Performance of an Intra- and Inter-Cell Interference Mitigation Algorithm in HSDPA System

Linear equalizer is known to effectively suppress intra-cell interference caused by the multi path propagation in high speed downlink packet access (HSDPA) system. Equalizer algorithms are commonly based on linear minimum mean square error (LMMSE) estimators, which can also take into account the colored interference from other cells. However, several receive antennas are required to efficiently cancel inter-cell interference. On the other hand, non-linear methods are attractive if only one receive antenna is present. However, these algorithms tend to require several auxliary parameters to be known. In this paper, we study a two stage single antenna receiver, combining non-linear and linear processing in HSDPA system. The first stage uses blind interference cancellation (BIC) algorithm to cancel the dominant part of the other cell interference and the second stage uses the LMMSE equalizer to suppress intra-cell interference. The performance of the two stage receiver is compared against conventional LMMSE equalizer. The results show that the studied non-linear algorithm achieves improved performance especially on the cell edge.