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Joint SCMA and waveform optimisation for WPDM-based logging cable telemetry systems under sampling clock offset

IET COMMUNICATIONS 2019年第3期13卷 345-353页

作者： Cui, Qian Shuang, Kai China Univ Petr Coll Geophys & Informat Engn Beijing 102249 Peoples R China China Univ Petr State Key Lab Petr Resources & Prospecting Beijing 102249 Peoples R China

This study introduces sparse code multiple access (SCMA) and wavelet packet division multiplexing (WPDM) to logging cable telemetry systems (LCTSs). The authors study the feasibility of SCMA for LCTSs and provide a WPDM-based system model, as well as the associated optimal waveform design under sampling clock offset (SCO) via a genetic algorithm. The performance advantages of the designed scheme over the conventional WPDM and orthogonal frequency division multiplexing (OFDM) are demonstrated by both analytical and simulation methods. Numerical results show the performance of the SCMA-based mapping method over quadrature amplitude modulation in terms of improved spectral efficiency. Furthermore, the new scheme outperforms conventional WPDM and OFDM in bit error rate performance and transmission rate under SCO. Such advantages with the flexible design of basis functions make SCMA and WPDM a significant candidate for LCTSs.

关键词： quadrature amplitude modulation OFDM modulation genetic algorithms error statistics wavelength division multiplexing telecommunication cables radiotelemetry code division multiple access joint SCMA waveform optimisation sparse code multiple access WPDM-based system model associated optimal waveform design SCO OFDM SCMA-based mapping method bit error rate performance sampling clock offset wavelet packet division multiplexing LCTS orthogonal frequency division multiplexing WPDM-based logging cable telemetry systems genetic algorithm quadrature amplitude modulation spectral efficiency transmission rate

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Optimal Power Allocation for SCMA Downlink Systems Based on Maximum Capacity

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IEEE TRANSACTIONS ON COMMUNICATIONS 2019年第2期67卷 1480-1489页

作者： Han, Shuai Huang, Yiteng Meng, Weixiao Li, Cheng Xu, Nuo Chen, Dageng Harbin Inst Technol Commun Res Ctr Harbin 150001 Heilongjiang Peoples R China Mem Univ Newfoundland Fac Engn & Appl Sci Dept Elect & Comp Engn St John NF A1C 5S7 Canada China Acad Space Technol Inst Telecommun Satellite Beijing 100094 Peoples R China Shanghai Huawei Technol Co Ltd Shanghai 518129 Peoples R China

sparse code multiple access (SCMA) is a novel type of non-orthogonal multiple access technology that combines the concepts of CDMA and OFDMA. The advantages of SCMA include high capacity, low time delay, and high date rate. In this paper, a power allocation algorithm is proposed for SCMA downlink systems where each tone is taken by more than one user to maximize the system's sum capacity. In SCMA systems, users are divided into different user groups. Thus, our proposed algorithm includes three-level power allocation. Since the power allocation problem is non-convex, the complexity of finding the optimal solutions is prohibitive. The Lagrange dual decomposition method is employed to efficiently solve the non-convex optimization problem. Results show that the optimized algorithm can significantly improve the sum capacity.

关键词： Optimal power allocation maximum capacity convex optimization sparse code multiple access

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The optimization scheme for joint iterative detection and decoding of polar coded SCMA system

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OPTICAL FIBER TECHNOLOGY 2020年 58卷 102283-102283页

作者： Zhang, Yongxing Ge, Wenping Zhang, Pengju Gao, Mengyao Xinjiang Univ Coll Informat Sci & Engn Urumqi 830046 Peoples R China

Polar coding and sparse code multiple access (SCMA) technique are excellent candidates for 5G, and have a promising prospect in optical communication, the joint design of polar coded sparse code multiple access (PC-SCMA) system is important to enhance the overall system performance. In this paper, a serial joint iterative detection and decoding scheme is proposed by passing message between serial max-log message passing algorithm and soft cancellation (SCAN) algorithm, the strategy can accelerate the algorithm convergence speed by reducing the number of required iterations, decrease the computational complexity and achieve ideal bit error rate (BER) performance. In order to further improve the BER performance, a cyclic redundancy check (CRC) is added in the joint iterative process as an early stopping criterion to avoid decoding divergence caused by a low signal to noise ratio (SNR). Simulation results demonstrate that the addition of a termination mechanism can obtain an excellent performance gain compares with the conventional JIDD algorithm.

