信源-信道联合编码的FGS增强层视频传输研究

Joint Source-Channel Coding for FGS Enhancement Layer Video Transmission

研究了基于IP无线网络中精细粒度可伸缩性(FGS)视频的传输。基于包交换的IP无线网络通常由两段链路组成:有线链路和无线链路。为了处理这种混合网络中不同类型数据包的丢失情况,对FGS视频增强层数据运用了一个具有比特平面间不平等差错保护(BPUEP)的多乘积码前向纠错(MPFEC)方案进行信道编码。对FGS增强层每一个比特平面(BP),在传输层,采用里德——索罗蒙码(RS)提供比特平面间的保护;而在链路层,则运用循环冗余校验码(CRC)串联率兼容穿孔卷积码(RCPC)提供数据包内保护。还提出了一个率失真优化的信源——信道联合编码的码率配置方案,仿真结果显示出该方案在提高接收端视频质量方面的优势。

The problem of transmitting a FGS Video Sequence over an IP-based wireless network consisting of both wired and wireless links is addressed. To combat the different types of packet loss in the heterogeneous network, the use of a multi-product code forward error correction（FEC）scheme capable of providing unequal error protection for all bitplanes is considered. At the transport layer, Reed-Solomon（RS）coding is used to provide inter-bitplane protection. In addition, rate-compatible punctured convolutional（RCPC）coding is used at the link layer to provide unequal intrapacket protection. Optimal bit allocation is performed in a rate-dlstortion optimized joint source-channel coding framework to achieve the best video quality. Simulation results illustrate the advantage of the proposed multi-product code FEC scheme over previously studied approaches.