1,826 results
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2. Hybrid multibeam forming and multiuser detection technique for MU-MIMO system
- Author
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Kumari, D. Lalitha and Prasad, M.N. Giri
- Published
- 2022
- Full Text
- View/download PDF
3. Integer codes capable of correcting burst asymmetric errors
- Author
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Nabin Kumar Pokhrel, Pankaj Kumar Das, and Aleksandar Radonjic
- Subjects
error correction ,asymmetric errors ,practical systems ,Applied Mathematics ,probability ,Syndromes ,integer codes ,94B35 ,syndrome ,bit error rate ,asymmetric bursts ,Computational Mathematics ,94B60 ,94B65 ,bit-error rate ,data length ,table lookup ,asymmetric burst ,paper analysis ,performance ,lookup table - Abstract
In this paper, we present a class of integer codes capable of correcting burst asymmetric errors. The presented codes are constructed with the help of a computer and have the potential to be used in various practical systems, such as optical networks and VLSI memories. In order to evaluate the performance of the proposed codes, the paper analyzes the probability of erroneous decoding for different bit error rates. The presented codes are also analyzed from a rate-efficiency point of view. The obtained results show that for many data lengths they require less check-bits than optimal burst error correcting codes. This is the peer-reviewed version of the paper: Pokhrel, Nabin Kumar, Das, Pankaj Kumar, Radonjic, Aleksandar, "Integer codes capable of correcting burst asymmetric errors" in Journal of Applied Mathematics and Computing (2022), [https://doi.org/10.1007/s12190-022-01770-7]
- Published
- 2023
4. An Integrated Orthogonal Frequency-Division Multiplexing Chirp Waveform Processing Method for Joint Radar and Communication Based on Low-Density Parity-Check Coding and Channel Estimation.
- Author
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Zhu, Chenchen, He, Pengfei, Wu, Shie, and Wang, Guorui
- Subjects
CHANNEL estimation ,CHANNEL coding ,MIMO radar ,DISCRETE Fourier transforms ,INFORMATION technology ,BIT error rate ,RADAR - Abstract
With the advancement of information technology construction, the integration of radar and communication represents a crucial technological evolution. Driven by the research boom of integrated sensing and communications (ISACs), some scholars have proposed utilizing orthogonal frequency-division multiplexing (OFDM) to separately modulate radar and communication signals. However, the OFDM symbols in this paper incorporate a cyclic prefix (CP) and a virtual carrier (VC) instead of zero padding (ZP). This approach mitigates out-of-band power caused by ZP, in addition to reducing adjacent channel interference (ACI). In addition, we introduce low-density parity-check (LDPC) and use an improved normalized min-sum algorithm (NMSA) in decoding. The enhanced decoding efficiency and minimized system errors render the proposed waveform more suitable for complex environments. In terms of signal processing methods, this paper continues to use radar signals as a priori information to participate in channel estimation. Further, we consider the symbol timing offset (STO) and carrier frequency offset (CFO) issues. In order to obtain more reliable data, we use the minimum mean-square error (MMSE) estimation based on the discrete Fourier transform (DFT) to evaluate the channel. Simulation experiments verify that the system we propose not only realizes the transmission and detection functions but also improves the performance index of the integrated signal, such as the bit error rate (BER) of 7 × 10
−5 , the peak side lobe ratio (PSLR) of −13.81 dB, and the integrated side lobe ratio (ISLR) of −8.98 dB at a signal-to-noise ratio (SNR) of 10 dB. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
5. Enhancement of Signals Characteristics with Least Effect of Optical Communication Losses for Dense Optical Communication Systems.
- Author
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Kumar, Chakresh and Kumar, Ghanendra
- Subjects
OPTICAL losses ,OPTICAL dispersion ,OPTICAL communications ,BIT error rate ,QUALITY factor ,POWER transmission - Abstract
In this paper, the major aim is to enhance the bandwidth and therefore increase the capacity of the optical fibre communication system by reducing the dispersion in the fibre. Dispersion compensation is necessary to reduce losses and cost of the system. In this paper, we are basically focusing on reducing or decreasing chromatic dispersion. Chromatic dispersion is a type of dispersion in which pulse broadening occurs due to delay in different spectral components. We here make use of dispersion compensated fibre (DCF) for reducing the dispersion in the WDM system. Here, we basically use three dispersion compensated techniques (pre-compensation, post-compensation and mix compensation). The comparison in the three models of dispersion compensated technique is made in terms of transmission power vs. Q factor and also transmission power vs. Bit Error Rate. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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6. Bit error rate performance of underwater optical wireless communication with hybrid modulation.
- Author
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Luo, Qiong, Chen, Chao, Ji, Jianhua, and Xu, Ming
- Subjects
OPTICAL communications ,WIRELESS communications ,ERROR rates ,BIT error rate ,OCEAN turbulence ,ATMOSPHERIC turbulence - Abstract
Turbulence effects can cause performance degradation for underwater optical wireless communication (UOWC) system. In this paper, a hybrid modulation (modulation–modulation, M–M) is presented to resist turbulence‐induced fading and improve the transmission performance of UOWC systems. The proposed differential phase shift keying‐multiple pulse position modulation (DPSK‐mPPM) is adopted as hybrid modulation to improve the bit error rate (BER) performance over UOWC turbulence channel of Gamma–Gamma distribution. Subsequently, the closed‐form average BER expressions of mPPM and hybrid DPSK‐mPPM modulation are derived and investigated, which are related to the oceanic turbulence parameters. The influence of the variation of anisotropy factor of ocean turbulence is analysed for the UOWC system over strong Gamma–Gamma turbulent channels. Finally, the numerical simulation results demonstrate the effectiveness of proposed DPSK‐mPPM to improve the BER performance compared to the traditional single modulation over UOWC channel under the same conditions. Furthermore, the work of this paper improves the practicality of the proposed DPSK‐mPPM scheme for underwater communication in complex oceanic environments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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7. A Study on the Maximum Reliability of Multi-UAV Cooperation Relay Systems.
- Author
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Ning, Ning, Zhou, Suiping, Bao, Weimin, and Li, Xiaoping
- Subjects
BIT error rate ,ERROR rates ,POWER transmission - Abstract
This paper studies the maximum reliability of multi-hop relay UAVs, in which UAVs provide wireless services for remote users as a coded cooperative relay without an end-to-end direct communication link. In this paper, the analytical expressions of the total power loss and total bit error rate are derived as reliability measures. First, based on the environmental statistical parameters, a LOS probability model is proposed. Then, the problem of minimizing the bit error rate of static and mobile UAVs is studied. The goal is to minimize the total bit error rate by jointly optimizing the height, elevation, power and path loss and introducing the maximum allowable path loss constraints, transmission power allocation constraints, and UAV height and elevation constraints. At the same time, the total path loss is minimized to achieve maximum ground communication coverage. However, the formulated joint optimization problem is nonconvex and generally difficult to solve. Therefore, we decomposed the problem into two subproblems and proposed an effective joint optimization iteration algorithm. Finally, the simulation results are given, and the analysis shows that the optimal height of different reliability measures is slightly different; thus, using the mobility of UAVs can improve the reliability of communication performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Novel Approach towards a Fully Deep Learning-Based IoT Receiver Architecture: From Estimation to Decoding.
- Author
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Boeding, Matthew, Hempel, Michael, and Sharif, Hamid
- Subjects
DEEP learning ,CONVOLUTIONAL neural networks ,GRAPH neural networks ,ORTHOGONAL frequency division multiplexing ,BIT error rate ,INTERNET of things - Abstract
As the Internet of Things (IoT) continues to expand, wireless communication is increasingly widespread across diverse industries and remote devices. This includes domains such as Operational Technology in the Smart Grid. Notably, there is a surge in resource-constrained devices leveraging wireless communication, especially with the advances of 5G/6G technology. Nevertheless, the transmission of wireless communications demands substantial power and computational resources, presenting a significant challenge to these devices and their operations. In this work, we propose the use of deep learning to improve the Bit Error Rate (BER) performance of Orthogonal Frequency Division Multiplexing (OFDM) wireless receivers. By improving the BER performance of these receivers, devices can transmit with less power, thereby improving IoT devices' battery life. The architecture presented in this paper utilizes a depthwise Convolutional Neural Network (CNN) for channel estimation and demodulation, whereas a Graph Neural Network (GNN) is utilized for Low-Density Parity Check (LDPC) decoding, tested against a proposed (1998, 1512) LDPC code. Our results show higher performance than traditional receivers in both isolated tests for the CNN and GNN, and a combined end-to-end test with lower computational complexity than other proposed deep learning models. For BER improvement, our proposed approach showed a 1 dB improvement for eliminating BER in QPSK models. Additionally, it improved 16-QAM Rician BER by five decades, 16-QAM LOS model BER by four decades, 64-QAM Rician BER by 2.5 decades, and 64-QAM LOS model BER by three decades. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Research on Tracking Technique Based on BPSK-CSK Signals.
