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arxiv: 1906.09159 · v1 · pith:VAS6ELQUnew · submitted 2019-06-21 · 📡 eess.SP · cs.NI

Performance Enhancement of Hybrid SWIPT Protocol for Cooperative NOMA Downlink Transmission

A.A.Amin , M.B.Uddin , S.Y.Shin This is my paper

Pith reviewed 2026-05-25 18:40 UTC · model grok-4.3

classification 📡 eess.SP cs.NI
keywords hybrid SWIPTcooperative NOMAdownlink transmissionergodic sum capacityoutage probabilityenergy efficiencymaximal ratio combining
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The pith

An enhanced hybrid SWIPT protocol for cooperative NOMA improves ergodic sum capacity and outage performance by reusing the idle link for extra transmission.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper establishes that integrating an enhanced hybrid SWIPT protocol with cooperative NOMA downlink transmission raises overall system performance. The cell center user relays information to the cell edge user while harvesting energy through time and power splitting, and the previously idle link carries additional data. Maximal ratio combining at the cell edge user further improves reliability. If the approach holds, networks could deliver higher capacity and lower outage rates without new spectrum or dedicated power sources. A sympathetic reader would care because the work directly targets battery drain in relays and efficiency limits in downlink NOMA setups.

Core claim

The paper claims that an enhanced hybrid SWIPT protocol, formed by using the idle link of the standard hybrid protocol for additional transmission in the CNOMA downlink, together with maximal ratio combining at the cell edge user, produces higher ergodic sum capacity, lower outage probabilities, and greater energy efficiency than the baseline HS-CNOMA with selection combining, with the gains confirmed through closed-form analysis and Monte-Carlo simulations.

What carries the argument

The enhanced hybrid SWIPT protocol that reuses the idle link for additional transmission while the cell center user relays to the cell edge user.

If this is right

  • Ergodic sum capacity rises compared with the baseline protocol.
  • Outage probabilities fall for the cell edge user under maximal ratio combining.
  • Energy efficiency improves across the downlink transmission.
  • The full protocol outperforms HS-CNOMA with selection combining on all reported metrics.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The idle-link reuse idea could extend to multi-relay or uplink cooperative NOMA where similar idle intervals appear.
  • Adjusting the time and power splitting factors in real channels might produce further measurable gains beyond the current fixed settings.
  • In dense deployments the same mechanism could lower total network power draw by reducing the need for separate relay batteries.

Load-bearing premise

The idle link can be used for extra transmission without creating interference or demanding additional resources.

What would settle it

Measurements or simulations in which activating the idle link raises interference enough to eliminate the reported capacity gains or increase outage probabilities would falsify the performance advantage.

Figures

Figures reproduced from arXiv: 1906.09159 by A.A.Amin, M.B.Uddin, S.Y.Shin.

Figure 1
Figure 1. Figure 1: System Model decoding, improved hybrid SWIPT is integrated with the considered model. In addition, hybrid SWIPT is the combination of time switching (TS) and power splitting (PS) methods as well [10-11,18]. Where T is total time duration to perform the DL transmission for CNOMA. So for the TS part, a fraction of time block for energy harvesting is 0 < α < 1. Firstly by αT time duration, BS transmits x1 wit… view at source ↗
Figure 2
Figure 2. Figure 2: Enhanced HS protocol for CNOMA 2.1. Direct Transmission and Energy Harvesting of Proposed Hybrid SWIPT based CNOMA According to the concept of DL NOMA, the multiplexed signal is directly transmitted to CCU and CEU which illustrates in Fig.1. Where, 0 < pN < pF ) and pN +pF = P. Here, P is total transmit power. Moreover, P = 1 is considered here and ρ is the SNR [10,18]. The multiplexed signal is transmitte… view at source ↗
Figure 3
Figure 3. Figure 3: ESC versus SNR performance of EHS-CNOMA and HS-CNOMA protocols [PITH_FULL_IMAGE:figures/full_fig_p011_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: ESC versus α of EHS-CNOMA and HS-CNOMA 6.1. Ergodic sum capacity Fig.3 illustrates that EHS-CNOMA with MRC outplayed HS protocol in case of ESC by transmitting x1 for the EH at CCU and information transfer for CEU. Higher SNR provides better ESC than lower SNR for 11 [PITH_FULL_IMAGE:figures/full_fig_p011_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: ESC versus d1 of EHS-CNOMA and HS-CNOMA [PITH_FULL_IMAGE:figures/full_fig_p012_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: OP versus SNR performance of EHS-CNOMA and HS-CNOMA protocols [PITH_FULL_IMAGE:figures/full_fig_p012_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: OP versus α of EHS-CNOMA and HS-CNOMA protocols [PITH_FULL_IMAGE:figures/full_fig_p013_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: OP versus d1 of EHS-CNOMA and HS-CNOMA protocols is considered in this case. So the EHS-CNOMA with MRC provides linearly increased ESC for α < 0.7. However, the provided ESC for EHS-CNOMA with MRC is saturated for α >= 0.7. Because for a longer duration of αT, (1 − α)T /2 duration is shorter. So CCU and CEU cannot properly receive and decode the 13 [PITH_FULL_IMAGE:figures/full_fig_p013_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: EE versus SNR performance of EHS-CNOMA and HS-CNOMA protocols [PITH_FULL_IMAGE:figures/full_fig_p014_9.png] view at source ↗
read the original abstract

