Power control and stepwise removal algorithms for a narrowband multiuser detector in a cellular system

With a narrowband multiuser detector (MUD), multiple users can simultaneously share the same channel without using a bandwidth expanding signature code when sufficient power differences at the receiver are maintained. In this paper, we estimate the capacity that can be achieved in a hypothetical cellular system with centralized power control, using a narrowband MUD based on successive cancellation. The power control algorithm is adapted to multiple users per channel in a cell. Capacity results from simulations based on user removal are presented for three removal algorithms. It is shown that the narrowband MUD has a significant potential for capacity gain due to a tighter packing of users in a channel.