Robust video watermarking algorithm for H.264/AVC based on texture feature by Wei-wei ZHANG, Ru ZHANG, Jian-yi LIU, Xin-xin NIU, Yi-xian YANG

“…On the basis of analyzing some existing video watermarking al ithms and combining with the new features of the H.264/AVC video coding standard,a new robust video watermarking algorithm based on texture feature was proposed.The proposed algorithm firstly performs the 4×4 integer discrete cosine transform on the current frame in purpose of identifying whether it is the texture block.Then the watermarking is embedded by adopting the way of differential energy for selecting the appropriate coefficients adaptively.The experimental result shows that the proposed algorithm has little impact on the video quality and bit-rate,moreover,its robustness can effectively resist the common attacks such as the gauss noise,low pass filter and re-coded performed on the video watermarking.…”
Get full text

Joint channel and impulsive noise estimation method for OFDM systems by Xinrong LYU, Youming LI, Mingchen YU

“…Aiming at the impulsive noise occurring in OFDM systems,an impulsive noise mitigation algorithm based on compressed sensing theory was proposed.The proposed algorithm firstly treated the channel impulse response and the impulsive noise as a joint sparse vector by exploiting the sparsity of both them.Then the sparse Bayesian learning framework was adopted to jointly estimate the channel impulse response,the impulsive noise and the data symbols,in which the data symbols were regarded as unknown parameters.Compared with the existing impulsive noise mitigation methods,the proposed algorithm not only utilized all subcarriers but also did not use any a priori information of the channel and impulsive noise.The simulation results show that the proposed algorithm achieves significant improvement on the channel estimation and bit error rate performance.…”
Get full text

Narrowband interference suppression in vector OFDM systems by ZHANG Guo-mei, ZHU Shi-hua

“…When signal-interference-ratio （SIR） is 15dB and the target bit error rate is 10-2, the proposed method can obtain 8dB gain compared to the least square （LS） detection with the vector length being 16.…”
Get full text

Transceiver design and performance analysis for uplink SCMA based on CP-free OFDM by Li ZHOU, Xiqing LIU

“…A typical sparse code multiple access (SCMA) system utilizes orthogonal frequency division multiplexing (OFDM) technology with cyclic prefix (CP) to combat multipath fading in wireless channels.Therefore, its capacity is reduced by the CP-insertion.To address this issue, the SCMA scheme based on CP-free OFDM using the time domain precoding (TDP) algorithm was proposed and the proposed scheme was termed as TDP-OFDM SCMA.The transceiver structure was designed, and the capacity plus the bit error rate (BER) performances under various channels with different overload rates and with channel estimation errors were evaluated via the simulations.Also, the power consumption problem in TDP-OFDM SCMA was discussed.The simulation results show that under the same overload rate, the capacity of TDP-OFDM SCMA can be increased by up to 25% if compared with the SCMA based on CP-OFDM.…”
Get full text

Channel impulse response insensitive feature for non-coherent signal detection in molecular communication by Limin XIAO, Xiangrong XU, Zhuangkun WEI, Shenghan LIU, Yiwen LIU

“…To solve the inter-symbol interference (ISI) and background noise challenges of molecular communication via diffusion (MCvD),four ISI-resistant signal-features were deployed,and a reliable non-coherent signal detection algorithm,which was insensitive to different types of molecular channel impulse response (CIR),was proposed.Also,an adaptive decision threshold and theoretical bound of bit error rate (BER) were deduced.Simulation results demonstrate a lower BER of the proposed non-coherent scheme compared to the state-of-the-art schemes in the same order of computational complexity,therefore suggesting its potential applications for future nano-scale MC.…”
Get full text

Performance of Polar code in diversity reception system by Pingheng ZHAI, Binsong SHEN, Jinbo LIANG

“…Diversity reception is one of the most effective ways to resist fading over Rayleigh fading channels,in order to improve the performance of Polar codes over Rayleigh fading channels,a diversity reception system based on Polar code was proposed.The information bit selectionsequences of Polar codes in diversity reception were determined,and the upper bound of BER for Polar codes in diversity reception system was derived.The simulation results show that when quadruple diversity reception is used,the encoding gain is greater than 3 dB and has 0.6 dB performance advantage compared to LDPC code.Experiment results show that,when eightfold diversity is used,the encoding gain is greater than 5 dB and has 1.5 dB performance advantage compared to LDPC code,and diversity reception can significantly improve the performance of the system.…”
Get full text

Nonlinear robust precoding for coordinated multipoint transmission by Zhe-qi GU, Zhong-pei ZHANG

