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Diversity Order Results for MIMO Optical Wireless Communications

IEEE WIRELESS COMMUNICATIONS LETTERS 2018年第1期7卷 74-77页

作者： Sapenov, Yerzhan Chaaban, Anas Rezki, Zouheir Abdallah, Mohamed Qaraqe, Khalid Alouini, Mohamed-Slim King Abdullah Univ Sci & Technol Comp Elect & Math Sci & Engn Div Thuwal 239556900 Saudi Arabia Univ Idaho Dept Elect & Comp Engn Moscow ID 83844 USA Hamad Bin Khalifa Univ Qatar Fdn Coll Sci & Engn Doha Qatar Texas A&M Qatar Elect Engn Program Doha Qatar

An optical wireless multiple-input multiple-output communication system employing intensity-modulation direct-detection is considered. The maximal diversity order of the channel is characterized by studying the outage probability. Then, spatial repetition coding is shown to be diversity-optimal as it achieves the channel's maximal diversity order. This diversity order is given by a simple expression which is suitable for any channel statistics of practical interest. The results are specialized to some practical channel statistics, and numerical results are provided to verify the results.

关键词： Intensity-modulation direct-detection optical wireless communications repetition coding diversity order

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Video Streaming in Distributed Erasure-Coded Storage Systems: Stall Duration Analysis

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IEEE-ACM TRANSACTIONS ON NETWORKING 2018年第4期26卷 1921-1932页

作者： Al-Abbasi, Abubakr O. Aggarwal, Vaneet Purdue Univ Sch Ind Engn W Lafayette IN 47907 USA

The demand for global video has been burgeoning across industries. With the expansion and improvement of video-streaming services, cloud-based video is evolving into a necessary feature of any successful business for reaching internal and external audiences. This paper considers video streaming over distributed systems where the video segments are encoded using an erasure code for better reliability, thus being the first work to our best knowledge that considers video streaming over erasure-coded distributed cloud systems. The download time of each coded chunk of each video segment is characterized, and the ordered statistics over the choice of the erasure-coded chunks is used to obtain the playback time of different video segments. Using the playback times, bounds on the moment generating function on the stall duration are used to bound the mean stall duration. Moment generating function-based bounds on the ordered statistics are also used to bound the stall duration tail probability, which determines the probability that the stall time is greater than a pre-defined number. These two metrics, mean stall duration and the stall duration tail probability, are important quality of experience (QoE) measures for the end users. Based on these metrics, we formulate an optimization problem to jointly minimize the convex combination of both the QoE metrics averaged over all requests over the placement and access of the video content. The non-convex problem is solved using an efficient iterative algorithm. Numerical results show a significant improvement in QoE metrics for cloud-based video compared to the considered baselines.

关键词： Distributed storage erasure codes stall duration tail latency repetition coding video streaming

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Experimental demonstration of MIMO-OFDM underwater wireless optical communication

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OPTICS COMMUNICATIONS 2017年 403卷 205-210页

作者： Song, Yuhang Lu, Weichao Sun, Bin Hong, Yang Qu, Fengzhong Han, Jun Zhang, Wei Xu, Jing Zhejiang Univ Ocean Coll Opt Commun Lab Zheda Rd 1 Zhoushan 316021 Zhejiang Peoples R China Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW Australia

In this paper, we propose and experimentally demonstrate a multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) underwater wireless optical communication (UWOC) system, with a gross bit rate of 33.691 Mb/s over a 2-m water channel using low-cost blue light-emitting-diodes (LEDs) and 10-MHz PIN photodiodes. The system is capable of realizing robust data transmission within a relatively large reception area, leading to relaxed alignment requirement for UWOC. In addition, we have compared the system performance of repetition coding OFDM (RC-OFDM), Alamouti-OFDM and multiple-input single-output OFDM (MISO-OFDM) in turbid water. Results show that the Alamouti-OFDM UWOC is more resistant to delay than the RC-OFDM-based system. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Alamouti coding MIMO OFDM repetition coding UWOC

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Approaching the Optimal Diversity-Multiplexing Tradeoff in a Four-node Cooperative Network

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2010年第12期9卷 3690-3700页

作者： Wang, Chao Fan, Yijia Thompson, John S. Skoglund, Mikael Poor, H. Vincent Royal Inst Technol KTH Sch Elect Engn Commun Theory Grp Stockholm Sweden InterDigital LLC New York NY USA Univ Edinburgh Inst Digital Commun Sch Engn & Elect Edinburgh Midlothian Scotland Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

