A denoising source separation based approach to interference cancellation for DS-CDMA array systems

Spreading codes provide a layer of interference suppression in a DS-CDMA system. This is not sufficient and can be augmented by schemes relying on second-order statistics and effective beamforming methods. These methods either require good channel state information or a separation in the look direction. This additionally requires the use of channel estimation or direction-of-arrival (DOA) estimation. This paper proposes icDSS - an interference cancellation method based on denoising source separation (DSS) (J. Sarela et al., 2004). Here, a source separation algorithm is built around a denoising procedure consisting of despreading the signals followed by thresholding. DSS can be used to suppress the interference as well as to denoise the system. Since icDSS does not use any information about the channel, this method is blind. The only information icDSS knows is the spreading code of the user of interest. Computer simulations demonstrate the performance and applicability of this algorithm.