- Author
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Chen, Yuxin, Cheng, Jie, Li, Xiaodong, Bai, Xue, and Nie, Zhixi
- Subjects
BIT error rate ,FAST Fourier transforms ,RESEARCH methodology ,GLOBAL Positioning System - Abstract
The code-shift keying (CSK) modulation method can achieve higher information transmission rates without changing the spread spectrum signal bandwidth. In order to optimise the spread spectrum modulation and demodulation of GNSS signals, in addition to the signal structure, binary phase-shift keying (BPSK) and CSK signals using time-division multiplexing are proposed. A tracking method based on the BPSK-CSK signals is also proposed, which generates the P-branch local codes by fast Fourier transform to obtain the code-slice spacings for the E-branch and the L-branch local codes. Then, the tracked BPSK signals and tracked CSK signals are compared and analysed. Finally, the bit error rate (BER) and tracking error of each method are compared and analysed by comparing with the tracking of conventional BPSK signals and tracking of CSK signals, in order to verify the convergence process of the I-branch integral value. The BPSK-CSK signal tracking method proposed in this paper combines the high information transmission rate of CSK-modulated signals and the low BER of BPSK signals, and the results provide a solid foundation for high-precision GNSS services. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Text-Based Fine-Grained Emotion Prediction.
- Author
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Singh, Gargi, Brahma, Dhanajit, Rai, Piyush, and Modi, Ashutosh
- Abstract
Text-based emotion prediction is an important task in the field of affective computing. Most prior work has been restricted to predicting emotions corresponding to a few high-level emotion classes. This paper explores and experiments with various techniques for fine-grained (27 classes) emotion prediction $^\dagger$ † . In particular, 1) we present a method to incorporate multiple annotations from different raters, 2) we analyze the model's performance on fused emotion classes and with sub-sampled training data, 3) we present a method to leverage the correlations among the emotion categories, and 4) we propose a new framework for text-based fine-grained emotion prediction through emotion definition modeling. The emotion definition-based model outperforms the existing state-of-the-art for fine-grained emotion dataset GoEmotions. The approach involves a multi-task learning framework that models definitions of emotions as an auxiliary task while being trained on the primary task of emotion prediction. We model definitions using masked language modeling and class definition prediction tasks. We show that this trained model can be used for transfer learning on other benchmark datasets in emotion prediction with varying emotion label sets, domains, and sizes. The proposed models outperform the baselines on transfer learning experiments demonstrating the model's generalization capability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Analysis of Filtered Multicarrier Modulation Techniques Using Different Windows for 5G and Beyond Wireless Systems.
- Author
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Debnath, Sourav, Ahmed, Samin, and Alam, S. M. Shamsul
- Subjects
MULTI-carrier modulation ,ADDITIVE white Gaussian noise channels ,PHASE shift keying ,BIT error rate ,RAYLEIGH fading channels ,WIRELESS channels ,ORTHOGONAL frequency division multiplexing - Abstract
In contemporary wireless communication systems, multicarrier modulation schemes have become widely adopted over single-carrier techniques due to their improved capacity to address challenges posed by multipath fading channels, leading to enhanced spectral efficiency. Orthogonal frequency division multiplexing (OFDM), a prevalent multicarrier scheme in 4G, is favored for its ease of implementation, interference resilience, and high data rate provision. But it falls short of meeting the requirements for 5G and beyond due to limitations such as out-of-band (OOB) emissions and cyclic prefixes. This paper introduces the filter bank multicarrier (FBMC) and universal filtered multicarrier (UFMC) with quadrature amplitude modulation (QAM) and phase shift keying (PSK) waveforms through Additive White Gaussian Noise channel (AWGN), Rayleigh fading channel and Rician channel. The objective of this paper is to enhance the performance of UFMC with reduced complexity through the new filtering approach for achieving optimal outcomes. The proposed scheme, incorporating Tukey filtering technique, demonstrates superior performance in reducing peak-to-average power ratio (PAPR) and improving bit error ratio (BER) compared to the original UFMC signal without necessitating additional power increments. Specifically, the UFMC system with Tukey filtering achieves a notable net gain of 5 dB. Simulation results demonstrate that utilizing various filter types in FBMC and UFMC systems, combined with QAM modulation, significantly reduces OOB emissions compared to conventional systems. In aspect to BER, Tukey window showed almost 10
−6 at 15 dB SNR in UFMC which is better than FBMC. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
12. Short-Block-Length Low-Density Parity-Check Codes-Based Underwater Acoustic Spread-Spectrum Communication System.
- Author
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Zhao, Zichen and Sun, Zongxin
- Subjects
UNDERWATER acoustic communication ,BIT error rate ,DATA transmission systems ,LOW density parity check codes ,TELECOMMUNICATION systems ,MOBILE communication systems ,VIDEO coding - Abstract
Low-density parity-check (LDPC) codes are commonly used in communication systems to improve the system performance, but LDPC codes takes too long for decoding, making communication inefficient and unsuitable for short-frame data transmission methods. In underwater acoustic channels, spread-spectrum communication becomes an effective way to realize long-distance communication. This paper combines short-block LDPC codes with a direct sequence spread spectrum and soft spread spectrum in underwater acoustic communication, addressing the problem of the inapplicability of conventional LDPC codes. The applicability of the proposed method in this paper is verified through simulation tests and pool experiments. The results indicate that the proposed communication system achieves lower bit error rates compared to the classical coding methods used in underwater acoustic spread-spectrum communication systems under the same channel conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
13. Investigation of LDPC codes with interleaving for 5G wireless networks
- Author
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Pathak, Pooja and Bhatia, Richa
- Published
- 2024
- Full Text
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14. Link Repair for Actual Environment-Oriented in Underwater Wireless Optical Communication Sensor Networks.
- Author
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HAORAN QIN and ZHIBIN XIE
- Subjects
OPTICAL communications ,WIRELESS sensor networks ,WIRELESS communications ,SENSOR networks ,OPTICAL sensors ,BIT error rate ,ROUTING algorithms - Abstract
Underwater wireless sensor network is an important part of the future large-scale internet of things (IoT). In this paper, we consider an optical communication link repair problem where the established topology of the network is damaged by complex underwater situations. In order to reconstruct the effective underwater optical communication link, this paper uses mobile relay to realize cooperative transmission. To realize effective communication, the bit error rate of the mixture EGG model is used as a cooperative transmission index, and the mobile energy consumption of the mobile relay node is taken into consideration. By optimizing deployment and coverage, the proposed algorithm can minimize the mobile energy consumption and guarantee the expected BER on the premise of solving the link failure problem. The simulation results show that the relay cooperative routing algorithm for reconstructing the communication link effectively, and present the attention terms for different deployment environments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. Deep learning based sequence detection with natural redundancy for memory sources.
- Author
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Wang, Zhen‐Yu, Yu, Hong‐Yi, Du, Jian‐Ping, Shen, Zhi‐Xiang, Zhu, Zhao‐Rui, and Shen, Cai‐Yao
- Subjects
BIT error rate ,WIRELESS communications ,HIGH performance computing ,MEMORY - Abstract
The current wireless communication system has higher performance demands for receivers. This paper considers exploiting the natural redundancy (NR) that is widely existed in the transmission sources to improve the receiver's performance of sequence detection. The type of NR discussed in this paper is the inherent redundancy in data caused by the correlation between symbols in the memory sources. Since the correlation between transmitted symbols is too challenging to obtain, deep learning (DL) is introduced into sequence detection, which has a powerful ability to extract complex patterns from data. Specifically, intended for a specific memory source that is convenient for performance analysis, namely the Markov source, an iterative sequence detection algorithm based on the long short‐term memory network is proposed. Simulation results demonstrate that the receiver's performance can be improved by exploiting the NR and the proposed DL‐based sequence detection scheme can obtain optimal bit error rate performance with blind state transition probability of the transmitted Markov source. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. DIR: Dynamic Request Interleaving for Improving the Read Performance of Aged Solid-State Drives.
