Ashutosh Sabharwal

Information Architectures for Femto-aided Cellular Networks

NSF NeTS Medium (2012-2016)

Principal Investigators : Sanjay Shakkottai, Salman Avestimehr and Ashutosh Sabharwal

Students and Participants :

Subhashini Krishnasamy (UT Austin)
Pedro Santacruz (Rice, PhD'13, after a post-doc at UT Austin, faculty member at Calstate)
Rajat Sen (UT Austin)
David Kao (Rice, PhD'12, after post-doc at Cornell with Salman Avestimehr, now at Google)
Alireza Vahid (PhD'16,Cornell)
Navid Naderializadeh (Cornell)
Richard Latimer (MS'14, Rice, now at Indeed.com)
Jingwen Bai (PhD'16, now at Intel Labs)
Xu Du (current PhD at Rice)
Jian Cao (current PhD at Rice)
Yoseph Maguire (Rice REU, 2016)
Connor Heggie (Rice REU, 2016)

New Landscape: Femto-aided cellular networks are fundamentally altering the landscape of commercial wireless deployments. From a planned and centrally managed cellular network architecture, we are devolving to a heterogenous (cellular base-stations and Femto base-stations) unplanned network, with loose coordination due to disparate time-scales and bandwidths in the backhaul interconnects between these nodes. From an operational perspective, this results in a vastly different information architecture – i.e., who knows what and when, from current cellular architectures. This places us squarely in an setting where Network State Information (NSI - traffic, channel quality, topology, statistics) is noisy, partially missing, delayed, and inconsistent across nodes. This project addresses the challenge of developing advanced information architectures through three inter-related thrusts: (i) advanced network-aware physical layers (ii) network protocols leveraging advanced PHYs, and operational designs and prototypes.

Broader Impact Outcomes:

PI Shakkottai presented research at the Verizon 5G Academic Roundtable to their key technology and business leaders.
Graduate Student Xu Du attended SPAWC 2015 (16th IEEE International Workshop on Signal Processing Advances in Wireless Communications).
Graduate Student Xu Du gave a presentation to Intel Labs, titled "Multiuser MIMO Sequential Beamforming with Full-duplex Training," on October 22, 2015.
PI Sabharwal collaborated with Intel Labs and has started two new collaborations, one with Qualcomm and other with Huawei. The collaborations are considering the practical considerations of deploying the new innovations in next-generation systems.
PI Sabharwal presented invited seminars at University of California at San Diego, Qualcomm, Southern Methodist University, Samsung, Intel and National Chiao-Tung University (Taiwan), within the final reporting period.
Rice grad student, Richard Latimer, graduated with an MS and is now working at Indeed.com.
Post-doctoral researcher, Wenzhuo Ouyang, leveraged his experience working on this grant to gain a position at ASSIA, Inc.
Rice graduate student, Jingwen Bai, spent summer 2015 in an internship at Intel’s Wireless Research Labs.
PI Sabharwal attended the 2014 Asilomar conference on Signals, Systems, and Computers, held in Pacific Grove, California. He also met with collaborators and presented the paper “MIMO broadcast channel with continuous feedback using full-duplex radios.”
PI Sabharwal served as the co-chair of the Technical Program Committee of ACM International Conference on Mobile Computing and Networking, held in Maui, Hawaii.
One of the students (Dr. Sharayu Moharir, Ph.D'14 at UT Austin) who has collaborated on research in this project has recently joined as an Assistant Professor at IIT Bombay (a premier research institution in India).
Ashu Sabharwal presented research results at Intel Labs (September 2013), Qualcomm Research (November 2013) and RFIC (May 2014).
Students working on this grant have had increased exposure by visiting collaborative institutions. Specifically, a recent visit by Dr. Pedro Santacruz from Rice University (Advisor: Dr. Ashutosh Sabharwal) to UT Austin initiated collaborations beyond this project (with faculty members at UT Austin). Pedro is now at UT Austin as a post-doctoral researcher (starting Sept 15, 2013).
We have discussed ideas resulting from this project with members in industry: (a) affiliate members at UT Austin through the WNCG program on scheduling/alignment and (b) Rice industry collaborators Vaneet Aggarwal at AT&T Research (co-author on one of papers), and (c) Dr. Avestimehr's collaborations with Qualcomm Research, Dr. Mohammad Maddah-Ali (Alcatel-Lucent), and Dr. Javad Abdoli (Huawei Technologies).
PhD student, Alireza Vahid, and his advisor Dr. Salman Avestimehr received the 2013 Qualcomm Innovation Award based on some of the ideas resulting from this project. They will collaborate with partners at Qualcomm to further broaden the scope and impacts of the project. See the news.

