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Receiver impairments play a significant role in determining system performance, particularly in adversarial environments subject to intentional jamming that seek to impair operation by collapsing the dynamic range of the receiver. Clock jitter is one of the key impairments that limits analog-to-digital (A/D) converters, and it causes significant challenges for channel decoding as it distorts the received signal’s timing, making compensation difficult. Motivated by this challenge, we consider performance and design for the two-look channel, which utilizes two receivers with independent clock jitter. Using a statistical characterization of the jitter, we derive the degree to which mutual information is increased in the two-look scenario versus the case when a single receiver is employed. This analysis motivates the consideration of optimal decoder design, but this is complicated by the nonlinear timing jitter model. Hence, we turn to a machine learning (ML)-based decoding framework. Numerical results demonstrate the improvement in mutual information from having two looks, and simulation results demonstrate the improved channel decoding performance. 

The onset of quantum computing calls for secrecy schemes that can provide everlasting secrecy resistant to increased computational power of an adversary. One novel physical layer scheme proposes that an intended receiver capable of performing analog cancellation of a known key-based interference would hold a significant advantage in recovering small underlying messages versus an eavesdropper performing cancellation after analog-to-digital conversion. This advantage holds even if an eavesdropper later obtains the key and employs it in their digital cancellation. Inspired by this scheme, a flexible software-defined radio receiver design capable of maintaining analog cancellation ratios over 40 dB, reaching up to and over 50 dB, is implemented. Using analog cancellation levels from the hardware testbed, practical everlasting secrecy rates up to 2.0 bits/symbol are shown to be gained by receivers performing interference cancellation in analog rather than on a digital signal processor.