ZTE Communications ›› 2025, Vol. 23 ›› Issue (1): 30-44.DOI: 10.12142/ZTECOM.202501005

• Special Topic • Previous Articles     Next Articles

Separate Source Channel Coding Is Still What You Need: An LLM-Based Rethinking

REN Tianqi1, LI Rongpeng1(), ZHAO Mingmin1, CHEN Xianfu2, LIU Guangyi3, YANG Yang4, ZHAO Zhifeng1,5, ZHANG Honggang6   

  1. 1.College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China
    2.Shenzhen CyberAray Network Technology Co. , Ltd. , Shenzhen 518000, China
    3.China Mobile Research Institute, Beijing 100053, China
    4.The Internet of Things Thrust, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou 511453, China
    5.Zhejiang Lab, Hangzhou 311121, China
    6.Faculty of Data Science, City University of Macau, Macao 999078, China
  • Received:2025-01-02 Online:2025-03-25 Published:2025-03-25
  • About author:REN Tianqi received his BE degree in electronic science and technology from Zhejiang University, China in 2024. He is currently pursuing his ME degree in electronic and information engineering with Zhejiang University. His research interests include application of large language models in communication scenarios and semantic communications.
    LI Rongpeng (lirongpeng@zju.edu.cn) is currently an associate professor with the College of Information Science and Electronic Engineering, Zhejiang University, China. He was a research engineer with the Wireless Communication Laboratory, Huawei Technologies Co., Ltd. from August 2015 to September 2016. He was a visiting scholar with the Department of Computer Science and Technology, University of Cambridge, UK from February 2020 to August 2020. His research interest currently focuses on networked intelligence for communications evolving (NICE). He received the Wu Wenjun Artificial Intelligence Excellent Youth Award in 2021. He serves as an Editor for China Communications.
    ZHAO Mingmin received his BEng and PhD degrees in information and communication engineering from Zhejiang University, China in 2012 and 2017, respectively. From December 2015 to August 2016, he was a visiting scholar with the Department of Electrical and Computer Engineering, Iowa State University, USA. From July 2017 to July 2018, he was a research engineer with Huawei Technologies Co., Ltd. He is currently a lecturer with the College of Information Science and Electronic Engineering, Zhejiang University. Since May 2019, he has been a visiting scholar with the Department of Electrical and Computer Engineering, National University of Singapore. His research interests include channel coding, algorithm design and analysis for advanced MIMO, cooperative communication, and machine learning for wireless communications.
    CHEN Xianfu received his PhD degree (with Hons.) from Zhejiang University, China in 2012. In 2012, he joined the VTT Technical Research Centre of Finland, as a research scientist and as a senior scientist from 2013 to 2023. He is currently a chief research engineer with the Shenzhen CyberAray Network Technology Co., Ltd., China. His research interests include various aspects of wireless communications and networking, with emphasis on human-level and artificial intelligence for resource awareness in next-generation communication networks. Dr. CHEN was the recipient of the 2021 IEEE Communications Society Outstanding Paper Award and the 2021 IEEE Internet of Things Journal Best Paper Award. He is an editor of IEEE Open Journal of the Communications Society, an academic editor of Wireless Communications and Mobile Computing, and an associate editor of China Communications.
    LIU Guangyi received his PhD degree from Beijing University of Posts and Telecommunications, China in 2006. He is currently the chief scientist of 6G in China Mobile Communication Corporation (CMCC), the founding member and the co-chair of the 6G Alliance of Network AI, and the vice-chair of the THz Industry Alliance in China and the Wireless Technology Working Group of IMT-2030 (6G) Promotion Group supported by Ministry of Information and Industry Technology of China. He has been leading the 6G research and development with CMCC since 2018. He has led the Research and Development of 4G's evolution and 5G in CMCC from 2006 to 2020. He has acted as a Spectrum Working Group Chair and the Project Coordinator of LTE Evolution and 5G eMBB in the Global TD-LTE Initiative from 2013 to 2020 and led the industrialization and globalization of TD-LTE evolution and 5G eMBB.
