In this paper, we propose an adaptive antenna index (AI) mapping scheme with the aid of partial channel state information (CSI) (i.e., channel gain order information) of legitimate channel. Based on the received partial CSI that is unknown to an eavesdropper (Eve), transmitter (Tx) adapts AI mapping patterns. In addition, Tx also adapts transmit power allocation to each transmit antenna according to the partial CSI. Since Eve is unaware of the partial CSI of the legitimate channel, it cannot successfully decode the AI patterns; and transmission over the legitimate channel is secured from wiretapping of Eve. Further, we offer an accurate analytical framework for ergodic secrecy rate (ESR) and bit error rate (BER) of 2-ary space shift keying modulated multiple-input single-output system in the presence of a passive eavesdropper. Moreover, the analytical results of ESR and BER demonstrate the robustness of the proposed scheme. All numerical results are thoroughly verified by using the Monte Carlo simulations.
In this paper, we propose an adaptive antenna index (AI) mapping scheme with the aid of partial channel state information (CSI) (i.e., channel gain order information) of legitimate channel. Based on the received partial CSI that is unknown to an eavesdropper (Eve), transmitter (Tx) adapts AI mapping patterns. In addition, Tx also adapts transmit power allocation to each transmit antenna according to the partial CSI. Since Eve is unaware of the partial CSI of the legitimate channel, it cannot successfully decode the AI patterns; and transmission over the legitimate channel is secured from wiretapping of Eve. Further, we offer an accurate analytical framework for ergodic secrecy rate (ESR) and bit error rate (BER) of 2-ary space shift keying modulated multiple-input single-output system in the presence of a passive eavesdropper. Moreover, the analytical results of ESR and BER demonstrate the robustness of the proposed scheme. All numerical results are thoroughly verified by using the Monte Carlo simulations.
In this paper, we investigate the physical layer security based on space shift keying (SSK) in which bit-to-spatial mapping of antenna indices dynamically adapts according to the partial channel state information (CSI) of the legitimate channel at the transmitter (Tx). Further, the Tx also adapts transmit power allocation to each transmit antenna according to partial CSI. Since an eavesdropper (Eve) is not (usually) aware of the legitimate CSI, it cannot successfully decode the antenna index; thus, transmission over the legitimate channel is secured from the wiretapping of Eve. An important virtue of the proposed scheme is that the Tx does not require full CSI of the legitimate and eavesdropper channels to secure the confidential information. The proposed work focuses on the secrecy rate (SR) and bit error rate (BER) of the considered multiple-input single-output system over Rayleigh fading channels. Approximate expressions of Bob's data rate for 2-ary and 4-ary SSK modulations are derived in closed-form. Furthermore, an upper-bound of Bob's data rate for Na-ary SSK modulation is also derived. In order to obtain the secrecy rate for the proposed scheme, we also evaluate Eve's data rate. Analytical results of SR and BER demonstrate the robustness of the proposed scheme. All numerical results are thoroughly verified by using extensive Monte Carlo simulations.
In this letter, a novel transmission scheme for spatial modulation (SM) is proposed to enhance the security of wiretap channel. In this scheme, partial channel state information (CSI) of the legitimate channel is exploited by the transmitter (Tx) to dynamically adapt the spatial and signal constellations mapping patterns that are unknown to Eve. Thus, Eve cannot successfully decode the confidential information over the wiretap channel. Further, an important virtue of the proposed transmission scheme, Tx does not need to know the full CSI of Eve and legitimate channels. To demonstrate the security guaranteed by the proposed scheme, bit error rate, secrecy rate, and secrecy outage probability are evaluated.
A tournament-based index obfuscation framework is proposed and analyzed for space shift keying (SSK) multiple-input multiple-output (MIMO) systems. Algebraic properties of Paley tournaments are exploited to construct deterministic yet nontrivial permutations of the transmit antenna indices. These permutations are refreshed on a per-channel basis through a channel-dependent cyclic shift derived from reciprocity. As a result, a matched index-domain channel is observed at the legitimate receiver, whereas an eavesdropper is forced to operate under a mismatched decoding metric. In contrast to conventional physical-layer security techniques, the proposed framework operates exclusively in the index domain and preserves the inherent energy-efficiency and low-complexity advantages of SSK. In practical SSK implementations where the number of transmit antennas is not a power of two, only a subset of valid antenna indices is used for information mapping, while the remaining antennas participate only in the obfuscation mechanism. Reliability and secrecy are characterized through average bit error rate, mutual information, generalized mutual information, secrecy rate, equivocation, and information leakage. Both passive and active adversarial scenarios are considered. Passive attacks include uninformed mismatched eavesdropping as well as partially correlated eavesdropping channels that emulate spatial proximity and common scattering. Active training-phase attacks, including pilot contamination and forced permutation manipulation, are also examined and mitigated through tournament-structure consistency checks leading to block acceptance/rejection. The proposed cyclic-shift realization is shown to operate effectively when the legitimate nodes observe consistent channel information, while its sensitivity to channel estimation mismatch is also discussed. Numerical results demonstrate that reliable communication is preserved at the legitimate receiver, while a substantial loss in the eavesdropper' achievable rate is induced even under correlated and active attack conditions. For benchmarking purposes, a comparison with artificial-noise based SSK is also included, highlighting the fundamental difference between power-domain and index-domain physical layer security mechanisms.
Based on the objective reality of channel estimation error, this paper introduces a novel artificial noise (AN) aided spatial modulation (SM) secrecy-enhancing scheme under imperfect channel state information (CSI). In the proposed scheme, SM is used to activate one antenna from the transmit antennas, and the information symbols will be transmitted with the designed AN at each timeslot. By utilizing the legitimate channel's imperfect CSI, AN is generated across two adjacent timeslots. Because the CSI is known at the legitimate receiver, then it can perfectly cancel the AN. However, the eavesdropper knows nothing of the legitimate channel's CSI, so it can not recover any useful information from the AN. At the receiver, a new detection scheme that detects across two adjacent timeslots is also proposed. With imperfect CSI, the secrecy rate of the proposed scheme is derived over Rayleigh fading channels in order to investigate the performance. Moreover, based on the secrecy performance analysis, the lower bound of the ergodic secrecy rate (ESR), the corresponding closed form of the lower bound, and the approximated expression are also derived. The simulation results verified in this paper prove that the proposed scheme with imperfect CSI can achieve satisfactory performance.
In this paper, we consider the secure transmission in ergodic fast fading multiple-input single-output single-antenna-eavesdropper (MISOSE) wiretap channels with only the statistics of eavesdropper's channel state information at the transmitter (CSIT). Two kinds of the legitimate CSIT are assumed, that is, full and statistical legitimate CSIT. With full legitimate CSIT, we generalize and optimize the previously proposed artificial noise (AN) aided secure beamforming to improve its secrecy rate performance. The AN covariance matrix in our scheme is more flexible than previous scheme and the region of non-zero secrecy rate is enlarged significantly according to our simulations. For the case with statistical legitimate CSIT, we further prove that the secure beamforming is secrecy capacity achieving for the Rayleigh faded channels. In this case, the AN is not necessary. Extensions to cases where legitimate receiver and eavesdropper have multiple antennas will also be discussed.