Research On SVC Rate Distortion-based Retransmission Of Network Coding

Automatic repeat request (ARQ) now has become an important method to provide reliable communication in a wireless communication environment. Ordinary ARQ mechanisms contain Stop-wait ARQ (SW-ARQ), Go-back-n-frame ARQ (GBN-ARQ) and Selective-repeat ARQ (SR-ARQ). Traditional ARQ mechanisms used in point-to-point transmission can achieve higher performance. However, the performance declined rapidly as the number of receiving nodes increases in multicast networks. Therefore, it’s a great need to design a more effective way to improve the transmission efficiency of retransmission multicast network.With the improvement of network coding, research on retransmission method based on network coding is more and more popular. Network coding has changed the concept that the relay was only regarded as a forward node in traditional network. It allows relay to encode related information before forwarding it. The encoded network has much greater information. For multicast retransmission system, network coding is widely used to reduce the number of retransmissions and increase the throughput in the network. This paper researched the retransmission algorithm of network coding and proposes a retransmission method which is random network coding. Experimental results demonstrated that the method can not only improve the network efficiency, but also reduce the encoding complexity with more feasibility.In the network with a certain lost package rate or congestion, SVC can restore the video image with a certain distortion when terminals receive part of the code flow. A calculation method highly approximate to distortion is needed to accurately measure the quality of video image. This paper proposed a method to calculate rate distortion accurately. The calculation method was applied to the retransmission of SVC streaming in wireless network. SVC streaming can be selected reasonably by accurate calculation of rate distortion. And the streaming with the best rate distortion performance can also be transferred preferentially. Simultaneously, the network coding technology is used on encoding video streaming in the relay node. The results show that the video transmission system combined with the network encoding can improve the reconstruction quality of SVC video and optimize the network performance.This paper discussed the basic principle of network coding and its development and application. The application of opportunity network coding to video streaming retransmission in wireless multicast networks was mainly researched. The key technology of network coding and the packets retransmission algorithm based on the network coding were also introduced and analyzed. The results show that the method based on network coding can effectively improve the retransmission efficiency and optimize the network throughput of wireless multicast network. For SVC transmission system, this paper improved the calculation method of rate distortion of SVC streaming based on the GOP and made some simulations. It can improve video reconstruction quality effectively by using this method to calculate the rate distortion and transmit the streaming after ordering it.