Analysis of the Uplink Capacity for Using HAPS in 3G Mobile Communication

[[abstract]]High altitude platform stations (HAPS) is a new means of providing Third Generation (3G) mobile services. It combines advantages of terrestrial and satellite systems such as line-of-sight, low multi-path fading and no shadowing for high elevation angles. It will change the design of communication network by the developing of the HAPS. Terrestrial mobile system has constructed throughout. We want to combine the existing terrestrial cellular systems and HAPS system to provide an ideal integrated system. First of all, we consider the uplink capacity for integrated HAPS-terrestrial code division multiple access (CDMA) system in which sharing band overlay. In this integrated system, we propose three integrated system models respectively to increase the system capacity and to serve remote area. Second, Previous studies have shown that platform instability caused by stratospheric winds may lead to system level performance degradation. We discuss instability of HAPS system, and we propose to combat this problem by using multiple HAPSs to provide diversity of signal reception.