DESIGN OF POWER-CONTROL MECHANISMS WITH PCM REALIZATION FOR THE UPLINK OF A DS-CDMA CELLULAR MOBILE RADIO SYSTEM

Power control (PC) is an important issue in a direct sequence-code div ision multiple access (DS-CDMA) cellular mobile radio system. Higher l ink performance and greater system capacity cannot be achieved unless an appropriate PC mechanism is employed. In previous research, a delta -modulation (DM) realization of strength-based and SIR-based PC mechan isms for uplink communication has been studied by simulation. In order to obtain higher PC trackability, in this paper we study a pulse-code -modulation (PCM) realization of the above two PC mechanisms for the u plink of a DS-CDMA cellular mobile radio system. The simulation result s presented here indicate that PC mechanisms with PCM realization for the uplink can achieve a lower outage probability and thus higher link performance than PC mechanisms with DM realization. We also obtain op timal design parameters such as the stepsize and the control mode for the two PCM PC mechanisms. In addition, we compare the two PCM PC mech anisms in terms of their outage probability and stability and find tha t the strength-based mechanism has a higher outage probability but gre ater stability than the SIR-based mechanism.