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IEEE Wireless Communications and Networking Conference (IEEE WCNC)

作者： Tseng, Fan-Shuo Lin, Chun-Tao Lin, Wei-Lun Chung, Hao Natl Sun Yat Sen Univ Inst Commun Engn Kaohsiung Taiwan Natl Taipei Univ Technol Dept Commun Engn Taipei Taiwan Feng Chia Univ Dept Commun Engn Taichung Taiwan

ISBN: (纸本)9781665442664

This paper studies the joint common beamforming (CB) and the superposition coding (SC) design for a two-user massive multiple-input single-output (MISO) system with non-orthogonal multiple access (NOMA). Conventional beamforming design has to estimate the uplink channel state information (CSI) of the near and the far users separately. By the channel reciprocity, the CB is then constructed by combining two uplink CSIs together with certain rules. The design needs two training phases to separately estimate the CSI of the two users but combine them subsequently. In this paper, we propose a model adopting common pilots for the near and far users to estimate an uplink combined channel. In this model, only one training phase is required, and the CB is then constructed by the estimated combined channel directly. With the estimated combined channel, the joint CB and SC design is equivalent to optimizing the pilot power allocation and SC factor. However, the associated optimization is not convex. We then adopt the majorization-minimization approach to conduct the optimization problem and numerically find that the solutions meet the optimum points. Simulations verify the effectiveness of our joint design and show the superior performance not only for the transmission rate but also the reduced overhead.

关键词： Non-orthogonal multiple access (NOMA) Multiple-input single-output (MISO) Common beamforming superposition coding Channel state information Majorization-minimization approach Channel estimation

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Diversity-and-Multiplexing Tradeoff of superposition coding Relaying Strategy without Channel State Feedback

Diversity-and-Multiplexing Tradeoff of Superposition Coding ...

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6th International Conference on Wireless Communications, Networking and Mobile Computing (WICOM)

作者： Zhao, Laiqiang Fu, Haiyang Jia, Xiangdong Nanjing Univ Posts & Telecommun Coll Commun & Informat Engn Nanjing Jiangsu Peoples R China

ISBN: (纸本)9781424437092

superposition coding relaying (SC-relaying) has the merit of high throughput. At the same time, the investigation of the diversity-multiplexing tradeoff (DMT) is also particularly useful for the design and analysis of cooperative relaying strategy. In this work, we consider a two-level rate SC-relaying strategy without the channel state feedback under short term power constraint. For the SC-relaying strategy, the optimizing DMT is investigated as well as its optimizing close-form explicit solution.

关键词： wireless communications cooperative relaying superposition coding diversity-and-multiplexing tradeoff

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A Practical Approach to Strengthen Vulnerable Downlinks using superposition coding

A Practical Approach to Strengthen Vulnerable Downlinks usin...

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IEEE International Conference on Communications (ICC)

作者： Vanka, S. Srinivasa, S. Haenggi, M. Univ Notre Dame Dept Elect Engn Emerging Wireless Architectures Lab Notre Dame IN 46556 USA

ISBN: (纸本)9781457720536

We propose and experimentally demonstrate a novel approach to improve the packet delivery efficiency on a vulnerable downlink (e. g., from a transmitter to a far-away receiver) using superposition coding, a multiuser transmission scheme that forgoes orthogonal transmission and deliberately introduces interference among signals at the transmitter. On a software-radio platform that uses off-the-shelf point-to-point channel codes, we show that a transmitter serving multiple links can use simple two-user superposition codes to dramatically improve (compared to time division multiplexing) the packet delivery efficiency on its most vulnerable links. Interestingly, our results suggest that superposing signals of far-away users on to those of high-traffic users yields the maximum benefits-implying that the degrees-of-freedom gain in doing so can more than compensate for the increased interference from signal superposition.

关键词： superposition coding Software Defined and Cognitive Radio Multiuser Systems Universal Software Radio Peripheral

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Transmission Strategies for Parallel Relay Networks Based on superposition coding

Transmission Strategies for Parallel Relay Networks Based on...

