Selective power control with active link protection for combined rate and power management

In wireless multimedia services, the system can provide a user with multiple data rates. This paper focuses on the combined control of rates and powers for the system, in which a finite number of transmission rates are available. This problem was first addressed by Kim, Rosberg and Zander (see Proc. IEEE VTC Fall, p.1653-57 1999) and two distributed power control algorithms were suggested. One of the suggested algorithms there is called selective power control (SPC). In this paper, we extend SPC by combining it with the active link protection (ALP) scheme. The main purpose of such an extension is trying to guarantee the minimum rate to users and to minimize the number of rate changes by smoothing the realized CIRs. Computational experiments are carried out on a DS-CDMA system. The results indicate that the modified SPC achieves smaller outages and less rate changes while giving the same or slightly higher system throughput, compared with SPC