Rate Adaption for Secure HARQ-CC System with Multiple Eavesdroppers

Abstract

In this paper, we studied the secure transmission of a hybrid automatic repeat request with chase combining (HARQ-CC) system, under the existence of multiple eavesdroppers and limited latency. First, we analyzed some critical performance metrics, including connection outage probability (COP), secrecy outage probability (SOP) and effective secrecy throughput (EST). Then, to maximize the EST, three optimization problems of rate adaption were discussed: (i) optimizing the code rate with a given secrecy redundancy rate by a parameterized closed-form solution; (ii) optimizing the secrecy redundancy rate with a given code rate by a fixed-point method; (iii) optimizing both code rate and secrecy redundancy rate by an iterative optimization algorithm. We also considered COP and SOP constraints among the problems while corresponding solutions were deduced. Finally, numerical and simulated results verified our conclusions that the approximated SOP matches well with Monte–Carlo simulation for a strict reliable constraint, and that the optimized transmitting rate enhances EST efficiently with multiple eavesdroppers and retransmissions. Moreover, the influence of the number of eavesdroppers on secrecy performance was analyzed. Briefly, secrecy performance inevitably deteriorates with increasing number of eavesdroppers due to raised information leakage.

A Survey on Reconfigurable Intelligent Surface for Physical Layer Security of Next-Generation Wireless Communications

“…The authors in [171] have proposed a suitable performance metric for URLLC networks, i.e., COP that maintains a trade-off between latency, reliability, security and network throughput. In another research work [172], the authors have analysed the performance of PLS in RIS-assisted hybrid automatic repeat request (HARQ) system. The system setup is composed of single antenna transmitter, receiver, Eve and an RIS in non-LoS scenario.…”

On the Secure Performance of Intelligent Reflecting Surface-Assisted HARQ Systems

“…It has been demonstrated that an eavesdropper cannot obtain the same diversity gain as a legitimate user, since re-transmissions rely solely on the latter user [ 31 ]. As another import metric, effective secrecy throughput (EST) with multiple eavesdroppers has been optimized in secure HARQ transmissions [ 32 ]. Additionally, Park proposed Kalman combining-based iterative detection and decoding schemes for multiple-input multiple-output (MIMO) systems with HARQ [ 33 ], and Wu et al achieved a tradeoff between timeliness and reliability for HARQ-CC aided non-orthogonal multiple-access (NOMA) systems [ 34 ].…”