Time splitting and power splitting incorporating, a hybrid Simultaneous Wireless Information and Power Transfer (SWIPT) based cooperative Non-Orthogonal Multiple Access (CNOMA) protocol is considered in this paper. Cell center user of the CNOMA system acts as a relay to enhance the reliability of the cell edge user (CEU). SWIPT is considered to empower the relay operation to avoid the battery draining issue. To enhance the system performance in terms of ergodic sum capacity (ESC) and outage probabilities (OP), an integration of CNOMA strategy and hybrid SWIPT protocol for the downlink (DL) transmission is proposed here. By utilizing the idle link of hybrid SWIPT protocol an enhanced hybrid SWIPT protocol is proposed here to enhance the performance of CNOMA DL transmission. Moreover, Maximal ratio combining is utilized as a diversity combining technique at CEU to enhance the performance as well. The performance of the proposed protocol is examined in terms of ergodic sum capacity, outage probabilities and energy efficiency. Finally, the analytical results are justified by the Monte-Carlo simulation. Numerical results demonstrate that the proposed protocol with effective CNOMA strategy achieves superior performance than HS-CNOMA with selection combining.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 1 minor

Summary. The paper proposes an enhanced hybrid SWIPT protocol (time and power splitting) integrated with cooperative NOMA for downlink transmission. The cell-center user acts as a relay powered by SWIPT; the idle link is utilized for additional transmission, maximal ratio combining is applied at the cell-edge user, and performance is evaluated via ergodic sum capacity, outage probability, and energy efficiency. Monte-Carlo simulations are used to claim superior results over HS-CNOMA with selection combining.

Significance. If the reported gains can be isolated from the choice of diversity combiner, the work would contribute to energy-efficient cooperative NOMA designs that exploit idle links in hybrid SWIPT. The simulation-based validation is standard for the field but does not rise to the level of parameter-free derivations or machine-checked proofs.

major comments (3)
  1. [Results / Numerical results] Results section (comparison of proposed protocol vs. HS-CNOMA): the proposed scheme applies maximal ratio combining at the CEU while the baseline uses selection combining. Because MRC is known to yield a strict SNR advantage over selection combining, the headline claim that superior ESC and OP are due to the enhanced hybrid SWIPT protocol plus CNOMA strategy is confounded; no ablation or matched-combiner experiment isolates the protocol contribution.
  2. [Abstract / System model] Abstract and performance evaluation: the time-splitting factor and power-splitting ratio are free parameters listed in the axiom ledger. The central performance claims appear to rest on specific (possibly optimized) choices of these parameters rather than holding independently; the manuscript does not demonstrate that the reported superiority survives variation of these parameters outside the simulated scenarios.
  3. [Abstract] Abstract: the statement that 'analytical results are justified by the Monte-Carlo simulation' is presented without the full derivation, exact channel models, or closed-form expressions being verifiable from the provided text. Consequently the support for the performance claims reduces to simulation matching whose assumptions cannot be independently checked.
minor comments (1)
  1. [Abstract] Abstract opening sentence contains a grammatical error ('Time splitting and power splitting incorporating, a hybrid...').