- Author
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Nie, Shi-Qiang, Zhang, Chi, and Wu, Wei-Guo
- Subjects
SOLID state drives ,BIT error rate ,COMPUTER systems ,PERFORMANCE technology - Abstract
Triple-level cell (TLC) NAND flash is increasingly adopted to build solid-state drives (SSDs) for modern computer systems. While TLC NAND flash effectively improves storage density, it faces severe reliability issues; in particular, the pages exhibit different raw bit error rates (RBERs). Integrating strong low-density parity-check (LDPC) code helps to improve reliability but suffers from prolonged and proportional read latency due to multiple read retries for worse pages. The straightforward idea is that dispersing page-size data across several pages in different types can achieve a lower average RBER and reduce the read latency. However, directly implementing this simple idea into flash translation layer (FTL) induces the read amplification issue as one logic page residing in more than one physical page brings several read operations. In this paper, we propose the Dynamic Request Interleaving (DIR) technology for improving the performance of TLC NAND flash-based SSDs, in particular, the aged ones with large RBERs. DIR exploits the observation that the latency of an I/O request is determined, without considering the queuing time, by the access of the slowest device page, i.e., the page that has the highest RBER. By grouping consecutive logical pages that have high locality and interleaving their encoded data in different types of device pages that have different RBERs, DIR effectively reduces the number of read retries for LDPC with limited read amplification. To meet the requirement of allocating hybrid page types for interleaved data, we also design a page-interleaving friendly page allocation scheme, which splits all the planes into multi-plane regions for storing the interleaved data and single-plane regions for storing the normal data. The pages in the multi-plane region can be read/written in parallel by the proposed multi-plane command and avoid the read amplification issue. Based on the DIR scheme and the proposed page allocation scheme, we build DIR-enable FTL, which integrates the proposed schemes into the FTL with some modifications. Our experimental results show that adopting DIR in aged SSDs exploits nearly 33% locality from I/O requests and, on average, reduces 43% read latency over conventional aged SSDs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Spatial diversity processing mechanism based on the distributed underwater acoustic communication system.
- Author
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Zhou, Manli, Zhang, Hao, Lv, Tingting, Gao, Yong, and Duan, Yingying
- Subjects
UNDERWATER acoustic communication ,DECISION feedback equalizers ,SPACE-time block codes ,BIT error rate ,INTERSYMBOL interference ,PHASE-locked loops ,TELECOMMUNICATION systems - Abstract
To address the problem of unreliable single-link underwater acoustic communication caused by large signal delays and strong multipath effects in shallow water environments, this paper proposes a distributed underwater acoustic diversity communication system (DUA-DCS). DUA-DCS employs a maneuverable distributed cross-medium buoy network to form multiple distributed, non-coherent, and parallel communication links. In the uplink, a receiving diversity processing mechanism of joint decision feedback equalizer embedded phase-locked loop and maximum signal-to-interference ratio combining (DFE-PLL-MSIRC) is proposed to achieve waveform-level diversity combining of underwater signals. A phase-locked loop module is embedded in each branch of the decision feedback equalizer to eliminate the residual frequency and phase errors after Doppler compensation. Meanwhile, the combining coefficients are determined based on the maximum signal-to-interference ratio criterion, taking into account the residual inter-symbol interference after equalization, resulting in efficient and accurate computation. Additionally, the combined decision values are fed back to the feedback filters in each branch to ensure more accurate feedback output. Simulation and lake experiment results demonstrate that, compared to the single-link communication system, DFE-PLL-MSIRC can achieve a diversity gain of more than 5.2 dB and obtain about 3 dB more diversity gain than the comparison algorithm. And the BER of DFE-PLL-MSIRC can be reduced by at least one order of magnitude, which is lower by at least 0.6 order of magnitude compared to the comparison algorithm. In the downlink, a transmitting diversity processing mechanism of complex orthogonal space-time block coding (COSTBC) is proposed. By utilizing a newly designed generalized complex orthogonal transmission matrix, complete transmission diversity can be achieved at the coding rate of 3/4. Compared to the single-link communication system, the system can achieve a diversity gain of more than 6 dB. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Experimental results on nonlinear distortion compensation using photonic reservoir computing with a single set of weights for different wavelengths.
- Author
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Gooskens, Emmanuel, Sackesyn, Stijn, Dambre, Joni, and Bienstman, Peter
- Subjects
FORWARD error correction ,BIT error rate ,WAVELENGTH division multiplexing ,SIGNAL processing ,DELAY lines ,COMPUTING platforms - Abstract
Photonics-based computing approaches in combination with wavelength division multiplexing offer a potential solution to modern data and bandwidth needs. This paper experimentally takes an important step towards wavelength division multiplexing in an integrated waveguide-based photonic reservoir computing platform by using a single set of readout weights for up to at least 3 ITU-T channels to efficiently scale the data bandwidth when processing a nonlinear signal equalization task on a 28 Gbps modulated on-off keying signal. Using multiple-wavelength training, we obtain bit error rates well below that of the 1.5 × 10 - 2 forward error correction limit at high fiber input powers of 18 dBm, which result in high nonlinear distortion. The results of the reservoir chip are compared to a tapped delay line filter and clearly show that the system performs nonlinear equalization. This was achieved using only limited post processing which in future work can be implemented in optical hardware as well. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. A Comparative Study of Performances Between the WDM PON System and the CWDM PON System in an Optical Access Network.
- Author
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Kherici, Cheikh and Kandouci, Malika
- Subjects
PASSIVE optical networks ,WAVELENGTH division multiplexing ,BIT error rate ,QUALITY factor ,OPTICAL fibers ,PERFORMANCE theory ,COMPUTER systems - Abstract
The growth of optical technology is currently being studied extensively to meet the significant demand for bandwidth. The passive optical network (PON) solves the problem of bandwidth as it extends the optical network to individuals and businesses [Sifta R, Munster P, Krajsa O, Filka M, "Simulation of bidirectional traffic in WDM-PON networks", Brno University of Technology, ISSN 0033–2097, R. 90 NR 1/2014.]. In this paper, a comparative study is made between the WDM PON system and the CWDM PON system using two different architectures, one for the WDM PON and the other for the CWDM PON, to illustrate the appropriate technique for the PON network by increasing the Q factor and the OSNR ratio while minimizing the bit error rate (BER < 10
–9 ). Both systems are simulated at 10 Gbps for four users of bidirectional SMF (Single Mode Fiber) fiber lengths and different powers. In order to determine the transmission performance for both systems, the link was designed for fiber lengths of 20, 30, 40, 50 and 60 km as well as for powers from −10 dBm up to 10 dBm for four users. The use of the EDFA amplifier in the WDM PON system is required in this document to minimize degradation caused by attenuation [Parkirti RDK, Singh R. Cost-efficient Colorless WDM-PON Based on RSOA for High Capacity. Int J Adv Res Comput Eng Technol (IJARCET). 2016;5]. On the contrary, in the CWDM PON system, the amplification is not essential because the wavelengths used in this system are not affected by the water peak which causes a strong attenuation of the wavelengths in the 1370–1410 nm range on optical fibers [Nazir M, Arshad F, Asif R. Design and evaluation of power budget for a bidirectional CWDM-Passive Optical Network. In: International Conference on Communication, Computing and Digital Systems (C-CODE), Islamabad, Pakistan, 04 May 2017.]. The peak of water vapor absorption is close to 1383 nm. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
20. Performance Comparison of Free-Space Optical (FSO) Communication Link Under OOK, BPSK, DPSK, QPSK and 8-PSK Modulation Formats in the Presence of Strong Atmospheric Turbulence.
- Author
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Sharoar Jahan Choyon, A. K. M. and Chowdhury, Ruhin
- Subjects
DIFFERENTIAL phase shift keying ,QUADRATURE phase shift keying ,ATMOSPHERIC turbulence ,BIT error rate ,TELECOMMUNICATION systems ,RADIO frequency ,FREE-space optical technology - Abstract
Free-space optical (FSO) communication system provides several advantages over radio frequency (RF) system offering high bandwidth, low cost, small space requirements and more secure transmission which is free from Electromagnetic Interference (EMI). However, when the transmitted light signal passes through the atmosphere it experiences attenuation and fluctuations due to atmospheric turbulence. This paper analyzes the bit error rate (BER) performance of FSO communication systems under strong atmospheric turbulence for on-off keying (OOK), binary phase-shift keying (BPSK), differential phase shift keying (DPSK), quadrature phase shift keying (QPSK) and 8-phase shift keying (8-PSK) for link distances of 500, 1,000, 1,500 and 2,000 m. The probability density function (pdf) of the received irradiance is modelled using the gamma-gamma distribution model. It is found that the system exhibits the best BER performance and compensates the lowest power penalty at BER of 10
- 9 for BPSK modulation compared with other modulation techniques which makes BPSK more appropriate to be used with FSO turbulent system. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
21. Performance Analysis of Artificial Noise-Assisted Location-Based Beamforming in Rician Wiretap Channels.
- Author
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Fu, Hua, Zhang, Xiaoyu, and Peng, Linning
- Subjects
RICIAN channels ,BEAMFORMING ,ANTENNA arrays ,ANTENNAS (Electronics) ,BIT error rate ,PHYSICAL layer security - Abstract
This paper studies the performance of location-based beamforming with the presence of artificial noise (AN). Secure transmission can be achieved using the location information of the user. However, the shape of the beam depends on the number of antennas used. When the scale of the antenna array is not sufficiently large, it becomes difficult to differentiate the performance between the legitimate user and eavesdroppers nearby. In this paper, we leverage AN to minimize the area near the user with eavesdropping risk. The impact of AN is considered for both the legitimate user and the eavesdropper. Closed-form expressions are derived for the expectations of the signal to interference plus noise ratios (SINRs) and the bit error rates. Then, a secure beamforming scheme is proposed to ensure a minimum SINR requirement for the legitimate user and minimize the SINR of the eavesdropper. Numerical results show that, even with a small number of antennas, the proposed beamforming scheme can effectively degrade the performance of eavesdroppers near the legitimate user. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Research on Image Signal Identification Based on Adaptive Array Stochastic Resonance.
