Research On Energy-efficient Image Transmission Algorithms In Mobile Internet

The rapid development of mobile Internet has brought the rapid growth of multimedia data services, not only to facilitate our life, but also promote the progress of social informatization. Because of the limited energy of the mobile terminal, the attenuation characteristics of the wireless channel, and the high-quality of service requirement of the multimedia applications, wireless image transmission has face great challenges. This thesis investigate the high efficiency transmission method of image in mobile Internet. And mainly focus on analysis of the cross layer optimization method and unequal error protection strategy.In this thesis, a method of wireless transmission of low energy consumption image based on cross layer optimization under the double constraints of time delay and quality of image is proposed. Firstly, the energy consumption of the transmission system in the process of transmitting a data frame and receiving the feedback frame is analyzed. Then, after analyzing the certain retransmission average number of frames of image data transmission time and frame loss rate, the thesis develops a dual image data frame energy consumption minimization problem in the presence of the mathematical model of delay and quality constraints. Finally, in order to minimize wireless transmission of the total energy consumption of the whole image, this thesis applies the cross layer optimization strategy, the joint optimization of transmit process in each frame of image data the respective modulation coding mode as well as retransmission limit and data frames each transmission transmit power. Simulation results show that the proposed method can significantly reduce the total energy consumption of wireless image transmission when guarantees the image quality and transmission delay.Considering the image transmission in the frequency selective fading channel, combined with the characteristics of orthogonal frequency division multiplexing wireless communication systems, this thesis proposes a method based on unequal error protection minimizing wireless transmission of the whole image energy consumption. Firstly, the transmission energy consumption in the process of transmitting all the image data frames is analyzed, and the distortion caused by the error bits in the frame transmission of the image data is also discussed. On this basis, the transmission power can be allocated to different parts of the image data frame, and the different parts of the data frame are matched to different channels through the channel selection. Further, this method aims to minimize the image wireless transmission required the total energy of the system under the certain quality constraints. Simulation results show that, compared with the typical equal power allocation scheme and unequal power allocation method, under different channel conditions, the proposed method enables to reduce the distortion of the transmission image. In addition, under the same distortion constraint conditions, this method consumes less energy consumption.