In this paper, the physical layer security of a multi-user jamming-assisted broadcast network in the presence of multiple eavesdroppers. Specifically, a base station (BS) is broadcasting data to multiple end-users via direct links in the presence of multiple passive wiretappers, while both the legitimate users and the eavesdroppers use a maximal-ratio combining scheme to achieve high spatial diversity gain. Furthermore, the BS is broadcasting a jamming signal that can not be canceled by the eavesdroppers to increase their decoding failure rates. All links are subject to Nakagami-m fading models. Relying on the upper incomplete moment-generating function of the combined Signal-to-interference-plus-noise ratio (SINR) at each wiretapper’s MRC output, tight approximate and asymptotic expressions for the secrecy outage probability (SOP) are derived considering two different scenarios, i.e., (i) absence and (ii) presence of the broadcasted artificial noise. The impact of the jamming signal level, severity fading parameter, and the number of MRC branches are examined, while the most influential parameter on the system’s security is retrieved. Numerical results and simulations reveal the accuracy of the obtained analytical expressions and gain more useful insights into the system’s secrecy.
In this paper, the physical layer security of a multi-user jamming-assisted broadcast network in the presence of multiple eavesdroppers. Specifically, a base station (BS) is broadcasting data to multiple end-users via direct links in the presence of multiple passive wiretappers, while both the legitimate users and the eavesdroppers use a maximal-ratio combining scheme to achieve high spatial diversity gain. Furthermore, the BS is broadcasting a jamming signal that can not be canceled by the eavesdroppers to increase their decoding failure rates. All links are subject to Nakagami-m fading models. Relying on the upper incomplete moment-generating function of the combined Signal-to-interference-plus-noise ratio (SINR) at each wiretapper’s MRC output, tight approximate and asymptotic expressions for the secrecy outage probability (SOP) are derived considering two different scenarios, i.e., (i) absence and (ii) presence of the broadcasted artificial noise. The impact of the jamming signal level, severity fading parameter, and the number of MRC branches are examined, while the most influential parameter on the system’s security is retrieved. Numerical results and simulations reveal the accuracy of the obtained analytical expressions and gain more useful insights into the system’s secrecy.
In this paper, the physical layer security of a dual-hop underlay uplink cognitive radio network is investigated over Nakagami-m fading channels. Specifically, multiple secondary sources (Si)1≤2≤Nare taking turns in accessing the licensed spectrum of the primary users and communicating with a multi-antenna secondary base station (D) through the aid of a multi-antenna relay R in the presence of M eavesdroppers (Ek)1≤k≤Mthat are also equipped with multiple antennas. Among the remaining nodes, one jammer is randomly selected to transmit an artificial noise to disrupt all the eavesdroppers that are attempting to intercept the communication of the legitimate links, i.e., Si-R and R-D. The received signals at each node are combined using maximum-ratio combining. Secrecy analysis is provided by deriving closed-form and asymptotic expressions for the secrecy outage probability. The impact of several key parameters on the system's secrecy, e.g., transmit power of the sources, number of eavesdroppers, maximum tolerated interference power, and the number of diversity branches is investigated. Importantly, by considering two scenarios, namely (i) absence and (ii) presence of a friendly jammer, new insights are obtained for the considered communication system. Especially, we tend to answer to the following question: Can better secrecy be achieved without jamming by considering a single antenna at eavesdroppers and multiple-ones at the legitimate users (i.e., relay and end-user) rather than sending permanently an artificial noise and considering that both the relay and the destination are equipped with a single antenna, while multiple antennas are used by the eavesdroppers? The obtained results are corroborated through Monte Carlo simulation and show that the system's security can be enhanced by adjusting the aforementioned parameters.
In this paper, the physical layer security of a dual-hop underlay uplink cognitive radio network is investigated over Nakagami-m fading channels. Specifically, multiple secondary sources are taking turns in accessing the licensed spectrum of the primary users and communicating with a multiantenna secondary base station D through the aid of a multiantenna relay R in the presence of M eavesdroppers that are also equipped with multiple antennas. Among the remaining nodes, one jammer is randomly selected to transmit an artificial noise to disrupt all the eavesdroppers that are attempting to intercept the communication of the legitimate links i.e., S-R and R-D. The received signals at each node are combined using maximal-ratio combining. Secrecy analysis is provided by deriving closed-form and asymptotic expressions for the secrecy outage probability. The impact of several key parameters on the system's secrecy e.g., transmit power of the sources, number of eavesdroppers, maximum tolerated interference power, and the number of diversity branches is investigated. Importantly, by considering two scenarios, namely (i) absence and (ii) presence of a friendly jammer, new insights are obtained for the considered communication system. Especially, we tend to answer to the following question: Can better secrecy be achieved without jamming by considering a single antenna at eavesdroppers and multiple-ones at the legitimate users (i.e., relay and end-user) rather than sending permanently an artificial noise and considering that both the relay and the destination are equipped with a single antenna, while multiple antennas are used by the eavesdroppers? The obtained results are corroborated through Monte Carlo simulation and show that the system's security can be enhanced by adjusting the aforementioned parameters.
