Piecewise-linear companding transform for peak-to-average power ratio reduction of OFDM signals by YANG Pin-lu, HU Ai-qun

“…In order to reduce the peak-to-average power ratio（PAPR） of orthogonal frequency division multiplexing（OFDM） signals,a piecewise-linear companding transform was proposed.Small amplitudes were multiplied by a scale factor,while large ones were not only multiplied by a scale factor but also added by a shift.The resulting companding transform was piecewise-linear and continuous.It can provide significant PAPR reduction performance with low compu-tational complexity,and has low influence on system performances through piecewise transform.It is shown by theoreti-cal analysis and simulation that,a good trade-off between PAPR reduction and bit-error-rate performances can be achieved by carefully choosing the two scales and the shift.Furthermore,compared with existing linear and nonlinear companding transforms,a better power spectral density performance can be achieved.…”
Get full text

Design and detection of hardware Trojan based on satisfiability don't cares by Lingjuan WU, Jiacheng ZHU, Shibo TANG, Jing TAN, Wei HU

“…Hardware Trojans are intended malicious design modifications to integrated circuits, which can be used to launch powerful low-level attacks after being activated.A new security threat of lightweight stealthy hardware Trojans leveraging discrete satisfiability don't care signals was demonstrated.These don't care could not be satisfied under normal operation and thus the circuit design with Trojan is functionally equivalent to the Trojan-free baseline.The attacker could activate the Trojan through simple yet effective fault injection.Experimental results on a 1024-bit RSA cryptographic core show that the proposed hardware Trojan can escape from logic synthesis optimization, and that the RSA private key can be retrieved by simply over-clocking the design.A defense technique that can effectively detect such stealthy Trojan design was provided.…”
Get full text

Research on the construction method of quasi-complementary sequence sets for peak-to-average power ratio reduction of multicarrier signal by Yubo LI, Meiyue WANG, Tao LIU, Xiaoyu CHEN

“…To solve the problem of limited number of sequences in the mutually orthogonal complementary code set and high peak-to-average power ratio (PAPR) in MC-CDMA system, a construction of asymptotically optimal a periodic binary QCSS with low column vector PAPR was proposed.The obtained QCSS with asymptotically optimal parameters had more sequences than the existing QCSS due to the designed mapping set.The QCSS based on the orthogonal Golay sequence set had column vector PAPR of at most 2.Experimental simulation results show that the constructed sequence sets can effectively reduce the time-domain MC-CDMA signal PAPR to 3 dB and have good bit error rate performance.…”
Get full text

Interference detection and diversity suppression algorithm of OFDM system under partial-band jamming by Guo LI, Ni WEN, Fengkui GONG, Jian ZHANG, Sihan ZHANG

“…For the currently widely-used OFDM system, which greatly improved the communication performance under the condition of partial-band jamming, an interference detection algorithm based on FCVE and an interference suppression algorithm based on frequency diversity were proposed.The threshold factor formula of FCVE algorithm was derived theoretically, and the interference detection threshold was calculated by using the threshold factor and the variance of the received signal, so as to achieve the interference detection with high accuracy.The simulation results show that the proposed FCVE algorithm significantly improves the interference detection probability of the classical FCME algorithm under the condition of high signal to interference ratio (SIR).Further, the interference can be greatly suppressed based on the idea of frequency diversity with the result of interference detection.The simulation results show that the bit error rate of the system can be reduced by two orders of magnitude under the same SIR.…”
Get full text

Distance criterion-based quantizer design for cooperative spectrum sensing by Yuanhua FU, Zhiming HE

“…In terms of sensing node’s energy and reporting channel’s bandwidth constrains problem for cooperative spectrum sensing in cognitive radio networks,an optimal quantizer design method based on distance criterion was proposed.First of all,the Bhattacharyya distance of received quantized data at the fusion center (FC) was calculated as performance criteria,the optimization mathematical model of the quantizer was constructed,and the optimum quantization thresholds were obtained by using particle swarm optimization algorithm.According to received sensing nodes’ quantized data at the FC,a log-likelihood ratio detector was constructed to decide the presence or absence of primary user signal,the upper bound to sensing performance of energy detector that without quantization was derived.Compared with the existing methods in literatures,the performance of proposed 3-bit quantization method approaches to the upper bound performance of energy detector,under the premise of obtaining comparable detection performance,the requirement of communication bandwidth is reduced.…”
Get full text

Underwater laser communication with sloped pulse modulation in turbid water by Taewoong Kang, Kiman Kim, Serim Kim, Donghun Lee

“…The communication link uses an avalanche photodiode module as the receiver. The bit error rate of a 5.4 × 10 −6 by 450-nm blue laser diode in turbid water with 1.4 Nephelometric Turbidity Unit was below the forward error correction limit. …”
Get full text

Performance analysis of dual-media cooperative communication based on wireless and power line under hybrid fading by Zhixiong Chen, Yifang Jing, Dongsheng Han, Lijiao Wang

