SCMA codebook design based on constellation rotation

Zhou, Yongkang; Yu, Qiyue; Meng, Weixiao; Li, Cheng

doi:10.1109/icc.2017.7996395

Cited by 91 publications

(82 citation statements)

References 12 publications

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“…Depending on ambient energy harvesting, tags are only activated in small fraction of time and mostly remain idle to harvest sufficient energy. The sparsity of ambient backscatter signals motivates us encoding data to multi-dimensional complex codewords [20], [28], [29], [36] selected by time-variant reflection coefficients [20], [37] and enables low-complexity decoding even for massive number of concurrent RF transmissions and higher-order modulation. Consequently, SC-BMA among RF tags can enable NOMA, while providing massive connectivity for low-cost RF tags.…”

Section: B System Modelmentioning

confidence: 99%

“…In addition, high-sampling rate of DL signals significantly reduces sampling period of UL backscatter signals, causing ISI in multipath propagation environments [23]. Moreover, non-orthogonality of sparse code may cause MAI among active tags, degrading detection performance of concurrent RF transmissions [28], [29], [36], [39]- [41]. Therefore, the detection of backscatter signals requires mitigation of the three interferences (i.e., SI, ISI and MAI).…”

Section: B System Modelmentioning

confidence: 99%

“…Then, D-CEA followed by low-complexity iterative D-MPA is newly implemented to effectively detect data in the presence of the ISI and MAI. Clearly, the ambient backscatter rather exploiting interferences significantly improves spectral efficiency in three-folds: fullduplex [2], [38]; NOMA with sparse code [28], [29], [36]; multipath-diversity combining [22]. To support multiple RF tags, link layer protocol of AmBC is composed of channel estimation and data transmission phase as described in Fig.…”

Section: B System Modelmentioning

confidence: 99%

“…Towad these goals, we describe the modulation and encoding models [28], [29], [36], [39], which include design of mapping function [31], [32] and sparse factor graph [36].…”

Section: Sparse-coded Load Modulationmentioning

confidence: 99%

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Novel Sparse-Coded Ambient Backscatter Communication for Massive IoT Connectivity

Kim

2018

Energies

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Low-power ambient backscatter communication (AmBC) relying on radio-frequency (RF) energy harvesting is an energy-efficient solution for batteryless Internet of Things (IoT). However, ambient backscatter signals are severely faded by dyadic backscatter channel (DBC), limiting connectivity in conventional orthogonal time-division-based AmBC (TD-AmBC). In order to support massive connectivity in AmBC, we propose sparse-coded AmBC (SC-AmBC) based on non-orthogonal signaling. Sparse code utilizes inherent sparsity of AmBC where power supplies of RF tags rely on ambient RF energy harvesting. Consequently, sparse-coded backscatter modulation algorithm (SC-BMA) can enable non-orthogonal multiple access (NOMA) as well as M-ary modulation for concurrent backscatter transmissions, providing additional diversity gain. These sparse codewords from multiple tags can be efficiently detected at access point (AP) using iterative message passing algorithm (MPA). To overcome DBC along with intersymbol interference (ISI), we propose dyadic channel estimation algorithm (D-CEA) and dyadic MPA (D-MPA) exploiting weighted-sum of the ISI for information exchange in the factor graph. Simulation results validate the potential of the SC-AmBC in terms of connectivity, detection performance and sum throughput.

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Section: B System Modelmentioning

confidence: 99%

Section: B System Modelmentioning

confidence: 99%

Section: B System Modelmentioning

confidence: 99%

“…Towad these goals, we describe the modulation and encoding models [28], [29], [36], [39], which include design of mapping function [31], [32] and sparse factor graph [36].…”

Section: Sparse-coded Load Modulationmentioning

confidence: 99%

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Novel Sparse-Coded Ambient Backscatter Communication for Massive IoT Connectivity

Kim

2018

Energies

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“…Powerimbalanced constellations help to amplify the "near-far effect" which is useful for enhanced interference cancellation in MPA. In contrast, existing LDS constructions are generally focused on "power-balanced" LDS [4], [9], [10], i.e., all the non-zero sequence entries connected to every resource node possess identical magnitude. So far, the design of optimal LDS and SCMA codebooks is still an open problem.…”

Section: Introductionmentioning

confidence: 99%

Power-Imbalanced Low-Density Signatures (LDS) From Eisenstein Numbers

Liu

Xiao

Mheich

2019

2019 IEEE VTS Asia Pacific Wireless Communications Symposium (APWCS)

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As a special case of sparse code multiple access (SCMA), low-density signatures based code-division multiple access (LDS-CDMA) was widely believed to have worse error rate performance compared to SCMA. With the aid of Eisenstein numbers, we present a novel class of LDS which can achieve error rate performances comparable to that of SCMA in Rayleigh fading channels and better performances in Gaussian channels. This is achieved by designing power-imbalanced LDS such that variation of user powers can be seen both in every chip window and the entire sequence window. As LDS-CDMA is more flexible in terms of its backwards compatibility, our proposed LDS are a promising sequence candidate for dynamic machine-type networks serving a wide range of communication devices.

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Blockchain‐Based Energy‐Efficient Heterogeneous Sensor Networks in Healthcare System

Janarthanan¹,

Venkatesh²

2022

Blockchain Technology in Corporate Governance

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SCMA codebook design based on constellation rotation

Cited by 91 publications

References 12 publications

Novel Sparse-Coded Ambient Backscatter Communication for Massive IoT Connectivity

Novel Sparse-Coded Ambient Backscatter Communication for Massive IoT Connectivity

Power-Imbalanced Low-Density Signatures (LDS) From Eisenstein Numbers

Blockchain‐Based Energy‐Efficient Heterogeneous Sensor Networks in Healthcare System

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