Multirate decorrelating detector for UMTS

A generalization of the conventional decorrelating detector, designed to deal with the multirate Universal Mobile Telecommunications System (UMTS) signal, is presented. First, the multiple access interference (MAI) is characterized taking into account the two-layered UMTS spreading codes. To this end, the elementary cross-correlation is defined. On the basis of this elementary cross-correlation, the equations that describe the UMTS signal matched filter (MF) outputs are derived and the proposed multirate decorrelating detector strategy is explained. This detector, that generalizes the standard single-rate decorrelating detector, outperforms other commonly employed receivers like the minimum mean-square error (MMSE) receiver and the correlation receiver.