A study of orthogonal matched filters for interference cancellation in the situation that different spreading codes exist

In this paper, we consider direct sequence code division multiple access (DS-CDMA) communications, (wireless LAN in the ISM band), where the undesired DS-CDMA signals have different PN sequence lengths compared with the desired DS-CDMA signal. In this situation the conventional orthogonal matched filter (OMF) receiver´s performance is poor, and so we propose a new OMF receiver to take into account these undesired signals. We show, through computer simulations, that our proposed OMF receiver will outperform the conventional OMF receiver.