“…A nonlinear robust precoding algorithm was proposed,which redesigned the feedback matrix，the forward matrix and the scaling matrix of the traditional tomlinson-harashima precoding algorithm based on the statistical characteristics of the downlink channel state information errors.Simulation results show that the nonlinear robust precoding algorithm can achieve better performance than the traditional linear and nonlinear precoding algorithms when the downlink channel state information errors exist.Due to the different downlink channel state information errors between user equipments in the coordinated multi-point transmission,the traditional “best-first” ordering algorithm was invalid.So an improved ordering algorithm was proposed to reduce the average bit error rate of the nonlinear robust precoding algorithm.…”
Get full text

Research on Simulation of Multi-Path Fading of Narrow-Band Channel Based on Stochastic Bridge by Lei Liu, Wei Xia, Jianghong Han

“…According to experimental, different wavelengths of beam were simulated to diffuse in percolation lattices with different scatters density. Coherence bandwidths, bit error rate and statistics characteristics of power were acquired to verify that stochastic ray model can fit to the characteristics of the multi-path fading channel, which can predict channel parameters in specific locations.…”
Get full text

Massive MIMO channel estimation and feedback based on compressed sensing by Pan MAO, Xiaoguang HUANG, Wei WANG, Jian SONG

“…Focused on the issue that the problem of low precision of channel estimation and complex feedback scheme in massive MIMO system,a compression sampling matching pursuit (BCC-CoSAMP) algorithm based on coefficient correlation was proposed in the differential channel estimation and feedback scheme.In this algorithm,the inner product of the relationship between two vectors in the CoSAMP algorithm was replaced by the vector relation based on the correlation coefficient,so the atoms with strong correlation of the original signal were quickly selected to improve the accuracy of channel estimation.The simulation results show that the proposed BCC-CoSAMP algorithm has an improved channel estimation accuracy compared with the CoSAMP algorithm and an average increase of the total system rate of 1.25 bit/(s.Hz) at low signal to noise ratio (SNR).…”
Get full text

Regularized threshold iteration method for impulsive noise suppression in underwater acoustic communication by Nana LI, Youming LI, Mingchen YU, Qianqian LU

“…Impulsive noise interference can seriously affect the performance of underwater acoustic communication systems.An impulsive noise suppression method based on regularized threshold iteration was presented.Firstly,the null subcarrier matrix was used to separate impulsive noise from Gaussian white noise and useful signals.Then,based on the theory of compressed sensing,the impulsive noise estimation problem was transformed into a regularization problem by introducing a threshold iteration,and the impulsive noise was estimated by using a threshold function to obtain the estimated value of the impulsive noise.Finally,the estimated impulsive noise was subtracted from the received signal.The simulation results show that the proposed method can effectively reduce the bit error rate (BER) and mean square error (MSE),and improve the reliability of signal transmission in underwater acoustic communication environment.…”
Get full text

Improved segmented CRC assisted puncturing Polar decoding by Yanhong NI, Xiangxiong LOU, Jianrong BAO

“…A segmented cyclic redundancy check (CRC) assisted decoding algorithm was proposed.This method makes use of the high parallelism of BP decoding and the high reliability of CRC verification,and uniformly or proportionally disperses CRC verification bits into the original information bits.Simulation results show that when the code length N is 1 024 and the SNR is 3.5 dB,the average iterations of segmented CRC（2,16×2）and CRC (2,24+8) are 2.7 and 2.8 times less than those of G matrix based decoding.When the code length M is 896,the two segmented methods with a bit error rate of 10^-5obtained about 0.7 dB gain compared with the non-CRC assisted BP puncturing decoding.…”
Get full text

Structure and performance analysis of binary differential stochastic process shift keying by Zhi-jiang XU, Xiao LING, Kang WANG, Li-min MENG

“…A novel modulation and demodulation structure based on binary differential stochastic process shift keying (BDSPSK) is proposed.The theoretical bit error rates (BER) under the Gaussian and quasi-static Rayleigh fading chan-nels are derived,respectively.To verify its performances and security,lots of simulations are done by using MATLAB.The simulations' results show that the BER of the proposed BDSPSK can reach 10⁻⁴when signal to noise ratio (SNR) is about −2 dB in the Gaussian channel or 25 dB in the Rayleigh fading channel.Meanwhile,the proposed method has a good concealment due to its undetectable property by the generalized second order cyclostationary spectrum,which makes it suit for secure communications in the physical layer.…”
Get full text

Ronit Frenkel in Conversation with Dale McKinley by Dale McKinley

“… Ronit Frenkel (RF): We’re going to be discussing mostly your last two books today, but before we start, maybe you can tell me a little bit about your background? Dale McKinley (DM): Sure. …”
Get full text

Channel estimation of UFMC system in multipath channel by Xiang YU, Yanni GAO, Sirui DUAN

