This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shif...This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shift keying(BPSK), quadrature phase shift keying(QPSK), quadrature amplitude modulation(QAM)-16 and QAM-64 with four error correction codes(convolutional code(CC), Reed-Solomon code(RSC)+CC, low density parity check(LDPC)+CC, Turbo+CC) is studied under three channel models(additive white Guassian noise(AWGN), Rayleigh, Rician) and three different antenna configurations(2×2, 2×4, 4×4). The bit error rate(BER) and the peak signal to noise ratio(PSNR) are taken as the measures of performance. The binary data and the color image data are transmitted and the graphs are plotted for various modulations with different channels and error correction codes. Analysis on the performance measures confirm that the Turbo + CC code in 4×4 configurations exhibits better performance.展开更多
With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its u...With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its utilities in a number of academic and real environments.There are a wide range of solutions to provide image watermarking frameworks,while each one of them is attempted to address an efficient and applicable idea.In reality,the traditional techniques do not have sufficient merit to realize an accurate application.Due to the fact that the main idea behind the approach is organized based on contourlet representation,the only state-of-the-art materials that are investigated along with an integration of the aforementioned contourlet representation in line with watermarking framework are concentrated to be able to propose the novel and skilled technique.In a word,the main process of the proposed robust watermarking framework is organized to deal with both new embedding and de-embedding processes in the area of contourlet transform to generate watermarked image and the corresponding extracted logo image with high accuracy.In fact,the motivation of the approach is that the suggested complexity can be of novelty,which consists of the contourlet representation,the embedding and the corresponding de-embedding modules and the performance monitoring including an analysis of the watermarked image as well as the extracted logo image.There is also a scrambling module that is working in association with levels-directions decomposition in contourlet embedding mechanism,while a decision maker system is designed to deal with the appropriate number of sub-bands to be embedded in the presence of a series of simulated attacks.The required performance is tangibly considered through an integration of the peak signal-to-noise ratio and the structural similarity indices that are related to watermarked image.And the bit error rate and the normal correlation are considered that are related to the extracted logo analysis,as well.Subsequently,the outcomes are fully analyzed to be competitive with respect to the potential techniques in the image colour models including hue or tint in terms of their shade,saturation or amount of gray and their brightness via value or luminance and also hue,saturation and intensity representations,as long as the performance of the whole of channels are concentrated to be presented.The performance monitoring outcomes indicate that the proposed framework is of significance to be verified.展开更多
Visible light communication(VLC),which is a prominent emerging solution that complements the radio frequency(RF)technology,exhibits the potential to meet the demands of fifth-generation(5G)and beyond technologies.The ...Visible light communication(VLC),which is a prominent emerging solution that complements the radio frequency(RF)technology,exhibits the potential to meet the demands of fifth-generation(5G)and beyond technologies.The random movement of mobile terminals in the indoor environment is a challenge in the VLC system.The model of optical attocells has a critical role in the uniform distribution and the quality of communication links in terms of received power and signal-to-noise ratio(SNR).As such,the optical attocells positions were optimized in this study with a developed try and error(TE)algorithm.The optimized optical attocells were examined and compared with previous models.This novel approach had successfully increased minimum received power from−1.29 to−0.225 dBm,along with enhanced SNR performance by 2.06 dB.The bit error rate(BER)was reduced to 4.42×10−8 and 6.63×10−14 by utilizing OOK-NRZ and BPSK modulation techniques,respectively.The optimized attocells positions displayed better uniform distribution,as both received power and SNR performances improved by 0.45 and 0.026,respectively.As the results of the proposed model are optimal,it is suitable for standard office and room model applications.展开更多
针对协作通信系统中源到中继及中继到目的两阶段的瞬时信道状态信息(CSI)影响系统整体误码率(BER)的问题,提出一种综合衡量两阶段信道系数的中继选择方案。首先,根据每个候选中继的CSI,比较源到中继及中继到目的的两阶段信道系数,选出...针对协作通信系统中源到中继及中继到目的两阶段的瞬时信道状态信息(CSI)影响系统整体误码率(BER)的问题,提出一种综合衡量两阶段信道系数的中继选择方案。首先,根据每个候选中继的CSI,比较源到中继及中继到目的的两阶段信道系数,选出两者中较差的信道状态;然后,按照较差的信道状态对候选中继排序,得到近似较优的中继节点集合;最后,从中选择两阶段信道系数之和最大者作为被选中继参与协作传输。仿真结果表明,当候选中继节点数为100及5,BER下降到10-4及10-5时,所提的中继选择方案与基于最优较差信道的中继选择方案、基于最近邻关系的中继选择方案相比,所需信噪比(SNR)分别降低了0.4 d B和0.2 d B。所提方案能够增加无线中继网络的信息传输范围,提高信息传输的可靠性。展开更多
该文提出一种名为无信号内干扰相关延迟键控(Correlation-Delay-Shift-Keying with No Intrasignal Interference,CDSK-NII)的新型混沌通信方案。采用重复混沌序列为参考信号,同时利用零和序列确保参考信号与信息信号严格正交,CDSK-NII...该文提出一种名为无信号内干扰相关延迟键控(Correlation-Delay-Shift-Keying with No Intrasignal Interference,CDSK-NII)的新型混沌通信方案。采用重复混沌序列为参考信号,同时利用零和序列确保参考信号与信息信号严格正交,CDSK-NII能够在解调过程中消除信号内干扰。在高斯白噪声信道和Rayleigh衰落信道中分析CDSK-NII的比特误码率。实验结果表明:由于无信号内干扰,CDSK-NII的比特误码率低于CDSK和通用相关延迟键控(GCDSK);随着复帧长度的增加,CDSK-NII的性能将进一步提升,比特误码率低于参考自适应相关延迟键控(RA-CDSK)。展开更多
文摘This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shift keying(BPSK), quadrature phase shift keying(QPSK), quadrature amplitude modulation(QAM)-16 and QAM-64 with four error correction codes(convolutional code(CC), Reed-Solomon code(RSC)+CC, low density parity check(LDPC)+CC, Turbo+CC) is studied under three channel models(additive white Guassian noise(AWGN), Rayleigh, Rician) and three different antenna configurations(2×2, 2×4, 4×4). The bit error rate(BER) and the peak signal to noise ratio(PSNR) are taken as the measures of performance. The binary data and the color image data are transmitted and the graphs are plotted for various modulations with different channels and error correction codes. Analysis on the performance measures confirm that the Turbo + CC code in 4×4 configurations exhibits better performance.
