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 Fall 08 Office Hours: Mon 4-5pm and Tue 2:30-3:30pm in 258 Cory

Announcements:

A representative sample list of talks and the associated slides is now avaiable (updated 07/08). This includes the slides for my tutorials at ISIT '07 and DySpAN '05, material on delay and feedback, control and communication, noisy feedback, and cognitive radio.

Publication list (updated 07/08) available.

Some current preprints are on the arXiv.org preprint server.

My areas of interest span 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, etc.

It is imperfect and incomplete, but an alternative perspective can be found using a Google Scholar search for my work. A few key papers get missed in that search, so this and this and this and this and this should bring them up. This might help if you are looking for related work as well.

• All publications categorized by subjective importance
• Representative talk slides
• UNI: Understanding Networks and Information
• RASP: Robust and Adaptive Signal Processing for cognitive radio
• Official publication/invited-talks list

A few recent research results: (Descriptions and much more can be found here and here.)

1. Rahul Tandra and Anant Sahai, "Overcoming SNR walls through macroscale features", Extended abstract accepted to Allerton 2008.
   
   
2. Parvathinathan Venkatisubramaniam and Anant Sahai, "Incentivizing anonymous `peer-to-peer' reviews", Extended abstract accepted to Allerton 2008.
   
   
3. Rahul Tandra and Anant Sahai, "Noise calibration, delay coherence and SNR walls for signal detection", Accepted to the 2008 IEEE Symposium on Dynamic Spectrum Access Networks (DySpAN).
   
   
4. Amin Gohari, Arash Parsa, and Anant Sahai "Exploiting Interference Diversity for Event-Based Spectrum Sensing", Accepted to the 2008 IEEE Symposium on Dynamic Spectrum Access Networks (DySpAN).
   
   
5. George Atia, Anant Sahai, and Venkatesh Saligrama, "Spectrum Enforcement and Liability Assignment in Cognitive Radio Systems", Accepted to the 2008 IEEE Symposium on Dynamic Spectrum Access Networks (DySpAN).
   
   
6. Kristen Ann Woyach and Anant Sahai, "A toy-model for the regulation of cognitive radios", Preliminary report, June 2008. (being extended for an invited paper to Allerton 2008)
   
   
7. Pulkit Grover and Anant Sahai, "Witsenhausen's counterexample as Assisted Interference Suppression", Submitted to a Special Issue on "Information Processing and Decision Making in Distributed Control Systems" in the International Journal of Systems, Control and Communications, 2008.
   Pulkit Grover and Anant Sahai, "A vector version of Witsenhausen's counterexample: Towards the convergence of control, communication and computation," Accepted to the 2008 Conference on Decision and Control, 2008.
   
   
8. Rahul Tandra, Mubaraq Mishra, and Anant Sahai, "What is a spectrum hole and what does it take to recognize one?", Accepted to the Proceedings of the IEEE for a special issue on Cognitive Radio, 2008 (revised)
   
   
9. Pulkit Grover and Anant Sahai, "Little Green Codes: Energy-Efficient Short-Range Communication", 2008 International Symposium on Information Theory in Toronto
   
   
10. Cheng Chang and Anant Sahai, "Trade-off of lossless source-coding error exponents", 2008 International Symposium on Information Theory in Toronto
    
    
11. Anant Sahai and Stark Draper, "The `hallucination' bound for the BSC", 2008 International Symposium on Information Theory in Toronto
    
    
12. Stark Draper and Anant Sahai, "Variable-length coding with noisy feedback," European Transactions on Telecommunications special issue on New Directions in Information Theory, June 2008.
    
    
13. Anant Sahai, "Why do 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
    
    
14. Rahul Tandra and Anant Sahai, "SNR Walls for signal detection," IEEE Journal on Special Topics in Signal Processing, pages 4-17, Feb 2008.
    Rahul Tandra and Anant Sahai, "SNR walls for feature detectors," IEEE DySpAN 2007
    
    
15. 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.
    
    
16. Hari Palaiyanur, Cheng Chang and Anant Sahai, "The source coding game with a cheating switcher," Submitted to the IEEE Transactions on Information Theory, 2007.
    "Lossy compression of active sources" ISIT 2008
    Hari Palaiyanur and Anant Sahai, "On the uniform continuity of the rate-distortion function" ISIT 2008
    Preliminary version presented at IEEE ISIT 2007
    
    
17. Krish Eswaran, Anand Sarwate, Anant Sahai, and Michael Gastpar, "Limited feedback achieves the empirical capacity," submitted to the IEEE Transactions on Information Theory, 2007.
    Preprint: arXiv: arXiv:0711.0237
    Krish Eswaran, Anand Sarwate, Anant Sahai, and Michael Gastpar, "Binary additive channels with individual noise sequences and limited active feedback," IEEE ISIT 2007
    
    
18. 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
    
    
19. Cheng Chang and Anant Sahai, "Universal Quadratic Lower Bounds on Source Coding Error Exponents," CISS 2007
    Cheng Chang and Anant Sahai, "Universal Fixed-Length Coding Redundancy," ITW 2007
    
    
20. Cheng Chang 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
    
    
21. Pulkit Grover and Anant Sahai, "Writing on Rayleigh faded dirt: a computable upper bound to the outage capacity," IEEE ISIT 2007
    Pulkit Grover and Anant Sahai, "On the Need for Knowledge of the Phase in Exploiting Known Primary Transmissions," IEEE DySpAN 2007
    
    
22. Anant Sahai and Sanjoy Mitter, "Source coding and channel requirements for unstable processes," submitted to IT Transactions. Revised.
    Preprint: arXiv: cs.IT/0610151
    
    
23. Anant Sahai and Sanjoy 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.

I also currently serve as the Treasurer for the IEEE Information Theory Society and the faculty adviser for the Berkeley chapter of Eta Kappa Nu.

• EECS 298: So far, 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 currently Fridays at 2pm, with special seminars in different slots occurring from time to time. I strongly recommend adding the Seminar's Google calendar to your calendar program.

  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. Talk with me.

• EECS 70: (Co-taught with Christos Papadimitriou) There are two sections of this course. One is the usual 70, but the other is a special section of the class that is the trial run of what is envisioned as a new unified lower-division mathematical/modeling course for the department. All students who have not yet taken either CS 70 or EE 126 are encouraged to take this special section of the class. It covers the basics of discrete mathematics and probability that are greatly useful in upper-division courses, graduate school, and throughout your career.
  
  
• EECS 290S: (Co-taught with David Tse) This year, advanced information theory will cover multiuser information theory, with a particular focus on deterministic models as a key modeling tool.

Teaching History:

• 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.
• Kristen Ann Woyach: Exploring regulatory issues in cognitive radio and spectrum sharing.

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.

Special thanks to our past and present research sponsors:

• United States National Science Foundation under grants: ANI-0230963, ANI-326503, CNS-403427, CCF-729122 as well as NSF Fellowships for my students.
• Unrestricted Gifts from Sumitomo Electric and Samsung Corporation
• Vodafone Foundation Fellowships for my students
• C2S2 and others supporting work done in the Berkeley Wireless Research Center.