- Author
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Zhao, Jingjing, Ma, Yumei, Pan, Zhenkuan, and Zhang, Huage
- Abstract
Aiming at the problems of low accuracy of image signal identification and poor anti-noise signal interference ability under strong noise environment, a signal identification method of correlated noisy image based on adaptive array stochastic resonance (SR) is proposed in this paper. Firstly, the two-dimensional grayscale image is transformed to a one-dimensional binary pulse amplitude modulation (BPAM) signal with periodicity by the row or column scanning method, encoding and modulation. Then, the one-dimensional low signal-to-noise ratio BPAM signal can be applied to the saturating nonlinearity array SR module for image signal identification processing and part of the noise energy is converted into signal energy. Finally, the one-dimensional image signal processed by the nonlinearities is demodulated, decoded and reverse scanned to get the restored grayscale image. The simulation results show that the image signal identification method proposed in this paper is highly efficient and accurate for the identification of noisy image signals of different sizes, and the bit error rate (BER) is also significantly reduced. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Intelligent based hybrid precoder for millimetre wave massive MIMO system.
- Author
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Rajarajeswarie, B. and Sandanalakshmi, R.
- Subjects
MACHINE learning ,WIRELESS communications ,BIT error rate ,PHASE shifters ,ANTENNA arrays - Abstract
The Millimeter-wave and Massive Multiple Input Multiple Output technologies are promising candidates to offer high data rates and system throughputs in the next-generation wireless communication systems. In massive MIMO systems, the precoder plays a leading role to cancel the interference between the data stream and thereby reduce the complexity of the receiver design. In the conventional fully digital precoding scheme, many Radio Frequency chains are essential for every antenna array. Therefore, a hybrid precoder is a feasible solution to reduce the RF chains and improve the antenna array gain by dividing the signal processing into analog and digital precoders. Designing a hybrid precoder is a non-convex optimization problem because the phase shifter in the analog precoder holds hardware constraints. To address this, an intelligent hybrid precoder is designed using deep learning algorithms. In this paper, the Deep Learning framework is incorporated for hybrid precoder as it renovates non-convex problems into a network training process. In this work, the hybrid precoder is based on decomposition techniques such as Uniform Channel Decomposition (UCD) and Generalized Triangular Decomposition method, which is implemented in the training process as it provides equal gain for all subchannels to diminish the inter subchannel interference. The simulation results validate the proposed work is superior in terms of the Bit Error Rate in comparison with other conventional decomposition techniques. The result shows that the deep learning-based hybrid precoder is better than the conventional with a 2 dB improvement between the UCD method and GMD method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Free-space optical link optimization in visible light communication system.
- Author
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Ngene, Chidi E., Thakur, Prabhat, and Singh, Ghanshyam
- Subjects
FREE-space optical technology ,TELECOMMUNICATION systems ,BIT error rate ,OPTICAL communications ,VISIBLE spectra ,DATA transmission systems - Abstract
Free space optical communication is a potential technology that exploits the visible light frequency band for communication. In this paper, a free-space optical link (FSOL) optimization in visible light communication (VLC) is used to improve the channel performance for signal strength and analyze the effect of signal failures in a communication system. The data transmission and reception phenomenon are established using a light-emitting diode (LED) as a carrier at transmitter and photodiode as a detector at the receiver, respectively. The OptiSystem tool uses to optimize the component parameters of this proposed communication system. The bit error rate (BER) analyzer displays the signals as an eye diagram with the challenges of components uncertainty for better signal performance. The optimized components solve the problem encountered transmitting improve and enhance the signals strength. The acceptable eye diagram displayed from the BER analyzer has been resolved as a result of component optimizations by adding and removing noise to ascertain the behavior of the channel. A better signal retrieve by the display of the acceptable eye diagram from the OptiSystem software used. The FSOL components optimization improve the loss of data, weak signal, loss of power, signal failure, and signal errors which guarantee multi-mobile users with the shared signal. OptiSystem software package used to fully characterize the FSOL system. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Design and Optimization of an Ultraviolet Scattering Communication System Based on Duty Cycle Regulation.
- Author
-
Jiao, Yu, Zhao, Yingkai, Kuang, Li, Lin, Ranxi, Ning, Jin, and Liu, Jianguo
- Subjects
BIT error rate ,PROBABILITY density function ,TELECOMMUNICATION systems ,OPTICAL communications ,RATE setting - Abstract
In this paper, a novel ultraviolet (UV) scatter communication scheme is presented, designed to dynamically adjust the signal duty cycle to optimize on–off keying (OOK) modulation and reduce the bit error rate (BER), particularly under varying rate settings. This approach addresses the significant challenge posed by LED tailing effects, which cause signal fluctuations and increase BER in high-speed communications. This BER suppression scheme is proposed for the first time in UV communication research, enhancing communication performance without the need for additional hardware or complex algorithms. A UV communication model that incorporates both path loss and LED tailing effects is introduced, with the probability density function of the signal from transmitter to receiver derived. By varying the signal duty cycle, tailing-induced BER is effectively minimized. Additionally, a closed-form expression for signal transmission BER using a single-scattering model is provided, and the proposed UV communication system is validated through comprehensive simulations and experimental tests. The results indicate that LED tailing has a pronounced impact on BER at higher communication speeds, while its effects are less significant at lower speeds. By optimizing the duty cycle parameters for various communication rates, findings demonstrate that lower duty cycle settings significantly reduce the BER at higher speeds. This further demonstrates the excellent performance of the proposed UV communication solution for OOK-modulated optical communication. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Performance Investigation of Joint LUT and GS Algorithm at the Transceiver for Nonlinear and CD Compensation.
- Author
-
Zhang, Xiaoying, Huo, Jiahao, Bai, Haolin, Qin, Peng, Huangfu, Wei, and Long, Keping
- Subjects
PULSE amplitude modulation ,BIT error rate ,DIGITAL signal processing ,OPTICAL dispersion ,SINGLE-mode optical fibers - Abstract
In order to meet the increasing requirements of speed and distance, an advanced digital signal processing (DSP) algorithm is preferred without changing the system structure in intensity modulation and the direct detection (IM/DD) system. As the transmission distance increases, the power fading induced by dispersion must be mitigated. In addition, linear and nonlinear inter symbol interference (ISI) introduced by bandwidth limitation and device imperfections becomes an obstacle to achieving higher capacity. The Gerchberg–Saxton (GS) algorithm was recently used to compensate for dispersion. In this paper, GS-based pre- and post-compensation schemes in the IM/DD system with nonlinearity were investigated. We investigated and compared the performance of the GS-based pre- and post-compensation algorithm in a 28 GB aud four-level pulse amplitude modulation (PAM-4) transmission over 40 km standard single-mode fiber (SSMF). The bit error rate (BER) achieved a threshold of 3.8 × 10
−3 using look-up-table (LUT), FFE, and the GS-based pre-compensation algorithm without iterations. Turning to the GS-based post-compensation scheme, 80 iterations are needed. However, the demand for FFE is reduced. The algorithm selection depends on the tolerance of the transmitter or receiver complexity in specific scenarios. The joint LUT and GS-based pre-compensation algorithm may be a preferable approach in scenarios where a low-complexity receiver is desired. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
27. Clipping Noise in Visible Light Communication Systems with OFDM and PAPR Reduction.
- Author
-
Alrakah, Hussien, Hijazi, Mohamad, Sinanovic, Sinan, and Popoola, Wasiu
- Subjects
ORTHOGONAL frequency division multiplexing ,OPTICAL communications ,BIT error rate ,TELECOMMUNICATION systems ,VISIBLE spectra - Abstract
This paper presents an analytical study of signal clipping that leads to the noise/distortion in the waveform of DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM)-based visible light communication (VLC) systems. The pilot-assisted (PA) technique is used to reduce the high peak-to-average power ratio (PAPR) of the time-domain waveform of the DCO-OFDM system. The bit error rate (BER) performance of the PA DCO-OFDM system is investigated analytically at three different clipping levels as well as without any clipping. The analytical BER performance is verified through simulation and then compared to that of the conventional DCO-OFDM without PAPR reduction at the selected clipping levels. The PA DCO-OFDM system shows improved BER performance at all three clipping levels. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Efficient Direct Detection of Twin Single-Sideband Quadrature-Phase Shift Keying Using a Single Detector with Hierarchical Blind-Phase Search.