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Helvetica} span.s1 {font: 7.5px Helvetica} xAbstract—In this paper, the physical layer security of a dualhop underlay uplink cognitive radio network is investigated over Nakagami-m fading channels. Specifically, multiple secondary sources are taking turns in accessing the licensed spectrum of the primary users and communicating with a multiantenna secondary base station (D) through the aid of a multiantenna relay R in the presence of M eavesdroppers that are also equipped with multiple antennas. Among the remaining nodes, one jammer is randomly selected to transmit an artificial noise to disrupt all the eavesdroppers that are attempting to intercept the communication of the legitimate links i.e., Si -R and R-D. The received signals at each node are combined using maximum-ratio combining. Secrecy analysis is provided by deriving closed-form and asymptotic expressions for the secrecy outage probability. The impact of several key parameters on the system’s secrecy e.g., transmit power of the sources, number of eavesdroppers, maximum tolerated interference power, and the number of diversity branches is investigated. Importantly, by considering two scenarios, namely (i) absence and (ii) presence of a friendly jammer, new insights are obtained for the considered communication system. Especially, we tend to answer to the following question: Can better secrecy be achieved without jamming by considering a single antenna at eavesdroppers and multiple-ones at the legitimate users (i.e., relay and enduser) rather than sending permanently an artificial noise and considering that both the relay and the destination are equipped with a single antenna, while multiple antennas are used by the eavesdroppers? The obtained results are corroborated through Monte Carlo simulation and show that the system’s security can be enhanced by adjusting the aforementioned parameters.
Cooperative jamming for multiuser multiple input multiple output (MIMO) broadcast channel is studied to enhance the physical layer security with the help of a friendly jammer. We assume the base station transmits multiple independent data streams to multiple legitimate users. During the transmission, however, there are multiple eavesdroppers with multiple antennas that have interests in the streams from the base station. In order to wiretap the desired streams, the eavesdroppers may collude or not, and maximize the signal-to-interference-plus-noise ratio (SINR) of the desired streams using receive beamforming. The optimal cooperative jammer is designed to keep the achieved SINR at eavesdroppers below a threshold to guarantee that the transmission from the base station to legitimate users is confidential. One main advantage of the proposed cooperative jamming scheme is that no modification is needed for the existing precoding schemes at the base station and decoding schemes at legitimate users. Thus, any existing practical precoding/decoding schemes for multiuser MIMO broadcast channel can be applied directly with the help of a friendly jammer using the proposed cooperative jamming.
This work investigates the physical layer secrecy of a multi-antenna hybrid satellite-terrestrial relay networks (HSTRN) with jamming, in which a satellite aims to make communication with a destination user by means of a relay, along with spatially random eavesdroppers.In order to weaken the signals of eavesdroppers, the conventional relay can also generate intentional interference, besides forwarding the received signal.Shadowed-Rician fading is adopted in satellite link, while Rayleigh fading is adopted in terrestrial link, eavesdropper link and jamming link.The analytical and asymptotic formulas for the system secrecy outage probability (SOP) are characterized.Practical insights on the diversity order of the network are revealed according to the asymptotic behavior of SOP at high signal-to-noise ratio (SNR) regime.Then, analysis of the system throughput is examined to assess the secrecy performance.In the end, numerical simulation results are presented to validate the theoretical analysis and point out: (1) The secrecy performance of the considered network is affected by the channel fading scenario, the system configuration; (2) Decrease of the relay coverage airspace can provide better SOP performance; (3) Jamming from the relay can improve secrecy performance without additional network resources.
In the perspective of information-theoretical security, inspired by the heterogeneity between legal and illegal channels, we consider the physical layer secrecy performance of a novel system model with a single antenna employed for both the transmitter and legal receiver, in the presence of a multiple antennas passive eavesdropper over dissimilar fading channels, where the legal/illegal channels are subject to Rayleigh/Nakagami-m and Nakagami-m/Rayleigh fading, respectively. We assume that the eavesdropper employs either maximal-ratio combining or selection combining reception in order to benefit from space diversity. Specifically, the exact closed-form expressions of the probability of existence of secrecy capacity and the secrecy outage probability are derived by utilizing statistical characteristics of the signal-to-noise ratio. Moreover, the delightful results reveal that the secrecy performance achieves a greater level when the Nakagami-m fading is supposed on the main link due to the line of sight component. In final, the analytical results are verified by Monte-Carlo simulation.