A novel cooperative diversity transmission protocol is proposed for a four-node network, in which a single-antenna source communicates with an N-antenna destination with the help of two K-antenna half-duplex decode-and-forward (DF) relays. The proposed shifted successive DF relaying (SSDFR) protocol asymptotically achieves the optimal diversity-multiplexing tradeoff (DMT) the system can provide. The resulting DMT performance does not require complex coding strategies at the relays, extremely strong or weak inter-relay channel conditions, or feedback from the destination to the source, which highlights the advantages of the proposed protocol over state of the art techniques.

关键词： Cooperative diversity diversity-multiplexing tradeoff (DMT) repetition coding

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Continuous media fingerprinting against time-varying collusion attacks

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INFORMATION SCIENCES 2015年 298卷 66-79页

作者： Cha, Byung-Ho Choi, Sang-Il Samsung Elect Suwon Gyeonggi Do South Korea Dankook Univ Dept Appl Comp Engn Yongin 448701 Gyeonggi Do South Korea

We analyze time-varying collusion attacks over continuous media such as music and movies. Inspired by communication systems, we propose countermeasures for time-varying collusion attacks to improve the performance of the proposed Multi-Carrier Code Division Multiple Access (MC-CDMA)-based fingerprinting system. In this paper, we focus on audio signals as continuous media. We first characterize the audio signals using the just-noticeable-difference (JND) of the human perceptual system model, called the human auditory system (HSA), at the fingerprint embedding, and provide the overall system model of our fingerprinting system as a framework for the analysis of time-varying collusion attacks. Then, we analyze the characteristics of time-varying collusion attacks in terms of their interference to and dynamics on audio. We provide advanced detectors as a countermeasure of interference and interleaving/repetition coding as a countermeasure of variation to improve the performance of the MC-CDMA-based fingerprinting system against time-varying collusion attacks. (C) 2014 Elsevier Inc. All rights reserved.

关键词： Multimedia fingerprinting Human perceptual system model Time-varying collusion attack Fingerprint-to-interference-plus-noise ratio Advanced detectors repetition coding

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MIMO visible light communication system with block Markov superposition transmission

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IET COMMUNICATIONS 2018年第6期12卷 696-703页

作者： Chen, Shengxiao Ma, Xiao Sun Yat Sen Univ Sch Elect & Informat Technol Guangzhou Guangdong Peoples R China Sun Yat Sen Univ Sch Data & Comp Sci Guangzhou Guangdong Peoples R China Sun Yat Sen Univ Guangdong Key Lab Informat Secur Technol Guangzhou Guangdong Peoples R China

This study is concerned with coded multiple-input multiple-output (MIMO) visible light communication (VLC) system, where unipolar M-level pulse amplitude modulation is assumed along with MIMO transmission techniques, including repetition coding, spatial multiplexing and spatial modulation. In order to evaluate the performance of MIMO-VLC system, the authors analyse the mutual information of the MIMO techniques, based on which the block Markov superposition transmission (BMST) codes are constructed to improve the bit-error rate (BER) performance of the system. In addition, they present a genie-aided lower bound to predict the performance of the BMST-VLC system in the low-BER region. Simulation results demonstrate that the proposed scheme can achieve significant coding gain compared with Reed-Solomon-coded MIMO-VLC system adopted in IEEE standard 802.15.7.

关键词： free-space optical communication error statistics pulse amplitude modulation space division multiplexing unipolar M-level pulse amplitude modulation BER bit-error rate BMST codes spatial modulation spatial multiplexing repetition coding coded multiple-input multiple-output visible light communication system block Markov superposition transmission MIMO VLC system

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On Space-Time coding for Free-Space Optical Systems

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IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第1期58卷 58-62页

作者： Bayaki, Ehsan Schober, Robert Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

Atmospheric turbulence-induced fading is one of the main impairments affecting free-space optics (FSO) communications. In this paper, we consider FSO systems with intensity modulation and direct detection (IM/DD) and derive a closed-form expression for the asymptotic pairwise error probability of general FSO space-time codes (STCs) for two lasers and an arbitrary number of photodetectors for channels suffering from Gamma-Gamma fading. Furthermore, we provide a simple design criterion for FSO STCs which is used to establish the quasi-optimality of previously proposed FSO repetition codes. We also show that STCs optimized for RF systems achieve full diversity in FSO systems but are suboptimal as far as the coding gain is concerned. Simulation results confirm the analytical findings of this paper.

