Joint MIMO and parallel interference cancellation for the HSDPA

The paper studies high data rate transmissions over frequency selective Rayleigh fading channels, in the downlink of the high speed data packet access (HSDPA) system of the Third Generation Partnership Project (3GPP). We propose, for HSDPA, a combination of transmit and receive diversity schemes, based on 2×2 multiple-input-multiple-output (MIMO), with a multiple access interference (MAI) cancellation scheme, which consists of a variation of the conventional parallel interference cancellation (PIC). Alamouti space-time coding/MIMO schemes achieve better results for channel profiles closer to a uniform power profile. However, these kinds of channel profiles present higher levels of inter-path interference (IPI), which is responsible for the increased higher level of MAI. On the other hand, PIC has a better performance in situations where several users present the same received power. For these reasons, the PIC fits perfectly with the 2×2 MIMO scheme. Hence, we consider the use of a specific type of clipped soft decision (CSD) PIC, optimized for MIMO operation. The use of MIMO combined with the proposed PIC scheme can achieve a high performance improvement over the corresponding schemes, and, hence, HSDPA is able to increase the data rate, also with a performance improvement in bit error rate (BER).