Asynchronous orthogonal decision-feedback multiuser detector (AODFD) and its alternative decoding strategies

This paper proposes a new CDMA multiuser detector, asynchronous orthogonal decision-feedback detector (AODFD), and its alternative decoding schemes. The proposed AODFD does not require an infinitely long whiten filter in its feed-forward stage, however, which is necessary in traditional ADDFD detector reported in the literature. The updating algorithm of the AODFD detector is also much simplified if compared with that of ADDFD that requires computational intensive z-transformed matrix inversion and spectral factorization. Results show that, despite its low complexity, the AODFD performs very well under multiple access interference. The proposed two new decoding strategies can also be chosen to cater for different operating scenarios.