Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Chinese Physics B

Performance analysis of quantum access network using code division multiple access model

Linxi Hu, Can Yang, Guangqiang He

Published Jun 1, 2017• 0 citations
Publisher

Abstract

A quantum access network has been implemented by frequency division multiple access and time division multiple access, while code division multiple access is limited for its difficulty to realize the orthogonality of the code. Recently, the chaotic phase shifters were proposed to guarantee the orthogonality by different chaotic signals and spread the spectral content of the quantum states. In this letter, we propose to implement the code division multiple access quantum network by using chaotic phase shifters and synchronization. Due to the orthogonality of the different chaotic phase shifter, every pair of users can faithfully transmit quantum information through a common channel and have little crosstalk between different users. Meanwhile, the broadband spectra of chaotic signals efficiently help the quantum states to defend against channel loss and noise.

DOI
10.1088/1674-1056/26/6/060304

Related papers

Quantum internet using code division multiple access

Jing Zhang, Yu-xi Liu, Şahin Kaya Özdemir +5 more

A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels.

arXiv:1204.1742•Scientific Reports•Jul 17, 2013•34 citations

Entanglement distribution over quantum code-division multiple-access networks

Changlong Zhu, Nan Yang, Yu-xi Liu +2 more

We present a method for quantum entanglement distribution over a so-called code-division multiple-access network, in which two pairs of users share the same quantum channel to transmit information. The main idea of this method is to use different broadband chaotic phase shifts, generated by electro-optic modulators and chaotic Colpitts circuits, to encode the information-bearing quantum signals coming from different users and then recover the masked quantum signals at the receiver side by imposing opposite chaotic phase shifts. The chaotic phase shifts given to different pairs of users are almost uncorrelated due to the randomness of chaos and thus the quantum signals from different pair of users can be distinguished even when they are sent via the same quantum channel. It is shown that two maximally entangled states can be generated between two pairs of users by our method mediated by bright coherent lights, which can be more easily implemented in experiments compared with single-photon lights. Our method is robust under the channel noises if only the decay rates of the information-bearing fields induced by the channel noises are not quite high. Our study opens up new perspectives for addressing and transmitting quantum information in future quantum networks.

arXiv:1507.02004•Physical Review A•Oct 26, 2015•10 citations

Quantum CDMA-based Continuous Variable Quantum Key Distribution using Chaotic Phase Shifters

Shahnoor Ali, Neel Kanth Kundu, Sourav Chatterjee

We present a quantum code-division multiple-access (q-CDMA) framework for multiuser continuous-variable quantum key distribution (CV-QKD) over a shared quantum channel. The proposed architecture employs chaotic phase shifters to encode and decode quantum states, enabling efficient multiplexing and demultiplexing of signals generated by multiple transmitters. In this scheme, quantum states from different users are chaotically phase-encoded and combined through a beam splitter network before transmission. At the receiver, synchronized chaotic phase shifters are used for decoding, followed by an inverse beam splitter structure to recover the individual user signals. This chaotic synchronization allows reliable state recovery and secure key establishment between each sender-receiver pair. For an arbitrary number of users, we derive the input-output quadrature relations describing the multiuser q-CDMA CV-QKD system. Using this model, we evaluate the achievable secret key rate under collective attacks with reverse reconciliation. We further investigate the impact of key system parameters including the correction factor, multiuser interference noise, environmental noise, and channel transmittance. A comparison between the asymptotic and finite-size regimes is also presented to highlight the associated performance trade-offs. These results provide a theoretical framework for assessing the performance of q-CDMA-based CV-QKD and support the development of scalable and secure multiuser quantum communication networks.

quant-pharXiv:2603.12777•IEEE Transactions on Communications•Mar 16, 2026•0 citations

Quantum code division multiple access based continuous-variable quantum key distribution

Shahnoor Ali, Neel Kanth Kundu

In this paper, we propose a quantum code division multiple access (q-CDMA) based continuous-variable quantum key distribution (CV-QKD) system. In the proposed system, the quantum states of two senders (Alice1,2) are chaotically encoded through chaotic phase shifters and then transmitted over a quantum channel. At the receiver, the quantum states are decoded via chaos synchronization to separate the quantum states sent by the different senders and received by the two receivers (Bob1,2) separately. We characterize the input-output relation of the quadrature between the two senders and receivers and then analyze the secret key rate (SKR) of the q-CDMA-based CV-QKD system. Our numerical results reveal that the q-CDMA approach can significantly enhance the SKR for both users when compared to the single-user case without the q-CDMA approach.

