Study of Technologies in 3～（rd） Generation Mobile Communication System Rake Receiver

In Code Division Multiple Access (CDMA) systems, Rake receiver is the core parts which use several base-band correlators to individually process several signal multi-path components. It can distinguish multi-path from received signals, overcome multi-path fading and achieve improved communications reliability and performance.In CDMA spreading systems, much work in system design and signal processing has been focused on lowering the required received power (e.g. [5]) mainly because, lower required received power leads to higher system capacity.In this paper, we concentrate on the low power architecture design for the Rake receiver inside the 3rd generation mobile communication system, namely 3G. Transformation is carried out for designing new hardware architectures for the implementation of the Rake finger in the Rake receiver. In particular, algorithmic transformation is done on the Rake finger to reduce the operation frequency of the complex operations. In the cases, the new architectures implement the same calculation as the traditional architectures and hence give exactly the same output for a given input. Experimental results show that significant power reduction is achieved when the proposed architectures are used for cdma2000 standard. Similar power reduction is expected if the architectures are employed for other CDMA standards such as WCDMA.