A Novel Rank Estimator for Inter-cell Interference Cancellation in CDMA Systems

Inter-cell interference is one of the major obstacles to reliable communications in the uplink of multipath code-division multiple-access (CDMA) systems. In recent years different algorithms have been developed to combat the detrimental effect of inter-cell interference by exploiting the orthogonality between the signal and noise subspaces. The knowledge of the number of unknown users is compulsory for these types of receivers. In this paper a novel estimator is proposed to estimate the number of unknown users by exploiting the statistical properties of the signal. Simulation results demonstrate that the proposed estimator can provide an accurate estimate of the number of unknown users with high probability.