In this paper, we propose a reduced complexity and power efficient System-on-Chip (SoC) architecture for adaptive interference suppression in CDMA systems. The adaptive Parallel-Residue-Compensation architecture leads to significant performance gain over the conventional interference cancellation algorithms. The multi-code commonality is explored to avoid the direct Interference Cancellation (IC), which reduces the IC complexity from O(K^2N) to O(KN). The physical meaning of the complete versus weighted IC is applied to clip the weights above a certain threshold so as to reduce the VLSI circuit activity rate. Novel scalable SoC architectures based on simple combinational logic are proposed to eliminate dedicated multipliers with at least 10X saving in hardware resource. A Catapult C High Level Synthesis methodology is apply to explore the VLSI design space extensively and achieve at least 4£ speedup. Multi-stage Convergence-Masking-Vector combined with clock gating is proposed to reduce the VLSI dynamic power consumption by up to 90%.