Can Quantum Receiver Beat the SIC Limit in Multiple Access Networks?

2026-06-18

AI Summary

This work investigates whether practical quantum receivers can surpass the channel capacity limits imposed by conventional successive interference cancellation (SIC) in multi-access networks. To this end, the authors propose a full-stack quantum receiver architecture that integrates front-end quantum sensing with back-end quantum signal processing. By leveraging ensembles of unentangled qubits and employing quantum-correlation measurements alongside parallel processing of superposition states, the approach efficiently extracts multi-user interference signals. Notably, this method achieves performance beyond the SIC limit without requiring complex entanglement resources, significantly enhancing spectral and detection efficiency—particularly at low signal-to-noise ratios—and thereby transcending the theoretical boundaries of classical multi-access channel capacity.

Abstract

Successive interference cancellation (SIC) is an important technique for 5G/B5G wireless receivers to resolve interfering signals from multiple users. While SIC has been proven to approach the channel capacity limit in many settings of multiple access networks, it remains unknown if this limit can be surpassed by an advanced yet practically implementable quantum receiver technique. In this work, we answer this quest by proposing a full-stack quantum receiver that integrates front-end quantum sensing with back-end quantum signal processing. The proposed technique leverages simple qubit ensembles without using any complex entanglement resources to parallelly extract interfering multiuser signals, with a channel capacity beyond the limit of SIC in some operational corners. In performance evaluation, we report notable quantum advantage over the ultimate multiple-access channel capacity limit and practical SIC algorithms in low-SNR regimes in terms of spectral efficiency and detection efficiency due to the receiver's ability to exploit quantum correlated measurements and superposition-enabled parallel processing.

Problem

• quantum receiver
• successive interference cancellation
• multiple access networks
• channel capacity limit
• quantum advantage

Innovation

• quantum receiver
• successive interference cancellation (SIC)
• quantum advantage
• multiuser detection
• quantum signal processing