Effect of positional instability of an aerial platform on its CDMA performance

The effect of the changes in the position and inclination of an aerial platform (AP) on the number of users per cell (M) in a code division multiple access (CDMA) cellular system is described. The AP at 21 km uses a multiple beam antenna system to create elliptical cells on the Earth's surface. Vertical errors in altitude of the AP of /spl plusmn/0.5 km cause M to decrease by 1 to 2%, while horizontal displacement errors of up to 0.3 km result in a decrease in M of approximately 1%. An inclination of 5/spl deg/ from the horizontal significantly impairs M by 38%.