Older News

  • 06/25/21: Our new paper "Nested Array-based Spatially Coupled LDPC Codes" has been published in the latest IEEE Transactions on Communications.

    Linear nested codes, where two or more sub-codes are nested in a global code, have significant potential for reliable multi-terminal communication. In this article, we show that nested spatially coupled low-density parity-check (SC-LDPC) are well-suited for this problem and proposed a line-counting based optimization scheme for minimizing the number of dominant absorbing sets in order to improve their performance in the high signal-to-noise ratio regime. Our results show that it is possible to design nested codes for multiple terminals that maintain good performance across a variety of rates and channel conditions.

  • 05/24/21: Our new paper "Spatially Coupled Generalized LDPC Codes: Asymptotic Analysis and Finite Length Scaling" has been published in the latest IEEE Transactions on Information Theory.

    In this paper, we show that by generalizing the code constraints, so-called spatially coupled generalized LDPC (SC-GLDPC) codes have capacity approaching performance at moderate block/constraint lengths and no observable error floors (see solid curves on right versus non spatially coupled on left). Such codes are an attractive choice for applications requiring excellent performance throughout the entire range of decoded error rates under strict latency and power constraints.

  • 04/15/21: Min Zhu presented (online) our research paper "Adaptive Doping of Spatially Coupled LDPC Codes" at the (delayed) 2020 IEEE Information Theory Workshop (ITW).

  • 01/26/21: Our new book chapter "Low‐Density Parity‐Check (LDPC) Codes for 5G Communications" has been published as part of the Wiley 5G Ref: The Essential 5G Reference Online, Wiley & Sons.

    In this article, we describe the fundamental advances in low‐density parity‐check (LDPC) codes over the last two decades with special emphasis on the class of LDPC codes selected for the 5G new radio standard. We conclude the article by presenting three of the more promising extensions of LDPC codes known to date (generalized LDPC codes, nonbinary LDPC codes, and spatially coupled LDPC codes), which could potentially replace conventional LDPC codes in future communication standards.

  • 12/10/20: Yanfang Liu presented (online) our research paper "On the Design of Generalized LDPC codes with Component BCJR Decoding" at the 2020 IEEE Global Communications Conference (GLOBECOM).

  • 11/20/20: Our new paper "Error Propagation Mitigation in Sliding Window Decoding of Braided Convolutional Codes" has been published in the latest IEEE Transactions on Communications.

    Braided Convolutional Codes can achieve capacity approaching performance, but suffer from infrequent but severe error propagation in a streaming environment (see the blue curve). In this paper, we show that such behavior can be detected and mitigated by a "resynchronization" of the decoder, yielding orders of magnitude better error control performance (red curve).

  • 11/13/20: Congratulations to Ahmad Golmohammadi for defending his PhD thesis "Spatially Coupled Codes for Source Compression". Well done Dr. Golmohammadi, you have done some excellent work!



  • 10/27/20: Min Zhu presented our research paper "Decoder Error Propagation Mitigation for Spatially Coupled LDPC Codes" at the 2020 International Symposium on Information Theory and Its Applications (online).

  • 09/20/20: Our new paper "Efficient Implementation of a Threshold Modified Min-Sum Algorithm for LDPC Decoders" has been published in the latest IEEE Transactions on Circuits and Systems.


    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.

  • 10/27/20: Yanfang Liu presented (online) our research paper "Efficient Implementation of a Threshold Modified Min-Sum Algorithm for LDPC Decoders" at the 2020 IEEE International Symposium on Integrated Circuits and Systems (ISICAS).

  • 07/01/20: Excited to start work as an Associate Editor for the IEEE Transactions on Information Theory!

  • 06/30/20: Congratulations to Andrew Cummins for defending (by zoom) his MSEE thesis "Iterative Threshold Decoding for Spatially Couped, Turbo-like Codes". Great job Andrew!

  • 06/25/20: Had a great time this week teaching an "Introduction to Probability" Workshop to undergraduate students from New Mexico regional universities, community colleges, and tribal colleges as part of the New Mexico EPSCoR STEM Advancement Program (STEMAP).

