Improved sample added LMMSE receiver based on interference mitigation for HSDPA downlink

In the downlink of wideband code division multiple access (WCDMA) or WCDMA- high speed downlink packet access (HSDPA) system, the frequency reuse factor is equal to 1, which leads to more possible co-channel interference from neighbor cells. In this situation, user equipment (UE) with traditional receiver will suffer from significant performance degradation at the edge of the cell. To solve this problem, a receiver structure considering interference mitigation has been proposed for long term evolution (LTE) of third-generation partnership project (3GPP). Such receiver makes use of all the interfering cells’ channel information to perform a linear minimum mean square error (LMMSE) equalization algorithm. In this article, an improved equalization algorithm is presented, which simply adds more samples to perform one equalization operation. Simulations show that the proposed algorithm can obtain a considerable performance improvement in frequency selective fading channel, with relative little additional complexity introduced.