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6th International Conference on Signal Processing and Communication Systems (ICSPCS)

作者： Garcia-Ugalde, F. Cedillo-Hernandez, M. Morales-Delgado, E. Psenicka, B. Univ Nacl Autonoma Mexico Fac Ingn Div Ingn Elect Mexico City 04510 DF Mexico

ISBN: (纸本)9781467323932;9781467323925

This paper presents a new robust watermarking system for digital images. The main challenge in every watermarking algorithm is to create a high capable, robust and imperceptible scheme. Unlike other watermarking methods, our system encodes the watermark using a convolutional encoder and embeds the encoded watermark in the transform domain of an image using a direct sequence spread spectrum technique to accomplish a high robustness. The embedded watermark bits are retrieved computing the correlation between the watermarked coefficients and the pseudorandom sequences used in the watermark embedding. In addition, the retrieved bits are decoded using the Viterbi algorithm to recover the hidden watermark. A low perceptibility of the watermark on the host image is preferred, therefore, some features of the human visual system are considered for achieving a high perceptual quality of the watermarked image. For assessing such quality, a structural similarity index measure is adopted. Our watermarking algorithm is robust to common image processes in the spatial domain.

关键词： Digital watermarking copyright protection contourlet domain convolutional encoder cropping

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Pruning the algorithm complexity of the Add-Compare Select Unit (ACSU) for the Viterbi Decoder - A Review 5

Pruning the algorithm complexity of the Add-Compare Select U...

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5th IEEE International Conference on Smart Instrumentation, Measurement and Application (ICSIMA)

作者： Rashid, Ruhaida Abdul Harun, Harlisya Mansor, Zuhanis Shamsudin, Norfadilah Nor, Sahzilawati Mohamed Univ Kuala Lumpur Malaysian Inst Aviat Technol UniKL MIAT Lot 2891Jalan Jenderam Hulu Dengkil 43800 Selangor Malaysia Univ Kuala Lumpur British Malaysian Inst UniKL BMI Batu 8Jalan Sungai Pusu Gombak 53100 Malaysia

ISBN: (纸本)9781538662885

Viterbi decoders are widely employed along with convolutional encoders to provide an excellent error correction probability in digital wireless transmissions. To achieve lower error rates, the constraint length (k) of the encoder, has to be defined at higher values. However, higher (k) results in increasingly complex implementations of the Viterbi algorithm. As a result, the power consumption of the Viterbi decoder will increase exponentially which is to the disadvantage of many wireless communication devices. Many reduced complexity decoding techniques of the Viterbi decoder presented in the past focused on algorithm and architecture specific levels. Most of the studies concentrated on the Add-Compare Select Unit (ACSU) of the decoder, due to its nature of repetitive processing;also add to the complexity of the process. This paper presents a review of several variations of the Viterbi algorithm performed in the ACSU. The comparison was made among several different algorithms with the most optimal algorithm presented in this paper. A combined algorithm approach is proposed at the end of the review for future improvement.

关键词： adaptive viterbi decoder adaptive M-algorithm convolutional encoder constraint length forward error correction trellis diagram

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Comparison of Turbo Decoder and Turbo Equalizer for Spectrally Efficient FDM System 10

Comparison of Turbo Decoder and Turbo Equalizer for Spectral...

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10th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP)

作者： Ghannam, Hedaia Darwazeh, Izzat UCL Dept Elect & Elect Engn London England

ISBN: (纸本)9781509025268

This paper investigates the design and application of turbo coding in spectrally efficient frequency division multiplexing (SEFDM) systems, where orthogonality is intentionally violated to increase spectral efficiency (SE). The work details a newly proposed system structure with a soft decoder and investigates the behavior of such system under different channel conditions and different values of compression factors (i.e. spectral efficiencies). Furthermore, the performance of SEFDM with turbo coding and decoding is contrasted with that of reported SEFDM systems using convolutional coding and receiver turbo equalization with interference cancellation (IC).