  • 06/20/20: Our new paper "Designing Protograph-Based Quasi-Cyclic Spatially Coupled LDPC Codes With Large Girth" has been published in the latest IEEE Transactions on Communications.


    In this paper, we introduce a systematic multi-stage graph lifting process that yields QC-SC-LDPC codes with large girth. Simulation results show the design leads to improved decoding performance, particularly in the error floor, compared to random constructions.

  • 06/22/20: Attending the 2020 IEEE International Symposium on Information Theory (online) to present our research paper "A Novel Design of Spatially Coupled LDPC Codes for Sliding Window Decoding".

  • 05/29/20: Honored to have my research selected as a National Science Foundation highlight of the New Mexico Smart Grid Center! An excerpt:

    "...experts predict that the number of networked devices will be three times the global population by 2023, an increase that will challenge the carrying capacity of communications infrastructure on a global scale. Professor David Mitchell and his students at New Mexico State University address the data deluge by improving the performance of LDPC codes inherent in most next-generation wireless technology (5G) communications. Their algorithms demonstrate previously unachievable gains in computational efficiency that lessen the energy costs of digital information exchange and enable efficient monitoring and management of our nation’s power resources in the future."

    Thanks to Brittney Van Der Werff and NM EPSCoR for the wonderful write-up and image (note the convolutional Tanner graphs protecting the information!)



  • 04/15/20: Our new paper “A Threshold-Based Min-Sum Algorithm to Lower the Error Floors of Quantized LDPC Decoders” has been published in the latest IEEE Transactions on Communications.

  • 02/19/20: Our new paper “Performance Bounds and Estimates for Quantized LDPC Decoders” has been published in the latest IEEE Transactions on Communications.

  • 02/02/20: Traveling to San Diego, CA, to present our research paper "On the Design of Spatially Coupled LDPC Codes for Low Latency Applications" at the Information Theory and Applications Workshop.

  • 12/08/20: Traveling to Waikoloa, HI, to present our research paper "Efficient Search and Elimination of Harmful Objects for the Optimization of QC-SC-LDPC Codes" at the IEEE Global Communications Conference (Globecom).

  • 11/22/19: Honored to be a recipient of the 2019 New Mexico EPSCoR Mentoring Award!



  • 11/02/19: Graduate students Ahmad Golmohammadi and Andrew Cummins and Post-doc Yanfang (Vivian) Liu traveled to Albuquerque, NM to present our research at the New Mexico Academy of Science Research Symposium.



  • 10/19/19: Had a great day representing NMSU with faculty and students from the College of Engineering at the 2019 Las Cruces Spooky Science Festival! We had fun explaining our research projects and got lots of good questions from the next generation of engineers! Thanks to fellow ECE faculty Wei and Wenjie and students Xiaochen and Hunter for your engaging and enthusiastic explanations.



  • 10/02/19: Follow me on twitter @MitchellCoding!
  • 10/01/19: Honored to receive the 2019 New Mexico EPSCoR Mentor Award. An excerpt from a nomination letter: "His enthusiasm, support for his students and peers, and passion for solving the most difficult and pressing technical problems facing the state are the engine that drives our work toward excellence. Furthermore, his ability to communicate and reach across disciplinary boundaries ensures everyone involved in our project is utilized to the utmost of their abilities."
  • 9/27/19: Enjoyed participating in the first webinar of the NM SMART GRID Center! Watch from 19:30 for an overview of our networking research goal.

