Mitchell Coding Group

Welcome to David's website

David G. M. Mitchell received the Ph.D. degree in Electrical Engineering from the University of Edinburgh, United Kingdom, in 2009. He is currently an Associate Professor in the Klipsch School of Electrical and Computer Engineering at the New Mexico State University, USA. He previously held Visiting Assistant Professor and Post-Doctoral Research Associate positions in the Department of Electrical Engineering at the University of Notre Dame, USA. He is a Senior Member of the IEEE and his research interests are in the area of digital communications, with emphasis on error control coding and information theory. Dr. Mitchell holds a U.S. patent and has published over 40 peer-reviewed IEEE journal and conference articles gathering more than 1400 citations. He received the National Science Foundation CAREER award in 2022, the National Science Foundation's most prestigious award in support of early-career faculty, and the 2019 NMSU Early Career Award for Exceptional Achievements in Creative Scholarly Activity. He has received two best paper awards and is the recipient of the 2019 New Mexico EPSCoR Mentor Award. Dr. Mitchell serves as an Associate Editor for the IEEE Transactions on Information Theory.

Recent News

• 04/01/23: Welcome to the group Dr. Mohsen Moradi! Mohsen obtained his PhD from Bilkent University in 2022 with Prof. Erdal Arikan. Before joining NMSU, he was a Postdoctoral Fellow at Bilkent University, advised by Prof. Tolga M. Duman. His main research interests include information theory, error correction coding, source coding, machine learning, and the analysis of algorithms.
  
  



• 03/01/23: Welcome to the group Dr. Salman Habib! Salman obtained his PhD in Electrical and Computer Engineering (ECE) at New Jersey Institute of Technology in 2021 with Prof. Joerg Kliewer. In 2022 he was at PetaIO Inc., Santa Clara, CA, where he developed techniques for determining the error-floor performance of high rate LDPC codes used for error correction in NAND flash storage devices. His research interests include coding theory, information theory, and machine learning.
  
  



• 11/11/22: Had a lovely trip to Brigham Young University to visit Dr. Willie Harrison and present the invited talk "Efficient Communication using Sparse Codes on Graphs" at the ECEN Colloquium.
  
  



• 09/30/22: Our new paper "A Unifying Framework to Construct QC-LDPC Tanner Graphs of Desired Girth" has been published in the latest IEEE Transactions on Information Theory.
  
  
  The performance of an LDPC code with parity-check matrix H depends on cycles in the associated Tanner graph. This paper presents a unifying framework to construct low-density parity-check (LDPC) codes with associated Tanner graphs of desired girth for which all existing designs must fit. Moreover, the derived necessary and sufficient conditions give rise to extremely efficient algorithms to construct such codes (as exemplified in the figure).
  
  
• 07/14/22: Traveling to the Coding Theory and Cryptography Workshop, ETH Zurich, held in honor of Joachim Rosenthal's 60th birthday. Dan Costello will be presenting our work "Modeling a Sliding Window Decoder for Spatially Coupled LDPC Codes". Happy birthday Joachim!


• 07/01/22: Welcome to the group Behrooz Mosallaei! Behrooz is currently pursuing his MSEE in the area of advanced wireless technologies in the smart grid.
  
  



• 07/01/22: Attending the 2022 IEEE International Symposium on Information Theory in Espoo, Finland, to present our paper "Systematic Doping of SC-LDPC Codes". PhD student Anthony Gómez-Fonseca (pictured) presented our other paper "Using Minors to Construct Generator Matrices for Quasi-Cyclic LDPC Codes". Great job Anthony!
  
  
  
  
• 07/01/22: Welcome to the group Dr. Masoumeh Alinia! Masoumeh obtained her PhD in Applied Mathematics (Coding and Information Theory) from Shahrekord University, with Prof. Mohammad Gholami. Her research interests are in the area of advanced error correcting codes, data compression, and machine learning.
  
  



• 04/15/22: Delighted to announce our new NSF project "RINGS: Resilient Edge Ecosystem for Collaborative and Trustworthy Disaster Response." Very excited to be a part of this unique public-private partnership.
  
  This project addresses networking and security challenges in next generation public safety and disaster response networks, where mission-critical emergency operations (e.g., search and rescue) need to be performed with limited surviving infrastructure, potentially augmented with diverse devices deployed by first responders. The project identifies the fundamental architectural and security challenges in fragmented networks, such as seamless multi-modal communications, resilient and verifiable computing, and trust management, and addresses them for viable deployment in disaster-response scenarios.
  
  
• 04/19/22: US Patent 11,309,915 is issued: "Efficient Implementation of a Threshold Modified Min-Sum Algorithm for LDPC Decoders".
  
  
  The proposed architecture introduces a novel lookup table based threshold attenuation technique, called threshold attenuated MSA (TAMSA). The TAMSA implementation (schematic above) is shown to improve bit error rate performance compared to conventional methods with no extra circuit power or circuit area compared to conventional AMSA, and only 0.07% extra leaf cells compared to conventional MSA.
  