    YANG Yang is a professor with the IoT Thrust, the Director of the Research Center for the Digital World with Intelligent Things (DOIT), and the associate vice-president for Teaching and Learning with The Hong Kong University of Science and Technology (Guangzhou), China. He is also an adjunct professor with the Department of Broadband Communication at Peng Cheng Laboratory, the chief scientist of IoT with Terminus Group, and a senior consultant for Shenzhen Smart City Technology Development Group, China. His research interests include multi-tier computing networks, 5G/6G systems, AIoT technologies, intelligent services and applications, and advanced wireless testbeds. He has been the chair of the Steering Committee of the Asia-Pacific Conference on Communications (APCC) from 2019 to 2021. Currently, he is serving the IEEE Communications Society as the chair for the 5G Industry Community and chair for the Asia Region at Fog/Edge Industry Community. He is a fellow of IEEE.
    ZHAO Zhifeng received his BE degree in computer science, ME degree in communication and information systems, and PhD degree in communication and information systems from the PLA University of Science and Technology, China in 1996, 1999, and 2002, respectively. From 2002 to 2004, he acted as a post-doctoral researcher with Zhejiang University, China, where his studies focused on multimedia next-generation networks (NGNs) and softswitch technology for energy efficiency. Currently, he is with the Zhejiang Lab as the Chief Engineering Officer. His research areas include software-defined networks (SDNs), wireless networks in 6G, computing networks, and collective intelligence. He is the Symposium Co-Chair of ChinaCom 2009 and 2010. He is the TPC Co-Chair of the 10th IEEE International Symposium on Communication and Information Technology (ISCIT 2010).
    ZHANG Honggang is a professor with the Faculty of Data Science, City University of Macau, China. He was the founding Chief Managing Editor of Intelligent Computing, a Science Partner Journal, and a professor with the College of Information Science and Electronic Engineering, Zhejiang University, China. He was an Honorary Visiting Professor with the University of York, UK, and an International Chair Professor of Excellence with the Université Européenne de Bretagne and Supélec, France. His research interests include cognitive radio networks, semantic communications, green communications, machine learning, artificial intelligence, intelligent computing, and the Internet of Intelligence. He is a co-recipient of the 2021 IEEE Communications Society Outstanding Paper Award and the 2021 IEEE Internet of Things Journal Best Paper Award. He was the leading guest editor for the special issues on green communications of the IEEE Communications Magazine. He is the associate editor-in-chief of China Communications. He is a fellow of IEEE.
  • Supported by:
    the National Key Research and Development Program of China(2024YFE0200600);the Zhejiang Provincial Natural Science Foundation of China(LR23F010005);the Huawei Cooperation Project(TC20240829036)

Abstract:

Along with the proliferating research interest in semantic communication (SemCom), joint source channel coding (JSCC) has dominated the attention due to the widely assumed existence in efficiently delivering information semantics. Nevertheless, this paper challenges the conventional JSCC paradigm and advocates for adopting separate source channel coding (SSCC) to enjoy a more underlying degree of freedom for optimization. We demonstrate that SSCC, after leveraging the strengths of the Large Language Model (LLM) for source coding and Error Correction Code Transformer (ECCT) complemented for channel coding, offers superior performance over JSCC. Our proposed framework also effectively highlights the compatibility challenges between SemCom approaches and digital communication systems, particularly concerning the resource costs associated with the transmission of high-precision floating point numbers. Through comprehensive evaluations, we establish that assisted by LLM-based compression and ECCT-enhanced error correction, SSCC remains a viable and effective solution for modern communication systems. In other words, separate source channel coding is still what we need.

Key words: separate source channel coding (SSCC), joint source channel coding (JSCC), end-to-end communication system, Large Language Model (LLM), lossless text compression, Error Correction Code Transformer (ECCT)