Research On Wireless Channel Capacity In High-speed Environment

With the rapid development of high-speed railway, comminication system for railway is required higher for railage. In order to protect the safety and stability of train, communication system for railway is requred to provide a reliable, stable, real-time data transmission. Besides, the growing passenger information services need a higher voice and data transmission rate. The bandwidth and rate of current digital mobile communication system for railway (GSM-R) is limited, and it is difficult to meet the needs of new business, so it’s necessary to refer and adopt advanced mobile communication technologies, such as multiple-input-multiple-output technology and wideband communication technology, for the evolution of next generation mobile communication system for railway. It’s very important to reaserch channel capacity in high-speed railway environment for next generation mobile communication system for railway, and it will lay a solid foundation for research and construction of next generation mobile communication system for railway.The work and innovations of this thesis are listed as follows:Firstly, the characteristics of wireless radio propagation in high-speed railway environment are analyzed and three kinds of channel models for high-speed railway environment are summarized.Secondly, based on characteristics of radio propagation in high-speed railway environment, the impact of direct path on channel capacity is analyzed and simulated in narrowband system. Besides, the impact of different power allocation (equal power allocation and water-filling power allocation) on capacity at transmitter is investigated.Thirdly, the calculation method of channel capacity in wideband system is investigated, and the impact of antenna and power allocation on capacity is investigated in high-speed railway environment.Fourthly, channel capacity under shadow fading is investigated in high-speed railway environment, divided into two cases with feedback delay. Then the impact of power allocation and feedback delay on channel capacity is analyzed.