“…As a candidate waveform of 5G,universal filter multi-carrier (UFMC) technology could inhibit out-of-band radiation,achieve loose synchronization and well support the short bursts of things in the transmission.However,in the UFMC transmission without cyclic prefix (CP),inter-symbol interference (ISI) and subcarrier interference (ICI) are generated in the multipath fading channel,which will affect the estimation accuracy in channel estimation.The interference of the UFMC system in multipath channel was firstly analyzed.After using the feedback equalization suppression ISI,the self-elimination algorithm was used to suppress the ICI according to the similarity between adjacent carriers,and the pilot coefficients were designed according to the UFMC system.Finally,the simulation results show that the proposed method applied to the UFMC can suppress the interference,improve the accuracy and reduce the bit error rate.…”
Get full text

Advance of performance modeling for Turbo receivers by Yun XUE, Bin JIANG, Xi-qi GAO

“…Aiming at the performance modeling for Turbo receivers,the research results are summarized,in the mean-while,the characteristics and future trends are concluded in terms of equivalent model,transitive parameter,performance abstraction and transitive relation.The Gaussian distribution of equivalent model for log-likelihood ratiois the founda-tionof performance modeling research.Representative methods for application scenarios such as performance analysis,performance optimization and joint design with link are to derive the transfer chart with mutual information as transitive parameter,to derive semi-analytical transitive relation with bit error rate or fidelity as transitive parameterand to derive semi-analytical transitive relation with mutual information as transitive parameter,respectively.These methods represent the development direction of performance modeling for turbo receivers.…”
Get full text

Privacy protection key distribution protocol for edge computing by Jian SHEN, Tianqi ZHOU, Chen WANG, Huijie YANG

“…Aiming at the privacy protection problem in the multi-application scenarios of edge computing, two policy-based key distribution protocols were proposed.The proposed protocols are based on the concept of constrained pseudo-random functions to achieve efficient and flexible policy selection.Specifically, based on the GGM pseudo-random number generator, the key distribution protocol with a prefix-predicate is constructed, which can effectively support lightweight and efficient key distribution.Moreover, based on the multilinear pairing, the key distribution protocol with a bit fixing predicate is constructed.This protocol can support flexible and fine-grained strategy selection and is suitable for dynamic and flexible multi-device scenarios in heterogeneous networks.Finally, the security proof of the proposed protocols is presented.…”
Get full text

RIS-assisted wireless communications: prototype validation and measurement progress by YANG Chenhong, SANG Jian, LI Xiao, TANG Wankai, JIN Shi

“…Then, the advancements in measuring RIS hardware was reviewed, characteristics were concluded in power consumption, bit levels, polarization, and active RIS. Furthermore, the measurement on RIS coverage enhancement were summarized, introducing the impact of deployment locations, phase design, and effective rank on performance of coverage enhancement. …”
Get full text

APG mergence and topological potential optimization based heuristic user association strategy by Zhirui HU, Meihua BI, Fangmin XU, Meilin HE, Changliang ZHENG

“…With<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML"> <msub> <mover accent="true"> <mi>N</mi> <mo>¯</mo> </mover> <mtext>p</mtext> </msub> </math></inline-formula> increases,the effect of β₀increases and that of N₀decreases.Take <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML"> <msub> <mover accent="true"> <mi>N</mi> <mo>¯</mo> </mover> <mtext>p</mtext> </msub> <mo>=</mo><mn>40</mn><mo>,</mo><mn>60</mn></math></inline-formula>as an example.The η gap between β₀=0.5 and β₀=0.9 increases from 5.97% to 14.17%, and the user rate gap increases from 47 bit/(s·Hz) to 155 bit/(s·Hz). The η gap between N₀ =20 and N₀ =60 decreases from 1.4% to 0.4%, and the user rate gap decreases from 76 bit/(s·Hz)to 29 bit/(s·Hz). …”
Get full text

Relaxation Digital-to-Analog Converters Featuring Self-Calibration and Parasitics-Induced Error Suppression in 180-nm CMOS by Roberto Rubino, Francesco Musolino, Pedro Toledo, Yong Chen, Anna Richelli, Paolo S. Crovetti

“…The first design is a single-ended ReDAC (SE-ReDAC) and operates at 880kS/s with a 10-bit resolution, while the second is based on a differential ReDAC (Diff-ReDAC) architecture and operates at 100kS/s with a 13-bit resolution. …”
Get full text

QSAR Studies of 6-Amino Uracil Base Analogues: A Thymidine Phosphorylase Inhibitor in Cancer Therapy by Surya Prakash B. N. Gupta, Neeraj Upmanyu, N. S. Hari Narayana Moorthy, S. Bhattacharya

Get full text