Secrecy Rate Performance Analysis of Jammer-Aided Symbiotic Radio with Sensing Errors for Fifth Generation Wireless Networks

Symbiotic radio (SR), which has recently been introduced as an effective solution for 5G wireless networks, stands out with system models that include hybrid devices that share the frequency spectrum and transmit information to the same receiver. However, the low bit rate and the small amount of energy harvested in SR, where backscatter communication systems are integrated, make the system vulnerable to eavesdropping. To ensure security, the secrecy rate is defined as the difference between the number of bits transmitted to the receiver over the information channel and the number of bits reaching the eavesdropper (ED) over the wiretap channel. This paper is the first work that aims to maximize the secrecy rate for friendly jammer-aided SR networks with EDs over time allocation and power reflection coefficient in the presence of sensing errors. The proposed model consists of a base station (BS), a hybrid transmitter (HT) in symbiotic relationship with the BS, a WiFi access point used by the HT for energy harvesting, a jammer cooperating with the HT and BS, an information receiver, and EDs trying to access the information of the HT and BS. The simulation results provide valuable insights into the impact of system parameters on secrecy rate performance. Although taking the sensing error into account degrades the system performance, the real-world applicability of the system with sensing error is more realistic. It is also observed that the proposed system has higher performance compared to the wireless powered communication networks in the literature, which only use the energy harvest-then-transmit protocol and the power reflection coefficient is assumed to be zero.