| In recent years, the demand for wireless high-speed digital multimedia serviceshas increased rapidly with the rapid development of the new generation andultra-wideband mobile communication systems. Therefore, there is great importantsignificance to research on how to improve the video transmission reliability to meetthe need of different people under the control of limited bandwidth.The paper studies the H.264/SVC technique, joint source and channel codingtechnique and MIMO-OFDM techniques. Primarily, an optimal joint source andchannel rate allocation algorithm based on an improved grid algorithm andGOP-based slope search algorithm with the priority of key frame in the time domainis proposed. The improved grid algorithm is proposed to compute the rate-distortioncurve for each frame. It could greatly reduce the amount of computation because itcan delete some unreasonable branches and complete the merge process in therecursive process. And convex function process was used to ensure the characteristicof convex of the rate distortion curve of each frame, which lead to the optimal rateallocation in the next step. The GOP-based slope search algorithm with the priorityof key frame in the time domain is used to get the final rate allocation results. Itcould improve the quality of the recovery video because it fully consider theimportance of the key frame in time domain and make full use of the rate-distortioncurves of each frame in a GOP. The algorithm is irrespective of the target rate andcan adapt to different bandwidth better combined with the traditional bisectionalgorithm.Then, an adaptive MIMO-OFDM sub-carrier bit power allocation algorithm isstudied. And an adaptive transmission scheme based on the proposed JSCC methodand adaptive MIMO-OFDM sub-carrier bit power allocation algorithm is proposed,which guarantees the reliable transmission in MIMO-OFDM system.Finally, the performance of the proposed algorithm is simulated. Thesimulation results show that the proposed transmission scheme can be applied todifferent bandwidth condition and improve the quality of the receiving video whilereducing the computational complexity. |
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