“…Theoretical formulas of outage probability and bit error rate after amplify–forward relay and maximal-ratio combining was derived on the basis of moment generation function of the total output signal-to-noise ratio of the system. …”
Get full text

Trojan message attack on the concatenated hash functions by Shi-Wei CHEN, INChen-Hui J

“…The Trojan message attack was proposed by Andreeva,et al.aiming at the hash functions with MD structure.First it was applied on the hash function beyond MD structure,that was,concatenated hash.Utilizing the property of the concatenated hash,and combining the Joux's multicollision and the “diamond” structure with the depth of n−l,a Trojan message of the length n 2^k· blocks for the 2n-bit concatenated hash was constructed,based on which a chosen-prefix Trojan message attack was first proposed.And the memory complexity of proposed attack is about 2l+2^n−l+1+n·2^k+1blocks and the time complexity is about O (n·2^n+k+l·2^l)computations of the compression function,much less than the ideal value O(n·2^2n+k).…”
Get full text

Low-complexity signal detection algorithm based on preconditioned conjugate gradient method by Hua QU, Jing LIANG, Jihong ZHAO, Weihua WANG

“…The simulation results show that the proposed algorithm can achieve the near-optimal bit error rate performance of minimum mean square error detection algorithm with a small number of iterations，and computation complexity reduces a order of magnitude. …”
Get full text

Successive relaying secure transmission scheme based on inter-relay interference cancellation by Yi ZOU, Kai-zhi HUANG, Xiao-lei KANG

“…A secure scheme based on inter-relay interference cancellation was proposed to solve untrusted relay eavesdropping problem in successive relaying systems.First inter-relay interference between trusted relay and untrusted relay was exploited as artificial noise to degrade untrusted relay’s eavesdropping condition,then interference iterative cancellation was adapted to improve signal quality at legitimate user by making use of correlation between signals in time domain.Based on this,a quick power allocation algorithm aiming to minimize untrusted relay’s sum rate was proposed.Analysis and simulation results show that the proposed scheme suppress untrusted relay’s eavesdropping without loss of communication efficiency,a promotion of at least 2 bit·s^-1·Hz^-1in secrecy rate can be observed.…”
Get full text

PCPIR-V:parallel privacy protected algorithms for nearest neighbor query based on Spark by Shi-zhuo DENG, Ji-tao YAO, Bo-tao WANG, Yue-mei CHEN, Ye YUAN, Yan-hui LI, Guo-ren WANG

“…To address the low-efficiency problem for query privacy protection on big data,parallel CPIR-V (PCPIR-V),which had a high level of privacy protection for nearest neighbor query,was presented and implemented based on spark.Two parallel strategies for PCPIR-V,Row strategy and Bit strategy,were proposed.To avoid redundant multiplications,the repeated products were cached based on a clustering technique while computing CPIR on Spark.According to the evaluation results of PCPIR-V on three datasets,the scalablity of PCPIR-V is good until the number of core is larger than 40.The cost of PCPIR-V with the method of caching partial multiplication results is reduced by 20% averagely.…”
Get full text

Nonlinear companding transform for PAPR reduction in lattice-OFDM system by Si-ming PENG, Yue-hong SHEN, Zhi-gang YUAN, Yu-wei MIAO, Wei JIAN

“…Therefore, the companded signals can not only achieve an improved PAPR and bit error ratio (BER) performance but also maintain the statistical characteristics of the original signals. …”
Get full text

Waveform Distortion of Gaussian Beam in Atmospheric Turbulence Simulated by Phase Screen Method by Zhi-Qiang Yang, Li-hong Yang, Lei Gong, Liguo Wang, Xinyi Wang

“…Finally, the relationship of intensity fluctuation, amplitude fluctuation, and bit error rate with distance is analyzed.…”
Get full text

An improved RFID authentication protocol based on quadratic residue by Zhiliang LIU

“…In view of the existing radio frequency identification(RFID) authentication protocol based on quadratic residue in the security and cost aspects of the loopholes and deficiencies,an improved RFID bidirectional authentication protocol based on the quadratic residue was designed.The improved protocol was mixed with random number encryption under the framework of the quadratic residue,which makes the message certification and identification more efficient and fast in database authentication and identification; the ultra-lightweight bit replacement operations and XOR encryption communication information was introduced,which reduces the cost of system computing; in database,the random number checking mechanism was added to avoid attacks such as agreement to be synchronized and denial of service attacks; finally,the GNY logical proof of the protocol was given,which shows the feasibility of the improved protocol.The protocol security and performance analysis indicate that the improved protocol has higher security and lower cost.…”
Get full text

Neural network decoding of the block Markov superposition transmission by Qianfan WANG, Sheng BI, Zengzhe CHEN, Li CHEN, Xiao MA

