Secure and Precise Wireless Transmission for Random-Subcarrier-Selection-Based Directional Modulation Transmit Antenna Array

Abstract

In this paper, a practical wireless transmission scheme is proposed to transmit confidential messages to the desired user securely and precisely by the joint use of multiple techniques including artificial noise (AN) projection, phase alignment (PA)/beamforming, and random subcarrier selection (RSCS) based on OFDM, and directional modulation (DM), namely RSCS-OFDM-DM. This RSCS-OFDM-DM scheme provides an extremely low-complexity structures for the transmitter and desired receiver and makes the secure and precise wireless transmission realizable in practice. For illegal eavesdroppers, the receive power of confidential messages is so weak that their receivers cannot intercept these confidential messages successfully once it is corrupted by AN. In such a scheme, the design of phase alignment/beamforming vector and AN projection matrix depend intimately on the desired direction angle and distance. It is particularly noted that the use of RSCS leads to a significant outcome that the receive power of confidential messages mainly concentrates on the small neighboring region around the desired receiver and only small fraction of its power leaks out to the remaining large broad regions. This concept is called secure precise transmission. The probability density function of real-time receive signal-to-interference-and-noise ratio (SINR) is derived. Also, the average SINR and its tight upper bound are attained. The approximate closed-form expression for average secrecy rate is derived by analyzing the first-null positions of SINR and clarifying the wiretap region. From simulation and analysis, it follows that the proposed scheme actually can achieve a secure and precise wireless transmission of confidential messages in lineof-propagation channel, and the derived theoretical formula of average secrecy rate is verified to coincide with the exact one well for medium and large scale transmit antenna array or in the low and medium SNR regions.

Two Efficient Beamformers for Secure Precise Jamming and Communication With Phase Alignment

“…where f c is the carrier frequency and ∆f is the subchannel bandwidth. The subcarrier assigned to n-th antenna is f n , where f n ∈ S sub [12].…”

“…As an enhanced secure version of DM, secure precise wireless transmission (SPWT) based on DM was proposed in [11], [12]. In such a scheme, the range-angle-dependent characteristic is established and there is a single main peak of CM is formed around the desired receiver.…”

“…Therefore, the authors in [14] added AN to the proximal Bob and Eve scenario, and extended the frequency offset optimization in the case of multiple eavesdroppers. To reduce the complexity of SPWT receiver, a SPWT structure using random subcarrier selection (RSS) of orthogonal frequency diversion multiplexing (OFDM) is proposed [12]. In [15], the authors proposed two practical RSS methods to achieve a SWPT per OFDM symbol by randomization procedure including integer mod, ordering, and block interleaving.…”

Energy-efficient alternating iterative secure structure of maximizing secrecy rate for directional modulation networks

“…Furthermore, a practical DM scheme with random frequency diverse array with the aid of AN is proposed to enhance physical layer security [23]. A new concept of secure and precise wireless transmission (SPWT) is proposed to achieve SPWT of CM in [24], which combined the techniques of AN projection, beamforming and random subcarrier selection. Since direction-of-arrival (DOA) scheme is of great significance for practical DM applications, the authors in [25] proposed three estimators of DOA based on hybrid structure to determine the position, which makes DM more feasible.…”

Performance Analysis of Directional Modulation With Finite-Quantized RF Phase Shifters in Analog Beamforming Structure

“…[8] proposed two secure schemes, Max-GRP plus NSP and Max-SLNR plus Max-ANLNR, for multicast DM scenario to improve the security. Inspired by the work in [9] and [10], secure and precise wireless transmission (SPWT) proposed in [11] combined AN projection, beamforming and random subcarrier selection based on orthogonal frequency division multiplexing (OFDM) to achieve SPWT of confidential messages. In the researches mentioned above, the DM synthesis on the baseband signal processing is assumed perfect or imperfect channel state information (CSI).…”