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Performance analysis of hybrid free space optical and visible light communications for underwater applications using spatial diversity

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OPTICAL AND QUANTUM ELECTRONICS 2022年第10期54卷 650-650页

作者： Zakaria, Islam Abaza, Mohamed Fedawy, Moustafa Aly, Moustafa H. Arab Acad Sci Technol & Maritime Transport Coll Engn & Technol Elect & Commun Engn Dept Cairo Egypt Arab Acad Sci Technol & Maritime Transport Coll Engn & Technol Elect & Commun Engn Dept Giza Egypt Arab Acad Sci & Technol & Maritime Transport Ctr Excellence Nanotechnol Giza Egypt Arab Acad Sci Technol & Maritime Transport Coll Engn & Technol Elect & Commun Engn Dept POB 1029 Alexandria Egypt

In this paper, we analyze a combination based on a hybrid triple hop terrestrial free-space optical (FSO), a fiber optic cable (FOC), and an underwater optical wireless communication (UOWC) link for providing high-speed optical connectivity between onshore and submerge systems. UOWC, scattering, absorption, and turbulence severely degrade the reliability and transmission rate of the UOWC link. In our manuscript, a bend-insensitive intermediate FOC link and a spatial diversity (SD) are exploited to improve the error performance of UOWC links, which involves the deployment of multiple input single outputs (MISO). For this purpose, different transmission signaling schemes, such as pulse position modulation (PPM) with spatial modulation (SM) and on-off keying (OOK) with repetition coding (RC), are employed to evaluate the system performance in terms of average bit error rate (ABER). The behavior of the entire system is obtained by applying a decode-and-forward (DF), where we consider log-normal channels for FSO and UOWC. The path loss and turbulence are obtained using intensity modulation and direct detection schemes. To obtain performance results, Monte Carlo-based statistical simulation method is applied to validate the analytical ABER performance of the system. The achieved results reveal that MISO-OOK-RC has superior ABER performance as compared to MISO-PPM-SM in higher signal-to-noise ratio (SNR) conditions with different underwater turbulence strengths.

关键词： Free-space optical communications Fiber optic cable Underwater optical wireless communication Hybrid system Spatial diversity repetition coding Hybrid modulation

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Space-Time Block Coded Spatial Modulation for Indoor Visible Light Communications

IEEE PHOTONICS JOURNAL

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IEEE PHOTONICS JOURNAL 2022年第1期14卷 1页

作者： Naser, Shimaa Bariah, Lina Muhaidat, Sami Al-Qutayri, Mahmoud Uysal, Murat Sofotasios, Paschalis Khalifa Univ Ctr Cyber Phys Syst Dept Elect Engn & Comp Sci Abu Dhabi 127788 U Arab Emirates Carleton Univ Dept Syst & Comp Engn Ottawa ON K1S 5B6 Canada Khalifa Univ Syst Chip Ctr Dept Elect Engn & Comp Sci Abu Dhabi 127788 U Arab Emirates Ozyegin Univ Dept Elect & Elect Engn TR-34794 Istanbul Turkey Tampere Univ Dept Elect Engn Tampere 33014 Finland

Visible light communication (VLC) has been recognized as a promising technology for handling the continuously increasing quality of service and connectivity requirements in modern wireless communications, particularly in indoor scenarios. In this context, the present work considers the integration of two distinct modulation schemes, namely spatial modulation (SM) with space time block codes (STBCs), aiming at improving the overall VLC system reliability. Based on this and in order to further enhance the achievable transmission data rate, we integrate quasi-orthogonal STBC (QOSTBC) with SM, since relaxing the orthogonality condition of OS'I'BC ultimately provides a higher coding rate. Then, we generalize the developed results to any number of active light-emitting diodes (LEDs) and any M-ary pulse amplitude modulation size. Furthermore, we derive a tight and tractable upper bound for the corresponding bit error rate (BER) by considering a simple two-step decoding procedure to detect the indices of the transmitting LEDs and then decode the signal domain symbols. Notably, the obtained results demonstrate that QOSTBC with SM enhances the achievable HER compared to SM with repetition coding (RC-SM). Finally, we compare STBC-SM with both multiple active SM (MASM) and RC-SM in terms of the achievable HER and overall data rate, which further justifies the usefulness of the proposed scheme.

关键词： MIMO VLC spatial modulation repetition coding SSK STBCs

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Performance Analysis of Transmission Techniques for Multi-User Optical MIMO Pre-coding for Indoor Visible Light Communication 2

Performance Analysis of Transmission Techniques for Multi-Us...

