Capacity enhancement with adaptive arrays in a CDMA-based LEO satellite system

The capacity enhancement achieved by adaptive antenna arrays at the base station in a CDMA-based multi-beam LEO system is investigated. The system outage probability is evaluated based on a comprehensive analysis of multiple access interference which includes the effects of power control algorithm, the channel fading and shadowing, and the antenna characteristics. Because the statistically optimal beams can be formed by adaptive arrays, the severe multiple access interference in satellite CDMA can be significantly suppressed. The numerical results demonstrate that there is a substantial increase in the uplink capacity by employing adaptive arrays at the base station.