User motion impact on performance of downlink mobile WiMAX system deployed via Stratospheric platform (SPF)

As the need for high speed connectivity in mobile environments increases, it becomes necessary to understand the impact of mobility on performance characteristics of wireless communication system. This paper presents an investigation of the mobility impact on performance of a WiMAX 802.16e downlink system deployed via Stratospheric platform for a ground user. It shows how user velocity and physical layer (PHY) setting can contribute to the performance. Simulation result shows performance degradation increases with mobile velocity increase as a result of increase distortion in the channel due to Doppler frequency spread. However after speed of 30 km/hr the system will keep same performance. Finally we found that WiMAX services, which require high level requirement, have an acceptable performance over SPF channel if the user exists at the centre of coverage whatever user's velocity is.