Conference on Decision and Control, 2008.
  
  
• R. Tandra, S. M. Mishra, and A. Sahai, "What is a spectrum hole and what does it take to recognize one?", Submitted to the Proceedings of the IEEE, 2008
  
  
• P. Grover and A. Sahai, "Little Green Codes: Energy-Efficient Short-Range Communication", Accepted to the 2008 International Symposium on Information Theory in Toronto
  
  
• C. Chang and A. Sahai, "Trade-off of lossless source-coding error exponents", Accepted to the 2008 International Symposium on Information Theory in Toronto
  
  
• A. Sahai and S. Draper, "The `hallucination' bound for the BSC", Accepted to the 2008 International Symposium on Information Theory in Toronto
  
  
• Anant Sahai and Pulkit Grover, "The price of certainty: `waterslide curves' and the gap to capacity". Submitted to the IEEE Transactions on Information Theory, 2007.
  
  
• A. Sahai, "Why block length and delay behave differently if feedback is present," IEEE Transactions on Information Theory. Pages 1860-1886, May 2008.
  Earlier Preprint: arXiv: cs.IT/0610138
  
  
• S. Draper and Anant Sahai, "Variable-length coding with noisy feedback," European Transactions on Telecommunications special issue on New Directions in Information Theory, Spring 2008.
  
  
• R. Tandra and Anant Sahai, "SNR Walls for signal detection," IEEE Journal on Special Topics in Signal Processing, pages 4-17, Feb 2008.
  R. Tandra and Anant Sahai, "SNR walls for feature detectors," IEEE DySpAN 2007
  
  
• H. Palaiyanur, C. Chang and A. Sahai, "The source coding game with a cheating switcher," Submitted to the IEEE Transactions on Information Theory, 2007.
  "Lossy compression of active sources" Accepted to ISIT 2008
  H. Palaiyanur and A. Sahai, "On the uniform continuity of the rate-distortion function" Accepted to ISIT 2008
  Preliminary version presented at IEEE ISIT 2007
  
  
• K. Eswaran, A.D. Sarwate, Anant Sahai, and M. Gastpar, "Limited feedback achieves the empirical capacity," submitted to the IEEE Transactions on Information Theory, 2007.
  Preprint: arXiv: arXiv:0711.0237
  K. Eswaran, A.D. Sarwate, A. Sahai, and M. Gastpar, "Binary additive channels with individual noise sequences and limited active feedback," IEEE ISIT 2007
  
  
• S. M. Mishra, R. Tandra, and Anant Sahai, "The Case for Multiband Sensing," Allerton 2007.
  
  
• Anant Sahai, "Balancing forward and feedback error correction for erasure channels with unreliable feedback," submitted to the IEEE Transactions on Information Theory, 2007.
  Preprint: arXiv: 0712.0871
  
  
• C. Chang and A. Sahai, "Universal Quadratic Lower Bounds on Source Coding Error Exponents," CISS 2007
  C. Chang and Anant Sahai, "Universal Fixed-Length Coding Redundancy," ITW 2007
  
  
• C. Cheng and Anant Sahai, "The price of ignorance: the impact on side-information for delay in lossless source coding," submitted to the IEEE Transactions on Information Theory, 2007.
  Preprint: arXiv:0712.0873
  
  
• P. Grover and Anant Sahai, "Writing on Rayleigh faded dirt: a computable upper bound to the outage capacity," IEEE ISIT 2007
  P. Grover and Anant Sahai, "On the Need for Knowledge of the Phase in Exploiting Known Primary Transmissions," IEEE DySpAN 2007
  
  
• S. M. Mishra, R. Tandra and Anant Sahai, "Coexistence with primary users of different scales," IEEE DySpAN 2007
  
  
• A. Sahai and S. Mitter, "Source coding and channel requirements for unstable processes," submitted to IT Transactions. Revised.
  Preprint: arXiv: cs.IT/0610151
  
  
• A. Sahai and S. Mitter, "The necessity and sufficiency of anytime capacity for control over a noisy communication link: Part I" IT Transactions, Pages 3369 - 3395, Aug 2006 and "Part II", submitted to IT Transactions Revised.
  preprints: arXiv: cs.IT/0601007 and arXiv: cs.IT/0610146
  
  

Before joining the faculty at Berkeley in 2002, I spent 2001 at the startup Enuvis, Inc. where I was on the theoretical/algorithmic side of a team that developed new techniques for GPS detection in very low SNR environments (such as those encountered indoors in urban areas). From 1994-2000, I was a graduate student at MIT studying Electrical Engineering and Computer Science (Course 6 in MIT-speak) and was based in the Laboratory for Information and Decision Systems under Prof. Sanjoy Mitter. My research interests there started in machine understanding but shifted toward the intersection of control and information theory. I did my undergraduate work in EECS here at the University of California at Berkeley from 1990-1994.

