Combined downlink beamforming and channel estimation for high data rates CDMA systems

We presented a method for efficiently combining channel estimation and downlink beamforming for CDMA systems, in cases where the RAKE receiver cannot be used for channel estimation. This method relies on an iterative scheme which iterates between a channel estimation scheme which is only stable when the multi-user interference is low and a beamforming operation which maximises the received signal to noise ratio. The simulation results presented show that this iterative scheme seems to converge to solutions which maximise the signal to noise plus interference ratio (SINR) which is an attractive feature since it is achieved without taking into account other user's statistics. In this new method the channel estimation and beamforming operations are iterated several times until convergence to a fixed solution.