Robustness-enhanced quantum integrated sensing and communication networks based on bivariate bicycle codes scheme.

Abstract

Quantum integrated sensing and communication (QISAC) enables simultaneous parameter estimation and secure information transmission based on shared entanglement resources, making it a promising research direction for future quantum information networks. In practical quantum channels, however, depolarizing noise, decoherence, and potential eavesdropping perturbations may degrade entanglement resources, increase the quantum bit error rate, and reduce both secrecy capacity and sensing performance. To address these limitations, this paper proposes a coding-enhanced QISAC (CE-QISAC) scheme. Based on the shared entanglement framework of existing QISAC protocols, the proposed scheme incorporates Bivariate Bicycle (BB) quantum low-density parity-check codes and a low-complexity belief propagation with localized statistics decoding (BP-LSD) algorithm to protect transmitted quantum states through error correction, thereby reducing the logical quantum bit error rate. The secrecy capacity under coding enhancement is analyzed according to the decoded logical error rate, while the waterfall effect of BB codes is further exploited to improve security detection sensitivity. Results show that the proposed scheme maintains high secrecy capacity in the nominal noise regime, mitigates the impact of depolarizing noise on parameter estimation, and reduces decoding complexity, providing a feasible approach for quantum integrated sensing and secure direct communication over noisy quantum channels.