In the introduction of this paper, we present a background on SDR, in section 2, we give a quick demonstration of main IS-95 features and ways to improve QoS in it. After a short recognition of key fading effects in section 3, we analyze in section 4 the principle of Rake reception. In section 5, we use simulation results to effectively categorize variable number of fingers of the flexible Rake receiver upon user defined level of QoS, and we show the importance of such approach in effectively utilizing hardware resources dedicated for performing digital signal processing tasks, and in reducing power consumption required for these tasks.