  
• 04/11/22: Welcome to the group undergraduate student Yousif Yosif! Yosif is currently doing a double major Electrical Engineering and Computer Science. He is interested in research in the intersection of Information Systems and Machine Learning.
  
  



• 03/25/22: Thanks to NM EPSCoR for recognizing my CAREER award! Proud to be a part of this excellent team.
• 3/12/22: Nice write-up in the Las Cruces Sun-News about my NSF CAREER award! Check it out to find out more about our research projects and educational outreach.
  
  
  
  
• 02/18/22: Our new paper "Concatenated Spatially Coupled LDPC Codes With Sliding Window Decoding for Joint Source-Channel Coding" has been published in the latest IEEE Transactions on Communications.
  
  
  In this paper, we show that concatenated SC-LDPC codes display a notable performance improvement compared to existing state-of-the-art JSCC schemes based on LDPC codes with comparable latency and complexity constraints.
  
  
• 02/11/22: Enjoyed participating as a panelist in the HSI Stem Hub CAREER workshop. We fielded some great questions from early-career researchers working at Hispanic-Serving Institutions across the USA. Good luck to all!


• 02/01/22: Excited to announce that I am a recipient of the 2022 NSF CAREER Award for the project "Sparse Graph-Based Codes for Network Data Compression.". Many thanks to my current and former students, mentors, and colleagues.
  
  The proposed research significantly advances the state of the art in network data compression by employing ideas from network coding, graph theory, iterative information processing, machine learning, and circuit design. This promises a significant transformative impact on many critical applications employing reliable networked data compression, for example in the fields of healthcare, environmental monitoring, and finance.
  
  The project also includes an integrated education plan to increase participation in Science, Technology, Engineering, and Mathematics (STEM), particularly among minority groups. This objective is supported by several complementary initiatives, including targeted K-12 activities as well as related teacher training and mentoring.
  
  
• 01/31/22: Our new paper "Ternary LDPC Error Correction for Arrhythmia Classification in Wireless Wearable Electrocardiogram Sensors" has been published in the latest IEEE Transactions on Circuits and Systems.
  
  
  This system for improved arrhythmia detection presents a hardware-friendly LDPC encoder circuit. Simulation results show that the ternary LDPC codes can significantly improve classification accuracy in the presence of errors. For example, with an error probability of up to 21% in the sensor output bitstreams, the classification accuracy remains above 99% with the proposed error correction system.
  
  
• 12/11/21: Dan Costello presented our paper "Modeling a Sliding Window Decoder for Spatially Coupled LDPC Codes" at the 2021 IEEE Global Communications Conference (GLOBECOM).


• 12/09/21: Yanfang Liu presented (online) our research paper "Ternary LDPC Error Correction for Arrhythmia Classification in Wireless Wearable Electrocardiogram Sensors" at the 2021 IEEE International Symposium on Integrated Circuits and Systems (ISICAS). Great job Vivian!


• 11/03/21: Congratulations to Dr. Ahmad Golmohammadi for completing his doctoral thesis. Ahmad will be leaving us to join Bose Corporation.
  
  
  
  In his doctoral research, he showed several fundamental results related to spatially coupled codes for source compression, including that they have distortion performance very close to the rate-distortion (RD) limit as well as showing notable performance improvement compared to existing state-of-the-art joint source-channel coding schemes based on LDPC codes with comparable latency and complexity constraints (both published in the IEEE Transactions on Communications). Congratulations to Ahmad and good luck in your future career!


• 10/23/21: Had a great day representing the College of Engineering at the 2021 Las Cruces Spooky Science Festival. We had fun explaining our research projects to future generations of talented engineering students as well as creating some 3-D printed halloween decorations!
  
  
  
  
• 10/01/21: Good luck to Dr. Yanfang (Vivian) Liu, who is leaving us to join Innogrit Corporation to work on research related to LDPC codes for data storage! In her post-doctoral work, she published several important theoretical papers related to generalized LDPC codes, showing their suitability for URLLC in 5G communications, as well as multiple hardware implementation papers for LDPC decoders for communications and biomedical applications.
  
  
  
  


• 09/01/21: Congratulations to graduate students Andrew Cummins ("Iterative Threshold Decoding of Spatially Coupled, Parallel-Concatenated Codes") and Anthony Gomez-Fonseca ("Necessary and Sufficient Girth Conditions for LDPC Tanner Graphs with Denser Protographs") that both presented their first papers at the IEEE International Symposium on Topics in Coding 2021.
  
  
  
  


• 07/18/21: Attending the 2021 IEEE International Symposium on Information Theory (online) to present our research paper "Necessary and Sufficient Girth Conditions for Tanner Graphs of Quasi-Cyclic LDPC Codes".



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