Publications till date

Journal

D. Kao, M. Maddah-Ali, and A. S. Avestimehr, "Blind Index Coding," to appear in Transactions on Information Theory.
N. Naderializadeh, A. El Gamal, and A. S. Avestimehr, "Fundamental Limits of Non-Coherent Interference Alignment via Matroid Theory," submitted to IEEE Transactions on Information Theory.
A. Vahid, M. A. Maddah-Ali, A. S. Avestimehr, and Y. Zhu, "Binary Fading Interference Channel with No CSIT," submitted to IEEE Transactions on Information Theory.
S. Moharir, S. Krishnasamy and S. Shakkottai, "Scheduling in Densified Networks: Algorithms and Performance," Accepted for publication in IEEE/ACM Transaction on Networking, 2016.
X. Du, J. Tadrous and A. Sabharwal, "Multiuser MIMO Sequential Beamforming with Full-duplex Training," to appear in IEEE Transactions on Wireless Communications.
A. Vahid, V. Aggarwal, A.S. Avestimehr, and A. Sabharwal, "Interference Management with Mismatched Partial Channel State Information," submitted to EURASIP Journal on Wireless Communications and Networking, September 2016.
J. Bai and A. Sabharwal, "Asymptotic Analysis of MIMO Multi-Cell Full-Duplex Networks," Submitted to IEEE Transactions on Wireless Communications, June, 2016
W. Ouyang, J. Bai and A. Sabharwal, "Leveraging one-hop information in massive MIMO full-duplex wireless systems," Submitted to IEEE/ACM Transactions on Networking, Sep, 2015
J. Bai, C. Dick and A. Sabharwal, "Vector Bin-and-Cancel for MIMO Distributed Full-Duplex" , under review, IEEE transactions on information theory, 2015.
S. Moharir and S. Shakkottai, MaxWeight Versus BackPressure: Routing and Scheduling in Multichannel Relay Networks, IEEE/ACM Transaction on Networking, Volume 23, Number 5, pp. 1584-1598, October 2015.
A. Gopalan, C. Caramanis, and S. Shakkottai, Wireless Scheduling with Partial Channel State Information: Large Deviations and Optimality Queueing Systems, Volume 80, Issue 4, pp. 293-340, August 2015.
A. Vahid, M. Maddah-Ali and A. S. Avestimehr, Capacity Results for Binary Fading Interference Channels with Delayed CSIT, accepted for publication in IEEE Transactions on Information Theory.
S. Lashgari, A. S. Avestimehr, and C. Suh, "Linear Degrees of Freedom of the X-Channel with Delayed CSIT", IEEE Transactions on Information Theory, Vol 60, No 4, April 2014.
N. Naderializadeh and A.S. Avestimehr, "ITLinQ: A New Approach for Spectrum Sharing in Device-to-Device Communication Systems," IEEE Journal on Selected Areas in Communications Special Issue on 5G Wireless Communication Systems, Vol 32, No 9, 2014.
J. Abdoli and A. S. Avestimehr, Layered Interference Networks with Delayed CSI: DoF Scaling with Distributed Transmitters, IEEE Transactions on Information Theory, 60(3), 2014.
M. Duarte, A. Sabharwal, V. Aggarwal (AT&T Research), R. Jana (AT&T Research), K. K. Ramakrishnan (AT&T Research), C. W. Rice (AT&T Research), N. K. Shankaranarayanan (AT&T Research), "Design and Characterization of a Full-Duplex Multiantenna System for WiFi Networks," IEEE Transactions on Vehicular Technology, 63 (3), March 2014.
J. Bai and A. Sabharwal, “Distributed Full-Duplex via Wireless Side-Channels: Bounds and Protocols,” IEEE Transactions on Wireless Communications, 12 (8), August 2013.
A. Sahai, V. Aggarwal (AT&T Research), Melda Yuksel (TOBB University) and A. Sabharwal, “Capacity of All Nine Models of Channel Output Feedback for the Two-User Interference Channel,” IEEE Transactions on Information Theory, 59(11), November 2013.
D. Kao and A. Sabharwal, "Two-User Interference Channels With Local Views: On Capacity Regions of TDM-Dominating Policies," IEEE Transactions on Information Theory, 59(11), November 2013.
N. Naderializadeh and A. S. Avestimehr, Interference Networks with No CSIT: Impact of Topology, submitted to IEEE Transactions on Information Theory, 2013.