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  • 08/24/19: Traveling to Visby, Sweden, to present our research papers "Spatially Coupled LDPC Codes for Joint Source-Channel Coding" and "Optimization of Nested Array-based LDPC Codes Via Spatial Coupling" at the 2019 IEEE Information Theory Workshop.
  • 08/18/19: Our new paper “Code Design Based on Connecting Spatially Coupled Chains” has been published in the latest IEEE Transactions on Information Theory.
  • 08/06/19: Traveling to Albuquerque, NM, to present an invited talk "LDPC Codes and the McEliece Cryptosystem for Post-Quantum Cryptography" at the Sandia National Labs Cybersecurity Research Spotlight Forum.
  • 07/07/19: Traveling to Paris, France, to present our research paper "A Modified Min-Sum Algorithm for Quantized LDPC Decoders" at the IEEE International Symposium on Information Theory.
  • 07/01/19: PhD student Andrew Cummins is traveling to Boston, MA, to present our poster "Iterative APP Threshold Decoding of Braided Convolutional Codes" at the 2019 North American School of Information Theory.
  • 06/04/19: Traveling to Albuquerque, NM, to present an invited talk "LDPC Codes for Post-Quantum Cryptography" at the Sandia National Labs Quantum Information Sciences Research Spotlight Forum.
  • 04/08/19: Traveling to Halifax, Canada, to present a plenary talk "Efficient communication using sparse codes on graphs" at Dalhousie University.
  • 04/01/19: Welcome to new post-doctoral research associate Yanfang (Vivian) Liu! Yanfang is joining our group after completing her PhD in Spain at the University Carlos III, Madrid.
  • 02/21/19: Welcome to new PhD student Andrew Cummins! Andrew is joining our group after working in industry for several years following his degrees from UT Austin.
  • 02/09/19: Traveling to San Diego, CA, to present our research paper "A Finite-Length Analysis of Spatially Coupled Generalized LDPC Codes" at the Information Theory and Applications Workshop.
  • 01/31/19: Honored to be recognized as an exemplary reviewer (top 2%) for the IEEE Transactions on Communications!
  • 01/15/19: Honored to receive the 2019 NMSU Early Career Award for Exceptional Achievements in Creative Scholarly Activity!



  • 12/11/18: Our new paper “Generalized LDPC Codes for Ultra Reliable Low Latency Communication in 5G and Beyond” has been published in the latest IEEE Access, Special Issue: Advances in Channel Coding for 5G and Beyond.
  • 12/02/18: Collaborators Dan Costello and Michael Lentmaier are traveling to Hong Kong, China to present our keynote research paper "Spatially Coupled Generalized LDPC Codes: Introduction and Overview" at the International Symposium on Turbo Codes and Iterative Information Processing.
  • 11/25/18: Graduate students Yanfang Liu and Cunlu Zhou are traveling to Guangzhou, China to present our research papers "Free Pseudodistance Growth Rates for Spatially Coupled LDPC Codes over the BEC," and "On Generalized LDPC codes for 5G Ultra Reliable Communication" at the IEEE Information Theory Workshop.
  • 11/14/18: Our new paper “Encoding of Spatially Coupled LDGM Codes for Lossy Source Compression” has been published in the latest IEEE Transactions on Communications.
  • 10/25/18: Delighted to receive supplemental funding from the National Science Foundation (NSF) for the three year project "Coding for 5G and Beyond: Limits and Efficient Algorithms." The proposed research promises to provide a significant transformative impact on many critical applications employing reliable networked wireless communication, for example in the fields of healthcare, environmental monitoring, finance, and so on.
  • 08/25/18: Had a great day representing NMSU with students from the College of Engineering at the 4th Annual Las Cruces Touch-a-Truck event! We had fun explaining our research projects and got lots of good questions from future generations of engineers! Thanks to Jesus and Arezoo for your engaging and enthusiastic explanations.



