High altitude platforms (HAPs) W-CDMA system over cities

The performance of downlink power control model, based on a n-th power distance law, is evaluated for high altitude platform station (HAPS) W-CDMA systems. The downlink capacity using this model is compared with the uplink capacity. It is shown that the uplink capacity is higher than the downlink capacity. As a case study it is shown that Madrid (the capital) can be covered by a platform with 169 beam. For a HAPS platform with 169 cells (beams) the total practical capacity of the system could be in the order of 10000 voice users or 1250 data users.