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68th IEEE Vehicular Technology Conference

作者： Huang, Jianzhong Yang, Yang Wang, Xinmei Wang, Peng Ping, Li Xidian Univ Dept Commun Engn Xian Peoples R China City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China

ISBN: (纸本)9781424417223;9781424417216

This paper is concerned with the transmission strategies and relay selection for decode-and-forward parallel relay networks (PRNs) based on superposition coding. Our focus is on the minimization of the aggregate transmission power that supports a given transmission rate. In this paper, two transmission strategies are investigated, i.e., an optimal-cooperation (OC) strategy requiring strict synchronization at the destination/relay nodes and a no-information-overlapping (NIO) strategy with no synchronization requirement for the ease of implementation using current technologies such as interleave-division multiple-access (IDMA). Furthermore, a reduced-relay-selection (RRS) strategy involving only 2-level superposition coding is given to trade off between complexity and performance. Numerical results show that the performance gap between OC and NIO is negligible, and selecting the best two relay nodes is adequate to achieve most performance gain even when the number of relay nodes is large.

关键词： parallel relay networks superposition coding transmission strategies relay selection

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Minimization of Expected Distortion with Layer-Selective Relaying of Two-Layer superposition coding

Minimization of Expected Distortion with Layer-Selective Rel...

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77th IEEE Vehicular Technology Conference (VTC)

作者： Wang, Jinsoo Kim, Yun Hee Cosman, Pamela C. Milstein, Laurence B. Kyung Hee Univ Dept Elect & Radio Engn Yongin Gyeonggi South Korea Univ Calif San Diego Dept Elect & Comp Eng La Jolla CA 92093 USA

ISBN: (纸本)9781467363372

This paper considers a relay system using two-layer superposition coding to minimize the expected distortion of a Gaussian source at the destination node. For the system, we propose two types of layer-selective relaying based on the local decoding result at the relay and the decoding result at the destination node fed back to the relay. One type of the proposed scheme uses decode-and-forward (DF) in the design of the relay signals, while the other type uses both DF and amplify-and-forward (AF). For the proposed scheme, we analyze the outage probabilities and evaluate the expected distortion according to the relay location. The results reveal that the proposed scheme improves the finite SNR performance, in particular when the relay node is closer to the source node than it is to the destination node.

关键词： superposition coding Relay Expected distortion Feedback Outage Probability

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Beamforming with superposition coding in Multiple Antenna Satellite Communications

Beamforming with Superposition Coding in Multiple Antenna Sa...

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IEEE International Conference on Communications (ICC) / Wireless Communications Symposium / 3rd Workshop on Optical Wireless Communications (OWC)

作者： Shi, Xiaoyan Thompson, John S. Safari, Majid Liu, Rongke Beihang Univ Sch Elect & Informat Engn Beijing Peoples R China Univ Edinburgh Sch Engn Edinburgh Midlothian Scotland

ISBN: (纸本)9781509015252

In this paper, we study an optimization algorithm for beamforming with superposition coding (SCBF) and its application to multiple antenna satellite communication systems. Motivated by the channel asymmetries that are caused by both the variability of the physical channel conditions and the heterogeneity among the satellite terminals, we propose to implement SCBF in the forward link of a multi-beam satellite system. Unlike existing orthogonal transmission schemes, we multiplex multiple users' information in the power domain through SCBF in order to utilize time and spectrum resources more efficiently. To facilitate non-orthogonal multiplexing transmission in an energy efficient manner, we solve a minimum power optimization problem. Dedicated algorithms with low computational complexities are then designed to find globally optimal solutions in all scenarios. Finally, we extend our method to the computation of the rate region problem.

关键词： Optimization superposition coding multi-beam satellites beamforming

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DIVERSITY-AND-MULTIPLEXING TRADEOFF AND THROUGHPUT OF superposition coding RELAYING STRATEGY

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Journal of Electronics(China) 2010年第2期27卷 166-176页

作者： Jia Xiangdong Yang Longxiang Wireless Communications Key Lab of Jiangsu Province Nanjing University of Posts and Telecommunications Nanjing 210003 China College of Mathematics and Information Science Northwest Normal University Lanzhou 730070 China

While the Network coding cooperative relaying (NC-relaying) has the merit of high spectral efficiency,superposition coding relaying (SC-relaying) has the merit of high throughput. In this paper,a novel concept,coded cooperative relaying,is presented,which is a unified scheme of the NC-relaying and SC-relaying. For the SC-relaying strategy which can be considered one-way coded relaying scheme with multi-access channel,the close-form solution of the outage probabilities of the basic signal and additional signal are obtained firstly. Secondly,the Diversity-and-Multiplexing Tradeoff (DMT) characteristics of basic signal and additional signal are investigated entirely as well as the optimal close-form solutions. The compared numerical analysis shows the evaluation error of throughput based on the close-form solution is about 0.15 nats,which is within the acceptable error range. Due to the mutual effect between the both source signals,the available maximal values of the two multiplexing gains are less than 1.

