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A multiple copyright identification watermarking algorithm based on code division multiple access

High Technology Letters 2008年第4期14卷 377-383页

作者：张帆 li Jie Su Yuting Zhang Chuntian College of-Computer ＆ Information Engineering Henan University Kaifeng 475001 P. R. China College of Electronic ＆ Information Engineering Tianjin University Tianjin 300072 P.R. China

A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access （CDMA） system. Multiple watermarks are embedded into digital images in the wavelet transform domain. Each of the watermarks is embedded and extracted independently without impacts to each other. Multiple watermarks are convolution encoded and block interleaved, and the orthogonal Gold sequences are used to spread spectrum of the copyright messages. CDMA encoded water-mark messages are embedded into the wavelet sub-bands excluding the wavelet HH1 sub-bands. The embedment amplitude is decided by Watson＇ s perceptual model of wavelet transform domain, and the embedmeut position in the selected wavelet sub-bands is decided randomly by a pseudo-random noise （PN） sequence. As a blind watermm＇king algorithm, watermarks are extracted without original image. The watermarking capacity of proposed algorithm is also discussed. When two watermarks are embedded in an image at the same time, the capacity is larger than the capacity when a single watermark is embedded, and is smaller than the sum of the capacity of two separately embedded watermarks. Experimental results show that the proposed algorithm improves the detection bits error rate （BER） observably, and the multiple watermarks have a preferable robustness and invisibility.

关键词： code division multiple access (CDMA) watermarking convolutional coding

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On the Use of NB-IoT over GEO Satellite Systems with Time-Packed Optical Feeder Links for Over-the-Air Firmware/Software Updates of Machine-Type Terminals

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SENSORS 2021年第12期21卷 3952-3952页

作者： Bas, Joan Dowhuszko, Alexis A. Ctr Tecnol Telecomunicac Catalunya CTTC CERCA Dept Array & Multisensor Proc Av Karl Friedriech Gauss 7Bldg B4 Castelldefels 08860 Spain Aalto Univ Dept Commun & Networking Espoo 02150 Finland

The verticals of 5G, such as the automotive, smart grid, and smart cities sectors, will bring new sensors and IoT devices requiring Internet connectivity. Most of these machine-type terminals will be sparsely distributed, covering a very large geographical area and, from time to time, will have to update their software, firmware, and/or other relevant data. Given this situation, one viable solution to implement the "Over-the-Air" update of these IoT terminals can be done with the aid of GEO satellite systems. However, due to the ultra-dense radio frequency reuse factor that contemporary High-Throughput Satellite (HTS) systems implement in the access link to serve the IoT terminals, the use of a time-packed Free Space Optical (FSO) link represents a practical solution to avoid the bottleneck that the satellite gateway experiences in the feeder link. The performance of both Detect-and-Forward and Decode-and-Forward relaying strategies are studied, assuming that the single-carrier M-PAM symbols that are transmitted on the optical feeder link are mapped into M-QAM symbols that modulate the multiple sub-carriers of the OFDM-based radio access link. In addition, the benefits of encapsulating the NB-IoT frames into DVB-S2(X) satellite frames is also analyzed in detail. The effects of the impairments introduced in both the optical feeder and radio access links are characterized in detail, and the end-to-end error correction capabilities of the Modulation and coding Schemes (MCS) defined in the contemporary releases of the NB-IoT and DVB-S2(X) standards are studied for different working regimes.

关键词： NB-IoT DVB-S2(X) high-throughput satellite optical feeder link over-the-air updates time-packing decode-and-forward scintillation beam-wander convolutional coding

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Complexity and diversity in sparse code priors improve receptive field characterization of Macaque V1 neurons

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PLOS COMPUTATIONAL BIOLOGY 2021年第10期17卷 e1009528-e1009528页

作者： Wu, Ziniu Rockwell, Harold Zhang, Yimeng Tang, Shiming Lee, Tai Sing Carnegie Mellon Univ Ctr Neural Basis Cognit Pittsburgh PA 15213 USA Carnegie Mellon Univ Neurosci Inst Pittsburgh PA 15213 USA Carnegie Mellon Univ Dept Math Pittsburgh PA 15213 USA Carnegie Mellon Univ Dept Biol Sci Pittsburgh PA 15213 USA Carnegie Mellon Univ Comp Sci Dept Pittsburgh PA 15213 USA Peking Univ Ctr Life Sci Beijing Peoples R China MIT Dept EECS 77 Massachusetts Ave Cambridge MA 02139 USA Univ Chicago Comm Computat Neurosci Chicago IL 60637 USA

