Analysis is done on the inter-carrier interference (ICI) that caused by multi-carrier communication system frequency offset. The application model of DFT/IDFT in ADSL access network is analyzed further;the hardware de...Analysis is done on the inter-carrier interference (ICI) that caused by multi-carrier communication system frequency offset. The application model of DFT/IDFT in ADSL access network is analyzed further;the hardware detection and software analysis scheme of the system are proposed for the accessing network. Experiments have proved that monitoring system can filter the network data flow and carry on statistical and analysis, achieving real-time monitoring.展开更多
In this paper a novel technique, Authentication and Secret Message Transmission using Discrete Fourier Transformation (ASMTDFT) has been proposed to authenticate an image and also some secret message or image can be t...In this paper a novel technique, Authentication and Secret Message Transmission using Discrete Fourier Transformation (ASMTDFT) has been proposed to authenticate an image and also some secret message or image can be transmitted over the network. Instead of direct embedding a message or image within the source image, choosing a window of size 2 x 2 of the source image in sliding window manner and then con-vert it from spatial domain to frequency domain using Discrete Fourier Transform (DFT). The bits of the authenticating message or image are then embedded at LSB within the real part of the transformed image. Inverse DFT is performed for the transformation from frequency domain to spatial domain as final step of encoding. Decoding is done through the reverse procedure. The experimental results have been discussed and compared with the existing steganography algorithm S-Tools. Histogram analysis and Chi-Square test of source image with embedded image shows the better results in comparison with the S-Tools.展开更多
文摘Analysis is done on the inter-carrier interference (ICI) that caused by multi-carrier communication system frequency offset. The application model of DFT/IDFT in ADSL access network is analyzed further;the hardware detection and software analysis scheme of the system are proposed for the accessing network. Experiments have proved that monitoring system can filter the network data flow and carry on statistical and analysis, achieving real-time monitoring.
文摘In this paper a novel technique, Authentication and Secret Message Transmission using Discrete Fourier Transformation (ASMTDFT) has been proposed to authenticate an image and also some secret message or image can be transmitted over the network. Instead of direct embedding a message or image within the source image, choosing a window of size 2 x 2 of the source image in sliding window manner and then con-vert it from spatial domain to frequency domain using Discrete Fourier Transform (DFT). The bits of the authenticating message or image are then embedded at LSB within the real part of the transformed image. Inverse DFT is performed for the transformation from frequency domain to spatial domain as final step of encoding. Decoding is done through the reverse procedure. The experimental results have been discussed and compared with the existing steganography algorithm S-Tools. Histogram analysis and Chi-Square test of source image with embedded image shows the better results in comparison with the S-Tools.
