Simulation And Optimization Of Mobile Video Transmission In Rail Transit Environment

With the rapid development of wireless communication technology and Internet technology, mobile video transmission has attracted lots of attention in both academic and engineering fields. In the next few years, mobile video will account for two-thirds of global mobile data traffic, which makes research about mobile video more important in the field of broadband wireless communication technologies. To the best of our knowledge, most research about mobile video transmission focus on the traditional urban cellular networks. Research in such dedicated scenarios as rail transit scenario is relatively less. In rail transit environment, broadband mobile communication has some unique characteristics. Radio channel is both time and frequency selective. There will be frequently group handover and the penetration loss will attenuates the received signal. These characteristics impose huge challenges to mobile video transmission.The system-level simulation for mobile video transmission and handover scheme to optimize mobile video transmission in rail transit environment are concerned in this paper. To begin with, research status at home and abroad and mobile communication technologies are introduced. Then, a channel simulator based on software radio technology is set up to study the performance of mobile video transmission in rail transit environment. The designed channel simulator can support different wireless communication protocols and have great advantages in terms of programmability and scalability. The effects of different train speed and channel model on the quality of the mobile video are analyzed based on the channel simulator. Also, a vehicular communication system for rail transit environment is proposed to provide broadband service such as mobile video for passengers. At last, based on the designed system, a novel handover scheme and QoE (Quality of Experience)-driven cognitive handover algorithm is proposed to ensure mobile video transmission. Compared with the traditional handover algorithm, the cognitive handover algorithm can achieve the maximum utility and decrease the handover times.