This article studies the scalable broadcast scheme realized with the joint application of layered source coding,unequal error protection （UEP） and random network coding from the theoretical point of *** success prob...
详细信息
This article studies the scalable broadcast scheme realized with the joint application of layered source coding,unequal error protection （UEP） and random network coding from the theoretical point of *** success probability for any non-source node in a heterogeneous network to recover the most important layers of the source data is *** probability proves that in this broadcast scheme every non-source node with enough capacity can always recover the source data partially or entirely as long as the finite field size is sufficiently ***,a special construction for the local encoding kernel at the source node is *** this special construction,an increased success probability for partial decoding at any non-source node is achieved,i.e.,the partial decodability offered by the scalable broadcast scheme is improved.
Past work on cooperative communications has indicated substantial improvements in channel reliability through cooperative transmission strategies. To exploit cooperation benefits for multimedia transmission over slow ...
详细信息
Past work on cooperative communications has indicated substantial improvements in channel reliability through cooperative transmission strategies. To exploit cooperation benefits for multimedia transmission over slow fading channels, we propose to jointly allocate bits among sourcecoding, channel coding and cooperation to minimize the expected distortion of the reconstructed signal at the receiver. Recognizing that, not all source bits are equally important in terms of the end-to-end distortion, we further propose to protect the more important bits through user cooperation. We compare four modes of transmission that differ in their compression and error protection strategies (single layer or multiple layer sourcecoding with unequal error protection, with versus without cooperation). Our study includes an i.i.d. Gaussian source as well as a video source employing an H.263+ codec. We present an information theoretic analysis for the Gaussian source to investigate the effects of the modulation scheme, bandwidth ratio (number of channel uses per source sample), and average link signal-to-noise ratios on the end-to-end distortion of the four modes studied. The information theoretic observations are validated using practical channel coding simulations. Our study for video considers error propagation in decoded video due to temporal prediction and jointly optimizes a sourcecoding parameter that controls error propagation, in addition to bits for sourcecoding, channel coding and cooperation. The results show that cooperation can significantly reduce the expected end-to-end distortion for both types of source and that layered cooperation provides further improvements and extends the benefits to a wider range of channel qualities.
We investigate inter-session network coding for networks with heterogeneous receivers in this paper. Based on layered source coding, we define the hierarchical inter-layer random network codes, and propose a hierarchi...
详细信息
ISBN:
(纸本)9780878492695
We investigate inter-session network coding for networks with heterogeneous receivers in this paper. Based on layered source coding, we define the hierarchical inter-layer random network codes, and propose a hierarchical multicast scheme. Moreover, we compare our hierarchical multicast scheme with the layered multicast schemes in theory and with simulations. Simulation results show that our hierarchical multicast scheme can achieve the optimal aggregate throughput for some networks where the layered multicast schemes are suboptimal.
This paper demonstrates a robust layered video scheme, based on data-partitioning and intended for IPTV streaming over wireless broadband. Equal error protection through rateless coding is applied, whereby higher-prio...
详细信息
ISBN:
(纸本)9781424477425
This paper demonstrates a robust layered video scheme, based on data-partitioning and intended for IPTV streaming over wireless broadband. Equal error protection through rateless coding is applied, whereby higher-priority data partitioned packets are protected by appropriate selection of quantization parameter and picture slicing, so as to regulate packet size. In the mobile WiMAX channel investigated, both packet drops from congestion and adverse channel conditions are shown to be affected by packet size. The main proposal is for adaptive rateless coding in which additional redundant data are retransmitted to heal corrupted packets. However, though these packets are always repairable, delay increases as the percentage of corrupted packets increases, affecting the design parameters. Intra-refresh macro blocks are added to prevent the objective video quality falling below an acceptable level. Picture slicing further reduces the packet size to increase robustness in the face of measurement noise during channel estimation and the effects of slow and fast fading.
暂无评论