In this paper, we investigate the secure transmission based on differential spatial modulation with artificial noise in multiple-input single-output wiretap networks, where a cooperative jammer help the secure transmission between transceivers in the presence of a passive eavesdropper. We derive exact and asymptotic closed-form expressions for secrecy outage probability and effective secrecy throughput of the network. Finally, numerical simulations demonstrate that increasing the transmit power of transmitter or cooperative jammer can improve the secrecy performance of the system, but too large transmit power at transmitter or cooperative jammer is not helpful. Moreover, increasing the number of antennas at transmitter or cooperative jammer brings up better secrecy performance.
In this paper, we investigate the secure transmission based on differential spatial modulation with artificial noise in multiple-input single-output wiretap networks, where a cooperative jammer help the secure transmission between transceivers in the presence of a passive eavesdropper. We derive exact and asymptotic closed-form expressions for secrecy outage probability and effective secrecy throughput of the network. Finally, numerical simulations demonstrate that increasing the transmit power of transmitter or cooperative jammer can improve the secrecy performance of the system, but too large transmit power at transmitter or cooperative jammer is not helpful. Moreover, increasing the number of antennas at transmitter or cooperative jammer brings up better secrecy performance.
In this paper, we investigate the secure transmission for differential quadrature spatial modulation (DQSM) with artificial noise (AN) in multiple-input single-output wiretap networks, where a cooperative jammer helps the secure transmission between transceivers in the presence of an eavesdropper. To evaluate the secrecy performance of the DQSM with AN in the considered wiretap networks, assuming Rayleigh fading, we derive exact and asymptotic closed-form expressions for secrecy outage probability and effective secrecy throughput under two practical scenarios, i.e., Scenario I, where the eavesdropper is passive and its channel state information (CSI) is unavailable, and Scenario II, where the eavesdropper is active and its CSI is available. Finally, numerical simulations demonstrate that increasing the transmit power of transmitter or cooperative jammer can improve the secrecy performance, but too large transmit power at the transmitter or cooperative jammer is not helpful. Moreover, increasing the number of antennas at the transmitter or cooperative jammer brings up better secrecy performance.
This paper studies the secrecy performance of cognitive wiretap networks, in which the secrecy secondary transmitter (Alice) transmits information to multiple secondary receivers (Bobs) in the presence of an eavesdropper (Eve). Specifically, to reduce the power consumption and complexity of the secondary users, this paper put forward a novel transmission scheme based on the differential spatial modulation (DSM), which can reduce the processing complexity at Alice and Bobs. Moreover, the exact and asymptotic closed-form expressions, for secrecy outage probability and effective secrecy throughput, are derived to assess the performance of the proposed DSM scheme. From the analysis, we demonstrate that a) the secrecy diversity is determined by the number of the Alice's antennas and the number of Bobs, b) the secrecy performance of the considered cognitive wiretap networks based on DSM outperforms the same networks without DSM.
We propose a secure transmission scheme for a relay wiretap channel, where a source communicates with a destination via a decode-and- forward relay in the presence of spatially random- distributed eavesdroppers. We assume that the source is equipped with multiple antennas, whereas the relay, the destination, and the eavesdroppers are equipped with a single antenna each. In the proposed scheme, in addition to information signals, the source transmits artificial noise signals in order to confuse the eavesdroppers. With the target of maximizing the secrecy throughput of the relay wiretap channel, we derive a closed-form expression for the transmission outage probability and an easy-to-compute expression for the secrecy outage probability. Using these expressions, we determine the optimal power allocation factor and wiretap code rates that guarantee the maximum secrecy throughput, while satisfying a secrecy outage probability constraint. Furthermore, we examine the impact of source antenna number on the secrecy throughput, showing that adding extra transmit antennas at the source brings about a significant increase in the secrecy throughput.
This paper proposes to employ multiple cooperative jammers to reduce the secrecy loss due to the correlation between main and wiretap channels. We consider slow-fading multiple-input single-output (MISO) wiretap channels with a passive single-antenna eavesdropper, in which an independent transmitter side and correlated receiver side are assumed. Considering that signal processing techniques as well as the blind growth of power at the source play a limited role in reducing the secrecy loss due to the receiver-side correlation, multiple cooperative jammers equipped with multiple antennas are introduced into the system. Owing to spatial diversity, the channel correlation from the different jammers to the destination and the eavesdropper varies. To interfere with the reception at the eavesdropper efficiently and consequently enhance security, some jammers in favorable channel conditions are selected to emit artificial noise (AN) with power optimization. Based on this, the secrecy outage probability is analyzed. The simulation results verify that the proposed scheme of multiple cooperative jammers provides substantial gains in terms of secrecy.
We design a new relay-aided secure transmission scheme, in which a source communicates with a destination through a trusted decode-and-forward relay in the presence of spatially random-distributed non-colluding eavesdroppers. We consider a general antenna configuration, in which the source, relay, destination, and eavesdroppers are equipped with multiple antennas. We assume that both the source and the relay transmit artificial noise signals in addition to information signals. We also assume that the source and the relay adopt different codebooks, and that the transmitted signals from the source and relay are not jointly processed at each eavesdropper. We first derive a closed-form expression for the transmission outage probability and a new expression for the secrecy outage probability. Notably, these expressions are valid for an arbitrary number of antennas at the source, relay, and destination. We then derive simple yet valuable expressions for the asymptotic transmission outage probability and the asymptotic secrecy outage probability, which reveal the secrecy performance when the number of antennas at the source grows sufficiently large. Using our expressions, we quantify a practical performance metric, namely, the secrecy throughput, under a secrecy outage probability constraint. We further determine the system and channel parameters that maximize the secrecy throughput, leading to analytical security solutions suitable for real-world deployment.
This paper investigates cooperative security in wireless networks, where a source (Alice) intends to transmit a confidential message to a legitimate destination (Bob), with the help of a cooperative jammer (Charlie), coexisting with multiple passive eavesdroppers (Eves). In particular, by assuming knowledge of Bob's perfect channel state information (CSI) but only Eves’ statistical CSIs, secrecy beamforming with artificial noise (AN) is utilized for secure transmission, and cooperative jamming (CJ) is explored to further enhance secrecy. We first derive an accurate closed-form expression for the secrecy outage probability (SOP), and establish the condition under which positive secrecy rate is achievable. Then, we provide a secure transmit design for maximizing the SOP constrained secrecy rate. Moreover, based on a strict mathematical analysis, we characterize the impact of the main channel quality and the number of Eves on transmit design and secrecy performance. Specifically, optimal power allocation ratio between the information-bearing signal and the AN signal increases as the main channel quality improves, and decreases with the number of Eves. Numerical results confirm that our design achieves performance improvement in terms of both secrecy rate and secure energy efficiency, as compared to the approach without CJ.