Performance analysis of adaptive modulation with optimum power control in cellular systems

We derive the system throughput and outage probability performance of adaptive modulation with optimal power control in log-normal shadowing and multipath Rayleigh fading channels. We propose two objective functions, namely, maximum SIR optimum power control and minimum outage probability optimum power control. A dynamic programming-based solution to find the optimum transmit power vector is presented. System performance achieved using the proposed objective functions is compared with the performance achieved using other objective functions considered by Qiu et al., (1999). Our results show that: (a) in terms of total system throughput, adaptive modulation with optimum power control gives the best performance compared to other schemes; (b) in terms of outage probability, minimum outage probability optimum power control gives the best performance; and (c) maximum SIR optimum power control benefits every user in the system by evenly distributing the system capacity.