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2nd IEEE International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET)

作者： Jha, Mahesh Kumar Kumar, Navin Lakshmi, Y. V. S. CMR Inst Technol Dept Telecom Bangalore Karnataka India Amrita Vishwa Vidyapeetham Univ Amrita Sch Engn Dept ECE Bangalore Karnataka India Ctr Dev Telemat Bangalore Karnataka India

ISBN: (纸本)9781509044429

In this paper, we analyzed different transmission techniques of multi-user visible light communication (VLC) system. Block diagonalization technique is used to avoid multiuse interference (MUI) in the transmitter. In addition, repetition coding (RC) and spatial modulation (SM) transmission techniques are used in this research work. We have analyzed the bit error rate (BER) performance for both of these transmission techniques. Furthermore, the BER performance with respect to light emitting diode (LED) i.e., the VLC emitter power is also considered. The simulation results show that the SM offers better performance especially at low signal to noise ratio (SNR).

关键词： Visible Light Communication MIMO Optical Wireless Communication LoS repetition coding Spatial Modulation Multi user Interface

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Symplectically entangled states and their applications to coding (vol 37, pg 3305, 2004)

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JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL 2004年第13期37卷 4147-4147页

作者： Vourdas, A Department of Computing University of Bradford Bradford BD7 1DP UK

An angular momentum (2j + 1)-dimensional Hilbert space H is considered. Symplectic transformations S on the tensor product of N of these spaces H ? ? H are studied for the case when the 2j + 1 is a power of a prime (Galois case). The corresponding operators are calculated numerically. The formalism is applied to quantum coding. A simple repetition code based on the space H_A spanned by the direct products of N angular momentum states with the same m, has distance 1. It is shown that a code based on the symplectically transformed space SH_A has (in general) larger distance. An example with three qutrits is discussed in detail.

关键词： Error-correcting codes Tolerant quantum computation Higher-dimensional systems Finite fourier-transform Phase-space Hilbert space Phase space Tensor products repetition coding quantum dense coding Hydrogen Angular momentum Quantum entanglement

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Downlink Cooperative Broadcast Transmission Based on Superposition coding in a Relaying System for Future Wireless Sensor Networks

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SENSORS 2018年第6期18卷 1973-1973页

作者： Liu, Yang Han, Guangjie Shi, Sulong Li, Zhengquan Jiangnan Univ Jiangsu Prov Engn Lab Pattern Recognit & Computat Wuxi 214122 Peoples R China Dalian Univ Technol Sch Software Key Lab Ubiquitous Network & Serv Software Liaoni Dalian 116024 Peoples R China Huawei Co Nanjing 210003 Jiangsu Peoples R China

This study investigates the superiority of cooperative broadcast transmission over traditional orthogonal schemes when applied in a downlink relaying broadcast channel (RBC). Two proposed cooperative broadcast transmission protocols, one with an amplify-and-forward (AF) relay, and the other with a repetition-based decode-and-forward (DF) relay, are investigated. By utilizing superposition coding (SupC), the source and the relay transmit the private user messages simultaneously instead of sequentially as in traditional orthogonal schemes, which means the channel resources are reused and an increased channel degree of freedom is available to each user, hence the half-duplex penalty of relaying is alleviated. To facilitate a performance evaluation, theoretical outage probability expressions of the two broadcast transmission schemes are developed, based on which, we investigate the minimum total power consumption of each scheme for a given traffic requirement by numerical simulation. The results provide details on the overall system performance and fruitful insights on the essential characteristics of cooperative broadcast transmission in RBCs. It is observed that better overall outage performances and considerable power gains can be obtained by utilizing cooperative broadcast transmissions compared to traditional orthogonal schemes.

关键词： broadcast channel relay channel repetition coding superposition coding successive interference cancellation

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Efficient Low-Redundancy Codes for Correcting Multiple Deletions 16

Efficient Low-Redundancy Codes for Correcting Multiple Delet...

