Blind Adaptive Constant Modulus RAKE Receiver for Downlink CDMA

Linear receiver structures for DS-CDMA systems are amongst the most promising techniques for interference suppression in the downlink since they offer an attractive trade off between performance, complexity and the need for side information. In this paper we investigated a code-constrained constant modulus RAKE receiver for direct sequence code division multiple access (DS-CDMA) channels. We propose a closed loop solution for linear receiver based on constrained optimisation technique that combines multipath signals using multiple constraints which are treated as variables and are jointly optimised with the receiver. The proposed algorithm jointly estimates the parameters of the channel and the receiver in order to suppress multi-access and intersymbol interference.