Secure CDMA Communication with Disguised Cooperative Jamming

Cooperative jamming in multi-node systems provides a means of injecting artificial noise into communication schemes for physical layer security applications, without requiring multiple antennas at each node. Eavesdroppers in CDMA systems are particularly vulnerable to a specific style of jamming called disguised jamming, where jammers transmit signals using the same spreading codes as legitimate users. Here, we propose a scheme to provide physical layer security in an uplink CDMA system through cooperative disguised jamming, where we formulate an optimal user/jammer matching scheme where the jammers for each user are selected to be robust to a large pool of potential eavesdroppers, as opposed to either being tailored to a specific eavesdropper or being completely generalized. We use secrecy outage probability (SOP) as our security metric, and note up to an 83 % decrease in maximum SOP among users, when comparing to a scheme which focuses on just one eavesdropper.