文摘With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its utilities in a number of academic and real environments.There are a wide range of solutions to provide image watermarking frameworks,while each one of them is attempted to address an efficient and applicable idea.In reality,the traditional techniques do not have sufficient merit to realize an accurate application.Due to the fact that the main idea behind the approach is organized based on contourlet representation,the only state-of-the-art materials that are investigated along with an integration of the aforementioned contourlet representation in line with watermarking framework are concentrated to be able to propose the novel and skilled technique.In a word,the main process of the proposed robust watermarking framework is organized to deal with both new embedding and de-embedding processes in the area of contourlet transform to generate watermarked image and the corresponding extracted logo image with high accuracy.In fact,the motivation of the approach is that the suggested complexity can be of novelty,which consists of the contourlet representation,the embedding and the corresponding de-embedding modules and the performance monitoring including an analysis of the watermarked image as well as the extracted logo image.There is also a scrambling module that is working in association with levels-directions decomposition in contourlet embedding mechanism,while a decision maker system is designed to deal with the appropriate number of sub-bands to be embedded in the presence of a series of simulated attacks.The required performance is tangibly considered through an integration of the peak signal-to-noise ratio and the structural similarity indices that are related to watermarked image.And the bit error rate and the normal correlation are considered that are related to the extracted logo analysis,as well.Subsequently,the outcomes are fully analyzed to be competitive with respect to the potential techniques in the image colour models including hue or tint in terms of their shade,saturation or amount of gray and their brightness via value or luminance and also hue,saturation and intensity representations,as long as the performance of the whole of channels are concentrated to be presented.The performance monitoring outcomes indicate that the proposed framework is of significance to be verified.
基金the grant names“ProfessionalDevelopment Research University Grant”(“UTM Vot No.05E69”and“TDR grant Vot No.05G27”).
文摘Visible light communication(VLC),which is a prominent emerging solution that complements the radio frequency(RF)technology,exhibits the potential to meet the demands of fifth-generation(5G)and beyond technologies.The random movement of mobile terminals in the indoor environment is a challenge in the VLC system.The model of optical attocells has a critical role in the uniform distribution and the quality of communication links in terms of received power and signal-to-noise ratio(SNR).As such,the optical attocells positions were optimized in this study with a developed try and error(TE)algorithm.The optimized optical attocells were examined and compared with previous models.This novel approach had successfully increased minimum received power from−1.29 to−0.225 dBm,along with enhanced SNR performance by 2.06 dB.The bit error rate(BER)was reduced to 4.42×10−8 and 6.63×10−14 by utilizing OOK-NRZ and BPSK modulation techniques,respectively.The optimized attocells positions displayed better uniform distribution,as both received power and SNR performances improved by 0.45 and 0.026,respectively.As the results of the proposed model are optimal,it is suitable for standard office and room model applications.
文摘针对协作通信系统中源到中继及中继到目的两阶段的瞬时信道状态信息(CSI)影响系统整体误码率(BER)的问题,提出一种综合衡量两阶段信道系数的中继选择方案。首先,根据每个候选中继的CSI,比较源到中继及中继到目的的两阶段信道系数,选出两者中较差的信道状态;然后,按照较差的信道状态对候选中继排序,得到近似较优的中继节点集合;最后,从中选择两阶段信道系数之和最大者作为被选中继参与协作传输。仿真结果表明,当候选中继节点数为100及5,BER下降到10-4及10-5时,所提的中继选择方案与基于最优较差信道的中继选择方案、基于最近邻关系的中继选择方案相比,所需信噪比(SNR)分别降低了0.4 d B和0.2 d B。所提方案能够增加无线中继网络的信息传输范围,提高信息传输的可靠性。
文摘该文提出一种名为无信号内干扰相关延迟键控(Correlation-Delay-Shift-Keying with No Intrasignal Interference,CDSK-NII)的新型混沌通信方案。采用重复混沌序列为参考信号,同时利用零和序列确保参考信号与信息信号严格正交,CDSK-NII能够在解调过程中消除信号内干扰。在高斯白噪声信道和Rayleigh衰落信道中分析CDSK-NII的比特误码率。实验结果表明:由于无信号内干扰,CDSK-NII的比特误码率低于CDSK和通用相关延迟键控(GCDSK);随着复帧长度的增加,CDSK-NII的性能将进一步提升,比特误码率低于参考自适应相关延迟键控(RA-CDSK)。
