Pub Date : 2023-01-01DOI: 10.1109/OJCAS.2023.3299052
Ti-Yu Chen;Zhi-Jing Lin;Tzi-Dar Chiueh
Massive Machine-type Communications (mMTCs) is a major use case for the 5G standard. The grant-free (GF) sparse-coded multiple access (SCMA) transmission is particularly spectrum efficient in the sporadic uplink traffic, which is characteristic of the mMTC networks. In this paper, an uplink GF-SCMA receiver with a user activity detection (UAD) function was designed and implemented. In particular, several new techniques were proposed to enhance the SCMA decoder performance; they include delayed serial update, early stopping, message passing algorithm equation reformulation, distance approximation, and sum circuit sharing. To meet the real-time operation requirements, we implemented key inner receiver function circuits, such as carrier frequency synchronization, user signature detection, channel estimation and compensation, soft SCMA detection, etc. on a Xilinx KCU1500 FPGA chip. Finally, an over-the-air (OTA) prototype has been constructed, demonstrating the efficient and reliable multi-user GF-SCMA uplink transmission of the proposed system.
{"title":"Grant-Free Sparse Code Multiple Access for Uplink Massive Machine-Type Communications and Its Real-Time Receiver Design","authors":"Ti-Yu Chen;Zhi-Jing Lin;Tzi-Dar Chiueh","doi":"10.1109/OJCAS.2023.3299052","DOIUrl":"https://doi.org/10.1109/OJCAS.2023.3299052","url":null,"abstract":"Massive Machine-type Communications (mMTCs) is a major use case for the 5G standard. The grant-free (GF) sparse-coded multiple access (SCMA) transmission is particularly spectrum efficient in the sporadic uplink traffic, which is characteristic of the mMTC networks. In this paper, an uplink GF-SCMA receiver with a user activity detection (UAD) function was designed and implemented. In particular, several new techniques were proposed to enhance the SCMA decoder performance; they include delayed serial update, early stopping, message passing algorithm equation reformulation, distance approximation, and sum circuit sharing. To meet the real-time operation requirements, we implemented key inner receiver function circuits, such as carrier frequency synchronization, user signature detection, channel estimation and compensation, soft SCMA detection, etc. on a Xilinx KCU1500 FPGA chip. Finally, an over-the-air (OTA) prototype has been constructed, demonstrating the efficient and reliable multi-user GF-SCMA uplink transmission of the proposed system.","PeriodicalId":93442,"journal":{"name":"IEEE open journal of circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/8784029/10019301/10195181.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49919368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-24DOI: 10.1109/OJCAS.2022.3219531
Ping-Hsuan Hsieh;Vanessa Chen
This Special Section of the IEEE Open Journal of Circuits and Systems is dedicated to a collection of articles on Smart Imaging, to promote techniques in both system and circuit levels to tackle various challenges as the requirements for image quality, efficiency, and levels of integration keep increasing and to provide insightful guidelines for intelligent vision in the years to come. This Special Section covers articles for applications including vision system, time-of-flight system, and terahertz imaging system.
{"title":"Introduction to the Special Section on Smart Imaging","authors":"Ping-Hsuan Hsieh;Vanessa Chen","doi":"10.1109/OJCAS.2022.3219531","DOIUrl":"https://doi.org/10.1109/OJCAS.2022.3219531","url":null,"abstract":"This Special Section of the IEEE Open Journal of Circuits and Systems is dedicated to a collection of articles on Smart Imaging, to promote techniques in both system and circuit levels to tackle various challenges as the requirements for image quality, efficiency, and levels of integration keep increasing and to provide insightful guidelines for intelligent vision in the years to come. This Special Section covers articles for applications including vision system, time-of-flight system, and terahertz imaging system.","PeriodicalId":93442,"journal":{"name":"IEEE open journal of circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/8784029/9684754/09963772.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49909765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-23DOI: 10.1109/OJCAS.2022.3218914
Mengqi Wang;Xiu Yao
The Advent of modern power electronics has brought tremendous impact on emerging power systems. In an emerging smart grid, as the number of inverter- and converter-based devices increases to more than hundreds of thousands, it is rather intuitive that the state-of-the-art technical solutions and industry practices will no longer be sustainable. The combination of power electronics and advanced control technologies serve as the key enabler of a wide range of smart grid applications. While tremendous progress has been made in advancing the standalone power electronics technologies, much less attention has been paid to bridging the gap between traditionally disjoint research areas – power electronics, power systems, and intelligent control – ultimately facilitating the vision of 100% carbonneutral energy systems come to fruition. There is a growing interest in the concepts of power electronics-enabled power systems around the world. This special section includes two high-quality papers, which cover the trending topic on the control strategy for inverters that are essential for Smart Grid applications.