arXiv:2502.09019•International Conference on Quantum Communications, Networking, and Computing (QCNC)•Mar 31, 2025•1 citation

Quantum key distribution with spectral amplitude coding OCDMA for a multiple access network

P. O. Amadi, Syed Alwee Aljunid, N. Ali +4 more

This study presents the design and analysis of a hybrid multi-user quantum key distribution (QKD) system utilizing spectral amplitude coding optical code division multiple access (SAC-OCDMA) encoding techniques. By assigning unique optical codes to each user, SAC-OCDMA enables spontaneous, asynchronous data transmission without any strict synchronization, which makes it scalable and flexible for quantum networks. In the architecture, each user’s quantum signal, initially prepared as weak coherent pulses and encoded using phase or polarization bases, is further spectrally sliced by a SAC-OCDMA encoder in a zero-based cross-correlation code. The physical impairments, comprising spontaneous Raman scattering, four-wave mixing, and crosstalk, were modeled and analyzed. We report a maximum secret key rate of ∼10 5 bps over a transmission distance of ∼58km . Furthermore, our analysis demonstrates that careful selection of launch power, simultaneous users, code weight, and spectral bin width is necessary for optimizing the trade-off between multi-user capacity and security performance. In comparison with wave division multiplexing QKD, which has much better spectral efficiency but strict channel allocation, the flexibility and asynchronous access to secure communication of our OCDMA-QKD design with zero cross-correlation coding are more aligned with the needs of quantum security.

Journal of Optical Communications and Networking•Oct 29, 2025•1 citation

Investigation of QOFDMA in Noisy Environment

Hussein Al-kinani, Mohammed Rabeea Almasaoodi, Abdulbasit M. A. Sabaawi +1 more

One of the most crucial challenges in quantum communication is the transmission of quantum information among multiple users over a common quantum channel. Quantum orthogonal frequency division multiple access (QOFDMA) enables the transmission of quantum information for multiple users through a shared quantum channel. QOFDMA combines the transmission efficiency of classical (OFDMA) with the advantages of quantum information processing. However, its performance in noisy environments faces significant challenges, particularly in the presence of quantum decoherence and phase noise. QOFDMA utilises the quantum Fourier transform (QFT) and its inverse (IQFT) to ensure high-accuracy information transmission over quantum channel. This work examines the resilience of QOFDMA under noisy conditions, focusing on its robustness. Using the Qiskit platform, we analyse the bit error rate (BER) to evaluate the impact of noise across various quantum rotational channels. The simulation results reveal significant trends in user BER performance under the noisy quantum channels, providing key insights into the system behaviour and robustness.

