Cross Layer Optimization Algorithm Based On Raptor Codefor Video Multicast

Now the fourth generation mobile communication has matured, people pay more attention to the quality of mobile broadband transmission network service(QoS), especially in the multi-input multi-output video multicast aspects(Multiple-Input-Multiple-Output, MIMO) system under with the advent of the fifth generation communications era, the key indicators of bandwidth utilization, throughput, and packet loss rate under the system have yet to be further improved.Firstly, cross-layer design more suitable for cross-layer optimization model of video transmission network model requires external environment, MIMO-OFDM system, combined with H.264 video compression standard, which is used in multicast video transmission technology, design policy-Based greedy nonlinear integer programming and search methods and analyzing the simulation results, the system in a wireless environment without increasing system resources and improve the system transmission capacity, and optimized video coding model.In this paper, cross-layer optimization model for the video quality of service, and uses a packet loss rate, bandwidth utilization, throughput, image contrast key objective indicators and subjective indicators, using quantitative parameters fully reflect the algorithm uses the following location, and then put forward in the chain Road transport used two link efficiency mechanisms, namely how to solve the more efficient use of bandwidth resources in a low-speed links and high-speed link in question, based on the combination of cross-layer optimization of WiMAX system QoS mechanism, in-depth exploration of IEEE 802.16 after e wireless standard features designed three kinds of resource scheduling algorithms, for different types of business and match to achieve under any conditions, can achieve high-quality service.Raptor code characteristics and advantages as well as application of streaming media in the post, set up cross-layer model which adapts, compared to other cross-layer model, increasing the adaptive modulation mode and hybrid technology since the request, according to information different situation timely modulation coding rate, without increasing the codec complexity while increasing throughput and resource utilization of the system is very suitable for the vagaries of the radio channel environment.By selecting the best combination of MCS mode and Raptor rate,cross-layer optimization algorithms based on Raptor codes is proposed so that video multicasting mobile networks can be got cross-layer optimization.In the mobile station relative speed of 1km / h, the case of the resource block K = 1820, Raptor error correction code to optimize the system other than the increase in the throughput of the downlink at least 28%; Raptor codes reduce channel resources saving at least 18%; Raptor optimization system when SNR is less than 13 dB, PSNR value is higher than the other two systems to optimize the maximum performance gain of up to 4dB above, but with the increase in SNR, the value of the PSNR converge. This article is in MATLAB simulation environment simulation, implemented on actual mobile broadband systems, results may vary depending on the parameter value change.