Kohno Ryuji

End-to-end channel capacity of MAC-PHY cross-layer multiple-hop MIMO relay system with outdated CSI

For high end-to-end channel capacity, the amplify-and-forward scheme multiple-hop multiple-input multiple-output relay system is considered. The distance between each transceiver and the transmit power of each relay are optimized to prevent some relays from being the bottleneck and guarantee high end-to-end channel capacity. According to the proposed transmission environment coefficient, the path loss can be described in a new way, and then the distance of multiple-hop relay system can be optimized more simply than the original one. However, when the system has no control on media access control (MAC) layer, performance of the system deteriorates because of the presence of interference signal. Thus, the specific transmission protocol on the MAC layer for multiple-hop system is proposed to reduce the power of interference signal and to obtain high end-to-end channel capacity. According to the proposed transmission protocol on the MAC layer, the system indicates the trade-off between the end-to-end channel capacity and the delay time. The end-to-end channel capacity of the outdated channel state information system is also analyzed.

Frame-patch matching based robust video watermarking using KAZE feature

A frame-patch matching based robust video watermarking using KAZE feature is proposed in this paper. We employed the KAZE feature for matching the feature points of frame-patch with those of all frames in video. In our method, the watermark information is embedded in Discrete Cosine Transform (DCT) domain of randomly generated blocks in the matched region. In the extraction process, we synchronized the embedded region from the distorted video by using KAZE feature matching. RST (rotation, scaling, translation) parameters are estimated and the watermark information can be extracted. Experimental results showed that our proposed method is very robust against geometrical attacks, video processing attacks, temporal attacks, and so on.