{"title":"Editorial IEEE Open Journal of Circuits and Systems: Special Section on Advanced Power Electronics Techniques for Smart Grid Applications","authors":"Mengqi Wang;Xiu Yao","doi":"10.1109/OJCAS.2022.3218914","DOIUrl":"https://doi.org/10.1109/OJCAS.2022.3218914","url":null,"abstract":"The Advent of modern power electronics has brought tremendous impact on emerging power systems. In an emerging smart grid, as the number of inverter- and converter-based devices increases to more than hundreds of thousands, it is rather intuitive that the state-of-the-art technical solutions and industry practices will no longer be sustainable. The combination of power electronics and advanced control technologies serve as the key enabler of a wide range of smart grid applications. While tremendous progress has been made in advancing the standalone power electronics technologies, much less attention has been paid to bridging the gap between traditionally disjoint research areas – power electronics, power systems, and intelligent control – ultimately facilitating the vision of 100% carbonneutral energy systems come to fruition. There is a growing interest in the concepts of power electronics-enabled power systems around the world. This special section includes two high-quality papers, which cover the trending topic on the control strategy for inverters that are essential for Smart Grid applications.","PeriodicalId":93442,"journal":{"name":"IEEE open journal of circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/8784029/9684754/09961069.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49909762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-26DOI: 10.1109/OJCAS.2022.3217065
Bob Ross;Cong Ling
Wang algebra was initiated by Ki-Tung Wang as a short-cut method for the analysis of electrical networks. It was later popularized by Duffin and has since found numerous applications in electrical engineering and graph theory. This is a semi-tutorial paper on Wang algebra, its history, and modern applications. We expand Duffin’s historic notes on Wang algebra to give a full account of Ki-Tung Wang’s life. A short proof of Wang algebra using group theory is presented. We exemplify the usefulness of Wang algebra in the design of T-coils. Bridged T-coils give a significant advantage in bandwidth, and were widely adopted in Tektronix oscilloscopes, but design details were guarded as a trade secret. The derivation presented in this paper, based on Wang algebra, is more general and simpler than those reported in literature. This novel derivation has not been shared with the public before.
{"title":"Wang Algebra: From Theory to Practice","authors":"Bob Ross;Cong Ling","doi":"10.1109/OJCAS.2022.3217065","DOIUrl":"10.1109/OJCAS.2022.3217065","url":null,"abstract":"Wang algebra was initiated by Ki-Tung Wang as a short-cut method for the analysis of electrical networks. It was later popularized by Duffin and has since found numerous applications in electrical engineering and graph theory. This is a semi-tutorial paper on Wang algebra, its history, and modern applications. We expand Duffin’s historic notes on Wang algebra to give a full account of Ki-Tung Wang’s life. A short proof of Wang algebra using group theory is presented. We exemplify the usefulness of Wang algebra in the design of T-coils. Bridged T-coils give a significant advantage in bandwidth, and were widely adopted in Tektronix oscilloscopes, but design details were guarded as a trade secret. The derivation presented in this paper, based on Wang algebra, is more general and simpler than those reported in literature. This novel derivation has not been shared with the public before.","PeriodicalId":93442,"journal":{"name":"IEEE open journal of circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/8784029/9684754/09930827.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41881318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper provides a framework for analyzing the loop dynamics of the clock and data recovery (CDR) system of ADC-based PAM-4 receivers, which will assist in extending the timing recovery loop bandwidth. This paper formulates an accurate linear model of linear and signed Mueller–Muller phase detector for baud-rate clock recovery. Different equalization configurations of continuous-time linear equalizer (CTLE) and feed-forward equalizer (FFE) are evaluated from a phase detector performance perspective to enable high CDR loop bandwidth. The impact of loop latency on the timing recovery of ADC-based PAM-4 receivers is also analyzed and demonstrated using accurate behavioral simulations. The analysis and behavioral results show that, to achieve high CDR loop bandwidth with a good jitter tolerance, the phase detector gain to noise ratio should be maximized, and CDR loop latency should be minimized.
