TY - GEN
T1 - Artificial Noise Aided Secure Transmission in Active RIS-Assisted CF System Without Eavesdroppers' CSI
AU - Huang, Zihang
AU - Dong, Limeng
AU - Tang, Xiao
AU - Huo, Yiran
AU - Shi, Jiale
N1 - Publisher Copyright:
© 2025 IEEE.
PY - 2025
Y1 - 2025
N2 - Reconfigurable Intelligent Surface (RIS) has emerged as a key technology capable of economically and efficiently reconfiguring wireless communication environments, and has been widely utilized to assist secure transmission in cell-free (CF) system in recent years. However, due to the presence of multiplicative fading effects, traditional passive RIS typically performs poorly when deployed far from the access point (AP) and users. Additionally, eavesdroppers (Eves) are malicious users hidden within the system, making it difficult for the system to acquire their channel state information (CSI). To address above issues, this paper investigates secure transmission of CF system aided by multiple active RISs. By considering no Eves' CSI, we propose an artificial noise (AN) aided transmssion strategy to enhance the secure transmission of system. In this strategy, the system total power is divided into two parts at the APs, one for the signal transmission and one for the AN signaling. To allocate the first part of power, we propose an efficient alternating optimization (AO) algorithm to optimize the active and passive beamformers at APs and RISs by ensuring that the users' quality of service (QoS) for communication is satisfied. To allocate the second part of residual power, we propose equal and unequal power allocation strategies for transmitting artificial noise (AN) so as to degrade Eves' signal reception performance. The simulation results show that compared with the benchmark schemes, our proposed method with the aide of active RISs in CF system can more effectively suppresse the performance of Eves, which in turn significantly enhances the secrecy rate for users in the system.
AB - Reconfigurable Intelligent Surface (RIS) has emerged as a key technology capable of economically and efficiently reconfiguring wireless communication environments, and has been widely utilized to assist secure transmission in cell-free (CF) system in recent years. However, due to the presence of multiplicative fading effects, traditional passive RIS typically performs poorly when deployed far from the access point (AP) and users. Additionally, eavesdroppers (Eves) are malicious users hidden within the system, making it difficult for the system to acquire their channel state information (CSI). To address above issues, this paper investigates secure transmission of CF system aided by multiple active RISs. By considering no Eves' CSI, we propose an artificial noise (AN) aided transmssion strategy to enhance the secure transmission of system. In this strategy, the system total power is divided into two parts at the APs, one for the signal transmission and one for the AN signaling. To allocate the first part of power, we propose an efficient alternating optimization (AO) algorithm to optimize the active and passive beamformers at APs and RISs by ensuring that the users' quality of service (QoS) for communication is satisfied. To allocate the second part of residual power, we propose equal and unequal power allocation strategies for transmitting artificial noise (AN) so as to degrade Eves' signal reception performance. The simulation results show that compared with the benchmark schemes, our proposed method with the aide of active RISs in CF system can more effectively suppresse the performance of Eves, which in turn significantly enhances the secrecy rate for users in the system.
KW - Active reconfigurable intelligent surface
KW - artificial noise
KW - cell-free
KW - eavesdropper
UR - http://www.scopus.com/inward/record.url?scp=105006428439&partnerID=8YFLogxK
U2 - 10.1109/WCNC61545.2025.10978494
DO - 10.1109/WCNC61545.2025.10978494
M3 - 会议稿件
AN - SCOPUS:105006428439
T3 - IEEE Wireless Communications and Networking Conference, WCNC
BT - 2025 IEEE Wireless Communications and Networking Conference, WCNC 2025
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2025 IEEE Wireless Communications and Networking Conference, WCNC 2025
Y2 - 24 March 2025 through 27 March 2025
ER -