Digital Nonlinear Distortion Compensation for Rydberg Atomic Receiver with Quadrature Amplitude Modulation

With the advancement of quantum physics and deeper exploration of atomic systems, the integration of atoms into communication systems has garnered significant attention. Among these efforts, the use of Rydberg atoms as a communication receiver has emerged as a prominent area of research. In this work, we introduce a new mathematical modeling approach to more accurately establish the input-output relationship of a Rydberg atomic receiver. We categorize this relationship into three segments: one linear region and two nonlinear regions, facilitating a comprehensive analysis of the nonlinear challenges associated with Rydberg atomic receiver. Our findings indicate that adjusting the Rabi oscillation frequency of the coupling laser can effectively extend the linear operating range of the receiver. Furthermore, focusing on complex quadrature amplitude modulation, we propose a digital nonlinear distortion compensation method specifically designed for Rydberg atomic receiver. This method demonstrates a significant improvement in performance, enhancing the demodulation bit error rate compared to conventional linearization techniques.

I. Introduction

The advancement of quantum mechanics has enabled signif-icant progress in quantum precision measurement, exemplified by the development of highly accurate atomic clocks with great precision [1] [2]. As a result, microwave measurement systems that leverage quantum technologies have emerged as a key area of research, promising to surpass the capa-bilities of traditional microwave measurement frameworks. In these quantum measurement systems, microwave electric fields interact directly with individual atoms. Notably, because atoms do not possess free electrons, Johnson-Nyquist noise [3] [4] is effectively absent. Furthermore, the sensitivity of these systems is determined solely by the resonance conditions between the atoms and the microwave fields, eliminating the reliance on macroscopic standing currents and mitigating the impact of antenna size. The exploration and advancement of quantum-enhanced measurement systems hold the potential to revolutionize various fields, including telecommunication, radar, and fundamental physical research [5] [6].