  • 08/15/18: Congratulations to M.Sc. student Xaviar Enriquez for passing his thesis defense "Raptor Coding for Computer Networks". Great job Xaviar! He has accepted a job offer at the U.S. Army Aviation and Missile Research Development and Engineering Center (AMRDEC).
  • 07/14/18: Pleased to be part of the team to receive funding from the National Science Foundation (NSF) for the five year project "The New Mexico SMART Grid Center: Sustainable, Modular, Adaptive, Resilient, and Transactive." The New Mexico SMART Grid Center will transform the existing electricity distribution infrastructure by holistically incorporating microgrid optimization, operations optimization, microgrid controls, and tariff and customer behavior in the design and demonstration of interconnected Distribution Feeder Microgrids (DFMs).
  • 07/08/18: PhD student Ahmad Golmohammadi is traveling to Madison, WI, to attend the Open Science Grid User School.
  • 06/16/18: Traveling to Vail, CO, with graduate students Ahmad Golmohammadi and Homayoon Hatami to present our research papers "Concatenated spatially coupled LDPC codes for joint source-channel coding", "Performance bounds for quantized spatially coupled LDPC decoders based on absorbing sets", and "Combating error propagation in window decoding of braided convolutional codes" at the IEEE International Symposium on Information Theory.
  • 05/23/18: Welcome to new Research Experience for Undergraduate students Jennifer Johanes and Tiger Ji! Jennifer is visiting from the The College of Brockport, State University of New York and Tiger is visiting from the Ohio State University. Both will be here for 3 months to work on research projects related to post-quantum cryptography. The REU program is supported by the National Science Foundation.
  • 05/15/18: Traveling to Vijayawada, India, for a research trip to promote NMSU and recruit graduate students.
  • 05/08/18: Welcome to new Ph.D. student Massimo Battaglioni! Massimo is visiting from the Marche Polytechnic University, Ancona, Italy, for 3 months.
  • 03/05/18: Congratulations to M.Sc. student Matthew Grimes for passing his thesis defense. Great job Matt! He has accepted a job offer at TRAX International.
  • 02/11/18: Traveling to San Diego, CA, to present our papers "Joint source-channel coding with concatenated spatially coupled LDPC codes" and "On decoding error propagation for braided convolutional codes" at the 2018 Information Theory and Applications Workshop.
  • 01/08/18: Traveling to Las Vegas, NV, with M.Sc. student Matthew Grimes to present our paper “Design of Nested Protograph-Based LDPC Codes with Low Error-Floors” at the 2018 IEEE Annual Computing and Communication Workshop and Conference.
  • 12/18/17: Our new paper “Continuous Transmission of Spatially Coupled LDPC Code Chains” has been published in the latest IEEE Transactions on Communications.
  • 12/01/17: Delighted to receive IMPACT funding from New Mexico State University for the two year project "RC-UDP: On Raptor Coding Over UDP For Reliable Communication in High-Bandwidth Networks."
  • 11/12/17: Nice write-up in the Las Cruces Sun-News about my research!



  • 10/10/17: Welcome to new Ph.D. student Yinfang (Vivian) Liu! Vivian is visiting from the University of Carlos III, Madrid for 6 months.
  • 09/15/17: Our new paper “Braided Convolutional Codes with Sliding Window Decoding” has been published in the latest IEEE Transactions on Communications.
  • 09/06/17: Delighted to receive funding from the National Aeronautics and Space Administration (NASA) for the one year project “Hybrid UWB/Optical Communications for Distributed Space Systems.”
  • 08/26/17: Had a great day representing NMSU with students from the College of Engineering at the 3rd Annual Las Cruces Touch-a-Truck event. We had fun explaining our research projects and got lots of good questions from future generations of engineers! Thanks to Jesus, Arezoo, Nathan, and Douglas for your engaging and enthusiastic explanations.



