Secrecy enhancement in MIMO-OFDM-IM systems with limited RF chains

Tao Jing, Zhen Li, Liwen Jiang +1 more

Nabil Romero‐Zurita, Mounir Ghogho, Des McLernon

Y.-W. Peter Hong, Pang-Chang Lan, C.‐C. Jay Kuo

Parul Awasthi, Vishal Awasthi

ABSTRACT Millimeter‐Wave (mmWave) massive Multiple Input Multiple Output (MIMO) with Orthogonal Frequency Division Multiplexing (OFDM) is a key enabler of next‐generation wireless communication, providing high spectral efficiency and improved data rates. Massive MIMO utilizes a large number of antennas at the base station to enhance spatial diversity, while OFDM mitigates inter‐symbol interference and enhances spectral efficiency. The combination of mmWave and massive MIMO with OFDM enables high‐capacity communication with reduced latency, making it ideal for 5G and beyond networks. Physical Layer Security (PLS) provides a robust alternative to traditional cryptographic techniques, leveraging information‐theoretic principles to counter advanced eavesdropping threats, including quantum computing attacks. However, conventional PLS key generation methods suffer from reduced secrecy due to the slow variation of channel characteristics. To enhance security, a deep learning‐based key generation approach is proposed using a deep graph convolutional neural network to extract virtual angle of arrival and angle of departure features. The proposed method achieves a bit agreement ratio of 0.5767 and a key generation rate of 1856.59 bits/s, significantly improving key secrecy. Secure data transmission is ensured using a hybrid deep Q‐learning with recurrent neural network framework, incorporating on‐off transmission schemes, which enhances security by achieving a secrecy capacity of 5.37 bps/Hz, maintaining a throughput of 119.55 Mbps, and a latency of 8.00 ms, ensuring scalability. Additionally, evaluations of the secrecy rate of 5.37 bps/Hz, secrecy outage probability of 10 −2 , and 95% Eavesdropper interception capability, demonstrate significant improvements over state‐of‐the‐art techniques.

Francesco Renna, Nicola Laurenti, H. Vincent Poor

Orthogonal frequency division multiplexing (OFDM) has been established as the preferred modulation choice for high-rate data transmission over dispersive channels, as it allows rejection of inter-symbol interference (ISI) and efficient utilization of the available spectrum. We address the issues of determining achievable secrecy rates and secrecy capacity for OFDM transmission in the presence of a generic eavesdropper. In doing so, we refrain from making the restrictive assumption made in previous works that the eavesdropper uses a standard fast Fourier transform (FFT)-based demodulator. First, the high SNR secrecy capacity under a total input power constraint is evaluated for both cyclic prefix and zero-padding suffix OFDM systems. It is shown that in both cases the result is sensibly lower than what we would get if the eavesdropper used an OFDM receiver. Then, optimal power allocation schemes are proposed for both types of OFDM systems and the secrecy rates are compared with results obtained by using existing power allocation methods described in the literature for parallel Gaussian wiretap channels and multiple-input multiple-output (MIMO) Gaussian wiretap channels.

Francesco Renna, Nicola Laurenti, H. Vincent Poor

Orthogonal frequency division multiplexing (OFDM) systems have enjoyed widespread adoption in high data rate wired and wireless networks, due to their ability to efficiently cope with slowly varying dispersive channels. This paper considers the information theoretic secrecy rates that are achievable by an OFDM transmitter/receiver pair in the presence of an eavesdropper that might either use an OFDM structure or choose a more complex receiver architecture. The analysis is performed through modeling of the OFDM system with an eavesdropper as a special case of a high dimensional multiple-input multiple-output (MIMO) wiretap channel, which allows the secrecy loss due to the OFDM structure constraints, and the information gain for an eavesdropper that uses a more complex receiver to be quantified. The results are expressed in terms of both ergodic rates and outage probabilities for multipath Rayleigh fading channels, and in terms of dependence on the signal to noise ratio (SNR) ratio between the main and eavesdropper channels.