System identification techniques-projection pursuit regression models (PPRs) and convolutional neural networks (CNNs)-provide state-of-the-art performance in predicting visual cortical neurons' responses to arbitrary input stimuli. However, the constituent kernels recovered by these methods are often noisy and lack coherent structure, making it difficult to understand the underlying component features of a neuron's receptive field. In this paper, we show that using a dictionary of diverse kernels with complex shapes learned from natural scenes based on efficient coding theory, as the front-end for PPRs and CNNs can improve their performance in neuronal response prediction as well as algorithmic data efficiency and convergence speed. Extensive experimental results also indicate that these sparse-code kernels provide important information on the component features of a neuron's receptive field. In addition, we find that models with the complex-shaped sparse code front-end are significantly better than models with a standard orientation-selective Gabor filter front-end for modeling V1 neurons that have been found to exhibit complex pattern selectivity. We show that the relative performance difference due to these two front-ends can be used to produce a sensitive metric for detecting complex selectivity in V1 neurons.

关键词： Neurons Convolution Neuronal tuning Monkeys coding mechanisms Kernel methods Vision convolutional coding

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Performance of Rate ½ convolutional Encoder with Adaptive Feedback-Controlled on Hyperchaotic-Chaotic States

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Procedia Computer Science 2011年 6卷 130-135页

作者： Davoud Arasteh Department of Electronic Engineering Technology Southern University and A & M College Baton Rouge Louisiana USA

In this paper we have studied the performance of rate-1/2 convolutional encoders with adaptive states developed in chaotic and hyperchaotic regions. These states are generated by varying the control parameters in a feedback-controlled system. Several sets of closed-loop simulations are performed to demonstrate the benefit of information-based chaos system. In particular, it is demonstrated that two varieties of an information-based systems provide improved performance over all the encoder choices when hyperchaos states are utilized. Special attention was paid to the algorithmic complexity of the systems for an entire class of rate-1/2 encoders. The decoder is able to recover the encrypted data and is able to reasonably estimate the bit error rate for different signal strengths under a noisy AWGN channel. This indicates that the encoder can update the information map in real time to compensate for changing data for both chaotic and hyperchaotic states. This is the evidence that occasional changes in the data stream can be handled by the decoder in a real time application. Numerical evidence indicates algorithmic complexity associated with the hyperchaotic-encrypted and convolutionally-encoded data, provide better security along with the increase in the error correcting capacity of the decoder.

关键词： Chaotic encryption convolutional coding algorithmic complexity Feedback-Controlled Hyperchaotic System

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Experimental study on repeater-free acoustic telemetry for downhole operations

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JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 2021年 202卷 108551-108551页

作者： Pagtalunan, Jed Parmar, Kaushik Kim, Seonghwan Moon, Bryan Park, Simon S. Univ Calgary Schulich Sch Engn Dept Mech & Mfg Engn Calgary AB Canada MKS Investments Ltd 736-6 Ave SW Calgary AB Canada

Measurement while drilling (MWD) enables real-time measurement of downhole conditions for directional drilling, but most commercial MWD telemetry techniques suffer from limited transmission speeds. Acoustic telemetry has the potential for significantly faster transmission speeds, but it has limited range due to drill string attenuation and noise. A common solution to this is to use acoustic repeaters, which incur high costs and require complex implementation. Instead of using repeaters, we utilized two carrier frequencies at the modes to transmit redundant data in combination with a lock-in amplifier (LIA) to extract the signals from the carriers. The extracted signals were then fused at the receiver to increase signal fidelity. An experimental setup was developed to transmit acoustic signals through a simulated drill string. The signals were first attenuated by the rubber section of the simulated drill string. The results show that the proposed system was able to achieve error-free transmission of packets at 64 bps up to 1.95 km without the use of a repeater which is orders of magnitude faster than current commercial MWD methods (mud-pulse and electromagnetic).

关键词： Acoustic telemetry Downhole drilling convolutional coding Lock-in amplifier

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Complexity Analysis of Chaotically Encrypted Rate-1/n convolutional Encoders

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Procedia Computer Science 2013年 20卷 528-534页

作者： Davoud Arasteh Electrical Engineering Department Southern University and A & M College Baton Rouge Louisiana USA

In this paper we have studied the performance of chaotically encrypted rate-1/n convolutional encoders. The design goal is to achieve a crypto-coding system that possesses the error correction and encryption features. The proposed system is able to achieve reasonable error correction performance for the proposed configuration with a certain encoder rate and constraint length. The performance of each system was determined by calculating the algorithmic complexity of the system outputs. Complexity of each decoding algorithm is compared to the results of the alternative algorithm. Numerical evidence indicates that algorithmic complexity associated with particular rate-1/n convolutional encoders increases as constraint length increases, while error correcting capacity of the decoder expands. Both code design and constraint length are control architectural parameters that have significant effect on system performance.