Workshop on Intelligent Infocommunication Networks, Systems and Services•Jan 1, 2025•0 citations
A quantum access network has been implemented by frequency division multiple access and time division multiple access, while code division multiple access is limited for its difficulty to realize the orthogonality of the code. Recently, the chaotic phase shifters were proposed to guarantee the orthogonality by different chaotic signals and spread the spectral content of the quantum states. In this letter, we propose to implement the code division multiple access quantum network by using chaotic phase shifters and synchronization. Due to the orthogonality of the different chaotic phase shifter, every pair of users can faithfully transmit quantum information through a common channel and have little crosstalk between different users. Meanwhile, the broadband spectra of chaotic signals efficiently help the quantum states to defend against channel loss and noise.
A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels.
We present a method for quantum entanglement distribution over a so-called code-division multiple-access network, in which two pairs of users share the same quantum channel to transmit information. The main idea of this method is to use different broadband chaotic phase shifts, generated by electro-optic modulators and chaotic Colpitts circuits, to encode the information-bearing quantum signals coming from different users and then recover the masked quantum signals at the receiver side by imposing opposite chaotic phase shifts. The chaotic phase shifts given to different pairs of users are almost uncorrelated due to the randomness of chaos and thus the quantum signals from different pair of users can be distinguished even when they are sent via the same quantum channel. It is shown that two maximally entangled states can be generated between two pairs of users by our method mediated by bright coherent lights, which can be more easily implemented in experiments compared with single-photon lights. Our method is robust under the channel noises if only the decay rates of the information-bearing fields induced by the channel noises are not quite high. Our study opens up new perspectives for addressing and transmitting quantum information in future quantum networks.
We present a quantum code-division multiple-access (q-CDMA) framework for multiuser continuous-variable quantum key distribution (CV-QKD) over a shared quantum channel. The proposed architecture employs chaotic phase shifters to encode and decode quantum states, enabling efficient multiplexing and demultiplexing of signals generated by multiple transmitters. In this scheme, quantum states from different users are chaotically phase-encoded and combined through a beam splitter network before transmission. At the receiver, synchronized chaotic phase shifters are used for decoding, followed by an inverse beam splitter structure to recover the individual user signals. This chaotic synchronization allows reliable state recovery and secure key establishment between each sender-receiver pair. For an arbitrary number of users, we derive the input-output quadrature relations describing the multiuser q-CDMA CV-QKD system. Using this model, we evaluate the achievable secret key rate under collective attacks with reverse reconciliation. We further investigate the impact of key system parameters including the correction factor, multiuser interference noise, environmental noise, and channel transmittance. A comparison between the asymptotic and finite-size regimes is also presented to highlight the associated performance trade-offs. These results provide a theoretical framework for assessing the performance of q-CDMA-based CV-QKD and support the development of scalable and secure multiuser quantum communication networks.
In this paper, we propose a quantum code division multiple access (q-CDMA) based continuous-variable quantum key distribution (CV-QKD) system. In the proposed system, the quantum states of two senders (Alice1,2) are chaotically encoded through chaotic phase shifters and then transmitted over a quantum channel. At the receiver, the quantum states are decoded via chaos synchronization to separate the quantum states sent by the different senders and received by the two receivers (Bob1,2) separately. We characterize the input-output relation of the quadrature between the two senders and receivers and then analyze the secret key rate (SKR) of the q-CDMA-based CV-QKD system. Our numerical results reveal that the q-CDMA approach can significantly enhance the SKR for both users when compared to the single-user case without the q-CDMA approach.
This study presents the design and analysis of a hybrid multi-user quantum key distribution (QKD) system utilizing spectral amplitude coding optical code division multiple access (SAC-OCDMA) encoding techniques. By assigning unique optical codes to each user, SAC-OCDMA enables spontaneous, asynchronous data transmission without any strict synchronization, which makes it scalable and flexible for quantum networks. In the architecture, each user’s quantum signal, initially prepared as weak coherent pulses and encoded using phase or polarization bases, is further spectrally sliced by a SAC-OCDMA encoder in a zero-based cross-correlation code. The physical impairments, comprising spontaneous Raman scattering, four-wave mixing, and crosstalk, were modeled and analyzed. We report a maximum secret key rate of ∼10 5 bps over a transmission distance of ∼58km . Furthermore, our analysis demonstrates that careful selection of launch power, simultaneous users, code weight, and spectral bin width is necessary for optimizing the trade-off between multi-user capacity and security performance. In comparison with wave division multiplexing QKD, which has much better spectral efficiency but strict channel allocation, the flexibility and asynchronous access to secure communication of our OCDMA-QKD design with zero cross-correlation coding are more aligned with the needs of quantum security.
One of the most crucial challenges in quantum communication is the transmission of quantum information among multiple users over a common quantum channel. Quantum orthogonal frequency division multiple access (QOFDMA) enables the transmission of quantum information for multiple users through a shared quantum channel. QOFDMA combines the transmission efficiency of classical (OFDMA) with the advantages of quantum information processing. However, its performance in noisy environments faces significant challenges, particularly in the presence of quantum decoherence and phase noise. QOFDMA utilises the quantum Fourier transform (QFT) and its inverse (IQFT) to ensure high-accuracy information transmission over quantum channel. This work examines the resilience of QOFDMA under noisy conditions, focusing on its robustness. Using the Qiskit platform, we analyse the bit error rate (BER) to evaluate the impact of noise across various quantum rotational channels. The simulation results reveal significant trends in user BER performance under the noisy quantum channels, providing key insights into the system behaviour and robustness.