关键词： sparse code multiple access Polar codes Joint iterative detection and decoding Serial message passing Early stopping criterion

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Improving Polar-coded SCMA System by Information Coupling and Parity Check

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SENSORS 2020年第23期20卷 6740-6740页

作者： Wu, Xi Wang, Yafeng Beijing Univ Post & Telecommun Key Lab Universal Wireless Commun Minist Educ Beijing 100876 Peoples R China

In this paper, the uplink information-coupled polar-coded sparse code multiple access (PC-SCMA) system is proposed. For this system, we first design the encoding method of systematic joint parity check and CRC-aided (PCCA) polar code. Using the systematic PCCA-polar code as base code, the partially information-coupled (PIC) polar code is constructed. Then, a joint iterative detection and successive cancellation list (SCL)-decoding receiver is proposed for the PC-SCMA system. For the receiver, the coupled polar decoder's extrinsic messages are calculated by the Bayes rule and soft cancellation (SCAN) algorithm. Based on the extrinsic information transfer (EXIT) idea, the PIC PCCA-polar code is optimized. Simulation results demonstrate that the PIC PCCA-PC-SCMA system outperforms the other polar (or LDPC) coded SCMA systems at various code rates and channel configurations. Additionally, compared with an uncoupled PC-SCMA system with SCL decoder, the complexity of PIC PCCA-PC-SCMA is reduced at a high E-b/N-0

关键词： sparse code multiple access polar code partially information coupling parity check successive cancellation list extrinsic information transfer

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A Threshold-Based Max-log-MPA Low Complexity Multiuser Detection Algorithm

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SENSORS 2020年第4期20卷 1016-1016页

作者： Zhang, Guanghua Gu, Zonglin Zhao, Qiannan Ren, Jingqiu Lu, Weidang Northeast Petr Univ Sch Elect Engn & Informat Daqing 163318 Peoples R China Zhejiang Univ Technol Coll Informat Engn Hangzhou 310014 Peoples R China

sparse code multiple access (SCMA) technology is a new multiple access scheme based on non-orthogonal spread spectrum technology, which was proposed by Huawei in 2014. In the algorithm application of this technology, the original Message Passing Algorithm (MPA) has slow convergence speed and high algorithm complexity. The threshold-based MPA has a high Bit Error Ratio (BER) when the threshold is low. In the Maximum logarithm Message Passing Algorithm (Max-log-MPA), the approximation method is used, which will cause some messages to be lost and the detection performance to be poor. Therefore, in order to solve the above problems, a Threshold-Based Max-log-MPA (T-Max-log-MPA) low complexity multiuser detection algorithm is proposed in this paper. The Maximum logarithm (Max-log) algorithm is combined with threshold setting, and the stability of user nodes is considered as a necessary condition for decision in the algorithm. Before message updating, the user information nodes are judged whether the necessary conditions for the stability of the user node have been met, and then the threshold is determined. Only users who meet the threshold condition and pass the necessary condition of user node stability can be decoded in advance. In the whole process, the logarithm domain MPA algorithm is used to convert an exp operation and a multiplication operation into a maximum value and addition operation. The simulation results show that the proposed algorithm can effectively reduce the computational complexity while ensuring the BER, and with the increase of signal-to-noise ratio, the effect of the Computational Complexity Reduction Ratio (CCRR) is more obvious.

关键词： sparse code multiple access threshold message passing algorithm multiuser detection maximum likelihood logarithm

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SCMA Receiver Design for Cellular Uplink Transmission Coexisted with D2D 11

SCMA Receiver Design for Cellular Uplink Transmission Coexis...

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11th IEEE International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Liu, Yukai Chen, Wen Wei, Fan Labeau, Fabrice Shanghai Jiao Tong Univ Dept Elect Engn Shanghai Inst Adv Com & Data Sci Minhang 200240 Peoples R China McGill Univ Dept Elect & Comp Engn 3480 Univ St Montreal PQ H3A 0E9 Canada

ISBN: (纸本)9781728135557

sparse code multiple access (SCMA) is one of the most concerned non-orthogonal multiple access schemes in 5G communication system. Meanwhile, device-to-device (D2D) communication is also one of the key technologies for 5G network to improve the spectral efficiency. In cellular systems with SCMA, the non-orthogonal nature renders resource blocks support for more users so that an overloaded system can be achieved. To further improve the system capacity, a D2D and uplink cellular coexisting network is proposed in this paper. The interference between D2D and cellular users are handled. Since conventional message passing algorithm (MPA) has the exponential complexity, the receiver for cellular users is based on some low complexity methods and that for D2D users is also associated with this method. Simulation results show that the proposed hybrid network has an acceptable BER performance loss compared to the general uplink SCMA system, while the proposed SCMA receiver can reduce the decoding complexity significantly compared to the conventional MPA.

关键词： device-to-device communication sparse code multiple access hybrid network low complexity decoder

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Performance Analysis for MmWave MIMO-SCMA systems Using Lens Antenna Array

Performance Analysis for MmWave MIMO-SCMA systems Using Lens...

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IEEE International Conference on Communications (IEEE ICC)

作者： Tang, Siyang Ma, Zheng Xiao, Ming Hao, Li Southwest Jiaotong Univ Key Lab Informat Coding & Transmiss Chengdu Sichuan Peoples R China KTH Royal Inst Technol Div Informat Sci & Engn Stockholm Sweden

ISBN: (纸本)9781728123738

The recent concept of beamspace multiple input multiple output (MEMO) can significantly reduce the number of required radio frequency (RE) chains in millimeter wave (mmWave) massive MEMO systems without obvious performance loss. However, the number of supported users cannot be larger than the number of RF chains in hybrid MEMO architectures. To break this fundamental limit, we introduce the concept of sparse code multiple access (SCMA) with beamspace MEMO, then a useful upper bound on the average symbol error probability is obtained through the union bound. The bound is tight in beamspace nunWave MEMO-SCMA systems for high SNR regions. The analytical result is compared with simulations, and the results confirm the effectiveness of the analysis for mmWave MEMO-SCMA channels.