  • 07/17/17: Delighted to receive funding from the National Science Foundation (NSF) for the three year project "Coding for 5G and Beyond: Limits and Efficient Algorithms." The proposed research promises to provide a significant transformative impact on many critical applications employing reliable networked wireless communication, for example in the fields of healthcare, environmental monitoring, finance, and so on.
  • 07/07/17: Pleased to be part of the team to receive funding from the National Science Foundation (NSF) for the three year project "Cyber Infrastructure Training and Mentoring (CI-TraM)." The proposed project serves the national interest by developing and increasing the cyberinfrastructure literacy of undergraduates who are interested in STEM careers.
  • 07/01/17: Traveling to Madrid, Spain, for a research visit to the University Carlos III to work on our joint project on generalized LDPC codes.
  • 06/25/17: Traveling to Aachen, Germany, to present our papers “Edge Spreading Design of High Rate Array-Based SC-LDPC Codes” and “A Protograph-Based Design of Quasi-Cyclic Spatially Coupled LDPC Codes” at the 2017 IEEE International Symposium on Information Theory.
  • 06/06/17: Ahmad Golmohammadi is presenting our poster “Encoding of Spatially Coupled LDGM Codes for Lossy Source Compression” and Homayoon Hatami is presenting our poster “Lower Bounds for Quantized LDPC Min-Sum Decoders Based on Absorbing Sets” at the 2017 North American School of Information Theory.
  • 06/04/17: Traveling to Norway for a research visit to the University of Bergen to work on our joint project to design spatially coupled LDPC codes.
  • 05/08/17: Our tutorial talk “Spatially Coupled LDPC Codes: From Theory to Practice” was well received at the 2017 European School of Information Theory, Madrid, Spain.
  • 03/07/17: Ahmad Golmohammadi is presenting our work “Monte Carlo Simulation for Next Generation Source and Channel Coding on OSG Connect,” at the Open Science Grid Annual Meeting, in San Diego, CA.
  • 02/12/17: Traveling to San Diego, CA, to present our papers "On the Finite Length Scaling Behavior of Spatially Coupled LDPC Codes" and “An optimized edge spreading approach to construct spatially-coupled LDPC codes” at the ITA Workshop.
  • 01/17/17: Welcome to new M.Sc. student Xaviar Enriquez!
  • 12/08/16: Promoted to Senior Member of the IEEE. Thanks to my referees!
  • 10/30/16: Traveling to Monterey, CA, with Ph.D. student Ahmad Golmohammadi to present our paper “On the Windowed Encoding Complexity of SC-LDGM Codes for Lossy Source Compression” at ISITA 2016.
  • 10/24/16: Welcome to Dr. Eirik Rosnes from the University of Bergen, visiting the ECE department this week to work with me on the design of spatially-coupled LDPC codes.
  • 10/10/16: Recognized for completing the OCIP “New2Online” program. Promoted to Distinguished Member of the NMSU Teaching Academy.
  • 09/10/16: Traveling to Cambridge, England, to present our paper “On the Block Error Rate of Spatially Coupled LDPC Codes for Streaming Applications” at IEEE ITW 2016.
  • 09/06/16: Traveling to Brest, France, to present our paper “New Perspectives on Braided Convolutional Codes” at ISTC 2016.
  • 08/27/16: Had a great time representing NMSU at the Annual Las Cruces “Touch-a-truck” event attended by 1000 learners from our community.
  • 08/17/16: Welcome to new student Matthew Grimes!
  • 08/16/16: Our new paper “Design of Spatially Coupled LDPC Codes Over GF(q) for Windowed Decoding” has been published in the latest IEEE Transactions on Information Theory.
  • 07/17/16: Traveling for research visits to University Carlos III, Madrid and the University of Notre Dame, IN.
  • 07/10/16: Traveling to Barcelona, Spain, to present our papers "Windowed Encoding of Spatially Coupled LDGM Codes for Lossy Source Compression" and "Performance bounds for Quantized LDPC Decoders based on Absorbing Sets" at ISIT 2016.
  • 01/30/16: Traveling to San Diego, CA, to present our paper “Windowed Encoding of Spatially Coupled LDGM Codes for Lossy Source Compression” at ITA 2016.
  • 01/21/16: Our new paper “Randomly Punctured LDPC Codes” has been published in the latest IEEE Journal on Selected Areas in Communications.
  • 08/20/15: Our new paper “Spatially Coupled LDPC Codes Constructed from Protographs” has been published in the latest IEEE Transactions on Information Theory.
  • 08/17/15: Welcome to my new Ph.D. student, Ahmad Golmohammadi. Khosh amadid!
  • 05/14/15: Traveling to Hong Kong, China, to present our papers "Approximating Thresholds of Punctured LDPC Codes on the AWGN Channel" and "Analyzing the Finite-length Performance of Generalized LDPC Codes" at ISIT 2015.
  • 04/01/15: I will be starting a new position as an Assistant Professor at New Mexico State University in Fall 2015. Go Aggies!
  • 03/15/15: Our new paper “Performance Comparison of LDPC Block and Spatially Coupled Codes over GF(q)” has been published in the latest IEEE Transactions on Communications.

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