- Author
-
Zhang, Hongbo, Liu, Jiao, Lu, Guo-Wei, Zhang, Min, Wan, Feng, Cai, Ju, Ling, Weiwei, and Hu, Liming
- Subjects
FORWARD error correction ,QUADRATURE amplitude modulation ,SINGLE-mode optical fibers ,LIGHT transmission ,PHOTODETECTORS ,BIT error rate - Abstract
We propose a novel reception scheme for twin single-sideband (twin-SSB) signals using just a single photodetector (PD), significantly reducing the system complexity and cost. To detect a twin-SSB with power-unbalanced quadrature-phase shift keying (QPSK) sidebands upon detection via a single PD at the receiver side, two QPSKs carried in two sidebands are coherently superposed and detected in a 16-ary quadrature amplitude modulation (16-QAM) format. This technique notably diminishes the linearity and effective number of bits required for the transmitter components in high-speed optical transmission systems. Moreover, a hierarchical blind-phase search (HBPS) algorithm is proposed to compensate for the imperfect phase rotation of QPSK signals during transmission. To demonstrate the effectiveness of our proposed method, we successfully conducted simulations of 112 Gb/s 16-QAM signal transmission over a 10 km standard single-mode fiber (SSMF), achieving bit error ratios (BERs) of 7.84 × 10 − 4 , well below the 7% hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10 − 3 . In addition, the synthetic transmission scheme proposed in this paper is compared with the traditional 16-QAM signal transmission scheme, and the results show that the proposed scheme does not introduce a performance cost with the same received optical power (ROP) and transmission distance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Spatial Simultaneous Functioning-Based Joint Design of Communication and Sensing Systems in Wireless Channels.
- Author
-
Luat, Pham Ngoc, Taparugssanagorn, Attaphongse, Kaemarungsi, Kamol, and Phoojaroenchanachai, Chatchamon
- Subjects
WIRELESS communications ,ARTIFICIAL neural networks ,TIME division multiple access ,WIRELESS channels ,BIT error rate ,CHANNEL estimation - Abstract
This paper advocates for spatial simultaneous functioning (SSF) over time division multiple access (TDMA) in joint communication and sensing (JCAS) scenarios for improved resource utilization and reduced interference. SSF enables the concurrent operation of communication and sensing systems, enhancing flexibility and efficiency, especially in dynamic environments. The study introduces joint design communication and sensing scenarios for single input single output (SISO) and multiple input multiple output (MIMO) JCAS receivers. An MIMO-JCAS base station (BS) is proposed to process downlink communication signals and echo signals from targets simultaneously using interference cancellation techniques. We evaluate the communication performance and sensing estimation across both Rayleigh and measured realistic channels. Additionally, a deep neural network (DNN)-based approach for channel estimation and signal detection in JCAS systems is presented. The DNN outperforms the traditional methods in the bit error rate (BER) versus signal-to-noise ratio (SNR) curves, leveraging its ability to learn complex patterns autonomously. The DNN's training process fine-tunes the performance based on specific problem characteristics, capturing the nuanced relationships within data and adapting to varying SNR conditions for consistently superior performance compared to the traditional approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Resource allocation and passive beamforming for IRS‐assisted short packet systems.
- Author
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Zhang, Yangyi, Guan, Xinrong, Wu, Qingqing, Ji, Zhi, and Cai, Yueming
- Subjects
FREQUENCY division multiple access ,TIME division multiple access ,BEAMFORMING ,RESOURCE allocation ,SIGNAL-to-noise ratio ,BIT error rate ,BANDWIDTH allocation - Abstract
This paper investigates an intelligent reflecting surface (IRS) assisted downlink short packet transmission system, where an access point sends short packets to multiple devices with the help of an IRS. Specifically, a performance comparison between the frequency division multiple access and time division multiple access is conducted for the considered system, from the perspective of average age of information (AoI). To minimize the maximum average AoI among all devices, the resource allocation and passive beamforming are jointly optimized. However, the formulated problem is difficult to solve due to the non‐convex objective function and coupled variables. Thus, an alternating optimization based algorithm is proposed by exploiting the semidefinite relaxation and bisection search techniques. Simulation results show that time division multiple access can achieve lower AoI by exploiting the time‐selective passive beamforming of IRS for maximizing the signal to noise ratio of each device consecutively. Moreover, it also shows that as the length of information bits becomes sufficiently large as compared to the available bandwidth, the proposed frequency division multiple access transmission scheme becomes more favourable due to more flexible power allocation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Reliable Pilot Search Method for Enhancing BER Performance in Underwater Acoustic OFDM Systems with MMSE Estimator.
- Author
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Nguyen, Thi Nga, Phan, Anh Huy, Cao, Van Loi, and Hiep, Pham Thanh
- Subjects
CHANNEL estimation ,BIT error rate ,MINI-Mental State Examination ,UNDERWATER acoustics ,IMPULSE response ,DATA transmission systems - Abstract
A small set of pilots in underwater acoustics OFDM (UWA-OFDM) systems tends to be insufficient for recovering the channel impulse response (CIR). This may result from the fast changes in the propagation environment and the requirement for high transmission data rates. A previous work, namely PE, considered the received subcarriers whose distances to their closest constellation points below the predetermined threshold T as potential pilots. However, extracting these pilots at the same time gives no chance to use some of them to facilitate searching for others. Fixing threshold T is also another limitation for searching pilot candidates. This paper proposes a reliable pilot search (RPS) method that consists of a multi-iterations pilot searching process with an adaptive threshold T a to improve the estimator in UWA-OFDM. The pilot search process gradually extracts reliable pilots at each iteration based on the threshold T a and evaluates them by performing channel estimation. Our method is compared to the MMSE and PE estimators on a wide range of settings, including the number of channel taps, pilot spacing, and various modulation schemes (i.e., MPSK and MQAM). The experimental results show that the RPS method often outperforms the MMSE and PE methods in terms of bit error rate (BER). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Optimized decoder for low-density parity check codes based on genetic algorithms.
- Author
-
El Ouakili, Hajar, El Ghzaoui, Mohammed, and El Alami, Rachid
- Subjects
DECODING algorithms ,GENETIC algorithms ,CODING theory ,BLOCK codes ,LINEAR codes ,GENETIC code ,LOW density parity check codes ,ERROR-correcting codes - Abstract
Low-density parity check (LDPC) codes, are a family of error-correcting codes, their performances close to the Shannon limit make them very attractive solutions for digital communication systems. There are several algorithms for decoding LDPC codes that show great diversity in terms of performance related to error correction. Also, very recently, many research papers involved the genetic algorithm (GA) in coding theory, in particular, in the decoding linear block codes case, which has heavily contributed to reducing the bit error rate (BER). In this paper, an efficient method based on the GA is proposed and it is used to improve the power of correction in terms of BER and the frame error rate (FER) of LDPC codes. Subsequently, the proposed algorithm can independently decide the most suitable moment to stop the decoding process, moreover, it does not require channel information (CSI) making it adaptable for all types of channels with different noise or intensity. The simulations show that the proposed algorithm is more efficient in terms of BER compared to other LDPC code decoders. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. A Neural-Network-Based Watermarking Method Approximating JPEG Quantization.
