Intelligent jamming design for disrupting DS-CDMA systems

In this paper, we investigate the problem of intelligent jamming design to attack a legitimate multiuser DS-CDMA downlink communication system. As the most common and realistic scenario, neither the channel state information (CSI) nor legitimate users´ spread sequences (signatures) are known to the jammer. Therefore, the first task before intelligent jamming design is to acquire the necessary information of the legitimate DS-CDMA system by eavesdropping and analyzing its signals. To achieve this goal, we adopt the mature iterative least-squares (ILS)-based algorithm which can blindly identify the users´ signatures in the DS-CDMA system. With the information of users´ signatures, we use the periodic-total-square-correlation (PTSC) interference metric to quantify the impairment of the legitimate DS-CDMA system caused by the jamming signal. We attempt to optimize the jamming signal that maximizes the PTSC interference to legitimate DS-CDMA users under a given jamming power budget. Simulation studies confirm our analytical predictions and illustrate the efficiency of the designed optimal jamming signal on disrupting DS-CDMA communications.