Aug 2026· Scientific Reports· Vol 16· 0 citations· 45 references
Medicine
TL;DR
This work presents a protocol-level framework that unifies ADT-enabled SDMA, OFDMA, and strict FFR within an intensity-modulation direct-detection DCO-OFDM model, and provides a reproducible benchmark for dense LiFi resource management.
Abstract
Dense deployment of LiFi and visible light communication attocells increases sensitivity to inter-cell interference, requiring coordinated interference and resource management. Angle-diversity transmitters (ADTs) for space-division multiple access (SDMA), OFDMA allocation, and fractional frequency reuse (FFR) have been studied separately under inconsistent assumptions, making it difficult to separate reuse-driven from activity- and resource-sharing effects. This work presents a protocol-level framework that unifies ADT-enabled SDMA, OFDMA, and strict FFR within an intensity-modulation direct-detection DCO-OFDM model. Each macrocell is served by a co-located multi-beam ADT defining beam-based microcells; users are classified as center or edge, and protected edge sub-bands are assigned using adjacency-aware graph coloring. Full-load and random-one-per-region regimes are evaluated in 10,000-trial Monte Carlo simulations with sensitivity sweeps over center-edge partitioning and user density. Both regimes achieve a mean SINR of about 28 dB, with no outage observed at 10 or 20 dB in the finite LOS sample. A dynamic extension incorporating mobility, receiver-orientation variation, a parametric first-order NLOS stress model, and variable multi-user OFDMA admission shows that OMN-PF improves edge-frame service success over conventional PF, while OMN-PF-A further improves high-threshold edge reliability with similar scheduled spectral efficiency. The framework provides a reproducible benchmark for dense LiFi resource management.
A modulation- and receive-filter-aware framework for the sensing-interference management in multi-cell OFDM-ISAC systems is developed and closed-form signal-to-interference-plus-noise ratio (SINR) expressions for each range--Doppler bin under matched filtering (MF) and reciprocal filtering (RF).
Kaitao Meng, Kawon Han, C. Masouros et al.· 0 citations
This paper explores the application of a fractional frequency reuse (FFR) strategy purposed for networks that integrate both D2D and RIS technologies in multicell cellular network scenarios, and demonstrates its effectiveness in improving network reliability and efficiency.
Misfa Susanto, Soraida Sabella, H. Fitriawan et al.· Bulletin of Electrical Engin...· 0 citations
Visible light communication (VLC) has emerged as a promising solution for high-capacity indoor wireless networks by utilizing the unlicensed optical spectrum and existing LED infrastructure; however, efficiently supporting multiple users under limited bandwidth and power constraints remains a key challenge. This paper proposes a code-domain non-orthogonal multiple access (CD-NOMA) framework that jointly exploits resource mapping and adaptive power allocation for multiuser VLC systems, integrated with DC-biased optical OFDM (DCO-OFDM) and evaluated in a realistic indoor environment with multiple LED transmitters and randomly distributed users under heterogeneous channel conditions. Simulation results show that, at 20 dB SNR, the proposed scheme achieves a bit error rate (BER) of 10−4, representing an order-of-magnitude improvement over OMA-TDMA and OMA-FDMA; in addition, it attains a system sum rate of $\mathbf{2 3 0}-\mathbf{2 4 0} \mathbf{~ M b p s}$ $(\mathbf{2 0}-\mathbf{3 0} \%$ gain) and improves edge-user throughput by more than 40%, while maintaining a fairness index above 0.85. These results demonstrate that the proposed CD-NOMA framework significantly enhances reliabil-ity, spectral efficiency, and fairness, making it a strong candidate for next-generation indoor VLC networks.
Dhabita Audrea Belindra, M. R. Perdana, Kusuma Djaka et al.· International Seminar on Int...· 0 citations
Overlapping optical cells create geometry-dependent inter-cell interference, while receiver-geometry and channel-estimation errors can reverse the effective non-orthogonal multiple access (NOMA) decoding order and increase successive interference cancelation (SIC) failures. This paper develops a chance-constrained receiver–scheduler co-design framework for a multi-cell NOMA visible-light communication network with an asymmetrically clipped DC-biased optical orthogonal frequency-division multiplexing physical layer. Correlated position, photodetector-orientation, and channel-estimation errors are propagated through nonlinear geometry-based scenarios. For each SIC direction, a joint three-SINR event defines a layer-, resource-, and direction-labeled probabilistic decodability graph. Candidate NOMA and orthogonal modes are screened on optimization scenarios, admitted by independent one-sided confidence bounds, and selected through resource-constrained mixed-integer linear programming. With the matching fixed, hierarchical powers are adapted under empirical conditional-value-at-risk constraints using trust-region sequential quadratic programming. Because candidate-edge certificates need not remain valid after global matching and power redistribution, the frozen complete assignment is independently recertified before held-out testing. Under the specified uncertainty generator, the proposed method maintains selected-pair outage probabilities of approximately 2.7×10−3–3.3×10−3 over the half-power-angle sweep, compared with 0.027–0.060 for nominal-CSI allocation. Additional experiments quantify network-wide outage, model misspecification, unbalanced deployments, feasibility, and computational cost. The results support reliable slow-timescale scheduling under the adopted link and uncertainty models, without implying distribution-free, waveform-level, or real-time guarantees.
A cross-layer end-to-end (E2E) resource orchestration framework for green CF-mMIMO ISAC systems with distributed multi-target detection is developed and a fundamental implementation trade-off is revealed: FIS provides lower detector-processing complexity and higher detection performance, whereas PIS substantially reduces fronthaul requirements.
Z. Behdad, Ozlem Tuugfe Demir, Ki Won Sung et al.· arXiv.org· 0 citations
To achieve a full spatial coverage and higher spectral efficiency for the future sixth generation (6G) wireless networks, simultaneous transmission and reflection reconfigurable intelligent surfaces (STAR-RISs) has been proposed as a technology solution. The outage and diversity performance of STAR-RIS-assisted rate-splitting multiple access (RSMA) is investigated on Nakagami-m fading channels. RSMA systems dynamically control the interference by splitting the shared and private streams to improve the reliability of the transmission system under different channel conditions. The analytical frameworks are established for the composite STAR-RIS channels: central limit theorem model for the case of large number of elements, curve-fitting model for the moderate number of elements and M-Fold Convolution model for the case of high signal to noise ratio diversity assessment. The energy-splitting (ES), mode-switching (MS), and time-switching (TS) STAR-RIS protocols are studied and closed-form formulas for outage probability are derived for the three protocols. The results show that increasing the number of STAR-RIS elements from 20 to 40 significantly improves the outage performance, yielding several orders of magnitude reduction in outage probability due to enhanced beamforming gain and spatial diversity. In addition, the reduced order of the MS protocol is mMk due to partial allocation of elements, and the ES/TS protocol has a diversity order of mM. It is found that the OP of the reflecting user is less than 10−6 at approximately 115 dB for M = 40, which demonstrates the effectiveness of the STAR-RIS Assisted RSMA systems in improving the reliability, spatial diversity and interference management in the future 6G wireless communication systems.
Shahnaz Fatima, B. P. Chapa, Mahesh Babu Ammisetty et al.· Engineering Research Express· 0 citations
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