- Author
-
Yamauchi, Shingo and Kawamura, Masaki
- Subjects
DIGITAL watermarking ,JPEG (Image coding standard) ,WATERMARKS ,RECURRENT neural networks ,BIT error rate ,IMAGE compression ,TANGENT function - Abstract
We propose a neural-network-based watermarking method that introduces the quantized activation function that approximates the quantization of JPEG compression. Many neural-network-based watermarking methods have been proposed. Conventional methods have acquired robustness against various attacks by introducing an attack simulation layer between the embedding network and the extraction network. The quantization process of JPEG compression is replaced by the noise addition process in the attack layer of conventional methods. In this paper, we propose a quantized activation function that can simulate the JPEG quantization standard as it is in order to improve the robustness against the JPEG compression. Our quantized activation function consists of several hyperbolic tangent functions and is applied as an activation function for neural networks. Our network was introduced in the attack layer of ReDMark proposed by Ahmadi et al. to compare it with their method. That is, the embedding and extraction networks had the same structure. We compared the usual JPEG compressed images and the images applying the quantized activation function. The results showed that a network with quantized activation functions can approximate JPEG compression with high accuracy. We also compared the bit error rate (BER) of estimated watermarks generated by our network with those generated by ReDMark. We found that our network was able to produce estimated watermarks with lower BERs than those of ReDMark. Therefore, our network outperformed the conventional method with respect to image quality and BER. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. A coding scheme to force the eavesdropper falling in error avalanche.
- Author
-
Zhao, Hang, Hu, Aiqun, and Yu, Jiabao
- Subjects
PHYSICAL layer security ,WIRELESS channels ,BIT error rate ,AVALANCHES ,CHANNEL coding ,ERROR rates ,TELECOMMUNICATION security - Abstract
In recent years, key generation schemes based on the reciprocity of wireless channels have gained widespread attention in the field of wireless physical layer security. However, due to the openness of wireless channels, eavesdroppers may obtain partial legitimate keys by eavesdropping on the wireless channel. To address this issue, this paper proposes a wireless channel coding scheme that induces an "avalanche" of errors for eavesdroppers, which could maximize eavesdropper's bit error rate. The design of this scheme is based on the significant differences between the eavesdropping channel and the legitimate channel, and the average bit key disagreement ratio of the keys generated by the legitimate channel is around 8%. The scheme selects polar codes with strong error correction capabilities and chooses a coding rate matching the error level of the legitimate channel, forcing the eavesdropping channel's error rate into an "avalanche" state, where the error rate approaches 50%. This paper presents the structure of the encoder and determines the coding rate through simulation. Simulation results demonstrate that this scheme can significantly degrade the error rate of the eavesdropping channel while ensuring the prevention of eavesdroppers from obtaining secret information transmitted through the legitimate channel. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Optimization and Application of Communication Resource Allocation Algorithm for Urban Rail Transit Planning.
- Author
-
Fang, Hui and Zhang, Wei
- Subjects
RECURRENT neural networks ,PUBLIC transit ,RESOURCE allocation ,BIT error rate ,SIMULATED annealing ,ALGORITHMS - Abstract
The construction and operation of China's rail transit system have entered a high-speed development stage, and the rapid increase of train speed and mileage has brought greater challenges to the safety and reliability of the rail transit system. Network planning evaluation is the key to the early decision-making of urban rail transit project, which directly determines the success or failure of the whole project. How to scientifically and reasonably evaluate the urban rail transit information resource network planning has become a difficult problem for many urban planners to solve. Therefore, this paper studies the optimization of the communication resource allocation algorithm and the comprehensive evaluation of its application for urban rail transit planning. In this paper, based on CVNN structure, the network prototype is an extension of RVNN structure. In the abstract, its processing unit is composed of a pair of real-number processors that can realize certain operations. HNN is a fully connected recurrent neural network based on the idea of the energy function, which is helpful to understand the calculation mode of HNN, and the research shows that HNN can solve many combinatorial optimization problems. In addition, the combination of neural network and genetic algorithm with simulated annealing mechanism can also bring new directions for research. On the basis of experimental analysis, it can be concluded that in general, the error reduction rate of the optimization scheme designed in this paper can reach 58.6% on average. In practical application, the accuracy of the optimal bit error rate is 52.4%. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. ANALYSIS OF THE ENERGY PER BIT TO NOISE POWER SPECTRAL DENSITY AND OPERATING SYSTEM MARGIN FOR LORA-BASED WIRELESS SENSOR NETWORK.
- Author
-
Ufot, Okon Nsa, Usoh, Midighe Abraham, and Udoka, Uduak Etim
- Subjects
WIRELESS sensor networks ,COMMUNICATION ,BIT error rate ,SPECTRAL energy distribution ,WIRELESS communications - Abstract
This paper presents the analysis of energy per bit to noise power spectral density (Eb/No) and system operating margin (SOM) for LoRa-based wireless sensor network with any specified bit error rate (BER) performance. Semtech SX1272 LoRa transceiver parameters were used for numerical examples. The results showed that for any given BER, the Eb/No decreases with increase in the spreading factor (SF) and for a given SF, the Eb/No increases with decrease in BER. For BER = 1.0E-06, the SF 7 has the highest Eb/No value of 7.832 dB while for the same BER = 1.0E-06 the SF 12 has the least Eb/No value of 6.770 dB. Also, the SF 7 has the least Eb/No value of 6.770 dB for BER = 1.0E-06 and the same SF7 has the highest Eb/No value of 10.061 dB for BER = 1.0E-15. In addition, the results showed that the value of SOM peaked at SF value of 10. Hence, for any given BER, the SOM increases for SF = 7 to SF = 10 and then the SOM decreases for SF = 10 to SF = 12. The results are useful in selecting LoRa communication link parameters to achieve any specified BER performance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
37. Dual-Buffer-Based Optical Datacenter Switch Design.
- Author
-
Bhattacharya, Pronaya, Tiwari, Amod Kumar, and Singh, Arunendra
- Subjects
OPTICAL switches ,SOFTWARE-defined networking ,MOORE'S law ,BIT error rate ,OPTICAL interconnects - Abstract
The unbounded growth of Cloud-based services and Internet-of-Things (IoT) using Software Defined Networking (SDN) has resulted in bandwidth requirements that have grown enormously over the years. To meet this exponential growth that is currently outpacing Moore's Law, we need Optical Interconnection Networks (OIN) that can satisfy the user's requirements. In a similar direction Arrayed Waveguide Gratings (AWG)-based optical interconnects have been heavily investigated in past and many switch designs have emerged over the period of time. This paper proposes a dual-buffer-based optical switch design where the primary buffer stores the contending packets, while the secondary input buffer stores the contending packets which are blocked by AWG for one slot duration only. Moreover, if a blocked packet is generated on the same node then All-Optical Negative Acknowledgement (AO-NACK) will be used for blocked packets. This paper investigates the various issues related to storage of blocked packets, the analysis is done both at physical and network layers in terms of bit error rate (BER) and packet loss probability, respectively. It is found that with proposed switch design BER is 10 times lower than the earlier design, and the number of re-transmitted packets at the load of 0.8, reduces to 26 from 32 as in earlier switch design. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. A robust and secure blind color image watermarking scheme based on contourlet transform and Schur decomposition.
- Author
-
Hu, Fangxu, Cao, Hongjiao, Chen, Siyu, Sun, Yehan, and Su, Qingtang
- Subjects
DIGITAL image watermarking ,DIGITAL watermarking ,DIGITAL images ,BIT error rate ,PIXELS ,SIGNAL-to-noise ratio ,WATERMARKS - Abstract
In order to protect the copyright of color digital images in the current Internet environment, this paper proposes a blind color image watermarking scheme based on nonsubsampled contourlet transform (NSCT) and Schur decomposition. In the stage of watermark embedding, NSCT is applied to acquire low-frequency coefficients of host images, and non-overlapping coefficient blocks of sized 4 × 4 are selected from the layered low-frequency coefficients by using Hash pseudo-random algorithm based on MD5. The watermark information encrypted by Lorenz chaotic mapping is embedded into the maximum eigenvalue of the matrix by quantization index modulation. In the extraction process, watermark information is extracted from the attacked watermarked image without using any original information. The simulation results show that all values of peak signal-to-noise ratio of the proposed watermarking scheme are more than 40 dB under the payload of 1/16 bit/pixel, and the values of Structural Similarity Index Metric are more than 0.97; when subjected to various common attacks, the mean of normalized cross-correlation is above 0.96, and the bit error rate is about 0.05; the key space is more than 2
624 ; the running time is about 1.5 s. Compared with other schemes, on the premise of ensuring invisibility and embedding capacity, the proposed scheme has been significantly improved in terms of security and robustness. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
39. Selective Mapping scheme based on Modified Forest Optimization Algorithm for PAPR reduction in FBMC system.
- Author
-
Vaigandla, Karthik Kumar and Benita, J.
