Adaptive power and rate allocation for service curve assurance in DS-CDMA network

This paper describes schemes for forward and reverse links in a direct sequence code-division multiple-access-based cellular network. The primary objective is to meet the diverse quality-of-service (QoS) needs of mobile hosts (MHs), and the secondary objective is to maximize the system throughput. The QoS needs of the MHs are modeled using the notion of a service curve. Furthermore, a notion of deviation is introduced as a measure of meeting service curve. The scheme proposed in this paper jointly adapts the transmitted power and the number of spreading codes assigned to each MH for receiving/transmitting its data bits. The scheme imposes practical constraints including bounds on the transmitted power for a base station and MHs, a bound on the number of spreading codes that an MH can handle, and minimum signal-to-interference-plus-noise ratio at the receiver. The proposed solutions are evaluated using discrete event simulations. The simulation results characterize the performance of the proposed solutions for several instances of the practical constraints.