{"title":"Loop Dynamics Analysis of PAM-4 Mueller–Muller Clock and Data Recovery System","authors":"Kunal Yadav;Ping-Hsuan Hsieh;Anthony Chan Carusone","doi":"10.1109/OJCAS.2022.3211844","DOIUrl":"10.1109/OJCAS.2022.3211844","url":null,"abstract":"This paper provides a framework for analyzing the loop dynamics of the clock and data recovery (CDR) system of ADC-based PAM-4 receivers, which will assist in extending the timing recovery loop bandwidth. This paper formulates an accurate linear model of linear and signed Mueller–Muller phase detector for baud-rate clock recovery. Different equalization configurations of continuous-time linear equalizer (CTLE) and feed-forward equalizer (FFE) are evaluated from a phase detector performance perspective to enable high CDR loop bandwidth. The impact of loop latency on the timing recovery of ADC-based PAM-4 receivers is also analyzed and demonstrated using accurate behavioral simulations. The analysis and behavioral results show that, to achieve high CDR loop bandwidth with a good jitter tolerance, the phase detector gain to noise ratio should be maximized, and CDR loop latency should be minimized.","PeriodicalId":93442,"journal":{"name":"IEEE open journal of circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9910561","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62854461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-26DOI: 10.1109/OJCAS.2022.3209152
Li-Wei Liu;Yen-Chin Liao;Hsie-Chia Chang
An error floor phenomenon, decoding performance, and throughput are three major concerns for LDPC decoders in NAND Flash applications. With a penalty method and an active iteration mechanism, we present a Unified Penalty Gradient Descent Bit Flipping (UP-GDBF) decoding algorithm, which not only possesses error-floor free property but also improves convergence speed in decoding performance. To fulfill the high-throughput requirement while maintaining reliable error correction capability, we propose an energy-based backtracking scheme to reduce 40% latency with a negligible 0.8% area overhead. Implemented in TSMC 16nm process, the proposed 4KB LDPC decoder can achieve a throughput of 19.3 Gbps with 0.120 mm2 area to satisfy ONFI 5.0 throughput requirement. Compared to existing approaches, our decoder architecture provides superior data rate and decoding performance in both 1KB and 4KB LDPC codes.
{"title":"UP-GDBF: A 19.3 Gbps Error Floor Free 4KB LDPC Decoder for NAND Flash Applications","authors":"Li-Wei Liu;Yen-Chin Liao;Hsie-Chia Chang","doi":"10.1109/OJCAS.2022.3209152","DOIUrl":"10.1109/OJCAS.2022.3209152","url":null,"abstract":"An error floor phenomenon, decoding performance, and throughput are three major concerns for LDPC decoders in NAND Flash applications. With a penalty method and an active iteration mechanism, we present a Unified Penalty Gradient Descent Bit Flipping (UP-GDBF) decoding algorithm, which not only possesses error-floor free property but also improves convergence speed in decoding performance. To fulfill the high-throughput requirement while maintaining reliable error correction capability, we propose an energy-based backtracking scheme to reduce 40% latency with a negligible 0.8% area overhead. Implemented in TSMC 16nm process, the proposed 4KB LDPC decoder can achieve a throughput of 19.3 Gbps with 0.120 mm2 area to satisfy ONFI 5.0 throughput requirement. Compared to existing approaches, our decoder architecture provides superior data rate and decoding performance in both 1KB and 4KB LDPC codes.","PeriodicalId":93442,"journal":{"name":"IEEE open journal of circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9902993","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62853951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present the BrainScaleS-2 mobile system as a compact analog inference engine based on the BrainScaleS-2 ASIC and demonstrate its capabilities at classifying a medical electrocardiogram dataset. The analog network core of the ASIC is utilized to perform the multiply-accumulate operations of a convolutional deep neural network. At a system power consumption of 5.6W, we measure a total energy consumption of $mathrm {192 ~mu text {J} }$