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the detailed and constructive feedback on our manuscript. Below we provide point-by-point responses to the major comments and outline the revisions we intend to make.

read point-by-point responses

  1. Referee: [Results / Numerical results] Results section (comparison of proposed protocol vs. HS-CNOMA): the proposed scheme applies maximal ratio combining at the CEU while the baseline uses selection combining. Because MRC is known to yield a strict SNR advantage over selection combining, the headline claim that superior ESC and OP are due to the enhanced hybrid SWIPT protocol plus CNOMA strategy is confounded; no ablation or matched-combiner experiment isolates the protocol contribution.

    Authors: We agree that the differing diversity combiners (MRC in the proposed scheme versus SC in the baseline) prevent clean isolation of the protocol contribution alone. The baseline comparison follows the HS-CNOMA scheme as originally defined with SC. To address the concern, we will add new simulation results in the revised manuscript that apply both MRC and SC to the proposed enhanced hybrid SWIPT protocol and compare against the baseline under matched combiners, thereby clarifying the gains attributable to the protocol itself. revision: yes

  2. Referee: [Abstract / System model] Abstract and performance evaluation: the time-splitting factor and power-splitting ratio are free parameters listed in the axiom ledger. The central performance claims appear to rest on specific (possibly optimized) choices of these parameters rather than holding independently; the manuscript does not demonstrate that the reported superiority survives variation of these parameters outside the simulated scenarios.

    Authors: The time-splitting factor and power-splitting ratio are chosen to optimize the reported metrics for the considered channel and power conditions, which is standard practice. We acknowledge that explicit demonstration of robustness across parameter ranges would strengthen the claims. In revision we will include additional numerical results showing ergodic sum capacity and outage probability for a range of these parameters, confirming that the superiority of the proposed protocol holds under variation within the simulated regimes. revision: partial

  3. Referee: [Abstract] Abstract: the statement that 'analytical results are justified by the Monte-Carlo simulation' is presented without the full derivation, exact channel models, or closed-form expressions being verifiable from the provided text. Consequently the support for the performance claims reduces to simulation matching whose assumptions cannot be independently checked.

    Authors: The manuscript provides the system model (including Rayleigh fading channels), the analytical expressions for ergodic sum capacity and outage probability, and the Monte-Carlo validation in Sections III–V. The abstract phrasing will be revised for precision. We will also expand the presentation of assumptions and derivations (or move detailed steps to an appendix) to ensure all expressions and channel models are fully verifiable from the text. revision: yes

Circularity Check

0 steps flagged

No circularity detected; analysis is self-contained

full rationale

The paper derives closed-form expressions for ergodic sum capacity, outage probability, and energy efficiency for the proposed hybrid SWIPT CNOMA protocol, then verifies them via Monte-Carlo simulation and compares numerically to a baseline. No equations or steps reduce by construction to fitted parameters renamed as predictions, self-citations that bear the central load, or definitional equivalences. The MRC versus selection-combining difference is an explicit methodological choice in the comparison rather than a hidden tautology in the derivation chain. The work is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

2 free parameters · 1 axioms · 0 invented entities

The central claim rests on standard wireless channel models and protocol parameters whose values are not fixed by prior literature but chosen to demonstrate gains.

free parameters (2)
  • time splitting factor
    Determines fraction of time allocated to energy harvesting versus information decoding in the hybrid SWIPT protocol.
  • power splitting ratio
    Determines fraction of received power allocated to energy harvesting versus information decoding.
axioms (1)
  • standard math Standard expressions for ergodic capacity and outage probability under Rayleigh or similar fading
    Used to obtain closed-form or analytical expressions for ESC and OP.

pith-pipeline@v0.9.0 · 5742 in / 1252 out tokens · 38218 ms · 2026-05-25T18:40:19.995112+00:00 · methodology

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Reference graph

Works this paper leans on

21 extracted references · 21 canonical work pages · 1 internal anchor

  1. [1]