关键词： Wireless communications Diversity-and-Multiplexing Tradeoff (DMT) Cooperative relaying superposition coding Network coding

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A Hybrid Network-superposition coding for Asymmetrical Two-Way Relay Channels

A Hybrid Network-Superposition Coding for Asymmetrical Two-W...

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70th IEEE Vehicular Technology Conference

作者： Park, Moonseo Oh, Seong Keun Ajou Univ Div Elect & Comp Engn Suwon 443749 South Korea

ISBN: (纸本)9781424425143

We consider an asymmetrical two-way relay channel (TWRC) which consists of one relay node and two user nodes in this paper. In TWRCs, we can efficiently use the channel by using the network coding at the relay with the exclusive OR (XOR) operation. However, due to the nature of the XOR, the rate from the relay to a user node should he the same as the rate from the relay to the other user node. When the channel is asymmetrical, this results in the waste of the channel capacity in the channel with a better channel gain. In this paper, we propose using a superposition coding on top of the XOR operation to utilize the better channel. By using the hybrid network-superposition coding, we can achieve more rate region than that of the XOR-based systems.

关键词： Network coding superposition coding two-way relay channel

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System-Level Throughput of NOMA Using Intra-beam superposition coding and SIC in MIMO Downlink When Channel Estimation Error Exists

System-Level Throughput of NOMA Using Intra-beam Superpositi...

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IEEE International Conference on Communication Systems (IEEE ICCS)

作者： Nonaka, Nobuhide Benjebbour, Anass Higuchi, Kenichi Tokyo Univ Sci Grad Sch Sci & Technol Tokyo Japan NTT DOCOMO INC Radio Access Network Dev Dept Tokyo Japan

ISBN: (纸本)9781479958320

We investigate the influence of channel estimation error on the achievable system-level throughput performance of our previous non-orthogonal multiple access (NOMA) scheme in a multiple-input multiple-output (MIMO) downlink. The NOMA scheme employs intra-beam superposition coding of a multiuser signal at the transmitter and spatial filtering of inter-beam interference followed by an intra-beam successive interference canceller (SIC) at the user terminal receiver. The intra-beam SIC cancels the inter-user interference within a beam. This configuration achieves reduced overhead for the downlink reference signaling for channel estimation at the user terminal in the case of non-orthogonal user multiplexing and enables the SIC receiver to be applied to the MIMO downlink. The channel estimation error in the NOMA scheme causes residual interference in the SIC process, which decreases the achievable user throughput. Furthermore, the channel estimation error causes error in the transmission rate control for the respective users, which may result in decoding error at not only the destination user terminal but also at other user terminals for the SIC process. However, we show that by using a simple transmission rate back-off algorithm, the impact of the channel estimation error is effectively abated and the NOMA scheme achieves clear average and cell-edge user throughput gains relative to orthogonal multiple access (OMA) similar to the case with perfect channel estimation.

关键词： channel estimation user terminal Downlink superposition coding Throughput rate control Noma

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Bits-to-Symbol Mappings for superposition coding Based HARQ Systems

Bits-to-Symbol Mappings for Superposition Coding Based HARQ ...

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IEEE Wireless Communications and Networking Conference (WCNC)

作者： Chaitanya, Tumula V. K. Larsson, Erik G. Linkoping Univ Dept Elect Engn ISY Linkoping Sweden

ISBN: (纸本)9781467359399;9781467359382

We consider the mapping of bits-to-superimposed constellation symbols in terms of the achievable rate on the channel for the HARQ system using superposition coding as proposed in [2]. We show that using a Gray mapping of bits-to-superimposed constellation symbols has better performance than the conventional natural mapping that results from superposition in signal space, for all the values of the superposition ratio. We also show through link-level simulations that the predicted gains in terms of achievable rate can be realized in practice using LDPC codes. Furthermore, we show that the optimal superposition ratio for the Gray mapping case results in conventional higher order constellation symbols after the superposition operation.

关键词： superposition coding bits-to-symbol mapping hybrid ARQ

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