Korean characters consist of 2 dimensional distributed consonantal and vowel graphemes. The purpose of reducing the 2 dimensional characteristics of Korean characters to linear arrangements at early stage of character...Korean characters consist of 2 dimensional distributed consonantal and vowel graphemes. The purpose of reducing the 2 dimensional characteristics of Korean characters to linear arrangements at early stage of character recognition is to decrease the complexity of following recognition task. By defining the identification codes for the vowel graphemes of Korean characters, the rules for combination of vowel graphemes are established, and a recognition algorithm based on the rules for combination of vowel graphemes, is therefore proposed for vertical vowel graphemes. The algorithm has been proved feasilbe through demonstrating simulations.展开更多
To improve the reliable performance of information transmission in cooperative relay networks, the scheme of the max-rate spatial channel pairing （SCP） based on maximum ratio combining （MRC） is proposed. The schem...To improve the reliable performance of information transmission in cooperative relay networks, the scheme of the max-rate spatial channel pairing （SCP） based on maximum ratio combining （MRC） is proposed. The scheme includes three steps： channel phase cancellation, MRC, and SCP. Eventually, the solution of the scheme is modeled as convex optimization. The objective function of the optimization problem is to maximize the transmission rate and the optimization variable is the strategy of pairing between the uplink spatial sub-channels of each user and the corresponding downlink spatial ones. The theorem of the arrangement inequalities is adopted to obtain the approximate closed-form solution of the optimal pairing for this convex optimization. Simulation results demonstrate that compared to the existing distributed space-time block coding and coherent combined schemes without SCP, the proposed max-rate SCP plus MRC algorithm achieves appreciable improvements in symbol error rate in medium and high signal-to-noise ratio regimes. The achievable performance gain is due to the use of maxrate SCP.展开更多
In this paper, a Complex Wavelet Packet （CWP-MC-CDMA） system uplink model is proposed, based Multi-Carrier Code Division Multiple Access based on the analysis of the principle of MC-CDMA and the use of the optimized...In this paper, a Complex Wavelet Packet （CWP-MC-CDMA） system uplink model is proposed, based Multi-Carrier Code Division Multiple Access based on the analysis of the principle of MC-CDMA and the use of the optimized complex wavelet packet. Considering that the base station can adopt multiple re- ceiver antennas in the uplink, we employ the Space Diversity Combining （SDC） technique to improve the sys- tem pertbrmance via multiple antennas. The uplink performance of proposed CWP-MC-CDMA system with SDC technique is investigated over Rayleigh lading channel, and corresponding bit error rate analysis is given in detail. The system can avoid the decrease of spectrum efficiency of conventional MC-CDMA due to inserting cyclic prefix. Theoretical analysis and simulation result show that the application of SDC technique can improve the CWP-MC-CDMA system ability to combat spatial lading and various interferences effectively. Moreover, the proposed system based on SDC technique has superior Bit Error Rate （BER） performance over the Discrete Fourier Transform （DFT） and SDC based MC-CDMA system and the real wavelet packet and SDC based MC-CDMA system.展开更多
Constant weight code is an important error-correcting control code in communications. Basic structure of constant weight codes for some arriving at Johnson bound, A（n, 2u, w）, is presented. Some correlative property...Constant weight code is an important error-correcting control code in communications. Basic structure of constant weight codes for some arriving at Johnson bound, A（n, 2u, w）, is presented. Some correlative propertys of the codes, the solution of arriving at Johnson bound, and the results on the couple constant code and some constant weight codes are discussed. The conclusion is verified through four examples.展开更多
The optimum choice of key parameters in the interleaving schemes used in RS codes/Viterbi-decoded convolutional codes concatenated coding systems is discussed. At the same time the simulation results and other optiona...The optimum choice of key parameters in the interleaving schemes used in RS codes/Viterbi-decoded convolutional codes concatenated coding systems is discussed. At the same time the simulation results and other optional interleaving schemes are given.展开更多
针对影子栈难以兼顾安全性和性能,软件实现的前向CFI(control-flow integrity)技术性能开销过大、难以进行实际部署,提出基于软硬件结合的CFI(control-flow integrity based on the combination of software and hardware,SHCFI)技术。...针对影子栈难以兼顾安全性和性能,软件实现的前向CFI(control-flow integrity)技术性能开销过大、难以进行实际部署,提出基于软硬件结合的CFI(control-flow integrity based on the combination of software and hardware,SHCFI)技术。通过二进制重写器对程序反编译,生成中间语言,并判断转移指令类型。对于后向控制流的保护,提出基于返回地址加密的平行影子栈方案,使用随机数对栈上的返回地址进行异或加密,将加密结果备份到原始栈固定偏移处的影子栈中,在函数返回时对影子栈中的地址异或解密,将解密结果作为实际的返回地址。对于前向控制流的保护,使用硬件ENDBRANCH状态机指令标记间接转移指令的目标地址,在运行时对目标地址进行合法性检查,以降低性能开销。实验结果表明,SHCFI加固后的程序能够有效地防御代码重用攻击,且具有良好的运行开销。展开更多
文摘Korean characters consist of 2 dimensional distributed consonantal and vowel graphemes. The purpose of reducing the 2 dimensional characteristics of Korean characters to linear arrangements at early stage of character recognition is to decrease the complexity of following recognition task. By defining the identification codes for the vowel graphemes of Korean characters, the rules for combination of vowel graphemes are established, and a recognition algorithm based on the rules for combination of vowel graphemes, is therefore proposed for vertical vowel graphemes. The algorithm has been proved feasilbe through demonstrating simulations.
