PDA+LDPC iterative detector for cooperative CDMA networks

The cooperative CDMA system proposed in this paper performs two phases of transmission. In phase I, each user node transmits its own information which is received by the base station (BS) as well as the other user nodes; in phase II, each partner node relays a processed version of the information received in the previous phase. Two iterative detectors are developed at the B S to combat multiple access interference (MAI). The first one named as PDA+LDPC-I performs detection just in the latter phase. The second one named as PDA+LDPC-II operates in both phases. During the latter phase, it firstly eliminates the signals corresponding to the users which were correctly decoded in the former phase, then performs detection on the resultant signals. Simulation results demonstrate that PDA+LDPC-II outperforms PDA+LDPC-I.