关键词： Millimeter-wave beamspace MEMO sparse code multiple access SER

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A Study on Performance Improvement by CRC-Aided GaBP for Large-Scale SCMA Detection 22

A Study on Performance Improvement by CRC-Aided GaBP for Lar...

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22nd International Symposium on Wireless Personal Multimedia Communications (WPMC)

作者： Li, Renjie Nishimura, Toshihiko Ohgane, Takeo Ogawa, Yasutaka Hagiwara, Junichiro Hokkaido Univ Fac Informat Sci & Technol Grad Sch Sapporo Hokkaido Japan

ISBN: (纸本)9781728154190

sparse code multiple access (SCMA) has attracted attention as a new non-orthogonal multiple access (NOMA) scheme that is suitable for device-to-device communications. In general, the NOMA signal detection becomes complicated as the number of users increases. Although the SCMA is a kind of low-density spreading, it requires an interference canceller. In this paper, Gaussian belief propagation (GaBP) is applied to detecting the SCMA signals because the complexity order of GaRP is the square of the graph size. In addition, we apply CRC-aided stopping of iterative processes to GaBP. The simulation results show that the CRC-aided GaRP provides much lower FER performance and that the number of iterations is highly reduced.

关键词： Gaussian belief propagation sparse code multiple access non-orthogonal multiple access cyclic redundancy check

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SGMA: Semi-granted multiple access for non-orthogonal multiple access (NOMA) in 5G networking

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JOURNAL OF NETWORK AND COMPUTER APPLICATIONS 2018年 112卷 115-125页

作者： Yang, Mao Li, Bo Bai, Zhicheng Yan, Zhongjiang Northwestern Polytech Univ Sch Elect & Informat Xian Shaanxi Peoples R China

With the rapid prosperity of mobile Internet, proliferating smart terminals, and deep penetration of Internet of things (IoTs), the fourth generation mobile communication system (4G) has become increasingly unable to meet the human needs. Therefore, the fifth generation mobile communication system (5G), being studied world-widely, needs to directly face to ultra-huge network capacity and the massive wireless connectivity. Non-orthogonal multiple access (NOMA), enabling different user equipments (UEs) sharing overlapping wireless resources, is regarded as one of the most promising key technologies of 5G, and has attracted great attention in both industry and academia in recent years. In order to guarantee the quality of service (QoS) and achieve low access latency and signaling overhead, NOMA needs to support two kinds of access methods: scheduling access and random access, named granted access and grant-free access respectively. However, how to efficiently support both granted and grant-free access simultaneously becomes a tricky challenge. In this article, we propose semi-granted multiple access, named SGMA. Other than strictly separating the wireless resources between granted and grant-free access, SGMA allows both of them to share the same resources. SGMA is a general method that can be used in several potential NOMA solutions. We also model SGMA and analyze the performance. Moreover, a heuristic resource allocation algorithm for SGMA is proposed. The simulation results show that SGMA further improves the network capacity and user connectivity of NOMA in 5G networking, and also adapts to the dynamic time-varying services. To the best of our knowledge, this is the first work to propose a multiple access method to allow the granted and grant-free access sharing the same wireless spectrum and further design the resource allocation algorithm in 5G NOMA system.

关键词： Non-orthogonal multiple access NOMA sparse code multiple access SCMA Resource allocation Random access 5G

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A Low-Complexity Energy-Minimization-Based SCMA Detector and Its Convergence Analysis

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2018年第12期67卷 12398-12403页

作者： Yuan, Weijie Wu, Nan Yan, Chaoxing Li, Yonghui Huang, Xiaojing Hanzo, Lajos Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Univ Technol Sydney Fac Engn & Informat Technol Sydney NSW 2007 Australia Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

sparse code multiple access (SCMA) has emerged as a promising non-orthogonal multiple access technique for the next-generation wireless communication systems. Since the signal of multiple users is mapped to the same resources in SCMA, its detection imposes a higher complexity than that of the orthogonal schemes, where each resource slot is dedicated to a single user. In this paper, we propose a low-complexity receiver for SCMA systems based on the radical variational free energy framework. By exploiting the pairwise structure of the likelihood function, the Bethe approximation is utilized for estimating the data symbols. The complexity of the proposed algorithm only increases linearly with the number of users, which is much lower than that of the maximum a posteriori detector associated with exponentially increased complexity. Furthermore, the convergence of the proposed algorithm is analyzed, and its convergence conditions are derived. Simulation results demonstrate that the proposed receiver is capable of approaching the error probability performance of the conventional message-passing-based receiver.

关键词： sparse code multiple access variational free energy Bethe approximation convergence analysis

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