Secure Transmission in mmWave Wiretap Channels: On Sector Guard Zone and Blockages

Abstract

Millimeter-wave (mmWave) communication is one of the key enabling technologies for fifth generation (5G) mobile networks. In this paper, we study the problem of secure communication in a mmWave wiretap network, where directional beamforming and link blockages are taken into account. For the secure transmission in the presence of spatially random eavesdroppers, an adaptive transmission scheme is adopted, for which sector secrecy guard zone and artificial noise (AN) are employed to enhance secrecy performance. When there exists no eavesdroppers within the sector secrecy guard zone, the transmitter only transmits information-bearing signal, and, conversely, AN along with information-bearing signal are transmitted. The closed-form expressions for secrecy outage probability (SOP), connection outage probability (COP) and secrecy throughput are derived under stochastic geometry. Then, we evaluate the effect of the sector secrecy guard zone and AN on the secrecy performance. Our results reveal that the application of the sector secrecy guard zone and AN can significantly improve the security of the system, and blockages also can be utilized to improve secrecy performance. An easy choice of transmit power and power allocation factor is provided for achieving higher secrecy throughput. Furthermore, increasing the density of eavesdroppers not always deteriorates the secrecy performance due to the use of the sector secrecy guard zone and AN.

Secure On-Off Transmission in UAV Relay-Assisted mmWave Networks

“…where step (d) is due to ( [40], Equation (0.410)) and ( [40], Equation (8.350.1)). Finally, we can calculate the SOP in the on-off transmission scheme by substituting (12) and (14) into (11). Remark 1.…”

“…In contrast to the conventional upper-layer security methods mainly based on cryptographic protocols [6], physical-layer security has been emerged as a powerful approach to protect information transmission against wiretapping by exploiting the randomness of wireless medium, e.g., noise and interference [7]. Some potential application scenarios and challenges in terms of physical-layer security are presented in [8][9][10][11]. In this paper, we focus on secure on-off transmission in UAV relay-assisted mmWave networks.…”