Reduced state maximum likelihood multiuser detection techniques for downlink td-cdma

摘要

Joint Detection (JD) techniques constitute an effective mean to defeat both InterSymbol and Multiple Access Interference (ISI and MAI respectively) arising in Code Division Multiple Access (CDMA) systems. The computational complexity of the optimum receiver for JD, the Maximum Likelihood Multiuser Detector (MLMD), increases exponentially with the number of users, and therefore is unfeasible. In this paper two suboptimum versions of MLMD, whose complexity is now proportional to the number of users, are illustrated. The basic idea behind these algorithms is to join the good performance of the Maximum Likelihood (ML) approach with the efficiency of a Reduced State (RS) technique, suitable for downlink connections.