IMPLEMENTATION OF PHYSICAL LAYER SECURITY FOR MULTIPLE-INPUT, MULTIPLE-OUTPUT COMMUNICATIONS VIA A WAVELET PACKET MODULATED SOFTWARE-DEFINED RADIO SYSTEM WITH NOISE MASKING

Abstract

This thesis discusses the theory, design, and implementation of a physical layer security (PLS) system on a multiple-input, multiple-output (MIMO) software defined radio (SDR) with wavelet packet modulation (WPM). The PLS implementation leverages channel state information, gained via channel reciprocity, and applies it to an artificial noise masking algorithm formulated for MIMO SDR systems. The masking algorithm is realized with static elements as well as random elements that could prevent an adversary from estimating the additive mask components. Over-the-air testing provides evidence that the artificial noise mask is effective at obscuring a transmitted signal from an eavesdropper while remaining transparent to the intended receiver. Bit error rate calculations are performed for varied signal-to-mask ratio and LOS vs. BLOS conditions.