- Subjects
OPTIMIZATION algorithms ,MOBILE communication systems ,BIT error rate ,FILTER banks ,MULTI-carrier modulation ,MATHEMATICAL optimization - Abstract
Filter Bank Multicarrier(FBMC)is considered as one of the most standardized waveform for fifth generation (5G) mobile communication system application FBMC endures lot of nonlinear effects which occurs because of high Peak Average Power Ratio (PAPR). High value of PAPR due to the large dynamic range of multicarrier signal is one of the most significant issues in FBMC multicarrier based modulation technique. This paper presents one investigated PAPR reduction technique named as Selected Mapping (SLM) to minimize high PAPR by utilizing the complex signal divide into real and imaginary parts and then select minimum PAPR signal based on Modified Forest Optimization Algorithm (MFOA)to achieve good PAPR which can maintain the FBMC based system performance with a required Bit Error Rate (BER). The associated method was produced with the aim of optimize the phase factors so that the phase rotation operation is accomplished to minimize PAPR by fixing the MFOA into the conventional SLM. The simulation results demonstrate that the proposed technique gives better performance in terms of BER and PAPR compared to other SLM based optimization techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. Impact of Rayleigh-Distributed PAPR on the Performance of a Pre-Clipped DCO-OFDM System.
- Author
-
Ratnam, Jayashree and Mali, Sabita
- Subjects
CUMULATIVE distribution function ,ORTHOGONAL frequency division multiplexing ,LIGHT sources ,BIT error rate - Abstract
The paper investigates the impact of Rayleigh-distributed statistical behavior of peak-to-average power ratio (PAPR) associated with a pre-clipped signal on the performance metrics of a direct current-biased optical orthogonal frequency division multiplexing (DCO-OFDM) system. The analytical model for the system takes into consideration a pre-clipped and dc-shifted baseband OFDM signal, driving an optical source over its linear operating range. The model employs a bias-scaling factor, which is heuristically varied over the entire range (0 to 1) to examine improvement in overall power efficiency. Further, it utilizes the cumulative distribution function (CDF) of the pre-clipped signal to get a weighted estimate of the available signal power within the clipped PAPR. The model also takes into consideration the clipping noise effects due to limited linearity of the optical source during electrical-to-optical conversion of baseband OFDM signal. Using this model, the paper aims to arrive at a realistic estimate of the system behavior in terms of bit error rate, electrical power-efficiency and spectral efficiency. Using theoretical simulation results, for a given set of operating parameters viz., signal power, PAPR, bias-scaling factor, modulation order and sub-carrier count, the paper examines the trade-offs involved in optimizing the performance metrics over appropriate dynamic range of the DCO-OFDM transmitter. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Adaptive Filtering: Issues, Challenges, and Best-Fit Solutions Using Particle Swarm Optimization Variants.
- Author
-
Khan, Arooj, Shafi, Imran, Khawaja, Sajid Gul, de la Torre Díez, Isabel, Flores, Miguel Angel López, Galvlán, Juan Castañedo, and Ashraf, Imran
- Subjects
PARTICLE swarm optimization ,ADAPTIVE filters ,OPTIMIZATION algorithms ,FILTERS & filtration ,TELECOMMUNICATION systems ,COMPUTATIONAL complexity - Abstract
Adaptive equalization is crucial in mitigating distortions and compensating for frequency response variations in communication systems. It aims to enhance signal quality by adjusting the characteristics of the received signal. Particle swarm optimization (PSO) algorithms have shown promise in optimizing the tap weights of the equalizer. However, there is a need to enhance the optimization capabilities of PSO further to improve the equalization performance. This paper provides a comprehensive study of the issues and challenges of adaptive filtering by comparing different variants of PSO and analyzing the performance by combining PSO with other optimization algorithms to achieve better convergence, accuracy, and adaptability. Traditional PSO algorithms often suffer from high computational complexity and slow convergence rates, limiting their effectiveness in solving complex optimization problems. To address these limitations, this paper proposes a set of techniques aimed at reducing the complexity and accelerating the convergence of PSO. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Optimal Relay Selection using jellyfish Optimization Algorithm for Image Transmission over Multiuser Cooperative Communication Networks.
- Author
-
Mohamed, Fatma K., Mohamed, Usama Sayed, and Ramzy, Safwat M.
- Subjects
MULTIUSER computer systems ,OPTIMIZATION algorithms ,IMAGE transmission ,WIRELESS cooperative communication ,TELECOMMUNICATION systems ,BIT error rate ,JELLYFISHES - Abstract
A recent study and research have shown that the relay selection schemes for cooperative communication can achieve full cooperative diversity gains and still maintains energy efficiency. Multi-source and multi-relay networks frequently cooperate to transfer their own data to the destination, mainly the access point, in cooperative wireless networks. In this paper, we use a jellyfish optimizer to select the number of relays to transmit packets of the image depending on the order of the data in the image according to its importance and at a constant rate. First, the relationships between the number of relays, peak signal-to-noise ratio (PSNR), and signal-to-noise ratio (SNR) are analysed. Second, the comparison between the performances of Equal Diversity (ED) and Unequal Diversity (UED) with Equal Error Protection (EEP) and Unequal Error Protection (UEP) is introduced using the set partitioning in hierarchical trees (SPIHT) image coder as a source coding. The jellyfish (JS) algorithm, as an efficient optimization technique, is applied for solving the problem of optimal relay selection method to reduce the bit error rate and to improve the transmitted image quality. Many useful and important results in the proposed work can be used in the enhancement of image transmission over cooperative networks. Relative to the traditional methods, the proposed method achieves better results for the transmission of images with high quality through cooperative communication networks. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Why to use Poisson regression for count data analysis in consumer behavior research.
- Author
-
Xia, Feihong
- Subjects
POISSON regression ,CONSUMER behavior research ,BEHAVIORAL assessment ,DATA analysis ,REGRESSION analysis ,BIT error rate - Abstract
Count data are often encountered in consumer behavior research. Normal regression, or ordinary least squares, has been used predominantly to analyze count data in experimental studies, while the appropriate models for count data analysis such as Poisson regression have not been fully embraced in consumer behavior research. The fact that only a small fraction of published papers in consumer behavior research with count data have used Poisson regression calls for a push to rethink the common approach of using normal regression for count data analysis. To demonstrate the importance and value of using Poisson regression for count data, we first discuss the parametric forms and properties of both normal regression and Poisson regression, and then show readers through large-scale simulated experiments that Poisson regression is the appropriate model to use for count data, not only because of better model fit but also because of lower error rates in hypothesis testing in various experimental settings, which is critical for consumer behavior researchers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. A Novel Deep Learning-Enabled Physical Education Mechanism.
- Author
-
Wang, Weiqi and Jiang, Jianan
- Subjects
PHYSICAL education ,EUGENICS ,OLYMPIC Games ,COACH-athlete relationships ,ATHLETE training ,BIT error rate - Abstract
Race walking is one of the key events in the Tokyo Olympic Games, and also one of the strengths of China in athletics events. In recent years, China has made remarkable achievements in various race-walking competitions. However, with the improvement of the performance of race walkers, more and more technical problems have emerged, and the number of fouls due to nonstandard movements has increased significantly. It is a pity that athletes are disqualified for technical fouls in long-distance race-walking competitions. Therefore, it is necessary to introduce scientific training methods to help coaches strictly monitor the training process of athletes and accurately detect their standard degree of action in real-time. This paper mainly proposes a novel mechanism for foul recognition in race walking based on deep learning. Firstly, the image frames in the video are preprocessed by the Yolo algorithm to obtain the athletes' separated images. The U-Net network mixed with the attention mechanism is used to detect the athletes' actions to identify fouls and nonstandard actions, so as to assist the coach to identify the athletes' nonstandard actions in training and adjust them in time. Experiments show that the above method can identify the foul actions and nonstandard actions of multiple athletes in training at the same time quickly, and the recognition accuracy is higher than human eyes. It is more conducive to assist the coach to monitor and standardize the athletes' actions in the long-term training process, so as to reduce the error rate and improve the performance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Demonstration of a Key Distribution Scheme Based on the Masking Effect of Fiber Channel Noise in Power Transmission System.
- Author
-
Wang, Xiangqing, Yang, Xiaokun, Wang, Dongfei, Liu, Bin, Zhang, Lan, Yang, Zufang, Zhu, Han, and Wu, Baohong
- Subjects
POWER transmission ,OPTICAL fiber communication ,OPTICAL communications ,BIT error rate ,TELECOMMUNICATION systems ,TELECOMMUNICATION - Abstract
This paper proposes a novel key distribution method based on the masking effect of fiber channel noise in a power transmission system. The two physical layer signal processing technologies used in this solution are frame synchronization and resampling. The random data sent and received is digitally processed by these two techniques. An experimental platform is built, and the key performance is assessed by analyzing the measured bit error rate (BER) dynamic curve, setting different decision thresholds and the amplitude of the state basis. Experimental results show that the key distribution rate can reach 10 kbit/s with a key consistency rate of 98%. This is of great significance to the development of safe optical communication technology in power transmission systems. In the power communication system, a large number of optical fiber communication devices are used. The key distribution method proposed in this paper can effectively improve the security of optical fiber communication, which is of great significance. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Deep learning based channel estimation optimization in VLC systems.