关键词： SEFDM OFDM Turbo decoder turbo equalizer Turbo encoder convolutional encoder non-orthogonal spectral efficiency

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An Adaptive Wireless Communication Protocol for Neural Data Transmission in Freely Behaving Subjects

An Adaptive Wireless Communication Protocol for Neural Data ...

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5th International IEEE Engineering-in-Medicine-and-Biology-Society (EMBS) Conference on Neural Engineering (NER)

作者： Aghagolzadeh, Mehdi Oweiss, Karim Michigan State Univ Dept Elect & Comp Engn E Lansing MI 48824 USA

ISBN: (纸本)9781424441419

Long-term continuous intracortical recording of neuronal ensembles in freely behaving subjects requires a reliable wireless communication channel for transmitting important biological information. The need for ultra low-power, fully implanted recording systems, however, make the design of the wireless transmission protocol more demanding. Here, we introduce an adaptive protocol that can cope with the variable characteristics of the errors in the wireless channel associated with different levels of subject mobility, for example, during rest and active states. The wireless channel is modeled as a finite-state Markov channel, in which states are binary symmetric channels with different binary error rates. A convolutional encoder with a specific code rate is incorporated into each state, for which the length of data transmission packets is optimally estimated. The protocol can switch between different states depending on subject mobility to ensure a highly reliable communication channel, while optimizing the power consumption by minimizing the average memory length required for storing packets prior to transmission.

关键词： Bit error rate convolutional codes Decoding Markov processes Markov processes Protocols Wireless communication active states adaptive wireless communication protocol average memory length binary error rates binary symmetric channels bioelectric phenomena biomechanics brain convolutional encoder data transmission packets encoding error correction codes finite state Markov channel finite state machines freely behaving subjects long-term continuous intracortical recording medical signal processing neural data transmission neuronal ensembles neurophysiology power consumption rest states specific code rate subject mobility telemedicine ultra low-power fully implanted recording systems

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VLSI implementation of 1/2 viterbi decoder for IEEE p802.15-3a UWB communication

VLSI implementation of 1/2 viterbi decoder for IEEE p802.15-...

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IEEE International Conference on Semiconductor Electronics

作者： Siswanto, Meilana Othman, Masuri Zahedi, Edmond Univ Kebangsaan Malaysia Inst Microelect & Nanoelect Bangi 43600 Selangor Malaysia Univ Kebangsaan Malaysia Fac Engn Dept Elect & Elect Syst Bangi 43600 Selangor Malaysia

ISBN: (纸本)9780780397309

This paper presents the design of 1/2 Viterbi decoder for UWB applications following the standard requirements of IEEE P802.15-3a. The main design issues of Viterbi decoder were add-compare-select unit (ACSU), memory management and trace-back methods. In order to meet the requirements of IEEE P802.15-3a UWB, the transition metric unit (TMU) is designed using a finite state machine (FSM) and a parallel carry look-ahead adder (CLA) used to design the addition part of the ACSIJ. After synthesis using Xilinx synthesis technology (XST), the synthesis report shows that the design has a minimum period of 1.888 ns, equivalent to a data rate of 529.661 Mbps fulfilling more than the standard requirements of IEEE P802.15-3a for UWB, which has a data rate range from 55 to 480 Mbps.

关键词： viterbi algorithm viterbi decoder convolutional encoder VLSI design

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Bit Error Rate Performance Analysis of convolutional Coded Orthogonal Frequency-Division Multiplexing System 57

Bit Error Rate Performance Analysis of Convolutional Coded O...