“…A neural network (NN)-based decoding algorithm of block Markov superposition transmission (BMST) was researched.The decoders of the basic code with different network structures and representations of training data were implemented using NN.Integrating the NN-based decoder of the basic code in an iterative manner,a sliding window decoding algorithm was presented.To analyze the bit error rate (BER) performance,the genie-aided (GA) lower bounds were presented.The NN-based decoding algorithm of the BMST provides a possible way to apply NN to decode long codes.That means the part of the conventional decoder could be replaced by the NN.Numerical results show that the NN-based decoder of basic code can achieve the BER performance of the maximum likelihood (ML) decoder.For the BMST codes,BER performance of the NN-based decoding algorithm matches well with the GA lower bound and exhibits an extra coding gain.…”
Get full text

Fast and low-complexity video down-sizing transcoder by Zhuo-yi LV, Ke-bin JIA, Wan-chi WIU

“…An efficient mode decision scheme for down-sizing video transcoding in H.264 using support vector machines (SVM)was proposed.In order to reduce the high computationa complexity of using conventional mode decision in the H.264 re-encoder,the proposed scheme used SVM to exploit the correlation between coding information extracted from the input high-resolution bit-stream and the coding modes of macro-blocks in down-sized video frames.The key techniques of training and predicting SVM including feature vector and kernel function were studied and then the SVM model was trained.After the hierarchical SVM classifier,improbable modes were eliminated and only a small number of candidate modes were carried out using the RDO operations.Hence,remarkable computing time could be saved,up to 67.31%,while maintaining nearly the same quality of the transcoded pictures.…”
Get full text

Receiver design of sparse Bayesian learning based MIMO-OFDM power line communication system by Xinrong LYU, Youming LI, Yongqing WU, Xiaobo TANG

“…The rich impulsive noise in the power line channel poses a huge challenge to the design of MIMO-OFDM transceiver.To solve this problem, a design scheme that can jointly estimate the channel and impulsive noise was proposed, which exploited the parametric sparsity of the classical multipath model and the sparsity of the time domain impulsive noise.In this scheme, the unknown channel model parameters and the impulsive noise were jointly regarded as a sparse vector.By observing the spatial correlation of MIMO system, a compressed sensing model based on multiple measurement vectors was constructed.The multiple response sparse Bayesian learning theory was introduced to jointly estimate the MIMO channel parameters and impulsive noise.The simulation results show that, compared with the traditional receiver scheme that considers MIMO channel estimation and impulsive noise suppression separately, the receiver proposed has a significant improvement in channel estimation performance and bit error rate performance.…”
Get full text

Fault analysis on elliptic curve cryptosystems with sliding window method by Jin-zhong ZHANG, Ying-zhan KOU, Tao WANG, Shi-ze GUO, Xin-jie ZHAO

“…Based on the principle of sign change fault attacks,an improved fault analysis method was presented against elliptic curve cryptosystems with sliding window method for point multiplication.When faults on double instruction it could effectively solve the “zero block failure” problem.Experiment results demonstrate that 15 times fault injections are enough to recover full 192bit key.When faults on add instruction,a new fault analysis method was proposed.Experiment results demonstrate one fault injection can reduce searching space 2⁷~2¹⁵.The method presented here can provide some ideas for fault attack on other cryptosystems using sliding window method.…”
Get full text

Differential spatial modulation scheme based on orthogonal space-time block coded by Zhi-cheng WANG, Zhi-gang CHEN, Lei WANG

“…Focusing on the problem that differential spatial modulation (DSM) couldn’t obtain transmit diversity and has high decoding complexity,a new differential spatial modulation scheme based on the orthogonal space-time block code was proposed and the proposed scheme is called OSTBC-DSM.There were two matrices in this scheme:the spatial modulation matrix and the symbol matrix.The former was aimed to activate different transmit antennas by setting the position of nonzero elements,and the latter structured symbolic matrix by using orthogonal space-time block codes (OSTBC) as the basic code block.The proposed scheme could obtain full transmit diversity and higher spectral efficiency compared with the conventional DSM schemes.Moreover,the OSTBC-DSM supported linear maximum likelihood (ML) decoding.The simulation results show that under different spectral efficiencies,the proposed OSTBC-DSM scheme has better bit error rate (BER) performance than other schemes.…”
Get full text

Improved optical generalized spatial modulation in Málaga turbulent channel by Hui ZHAO, Weiwen MA, Jin LI, Wenchao DENG, Hui WAN, Tianqi ZHANG, Yuanni LIU

“…Aiming at the problems of space resource waste and error bit performance limitation caused by fixed optical antenna combination set used in traditional optical generalized spatial modulation (OGSM), an improved scheme based on low complexity adaptive optical antenna combination set selection algorithm was proposed.First, the Euclidean distance matrix between optical antenna combinations was calculated using channel state information.Then, based on the principle of Euclidean distance equivalence and the idea of maximum norm antenna selection, the optical antenna combination with poor channel state was deleted, and the final reserved optical antenna combination was the optimal optical antenna combination set in the current state.The traversal of all optical antenna combinations was avoided and the complexity of the algorithm was reduced to a large extent.The simulation results show that the BER performance of the improved OGSM scheme outperforms the conventional OGSM under different conditions.…”
Get full text