    D. Zou, D. Deng, Y. Rao, X. Li and K. Yu, Relay selection for cooperative NOMA system over correlated fading channel, Physical Communication, 35, 2019, pp. 100702, https://10.1016/j.phycom.2019.04. 016

    work page doi:10.1016/j.phycom.2019.04 2019

  2. [2]

    L. Dai, B. Wang, Z. Ding, Z. Wang, S. Chen and L. Hanzo, A Survey of Non-Orthogonal Multiple Access for 5G, in IEEE Communications Surveys and Tutorials, 20 (3), 2018, pp. 2294-2323, https://doi: 10.1109/COMST.2018.2835558

    work page doi:10.1109/comst.2018.2835558 2018

  3. [3]

    Y. Li, Y. Li, Y. Chen, Y. Ye and H. Zhang, Performance analysis of cooperative NOMA with a shared AF relay,IET Communications, 2018, 12(19), 2018, pp. 2438 - 2447, https://doi:10.1049/iet-com. 2018.5415. 16

    work page doi:10.1049/iet-com 2018

  4. [4]

    S. M. R. Islam, N. Avazov, O. A. Dobre and K. Kwak, Power domain non-orthogonal multiple access (NOMA) in 5G systems: Potentials and challenges, IEEE Commun. Surveys Tuts., 2017,19(2), pp. 721- 742, https://doi:10.1109/COMST.2016.2621116

    work page doi:10.1109/comst.2016.2621116 2017

  5. [5]

    Z. Ding, X. Lei, G. K. Karagiannidis, R. Schober, J. Yuan and V. K. Bhargava, A survey on non- orthogonal multiple access for 5G networks: Research challenges and future trends, IEEE J. Sel. Areas Commun., 2017, 35(10), pp. 2181-2195, https://doi:10.1109/JSAC.2017.2725519

    work page doi:10.1109/jsac.2017.2725519 2017

  6. [6]

    Song and X

    G. Song and X. Wang, Comparison of interference cancellation schemes for non-orthogonal multiple access system, Proc. 2016 IEEE 83rd Veh. Technol. Conf., May 2016, pp. 1-5, https://doi:10.1109/ VTCSpring.2016.7504172

    work page arXiv 2016

  7. [7]

    J. N. Laneman, D. N. C. Tse and G. W. Wornell, Cooperative diversity in wireless networks: Efficient protocols and outage behavior, IEEE Trans. Inf. Theory, 2004, 50(12), pp. 3062-3080, https://doi: 10.1109/TIT.2004.838089

    work page doi:10.1109/tit.2004.838089 2004

  8. [8]

    Md. Fazlul Kader, Mohammed Belal Uddin, S.M.Riazul Islam and Soo Young Shin, Capacity and outage analysis of a dual-hop decode-and-forward relay-aided NOMA scheme, Digital Signal Processing, 2019, 88, pp. 138-148, https://doi.org/10.1016/j.dsp.2019.02.014

    work page doi:10.1016/j.dsp.2019.02.014 2019

  9. [9]

    Y. Liu, Z. Ding, M. Elkashlan and H. V. Poor, Cooperative Non-orthogonal Multiple Access With Simul- taneous Wireless Information and Power Transfer, IEEE Journal on Selected Areas in Communications, 2016, 34(4), pp. 938-953, https://doi:10.1109/JSAC.2016.2549378

    work page doi:10.1109/jsac.2016.2549378 2016

  10. [10]

    T. N. Do, D. B. da Costa, T. Q. Duong and B. An, Improving the Performance of Cell-Edge Users in MISO-NOMA Systems Using TAS and SWIPT-Based Cooperative Transmissions, IEEE Transactions on Green Communications and Networking, 2018, 2(1), pp. 49-62, https://doi:10.1109/TGCN.2017. 2777510

    work page doi:10.1109/tgcn.2017 2018

  11. [11]

    N. T. Do, D. Benevides da Costa, T. Q. Duong and B. An, Transmit antenna selection schemes for MISO- NOMA cooperative downlink transmissions with hybrid SWIPT protocol, IEEE International Conference on Communications (ICC), Paris, France, 2017, pp. 1-6, https://doi:10.1109/ICC.2017.7997005

    work page doi:10.1109/icc.2017.7997005 2017

  12. [12]

