Traffic-aided multiuser detection for random-access CDMA networks

Traffic burstiness has been observed for multimedia packet switching networks. This burstiness results in the predictability of user activity at the individual source level, and the exploitation of such predictability in the receiver design for a random-access CDMA packet switching network is investigated in this paper. A decorrelating detector is considered for performance and complexity tradeoff and it is shown that the conventional approach of assuming all users are active results in substantial performance loss. A two-stage multiuser detection is proposed where the first stage tracks active output to the second stage multiuser detector for symbol detection. It is demonstrated that by using the traffic predictability, an accurate estimate of an active set of users is possible with a simple matched filterbank at the first stage.