Achieving Unconditional Security for MIMO-BAN under Short Blocklength Wiretap Code

摘要

For current MIMO physical layer security, most of the existing works study how to increase the secrecy capacity. However, the unconditional secure transmission fully achieving the secrecy capacity is difficult to realize, because the theoretical capacity can be achieved only by a wiretap code with infinite blocklength [1]. In most cases, the long codelength secure code is needed to approach the secrecy capacity [14]. Even though the short blocklengh code is prospective for timely and lower burden communication networks, not much exploration has been done to fulfil the unconditional security by a short length wiretap code. In this work, we investigate a lightweight strategy to achieve unconditional secrecy for the practical MIMO Beamforming artifacial noise (MIMO-BAN) physical layer security system under short blocklength wiretap code. Firstly, we analyse the modulated impact on MIMO-BAN secrecy capacity. Then we investigate the achievable secrecy performance for MIMO-BAN physical layer secure system under practical short blocklengh secure code. Based on this, we propose a light wight secrecy strategy, which could guarantee required quality of the main channel while keeping eavesdropper's BER approaching to 0.5. The simulation results verify our analytical performance predictions and demonstrate its feasibility.