Results 271 to 280 of about 255,246 (314)
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Sparse Code and Hybrid Multiple Access Techniques
2020Next-generation wireless networks require higher spectral efficiency and lower latency to meet the demands of various upcoming applications. Recently, non-orthogonal multiple access (NOMA) schemes are introduced in the literature for 5G and beyond. Various forms of NOMA are considered like power domain, code domain, pattern division multiple access ...
Sanjeev Sharma, Kuntal Deka
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Fractional Sparse Code Multiple Access and Its Optimization
IEEE Wireless Communications Letters, 2018This letter proposes a fractional sparse code multiple access (FrSCMA) system in which each user directly maps a varying number of error-correction coded symbols onto the resource elements per channel use. The dynamic sparse mapping leads to a fractional spreading factor, often smaller than that in the existing multidimensional constellation (MDC ...
Yicheng Wang +4 more
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Sparse Code Multiple Access Scheme Based on Variational Learning
IEEE Transactions on Communications, 2022Sparse code multiple access (SCMA) technology has been widely studied thanks to its outstanding overload performance, which provides greater device access on limited time-frequency resources. We propose a variational learning based end-to-end SCMA network model termed as V-SCMA.
Quan Yuan +4 more
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Modified Sphere Decoding for Sparse Code Multiple Access
IEEE Communications Letters, 2018Sparse code multiple access (SCMA), a novel non-orthogonal multiple access scheme for fifth generation wireless, has drawn much attention. Since optimal SCMA detection incurs high computational complexity, we develop a modified single tree search (MSTS) to obtain soft outputs for coded SCMA.
Lanping Li +3 more
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Sparse code multiple access for downlink multiple access of 5G wireless networks
Computer Communications, 2020Abstract Mobile data traffic as the two main forces for the development of future communications, mobile Internet and Internet of Things give the fifth generation of mobile communications (5G) unlimited possibilities and prospects. A large number of mobile device access and shortage of spectrum resources are also issues that 5G needs to face.
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Sparse Code Multiple Access for 5G Radio Transmission
2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), 2017Non-orthogonal multiple access has been extensively discussed in New Radio (NR), the study item working on 5G air interface in 3GPP. Sparse code multiple access (SCMA) is one of the proposed MA schemes. In this paper, the basic concept of SCMA is introduced, including codebook mapping, multiple access procedure, and advanced receivers. Then, link level
Yiqun Wu +3 more
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Efficient Row-Layered Decoder for Sparse Code Multiple Access
IEEE Transactions on Circuits and Systems I: Regular Papers, 2021Sparse code multiple access (SCMA) is a promising technology for the development of wireless communication, which supports a large number of overloading users and enjoys high spectral efficiency. However, conventional SCMA decoders suffer very high complexity in implementations.
Xu Pang +4 more
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SARA: Sparse Code Multiple Access-Applied Random Access for IoT Devices
IEEE Internet of Things Journal, 2018In this paper, we study a random access (RA) procedure to support the massive connectivity of the Internet of Things (IoT) devices, also known as the IoT connectivity. Compared with the previous RA procedures that have limitations to support the IoT connectivity due to the exponentially increased access delay, we develop an RA procedure by applying the
Seokjae Moon, Hyun-Suk Lee, Jang-Won Lee
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Polar coded iterative multiuser detection for sparse code multiple access system
China Communications, 2018Polar coded sparse code multiple access (SCMA) system is conceived in this paper. A simple but new iterative multiuser detection framework is proposed, which consists of a message passing algorithm (MPA) based multiuser detector and a soft-input soft-output (SISO) successive cancellation (SC) polar decoder.
Hang Mu +5 more
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Iterative multiuser receiver in sparse code multiple access systems
2015 IEEE International Conference on Communications (ICC), 2015Sparse code multiple access (SCMA) is a novel non-orthogonal multiple access scheme, in which multiple users access the same channel with user-specific sparse codewords. In this paper, we consider an uplink SCMA system employing channel coding, and develop an iterative multiuser receiver which fully utilizes the diversity gain and coding gain in the ...
Yiqun Wu, Shunqing Zhang, Yan Chen
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