ICA-RAKE switching for jammer cancellation in DS-CDMA array systems

The paper considers the use of independent component analysis (ICA) combined with a RAKE receiver as a method for cancellation of interference caused by either continuous or pulsed jamming in a multiple antenna system employing direct sequence spread spectrum communication. We have explained the use of blind interference mitigation using independent component analysis elsewhere (see Ristaniemi, T. et al., Proc. IEEE Int. Conf. on Communications, 2002; Raju, K. et al., Proc. IEEE Int. Symp. on Circuits and Systems - ISCAS, 2002). This paper extends the technique by introducing a branch switching between conventional RAKE and ICA-RAKE receivers that automatically switches between the two detectors. The goal is to activate ICA preprocessing only when it is expected to improve conventional detection. We utilize training symbols or a preamble in this switching. The proposed method exploits the advantages of ICA during situations of high jamming and uses conventional RAKE when the strength of the jammer is inconsequential. Numerical experiments in various jamming scenarios are shown to validate the performance of this technique.