# Detecting and Receiving Phase Modulated Signals with a Rydberg Atom-Based Mixer

## TL;DR

This paper demonstrates the use of Rydberg-atom based mixers for detecting and receiving various digital phase-modulated signals, including BPSK, QPSK, and QAM, over a 19.626 GHz carrier, showcasing atom-based communication capabilities.

## Contribution

It introduces a method for digital signal reception using Rydberg atoms, extending previous phase detection to practical digital modulation schemes.

## Key findings

- Successful detection of BPSK, QPSK, and QAM signals with Rydberg atoms.
- Measured Error Vector Magnitude (EVM) as a function of symbol rate.
- Analysis of the bandwidth capabilities of the Rydberg-atom receiver.

## Abstract

Recently, we introduced a Rydberg-atom based mixer capable of detecting and measuring the phase of a radio-frequency field through the electromagnetically induced transparency (EIT) and Autler-Townes (AT) effect. The ability to measure phase with this mixer allows for an atom-based receiver to detect digital modulated communication signals. In this paper, we demonstrate detection and reception of digital modulated signals based on various phase-shift keying approaches. We demonstrate Rydberg atom-based digital reception of binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), and quadrature amplitude (QAM) modulated signals over a 19.626~GHz carrier to transmit and receive a bit stream in cesium vapor. We present measured values of Error Vector Magnitude (EVM, a common communication metric used to assess how accurate a symbol or bit stream is received) as a function of symbol rate for BPSK, QPSK, 16QAM, 32QAM, and 64QAM modulation schemes. These results allow us to discuss the bandwidth of a Rydberg-atom based receiver system.