Conferences

H. Yang, N. Naderializadeh, A. S. Avestimehr, and J. Lee, "Topological Interference Management with Reconfigurable Antennas," IEEE International Symposium on Information Theory, July 2016.
D. Kao, M. Maddah-Ali, and A. S. Avestimehr, "Blind Index Coding," IEEE International Symposium on Information Theory (ISIT), July 2015. (Selected for semi-plenary presentation).
D. Kao, M. Maddah-Ali, and A. S. Avestimehr, "Blind Index Coding over Wireless Channels: The Value of Repetition Coding," IEEE International Conference on Communications (ICC), June 2015.
S. Krishnasamy, R. Sen, R. Johari and S. Shakkottai, "Regret of Queueing Bandits," to appear in the Proceedings of the Thirtieth Annual Conference on Neural Information Processing Systems (NIPS), Barcelona, Spain, December 2016.
X. Du, J. Tadrous, C. Dick, and A. Sabharwal, "MU-MIMO beamforming with full-duplex open-loop training," 2015 IEEE 16th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Stockholm, 2015, pp. 301-305.
S. Krishnasamy and S. Shakkottai, "Spectrum Sharing and Scheduling in D2D-Enabled Dense Cellular Networks," Proceedings of 13th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt), Mumbai, India, May 2015 (invited paper).
S. Moharir, S. Krishnasamy and S. Shakkottai, "Scheduling in Densified Networks: Algorithms and Performance," Proceedings of the 52nd Allerton Conference on Communication, Control, and Computing, Urbana, IL, October 2014.
A. Vahid, M. Maddah-Ali and A. S. Avestimehr, Communication Through Collisions: Opportunistic Utilization of Past Receptions, INFOCOM 2014.
J. Bai, S N. Diggavi and A. Sabharwal, "On the degrees-of-freedom of multi-user MIMO full-duplex network," Proceedings of IEEE International Symposium on Information Theory (ISIT) 2015. Yes.
E. Everett, A. Sabharwal, "A signal-space analysis of spatial self-interference isolation for full-duplex wireless," Proceedings of IEEE International Symposium on Information Theory (ISIT), 2014.
J. Bai, C. Liu, A. Sabharwal, "Increasing cellular capacity using ISM band side-channels: a first study," 4th workshop on All things cellular: operations, applications, and challenges (AllThingsCellular’14), 2014.
X. Du, J. Tadrous, C. Dick, and A. Sabharwal, "MIMO Broadcast Channel with Continuous Feedback using Full-duplex Radios," Asilomar Conference on Signals, Systems, and Computers, 2014.
D. Kao and A. S. Avestimehr, Linear Degrees of Freedom of the MIMO X-Channel with Delayed CSIT, in Proceedings of IEEE International Symposium on Information Theory (ISIT), 2014.
N. Naderializadeh and A.S. Avestimehr, "ITLinQ: A New Approach for Spectrum Sharing in Device-to-Device Communication Systems," in Proc. of IEEE DySPAN, 2014.
N. Naderializadeh and A. S. Avestimehr, "ITLinQ: A New Approach for Spectrum Sharing in Device-to-Device Communication Systems," in Proceedings of IEEE International Symposium on Information Theory (ISIT), 2014.
A. Sahai, S. Diggavi (UCLA) and A. Sabharwal, "On Uplink/Downlink Full-duplex Networks," Proceedings of Asilomar Conference on Signals and Systems, 2013.
J. Bai, C. Dick (Xilinx) and A. Sabharwal, "K-User Symmetric MIMO Distributed Full-duplex Network via Wireless Side-channels," Fifty-first Annual Allerton Conference Allerton House, UIUC, Illinois, USA, October 2 - 3, 2013.
S. Lashgari, A. S. Avestimehr, and C. Suh, "A Rank Ratio Inequality and the Linear Degrees of Freedom of X-Channel with Delayed CSIT," Allerton Conference on Communication, Control, and Computing, 2013.
A. Sahai, S. Diggavi, A Sabharwal, "On Degrees-of-Freedom of Full-Duplex Uplink/Downlink Channel," to be presented at Information Theory Workshop, September 2013, Seville, Spain.
N. Naderializadeh and A. S. Avestimehr, "Impact of Topology on Interference Networks with No CSIT," to appear in proceedings of IEEE International Symposium on Information theory (ISIT) 2013.
J. Abdoli and A. S. Avestimehr, "On Degrees of Freedom Scaling in Layered Interference Networks with Delayed CSI," to appear in proceedings of IEEE International Symposium on Information theory (ISIT) 2013.
P. E. Santacruz, V. Aggarwal, and A. Sabharwal, "Beyond Interference Avoidance: Distributed Sub-network Scheduling in Wireless Networks with Local Views," INFOCOM 2013 April 14, Turin, Italy.
D.T.H. Kao and A. Sabharwal, "Node cooperation with local views in the two-user interference channel," Proc. of Asilomar of Signals, Systems and Computers, November 2012.
D.T.H. Kao, and A. Sabharwal "An Upper Bound on the Capacity of Vector Dirty Paper with Unknown Spin and Stretch", Proc. of Information Theory Proceedings (ISIT), Istanbul, Turkey, 2013.

Book Chapters

R. Latimer, J. Holloway, A. Veeraraghavan, and A. Sabharwal, "SocialSync: Sub-frame synchronization in a smartphone camera network," In L. Agapito, M. M. Bronstein, and C. Rother, editors, Computer Vision - ECCV 2014 Workshops, volume 8926 of Lecture Notes in Computer Science, pages 561-575. Springer International Publishing, 2015

Technical Reports

A. Reddy and S. Shakkottai, "Scheduling in wireless networks with ergodic interference alignment", Technical Report, UT Austin 2013.