- Author
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Salama, Wessam M., Aly, Moustafa H., and Amer, Eman S.
- Subjects
CHANNEL estimation ,FREQUENCY division multiple access ,BIT error rate ,MATHEMATICAL optimization ,ORTHOGONAL frequency division multiplexing - Abstract
This paper aims to improve the channel estimation (CE) in the indoor visible light communication system. The proposal of this paper deals with a system that depends on a comparison between Deep Neural Network (DNN), Yolo v3, and Kalman filter (KF) algorithm, for two optical modulation techniques; asymmetrically clipped optical-orthogonal frequency-division multiplexing (ACO-OFDM) and direct current optical-orthogonal frequency division multiplexing (DCO-OFDM). The CE can be evaluated by the error rates in the received bits, where increased error means a performance decrease of the system and vice versa. Receiving less errors at the receiver indicates improved CE and system performance. Hence, the main aim of our work is to decrease the error rate by using different estimators. Furthermore, we apply automatic hyper-parameter approach and Bayesian optimization, to Yolo v3 model to improve the system performance and reduce the positioning error. The metric parameter of bit error rate (BER) aims to determine the improvement ratio in different systems. The model in this paper is based on training with OFDM samples of signal with labels which are received and are corresponding to the signals of OFDM. At a BER = 10
−3 with DCO-OFDM, the DNN outperforms KF with 1.7 dB (8.09%) at the bit energy per noise (E b / N o) axis. Also, for ACO-OFDM at BER = 10−3 , the DNN achieves better results than KF by about 1.9 dB (11.8%) at the (E b / N o) axis. For different values of M in QAM, the DNN outperforms KF for ACO-OFDM by average improvement of ~ 1.2 dB (~ 13%). [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
47. Performance enhancing of MIMO‐OFDM system utilizing different interleaving techniques with rate‐less fountain raptor code.
- Author
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Kasban, H., Hashima, Sherief, Nassar, Sabry, Mohamed, Ehab Mahmoud, and El‐Bendary, Mohsen A. M.
- Subjects
WIRELESS channels ,FREQUENCY division multiple access ,MIMO systems ,CHANNEL coding ,BIT error rate ,WIRELESS communications - Abstract
Due to the importance of both rate‐less digital fountain codes and Multi‐Input Multi‐Output (MIMO) schemes in Fifth and Sixth Generation (5G/6G) wireless networks, this paper investigates enhancing the performance of MIMO‐Orthogonal Frequency Division Multiplexing (MIMO‐OFDM) based system by employing the rate‐less fountain codes. The rate‐less codes, such as the Tornado codes and Raptor codes, have a flexible code rate that differs from the classical channel coding schemes. This paper uses Raptor code to study the MIMO system's performance with the rate‐less codes over different wireless communications channels. The proposed MIMO‐fountain code‐based system has been tested over the various wireless communication channel conditions concerning the varied Frequency Doppler (FD). In the proposed rate‐less wireless communication system, multiple interleaving techniques and equalizers are used to improve its performance. Computer‐based simulation experiments are assigned to evaluate the MIMO‐fountain code system using the different data transmission scenarios. Simulation results confirm the superiority of the presented wireless rate‐less system compared to fixed‐rate wireless systems in terms of Bit Error Rate (BER) and throughput. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Data-aided Weight with Subcarrier Grouping for Adaptive Array Interference Suppression.
- Author
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He He, Jun-Han Wang, Shun Kojima, Kazuki Maruta, and Chang-Jun Ahn
- Subjects
INTERFERENCE suppression ,BIT error rate ,MEAN square algorithms ,MOBILE communication systems ,MATRIX inversion ,CHANNEL estimation ,SIGNAL-to-noise ratio - Abstract
The effect of additive noise on the channel state information (CSI) quality is a crucial issue in mobile communication systems. The adaptive subcarrier grouping (ASG) for sample matrix inversion (SMI) based minimum mean square error (MMSE) adaptive array has been previously proposed. However, this method needs to know the signal-to-noise ratio (SNR) in advance to set the threshold, perform grouping, and take the average, causing an insufficient number of signal samples. As a result, the ability to eliminate noise is limited. In this paper, we propose a new method based on data-aided weight calculation and the least mean square (LMS) algorithm without SNR information, which increases the number of samples. The decision results and initial weight are obtained by the SMI method with subcarrier grouping, and then the LMS method with subcarrier grouping is applied to reduce the channel estimation error as well as the amount of computation. Simulation results demonstrate that the proposed scheme is an efficient approach to improve Bit Error Rate (BER) performance under various Rician K factors. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. High capacity, secure audio watermarking technique integrating spread spectrum and linear predictive coding.
- Author
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Korany, Noha O., Elboghdadly, Namat M., and Elabdein, Mohamed Z.
- Subjects
LINEAR predictive coding ,DIGITAL watermarking ,DISCRETE wavelet transforms ,BIT error rate ,AUDITORY masking - Abstract
This paper introduces a method adjustable audio watermarking approach with high auditory quality by exploiting the Spread Spectrum (SS) and the psychoacoustic modeling-based Discrete Wavelet Packet Transform (DWPT). The psychoacoustic model is used to shape the amplitude of the watermark signal during the embedding phase, ensuring a high level of imperceptibility. The approach based DWPT carefully mimics the multi- resolution properties of the human ear and incorporates simultaneous and temporal auditory masking. This paper aims to increase data payload and security. The watermark bits positions in the watermarking domain are determined by the logistic chaotic map in a random manner ensuring a high security level. The watermark used is an audio signal in parametric representation using Linear Predictive Coding (LPC) to accomplish a higher data payload. The LPC technique predicts a small number of coefficients, which represent different speech parameters, that are then applied in digital filters to create a synthetic version of the original speech signal. Various host audio signals are examined under various watermarking threats to assess the performance of the watermarking system. Experimental results expose that the introduced scheme provides a good measure of imperceptibility and robustness which are evaluated by the Objective Difference Grade (ODG) and the Bit Error Rate (BER%) respectively. The ODG's values were between -0.74 and -2.75, while the BER was in the range of 0 to 7.54%. The comparison introduced between the standard psychoacoustic model-1 (Standard PM) and the enhanced psychoacoustic model-1 based DWPT (Enhanced PM) for audio watermarking shows that Enhanced PM enhances the status of insufficient time-frequency resolution. A comparison of the proposed method to other state-of-the-art audio watermarking algorithms shows that it is a feasible alternative. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Image Robust Watermarking Method Based on DWT-SVD Transform and Chaotic Map.
- Author
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Wu, Weishuai, Dong, Yujiao, and Wang, Guangyi
- Subjects
IMAGE encryption ,DIGITAL watermarking ,WATERMARKS ,DISCRETE wavelet transforms ,BIT error rate ,SINGULAR value decomposition - Abstract
The existing watermarking algorithms make it difficult to balance the invisibility and robustness of the watermark. This paper proposes a robust image watermarking method based on discrete wavelet transform (DWT), singular value decomposition (SVD), and chaotic maps. This method is a semiblind watermarking method. First, a chaotic logistic-tent map is introduced, employing an extensive chaotic parameter domain. This map is amalgamated with Arnold's transformation to encrypt the watermark image, thereby bolstering the security of the watermark information. Subsequently, the frequency domain is obtained by applying DWT to the carrier image. Embedding watermarks in the frequency domain ensures the invisibility of the watermark, with a preference for a high-frequency subband after the DWT of the carrier image for enhanced watermark robustness. SVD is then applied to both the high-frequency subband of the carrier image after DWT and the encrypted watermark image. The final step involves embedding the singular values of the encrypted watermark image into the carrier image's singular values, thereby completing the watermark information embedding process. In simulation experiments, an invisibility test was conducted on various carrier images, yielding peak signal-to-noise ratio (PSNR) values consistently exceeding 43, and structural similarity (SSIM) close to 1. Robustness testing against various types of attacks resulted in normalized correlation (NC) values consistently surpassing 0.9, with bit error rate (BER) values approaching 0. In conclusion, the proposed algorithm satisfies imperceptibility requirements while demonstrating formidable robustness. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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