    W. Han, J. Ge and J. Men, Performance analysis for NOMA energy harvesting relaying networks with transmit antenna selection and maximal-ratio combining over Nakagami-m fading, IET Communications, 2016, 10(18), pp. 2687-2693, https://doi:10.1049/iet-com.2016.0630

    work page doi:10.1049/iet-com.2016.0630 2016

  13. [13]

    M. F. Kader and S. Y. Shin, Coordinated Direct and Relay Transmission Using Uplink NOMA, IEEE Wireless Communications Letters, 2018, 7(3), pp. 400-403, https://doi:10.1109/LWC.2017.2779778. 17

    work page doi:10.1109/lwc.2017.2779778 2018

  14. [14]

    Z. Ding, M. Peng and H. V. Poor, Cooperative Non-Orthogonal Multiple Access in 5G Systems, IEEE Communications Letters, 2015, 19(8), pp. 1462-1465, https://doi:10.1109/LCOMM.2015.2441064

    work page doi:10.1109/lcomm.2015.2441064 2015

  15. [15]

    Alghorani and M

    Y. Alghorani and M. Seyfi, On the Performance of Reduced-Complexity Transmit/Receive-Diversity Systems Over MIMO-V2V Channel Model, IEEE Wireless Communications Letters, 2017, 6(2), pp. 214-217, https://doi:10.1109/LWC.2017.2661759

    work page doi:10.1109/lwc.2017.2661759 2017

  16. [16]

    M. B. Shahab and S. Y. Shin, A Time Sharing Based Approach to Accommodate Similar Gain Users in NOMA for 5G Networks, IEEE 42nd Conference on Local Computer Networks Workshops (LCN Workshops), Singapore, 2017, pp. 142-147, https://doi:10.1109/LCN.Workshops.2017.76

    work page doi:10.1109/lcn.workshops.2017.76 2017

  17. [17]

    Wei Duan, Jinjuan Ju, Qiang Sun, Yancheng Ji, Zhiliang Wang, Jeaho Choi, Guoan Zhang, Capacity Enhanced Cooperative D2D Systems over Rayleigh Fading Channels with NOMA, CoRR abs/1810.06837 (2018), https://arxiv.org/abs/1810.06837

    work page internal anchor Pith review Pith/arXiv arXiv 2018

  18. [18]

    Ahmed Al Amin, Soo Young Shin, Investigate the Dominating Factor of Hybrid SWIPT Protocol by Performance Analysis of the Far User of Hybrid SWIPT based CNOMA Downlink Transmission, International Conference on Electrical, Computer and Communication Engineering (ECCE 2019), Coxs Bazar, Bangladesh, 2019

    work page 2019

  19. [19]

    M. F. Kader, S. Y. Shin and V. C. M. Leung, Full-Duplex Non-Orthogonal Multiple Access in Co- operative Relay Sharing for 5G Systems, IEEE Transactions on Vehicular Technology, 2018, 67(7), pp. 5831-5840, https://doi:10.1109/TVT.2018.2799939

    work page doi:10.1109/tvt.2018.2799939 2018

  20. [20]

    F., Uddin, M.B., Islam, A., Shin, S.Y.,: Cooperative Non Orthogonal Multiple Access with SWIPT over Nakagami -m Fading Channels, Trans Emerging Tel Tech, 2018 [Accepted]

    Kader, M. F., Uddin, M.B., Islam, A., Shin, S.Y.,: Cooperative Non Orthogonal Multiple Access with SWIPT over Nakagami -m Fading Channels, Trans Emerging Tel Tech, 2018 [Accepted]

    work page 2018

  21. [21]

    Huang, M

    Y. Huang, M. Liu and Y. Liu, Energy-Efficient SWIPT in IoT Distributed Antenna Systems, IEEE Internet of Things Journal, 5(4), 2018, pp. 2646-2656, https://doi:10.1109/JIOT.2018.2796124. 18

    work page doi:10.1109/jiot.2018.2796124 2018