A low-power ASIC implementation of 2Mbps antenna-rake combiner for WCDMA with MRC and LMS capabilities

An ASIC implementation of a WCDMA mobile terminal with 2-dimensional adaptive antenna-rake combining is presented in this paper. System analysis shows that adaptive antenna-rake combining techniques can significantly enhance the performance and capacity of cellular systems compared to conventional CDMA systems. A hardware efficient receiver architecture is implemented supporting both maximal ratio combining (MRC) and least mean squares (LMS) algorithm. Moreover, the proposed architectures allows for a dynamic and flexible allocation of available processing resources (total of 20 fingers) to different antennas and multipaths based on the instantaneous channel profile. The presented receiver can operate in both normal and space time transmit diversity (STTD) modes. The system was implemented in a 0.18/spl mu/m CMOS process and the improvement was validated through real-time field trials.