Complexity analysis of an interpolation based RAKE receiver for WCDMA systems

This paper proposes and analyses a low complexity baseband architecture for DS-CDMA receivers, e.g., for 3rd generation mobile systems. Our focus is on the baseband channel selection/pulse-shaping filtering and delay tracking and despreading units of a RAKE receiver. An interpolation based approach is developed for code synchronization. This approach allows the use of modest oversampling, two samples per chip, in the baseband processing while it provides essentially the same receiver performance as an oversampled receiver structure with 8 or more samples per chip. The focus is on the complexity evaluation and comparison with the oversampled receiver architecture, taking into account also the complexity of the channel filtering section using optimized multirate digital filtering techniques.