To spread or not to spread, this is the question

TDMA and DS-CDMA are two access methods proposed for digital cellular systems and given the status of standard in the U.S. It is shown in this paper that a capacity comparison between them is scenario specific. In the case of terrestrial cellular CDMA is the winner, whereas in the scenario of a single isolated cell, or for a satellite based cellular system, TDMA appears to be superior. Lastly, there can be a regulatory reason which can prevent the implementation of DS-CDMA like in the Private Land Mobile case, where spectrum is usually licensed on the basis of single narrowband channels and thus a contiguous wide band spectrum is not available