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Annual ACM-Society for Industrial and Applied Mathmatics Symposium on Discrete Algorithms

作者： Joshua Brakensiek Venkatesan Guruswami Samuel Zbarsky Department of Mathematical Sciences Carnegie Mellon University Computer Science Department Carnegie Mellon University

ISBN: (纸本)9781510819672

We consider the problem of constructing binary codes to recover from k-bit deletions with efficient encoding/decoding, for a fixed k. The single deletion case is well understood, with the Varshamov-Tenengolts-Levenshtein code from 1965 giving an asymptotically optimal construction with ≈ 2~n/n codewords of length n, i.e., at most log n bits of redundancy. However, even for the case of two deletions, there was no known explicit construction with redundancy less than n~(Ω(1)). For any fixed k, we construct a binary code with ck log n redundancy that can be decoded from k deletions in O_k(n log~4 n) time. The coefficient ck can be taken to be O(k~2 log k), which is only quadratically worse than the optimal, non-constructive bound of O(k). We also indicate how to modify this code to allow for a combination of up to k insertions and deletions. We also note that among linear codes capable of correcting k deletions, the (k + 1)-fold repetition code is essentially the best possible.

关键词： deletions binary code Codes redundancy MED12 gene logs logarithm (log) repetition coding

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Coded Slotted ALOHA Schemes for Erasure Channels

Coded Slotted ALOHA Schemes for Erasure Channels

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Ad-Hoc and Sensor Networks Symposium

作者： Zhuo Sun Yixuan Xie Jinhong Yuan Tao Yang The University of New South Wales

ISBN: (纸本)9781479966653

In this paper we investigate the coded slotted ALO-HA (CSA) schemes with repetition codes and maximum distance separable (MDS) codes over erasure channels. We derive the extrinsic information transfer (EXIT) functions of the CSA schemes over erasure channels, which allow an asymptotic analysis of the packet recovering process. Moreover, we define a traffic load threshold provided that the recovered probability is more than a given recovery ratio. The optimal distribution of the codes chosen by users in the CSA schemes is then designed to maximize the peak throughput and traffic load threshold. By performing the asymptotic analysis, we show that our optimal distributions improve the traffic load threshold by 60% for ε = 0.1 and 86% for ε = 0.135 compared to the optimal distribution for collision channels. Using repetition codes as an example, simulation results show that the obtained distributions enhance the peak throughput for erasure channels when both packet erasure channels and slot erasure channels are considered.

关键词： optimal distribution erasure channel Simulation results Transportation load RECYCLING RATE repetition Slotted ALOHA Channels channels Scheme Codes repetition coding

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On the Minimum Trapping Distance of Repeat Accumulate Accumulate Codes

On the Minimum Trapping Distance of Repeat Accumulate Accumu...

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Annual Allerton Conference on Communication, Control, and Computing

作者： Jorg Kliewer Kamil S. Zigangirov Daniel J. Costello, Jr. Klipsch School of Electrical and Computer Engineering New Mexico State University Department of Electrical Engineering University of Notre Dame

ISBN: (纸本)9781424429257

We consider the ensemble of codes formed by a serial concatenation of a repetition code with two accumulators through uniform random interleavers. For this ensemble, asymptotic expressions for the normalized minimum trapping distance are derived. We employ a variant of the Gallager-Zyablov-Pinsker bit flipping decoding algorithm on a binary symmetric channel, where the analysis is based on the factor graph of the code. In particular, we show that the minimum trapping distance can be determined by solving a non-linear optimization problem. As a result we find that the minimum trapping distance grows linearly with block length for code rates of 1/3 and smaller, albeit with very small growth rate coefficients.

关键词： Codes repetition coding Factor Graph trapping binary symmetric channel cyclic code rate

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Coded Machine Learning: Joint Informed Replication and Learning for Linear Regression

Coded Machine Learning: Joint Informed Replication and Learn...

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Annual Allerton Conference on Communication, Control, and Computing

作者： Shahroze Kabir Frederic Sala Guy Van den Broeck Lara Dolecek UCLA Los Angeles CA

This paper is concerned with coded machine learning: protecting machine learning algorithms from noise in test data by an informed channel coding approach. Unlike with traditional data storage, we do not seek to ensure that all test data is correctly read from storage and used as a noiseless input to the algorithm. Rather, we seek to protect data in a way that minimizes the effect on the algorithm output (i.e., minimizes a loss compared to the hypothetical noiseless output). We focus on the case where the collected test data, derived from low-power sensors and devices, is inherently noisy. We show that a smart replication strategy is an effective choice to reduce the impact on the algorithm output for linear regression algorithms. We focus on two scenarios. The first case is where the regression model is fixed, and we must allocate a fixed budget of redundancy for our replication scheme (in order to minimize the loss on the output due to noisy test data). Analyzing this case is necessary to build our understanding for the second case which is more novel. The second case involves a scenario where we may learn an optimized model and jointly protect it. We illustrate the advantages of our approach with practical experiments.

关键词： Channel coding Machine Learning repetition coding Linear Regression

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