An MPI mitigation technique for high order data modulations in the presence of intracell interference

Increasing throughput using high order data modulations in downlink WCDMA systems requires the elimination of the multipath interference (MPI). Linear chip equalizers using zero forcing (ZF) and minimum mean square error (MMSE) were proposed in downlink. A multipath interference canceller (MPIC) using weighted multi-stage parallel interference cancellation (PIC) was introduced in high speed downlink packet access (HSDPA) systems. We propose a multipath interference mitigation algorithm which removes the MPI in the presence of intracell interference. The proposed algorithm employs a linear tentative decision device with null zone in order to eliminate the MPI for intracell interference. As the intracell interference power increases, the proposed algorithm exhibits better performance compared with the RAKE and the MPIC.