Total capacity in a shared CDMA LEOS environment

We are interested in determining the feasibility of having multiple service providers share the same spectrum in transponder-type. Satellite-based, code-division multiple-access mobile communications. To accomplish this, we compare the total capacity when n systems are operational to that when only a single system uses the frequency band. This comparison is made for both the uplink and the downlink under one of two possible constraints, either a maximum power flux density (PFD) limit per system, or an aggregate PFD limitation. While there are circumstances when the total capacity of multiple systems can achieve a greater value than that of a single service provider, conditions depend on the degree of shadowing, and whether or not the PFD limit is on a per system basis or on an aggregate basis from all systems