关键词： Space-time coding free-space optical systems intensity modulation and direct detection gamma-gamma fading repetition coding

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A Link Between Multiuser MMSE and Canonical Correlation Analysis

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IEEE WIRELESS COMMUNICATIONS LETTERS 2024年第1期13卷 44-48页

作者： Ibrahim, Mohamed Salah Karakasis, Paris A. Sidiropoulos, Nicholas D. Univ Virginia Dept Elect & Comp Engn Charlottesville VA 22904 USA Interdigital Commun Res & Innovat Dept Conshohocken PA 19428 USA

Recent work has shown that repetition coding followed by interleaving induces signal structure that can be exploited to separate multiple co-channel user transmissions, without need for pilots or coordination/synchronization between the users. This is accomplished via a statistical learning technique known as canonical correlation analysis (CCA), which works even when the channels are time-varying. Previous analysis has established that it is possible to identify the user signals up to complex scaling in the noiseless case. This letter goes one important step further to show that CCA in fact yields the linear MMSE estimate of the user signals up to complex scaling, without using any explicit training. Instead, CCA relies only on the repetition and interleaving structure. This is particularly appealing in asynchronous ad-hoc and unlicensed setups, where tight user coordination is not practical.

关键词： Multiuser interference canonical correlation analysis (CCA) repetition coding minimum mean square error (MMSE) estimation

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Linear Transceiver Design for MIMO Relay Broadcast Channels with Max-Min Fairness 79

Linear Transceiver Design for MIMO Relay Broadcast Channels ...

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IEEE 79th Vehicular Technology Conference (VTC-Spring)

作者： Monroy, Edwin Choi, Sunghyun Seoul Natl Univ Coll Engn Int IT Policy Program Seoul South Korea Seoul Natl Univ Dept Elect & Comp Engn Seoul South Korea Seoul Natl Univ INMC Seoul South Korea

ISBN: (纸本)9781479944828

The multiple-input multiple-output relay broadcast channel with one source, one relay, and two destinations is studied. It is assumed that the source and the relay cooperatively serve one of two destinations, which may have a weaker channel from the source (due to, for example, being located far from the source), while the source alone serves the other destination that has a stronger channel. Given the asymmetry in the use of the relay as well as in the channel strengths, the performance of the system is evaluated through the minimum of the rates for the two destinations instead of the sum of the rates. A new linear transmit and receive beamforming scheme is proposed for this max-min fairness problem that can be implemented in practical scenarios. Numerical results show that the proposed scheme yields a significant gain over existing schemes.

关键词： MIMO relay broadcast channel half-duplex relay max-min fairness interference alignment repetition coding

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Adaptive Unipolar MIMO-OFDM for Visible Light Communications 28

Adaptive Unipolar MIMO-OFDM for Visible Light Communications

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28th European Conference on Networks and Communications (EuCNC)

作者： Al-Nahhal, Mohamed Basar, Ertugrul Uysal, Murat Ozyegin Univ Dept Elect & Elect Engn TR-34794 Istanbul Turkey Koc Univ Dept Elect & Elect Engn CoreLab TR-34450 Istanbul Turkey

ISBN: (纸本)9781728105468

Unipolar orthogonal frequency division multiplexing (U-OFDM) appears as an attractive optical OFDM solution for emerging visible light communication (VLC) systems. This paper proposes spectral efficiency improvement for U-OFDM systems by applying adaptive transmission over realistic VLC links. This adaptive transmission includes switching among a number of multiple-input multiple-output (MIMO) modes combined with appropriate modulation size selection. The considered MIMO modes are repetition coding, spatial modulation, and spatial multiplexing, where each mode supports different modulation sizes. The selection of the corresponding MIMO mode and its modulation size is based on the received signal-to-noise ratio and target bit error rate. The proposed U-OFDM system is applied over different VLC MIMO setups with realistic channel models for 8 x 8, 4 x 4 and 2 x 2 MIMO systems. Our simulation results show that the proposed adaptive system provides a significant spectral efficiency improvement over stand-alone U-OFDM MIMO modes/setups.

关键词： Visible light communication unipolar OFDM adaptive transmission MIMO modes switching repetition coding spatial modulation spatial multiplexing

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