基金The Open Research Fund of National Mobile Communications Research Laboratory of Southeast University(No.2013D02)the Open Research Fund of National Key Laboratory of Electromagnetic Environment of China Research Institute of Radio Wave Propagation(No.201500013)the National Natural Science Foundation of China(No.61271230,61472190)
文摘To improve the reliable performance of information transmission in cooperative relay networks, the scheme of the max-rate spatial channel pairing （SCP） based on maximum ratio combining （MRC） is proposed. The scheme includes three steps： channel phase cancellation, MRC, and SCP. Eventually, the solution of the scheme is modeled as convex optimization. The objective function of the optimization problem is to maximize the transmission rate and the optimization variable is the strategy of pairing between the uplink spatial sub-channels of each user and the corresponding downlink spatial ones. The theorem of the arrangement inequalities is adopted to obtain the approximate closed-form solution of the optimal pairing for this convex optimization. Simulation results demonstrate that compared to the existing distributed space-time block coding and coherent combined schemes without SCP, the proposed max-rate SCP plus MRC algorithm achieves appreciable improvements in symbol error rate in medium and high signal-to-noise ratio regimes. The achievable performance gain is due to the use of maxrate SCP.
基金Supported by China Postdoctoral Science Foundation, and Science Foundation of Jiangsu Province (BK2003089).
文摘In this paper, a Complex Wavelet Packet （CWP-MC-CDMA） system uplink model is proposed, based Multi-Carrier Code Division Multiple Access based on the analysis of the principle of MC-CDMA and the use of the optimized complex wavelet packet. Considering that the base station can adopt multiple re- ceiver antennas in the uplink, we employ the Space Diversity Combining （SDC） technique to improve the sys- tem pertbrmance via multiple antennas. The uplink performance of proposed CWP-MC-CDMA system with SDC technique is investigated over Rayleigh lading channel, and corresponding bit error rate analysis is given in detail. The system can avoid the decrease of spectrum efficiency of conventional MC-CDMA due to inserting cyclic prefix. Theoretical analysis and simulation result show that the application of SDC technique can improve the CWP-MC-CDMA system ability to combat spatial lading and various interferences effectively. Moreover, the proposed system based on SDC technique has superior Bit Error Rate （BER） performance over the Discrete Fourier Transform （DFT） and SDC based MC-CDMA system and the real wavelet packet and SDC based MC-CDMA system.
文摘Constant weight code is an important error-correcting control code in communications. Basic structure of constant weight codes for some arriving at Johnson bound, A（n, 2u, w）, is presented. Some correlative propertys of the codes, the solution of arriving at Johnson bound, and the results on the couple constant code and some constant weight codes are discussed. The conclusion is verified through four examples.
文摘The optimum choice of key parameters in the interleaving schemes used in RS codes/Viterbi-decoded convolutional codes concatenated coding systems is discussed. At the same time the simulation results and other optional interleaving schemes are given.
文摘针对影子栈难以兼顾安全性和性能,软件实现的前向CFI(control-flow integrity)技术性能开销过大、难以进行实际部署,提出基于软硬件结合的CFI(control-flow integrity based on the combination of software and hardware,SHCFI)技术。通过二进制重写器对程序反编译,生成中间语言,并判断转移指令类型。对于后向控制流的保护,提出基于返回地址加密的平行影子栈方案,使用随机数对栈上的返回地址进行异或加密,将加密结果备份到原始栈固定偏移处的影子栈中,在函数返回时对影子栈中的地址异或解密,将解密结果作为实际的返回地址。对于前向控制流的保护,使用硬件ENDBRANCH状态机指令标记间接转移指令的目标地址,在运行时对目标地址进行合法性检查,以降低性能开销。实验结果表明,SHCFI加固后的程序能够有效地防御代码重用攻击,且具有良好的运行开销。