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57th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)

作者： Bhuyan, Nasimul Hyder Manif Ahmed, Mamun Faisal, Mohammed Salauddin, Mohammad BAIUST CSE Dept Mainamati Cantonment Comilla Bangladesh CBIU CSE Dept Coxs Bazar Bangladesh QUBEE Bangladesh Dhaka Bangladesh YOUNGONE Bangladesh Chittagong Bangladesh

ISBN: (纸本)9781509037315

In this paper, the performance of a convolutional encoded orthogonal frequency-division multiplexing (OFDM) based wireless communication system has been simulated in terms of bit error rate (BER). In FEC channel coding, the OFDM based wireless communication system incorporates a convolutional encoder under various digital modulation schemes (QAM, QPSK, 8QAM, 8PSK, 16QAM, 16PSK, 32QAM and 32PSK). The computer simulation results on BER over an Additive White Gaussian Noise (AWGN) and other fading (Rayleigh and Rician) channels demonstrate that the convolutional encoded OFDM system outperforms with QAM modulation technique as compared to other digital modulation schemes and the system is highly effective to combat inherent interferences under Rayleigh and Rician fading channels. It has been anticipated from the simulation study with synthetically generated data that the performance of the communication system degrades with the increasing of noise power.

关键词： BER OFDM convolutional encoder AWGN QAM Rayleigh fading Rician fading

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Copyright Protection of Color Imaging Using Robust-Encoded Watermarking

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作者： Cedillo-Hernandez, M. Brno University of Technology

In this paper we present a robust-encoded watermarking method applied to color images for copyright protection, which presents robustness against several geometric and signal processing distortions. Trade-off between payload, robustness and imperceptibility is a very important aspect which has to be considered when a watermark algorithm is designed. In our proposed scheme, previously to be embedded into the image, the watermark signal is encoded using a convolutional encoder, which can perform forward error correction achieving better robustness performance. Then, the embedding process is carried out through the discrete cosine transform domain (DCT) of an image using the image normalization technique to accomplish robustness against geometric and signal processing distortions. The embedded watermark coded bits are extracted and decoded using the Viterbi algorithm. In order to determine the presence or absence of the watermark into the image we compute the bit error rate (BER) between the recovered and the original watermark data sequence. The quality of the watermarked image is measured using the well-known indices: Peak Signal to Noise Ratio (PSNR), Visual Information Fidelity (VIF) and Structural Similarity Index (SSIM). The color difference between the watermarked and original images is obtained by using the Normalized Color Difference (NCD) measure. The experimental results show that the proposed method provides good performance in terms of imperceptibility and robustness. The comparison among the proposed and previously reported methods based on different techniques is also provided.

关键词： Digital watermarking image normalization geometric and signal processing distortions convolutional encoder Viterbi decoder discrete cosine transform.

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A novel transformer autoencoder for multi-modal emotion recognition with incomplete data

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NEURAL NETWORKS 2024年 172卷 106111页

作者： Cheng, Cheng Liu, Wenzhe Fan, Zhaoxin Feng, Lin Jia, Ziyu Dalian Univ Technol Dept Comp Sci & Technol Dalian Peoples R China Huzhou Univ Sch Informat Engn Huzhou Peoples R China Renmin Univ China Psyche AI Inc Beijing Peoples R China Univ Chinese Acad Sci Inst Automat Chinese Acad Sci Brainnetome Ctr Beijing Peoples R China

Multi -modal signals have become essential data for emotion recognition since they can represent emotions more comprehensively. However, in real -world environments, it is often impossible to acquire complete data on multi -modal signals, and the problem of missing modalities causes severe performance degradation in emotion recognition. Therefore, this paper represents the first attempt to use a transformer -based architecture, aiming to fill the modality -incomplete data from partially observed data for multi -modal emotion recognition (MER). Concretely, this paper proposes a novel unified model called transformer autoencoder (TAE), comprising a modality -specific hybrid transformer encoder, an inter -modality transformer encoder, and a convolutional decoder. The modality -specific hybrid transformer encoder bridges a convolutional encoder and a transformer encoder, allowing the encoder to learn local and global context information within each particular modality. The inter -modality transformer encoder builds and aligns global cross -modal correlations and models longrange contextual information with different modalities. The convolutional decoder decodes the encoding features to produce more precise recognition. Besides, a regularization term is introduced into the convolutional decoder to force the decoder to fully leverage the complete and incomplete data for emotional recognition of missing data. 96.33%, 95.64%, and 92.69% accuracies are attained on the available data of the DEAP and SEED -IV datasets, and 93.25%, 92.23%, and 81.76% accuracies are obtained on the missing data. Particularly, the model acquires a 5.61% advantage with 70% missing data, demonstrating that the model outperforms some state-of-the-art approaches in incomplete multi -modal learning.