• Spring 2008: Once again, the time for the NET/COM/DSP (EE298) seminar has not been changed since the original time avoided conflicts with other courses. Please add yourself to the mailing list so that you get an announcement. The usual timeslot for the seminar is Mondays at 2pm, with special seminars in different slots occurring from time to time.

  For one unit of credit, only attendance is required. For more than that, you will have to prepare a written report about one of the talks going into some more detail.

• Spring 2008: I am teaching EECS 229A: Information Theory, a grad course. Requires 226A.
  
  
• Spring 2008: I am teaching EECS 301: Teaching Techniques for Electrical Engineering, a course for first-time graduate student instructors in EECS.
  
  

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• Fall 2007, Spring 2003 I taught EE224a: Digital Communications. This is the graduate communications course that is a survey of coding, modulation, equalization, etc. In 2007, this course does not require 226A as a prereq.

• Spring 2007: I taught EECS 123: Digital Signal Processing, an undergraduate class that covers discrete-time signal processing at an intermediate level.

• Spring 2007: I taught EECS 301: Teaching Techniques for Electrical Engineering, a course for first-time graduate student instructors in EECS. The main focus of this course is to allow first-time GSIs to practice their teaching and get feedback regarding their technique.

• Fall 2006, Fall 2004 Michael Gastpar and I team taught the graduate advanced information theory course EE290S. Though the topics varied each term, we have covered multiuser information theory, state-of-the art results on feedback, and different approaches to dealing with non-probabilistic uncertainty: universal coding, compound channels, AVCs, and individual sequences.

• Spring 2006, Spring 2004: I taught Information Theory. Course information can be found online, but bspace.berkeley.edu was used to post homework, notes, etc. for students.

• Spring and Fall 2005, Spring 2002 : I taught EECS 126: Probability and Stochastic Processes, an undergraduate class that covers the basics of probability theory together with an introduction to Gaussian random vectors, Markov chains, and Poisson processes.

• Fall 2003 I taught the undergraduate signals and systems course EE 120.

• Fall 2002: I taught the graduate class EE226A: Stochastic Processes and Systems, a class that covers the basics of detection, estimation, linear filtering, with a particular focus of Gaussian processes, Poisson processes, and Markov processes.

• Rahul Tandra: Master's thesis on limits to low SNR detection due to uncertainty. Continuing to work in the area of opportunistic spectrum use and spectrum sensing. Did summer internship at Qualcomm in 06.
• S. Mubaraq Mishra: Working on doctoral research on cooperation and architectural issues for cognitive radios. (Joint with Brodersen in BWRC) Summer internship at Wionics Research with Realtek in 06.
• Hari Palaiyanur: Master's thesis on applications of sequential decoding to anytime problems. Did summer internship at Nokia Research in 07. Currently exploring the information theory of active models of perception.
• Pulkit Grover: Explored model uncertainty issues from an information theoretic perspective. Summer internship at Wionics Research with Realtek in 07. Currently working on understanding the computational complexity of iterative decoding from a power-consumption perspective.

Visitors:

• Hidekazu Miyoshi: visiting from SEI Innovation Core in Japan. Exploring cognitive radio issues.
• Mukul Agarwal: A student of Prof. Sanjoy Mitter in LIDS. Spent Summer 06 visiting me here in Wireless Foundations. Exploring the nature of information flows in systems.

Alums:

• Cheng Chang: Did a Master's thesis on UWB-based sensors: localization and positioning. Doctoral thesis on multiuser anytime information theory with a focus on multiterminal source coding. Joined HP Labs as postdoc in Jan 08.
• Danijela Cabric: A student of Bob Brodersen whom I coadvised on spectrum sensing issues. Great thesis and is now at UCLA as an Assistant Professor.
• Niels Hoven: Master's thesis on power control for cognitive radios. Did summer internship at Philips Research in 06. Currently taking an indefinite break from graduate school.
• Stark Draper: Postdoc with myself, Kannan Ramchandran, and David Tse. Worked on feedback and delay issues, especially in the soft deadline context, as well as streaming Slepian Wolf problems. Spent a year at MERL in Cambridge, and is now at U. Wisconsin Madison as Assistant Professor.
• Qing Xu: Master's thesis on anytime capacity of erasure type channels. Currently at a Bay Area startup.
• Tunc Simsek: Brilliant doctoral thesis on anytime coding with feedback. Now at Mathworks. (Joint with Varaiya)
• Hansen Bow: Undergrad researcher with me who is now at MIT working on BioMEMS. With me, he did some of our earliest work on spectrum sharing as well as work on positioning in UWB systems.
• Moshe Malkin: Undergrad researcher with me who is now at Stanford working with Prof. Cioffi. With me, he did some work on positioning in UWB systems.
• Amirali Zohrenejad: Undergrad researcher with me who is now at Microsoft working in wireless networking. With me, he did some early work on randomized encoding strategies for tracking random walks.