Streaming video is becoming increasingly popular among Internet multimedia applications. A robust coding scheme for DCT-based scalable video streaming over the Internet is proposed in this paper. Compared with convent...Streaming video is becoming increasingly popular among Internet multimedia applications. A robust coding scheme for DCT-based scalable video streaming over the Internet is proposed in this paper. Compared with conventional MPEG4-FGS (fine granular scalable) and progressive FGS(PFGS), the proposed method generates the base layer including some sub-base layers by DCT coefficient reordering and VLC reshuffling, which enables the video stream of to adapt itself to long-term bandwidth time-varying of channel. Furthermore, a novel end-to-end transmission architecture for scalable video streaming over the Internet is also presented, in which an adaptive unequal packet loss protection (AUPLP) strategy is proposed to determine the currently available network bandwidth and adjust the sending rates according to different situations, such as network congestion or unreliable transmission. Experimental results show that the proposed progressive scalable scheme can improve the average coding efficiency up to 1.2 dB compared with MPEG4-FGS and PFGS in lower bandwidth, and the AUPLP strategy can improve the transmitting performances not only of the proposed scheme, but also of MPEG4-FGS, PFGS system.展开更多
On the basis of the analysis of the effect of PHase Noise (PHN) and Common Phase Error (CPE) on Orthogonal Frequency Division Multiplexing (OFDM) systems, a cost function is constructed. By the cost function and the i...On the basis of the analysis of the effect of PHase Noise (PHN) and Common Phase Error (CPE) on Orthogonal Frequency Division Multiplexing (OFDM) systems, a cost function is constructed. By the cost function and the idea of Least-Mean-Square (LMS) adaptive algorithm, the adaptive algorithm for the correction of CPE is presented. The simulations have been performed to investigate the performance for tracking PHN and estimating CPE, the results show that the algorithm performs soundly.展开更多
Generalized self-shrinking sequences, simply named the GSS sequences, are novel periodic sequences that have many advantages in cryptography. In this paper, we give several results about GSS sequence's application...Generalized self-shrinking sequences, simply named the GSS sequences, are novel periodic sequences that have many advantages in cryptography. In this paper, we give several results about GSS sequence's application to cryptography. First, we give a simple method for selecting those GSS sequences whose least periods reach the maximum. Second, we give a method for describing and computing the auto-correlation coefficients of GSS sequences. Finally, we point out that some GSS sequences, when used as stream ciphers, have a security weakness.展开更多
文摘Streaming video is becoming increasingly popular among Internet multimedia applications. A robust coding scheme for DCT-based scalable video streaming over the Internet is proposed in this paper. Compared with conventional MPEG4-FGS (fine granular scalable) and progressive FGS(PFGS), the proposed method generates the base layer including some sub-base layers by DCT coefficient reordering and VLC reshuffling, which enables the video stream of to adapt itself to long-term bandwidth time-varying of channel. Furthermore, a novel end-to-end transmission architecture for scalable video streaming over the Internet is also presented, in which an adaptive unequal packet loss protection (AUPLP) strategy is proposed to determine the currently available network bandwidth and adjust the sending rates according to different situations, such as network congestion or unreliable transmission. Experimental results show that the proposed progressive scalable scheme can improve the average coding efficiency up to 1.2 dB compared with MPEG4-FGS and PFGS in lower bandwidth, and the AUPLP strategy can improve the transmitting performances not only of the proposed scheme, but also of MPEG4-FGS, PFGS system.
基金Supported by the National Natural Science Foundation of China (No.60332030).
文摘On the basis of the analysis of the effect of PHase Noise (PHN) and Common Phase Error (CPE) on Orthogonal Frequency Division Multiplexing (OFDM) systems, a cost function is constructed. By the cost function and the idea of Least-Mean-Square (LMS) adaptive algorithm, the adaptive algorithm for the correction of CPE is presented. The simulations have been performed to investigate the performance for tracking PHN and estimating CPE, the results show that the algorithm performs soundly.
文摘Generalized self-shrinking sequences, simply named the GSS sequences, are novel periodic sequences that have many advantages in cryptography. In this paper, we give several results about GSS sequence's application to cryptography. First, we give a simple method for selecting those GSS sequences whose least periods reach the maximum. Second, we give a method for describing and computing the auto-correlation coefficients of GSS sequences. Finally, we point out that some GSS sequences, when used as stream ciphers, have a security weakness.