关键词： Multi-modal signals Emotion recognition Incomplete data Transformer autoencoder convolutional encoder

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A Centrifugal Pump Fault Diagnosis Framework Based on Supervised Contrastive Learning

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SENSORS 2022年第17期22卷 6448页

作者： Ahmad, Sajjad Ahmad, Zahoor Kim, Jong-Myon Univ Ulsan Dept Elect Elect & Comp Engn Ulsan 44610 South Korea PD Technol Cooperat Ulsan 44610 South Korea

A novel intelligent centrifugal pump (CP) fault diagnosis method is proposed in this paper. The method is based on the contrast in vibration data obtained from a centrifugal pump (CP) under several operating conditions. The vibration signals data obtained from a CP are non-stationary because of the impulses caused by different faults;thus, traditional time domain and frequency domain analyses such as fast Fourier transform and Walsh transform are not the best option to pre-process the non-stationary signals. First, to visualize the fault-related impulses in vibration data, we computed the kurtogram images of time series vibration sequences. To extract the discriminant features related to faults from the kurtogram images, we used a deep learning tool convolutional encoder (CE) with a supervised contrastive loss. The supervised contrastive loss pulls together samples belonging to the same class, while pushing apart samples belonging to a different class. The convolutional encoder was pretrained on the kurtograms with the supervised contrastive loss to infer the contrasting features belonging to different CP data classes. After pretraining with the supervised contrastive loss, the learned representations of the convolutional encoder were kept as obtained, and a linear classifier was trained above the frozen convolutional encoder, which completed the fault identification. The proposed model was validated with data collected from a real industrial testbed, yielding a high classification accuracy of 99.1% and an error of less than 1%. Furthermore, to prove the proposed model robust, it was validated on CP data with 3.0 and 3.5 bar inlet pressure.

关键词： centrifugal pumps convolutional encoder contrastive learning fault diagnosis deep learning

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MODELLING OF 'SATELLITE-TO-AIRCRAFT' LINK FOR SELF-SEPARATION

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TRANSPORT 2013年第4期28卷 361-367页

作者： Kharchenko, Volodymir Barabanov, Yurii Grekhov, Andrii Natl Aviat Univ Dept Air Nav Syst UA-03680 Kiev Ukraine

The aim of this paper is to design the original model of communication channel 'Satellite-to-Aircraft' for self-separation with error-control coding using MATLAB Simulink software. Studying the signal transmission through a communication channel without coding and with convolutional coding the following parameters were changed: losses in a free space from 0 dB to 225 dB;noise temperature of an aircraft receiver 20 K and 290 K;simultaneous changing of antennas diameter;phase offsets from 0 degrees to 20 degrees;nonlinearity of satellite high power amplifier;satellite phase noise;and a data bit rate. BER is vanishing for free space path losses changing from 0 dB to 221 dB at the use of convolutional coding and a noise temperature 20 K, for diameters of all antennas of more than 1.2 m, and at phase shifts up to 4 degrees. The signal constellation shows a presence of strong distortions during signal transmission. The proposed model can be used as a basic model for investigation of communication between two unmanned aircraft systems.

关键词： free-flight self-separation ADS-B BER communication channel aircraft satellite convolutional encoder BPSK free space loss phase/frequency offset memory-less nonlinearity phase noise Viterbi decoder amplifier back-off level noise temperature antenna diameter

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