PIC receiver implementations for the asynchronous UMTS scenarios

In this paper, three different implementations of a multistage partial parallel interference cancellation (PIC) receiver for the asynchronous UMTS signal are presented and compared. The proposed structures take into account the scrambling and channelization codes employed in UMTS and two of them are advanced structures specifically designed to attempt to remove completely the multiuser interference thanks to the addition of specific data buffers for this scenario.The advanced structures proposed outperform the direct implementation of the PIC receiver derived from synchronous CDMA scenarios by taking into account the whole set of interference terms. Also, no windowing is necessary at the receiver and no framing transmission is required.