关键词： Chaotic encryption convolutional coding algorithmic complexity

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Serial concatenation of space-time and recursive convolutional codes

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ETRI JOURNAL 2003年第2期25卷 144-147页

作者： Ko, YJ Kim, JI ETRI Basic Res Lab Taejon South Korea ETRI Mobile Telecommun Res Lab Taejon South Korea

We propose a new serial concatenation seheme for space-time and recursive convolutional codes, in which a space-time code is used as the outer code and a single recursive convolutional code as the inner code. We discuss previously proposed serial concatenation schemes employing multiple inner codes and compare them with the new one. The proposed method and the previous one with joint decoding, both performing a combined decoding of the simultaneous output signals from multiple antennas, give a large performance gain over the separate decoding method. In decoding complexity, the new concatenation scheme has a lower complexity compared with the multiple encoding/joint decoding scheme due to the use of the single inner coded Simulation results for a communication system with two transmit and one receive antennas in a quasi-static Rayleigh fading channel show that the proposed scheme outperforms the previous schemes.

关键词： space-time codes Serial Publications DEcoding Codes Scheme decoding scheme Recursive COMMUNICATION SYSTEMS multiple antenna convolutional coding

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A QPSK/16-QAM OFDM-based 29.1Mbps LINC transmitter for Body Channel Communication

A QPSK/16-QAM OFDM-based 29.1Mbps LINC transmitter for Body ...

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IEEE Asian Conference on Solid-State Circuits (ASSCC)

作者： Ping-Yuan Tsai Shu-Yu Hsu Jen-Shin Chang Tsan-Wen Chen Chen-Yi Lee Department of Electronics Engineering and Institute of Electronics National Chiao-Tung University Hsinchu Taiwan

ISBN: (纸本)9781467327701

This paper proposed a high speed Body Channel Communication (BCC) transmitter under IF 20MHz, adopting the OFDM modulation and uneven multi-level LINC technique to reduce the power and complexity of the front-end circuit. The OFDM uses 16-QAM modulation to enhance the data rate and could select to use a convolutional code to increase the coding gain. The phase modulator in the LInear amplification with Nonlinear Component (LINC) transmitter uses not only clockgating scheme but also the glitch free protection. A detection and calibration DSP are also integrated to solve the LINC branch mismatch problem. Finally the capacitive sensing circuit provides the information of the connectivity between pastes and human. The chip is implemented by 90nm CMOS process, with die area 1.3mm 2 . The maximum data rate could achieve 29.1Mbps. The total power is 1.925mW, resulting in 0.07nJ/bit transmission energy and 2.92 bps/Hz spectral efficiency.

关键词： connectivity between pastes Pastes connectivity Between Orthogonal frequency division multiplexing Transmitter Transmitters Quadrature amplitude modulation convolutional coding phase modulator Data transfer rates Communication Research

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ITERATIVE MULTIUSER DETECTION PERFORMANCE EVALUATION ON A SATELLITE MULTIBEAM COVERAGE

ITERATIVE MULTIUSER DETECTION PERFORMANCE EVALUATION ON A SA...

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European Signal Processing Conference

作者： J.P. Millerioux M.L. Boucheret C. Bazile A.Ducasse University of Pisa

This paper deals with the use of non-linear multiuser detection techniques to mitigate co-channel interference on the reverse link of multibeam satellite systems. The considered system is inspired by the DVB-RCS standard, with the use of convolutional coding. The algorithms consist of iterative parallel interference cancellation schemes with semi-blind channel estimation. We propose a simple approach for statistical evaluation on a multibeam coverage, and present results obtained on a coverage designed on a digital Ka-band focal array feed reflector antenna.

关键词： Coverage reverse link Cochannel interference Performance Evaluation simplicial approximation inspection technique channel blind estimation convolutional coding Statistical Computing Interference cancellation Reflector antennas

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Decoding Real Numbered Block and convolutional Codes with Erasure and Impulsive Noise Channels

Decoding Real Numbered Block and Convolutional Codes with Er...

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European Signal Processing Conference

作者： S. Jafarzadeh M. Khatami F. Marvasti Department of Micro and Nanotechnology Technical University of Denmark Lyngby Denmark Sound Technology Inc Analogic Ultrasound Group USA

In this paper, a class of real numbered block and convolutional codes are encoded and decoded using various iterative methods to remove channel impulsive noise and erasures. In order to recover the received vector, two iterative algorithms are used for erasure and impulsive noise distortions. Similarities of real number convolutional codes to linear block codes are discussed. An iterative method with adaptive thresholding is described for the reconstruction of impulsive noise using sparse signal processing.

关键词： Real number codes Impulsive noise cancellation Erasure channel convolutional codes Iterative technique IMAT method convolutional coding Impulse noise erasure channel iterative methods linear block code Real number adaptive thresholding

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