Low-Density Spreading Design Based on an Algebraic Scheme for NOMA Systems

Millar, Goldwyn; Kulhandjian, Michel; Alaca, Ayşe; Alaca, Şaban; DrAmours, Claude; Yanıkömeroğlu, Halim

doi:10.1109/lwc.2022.3140223

Cited by 4 publications

(15 citation statements)

References 16 publications

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“…The limit in (18) follows from Theorem 1. Combining (18) with (9) finally yields (14), which completes the proof.…”

Section: Alternative Outer Bound For Symmetric Loadingmentioning

confidence: 65%

“…, (48) we conclude that the sum-rate upper bound (28) implied by Proposition 2 is tighter in the low-SNR regime than the corresponding simple "symmetric construction" bound in (14), as long as there exists a pair of constants (µ 1 , µ 2 ) ∈ D such that (cf. ( 40))…”

Section: Proof See Appendix Dmentioning

confidence: 81%

“…Finally, the preceding observations are further corroborated in Figure 3, where a setting with β 1 = 1.5, β 2 = 2 and snr 2 = 0.1 × snr 1 is considered (similarly to Figure 1). Here, the sum-rate constraints depicted in Figure 2 (excluding the "symmetric construction" upper bound (14)) are plotted as a function of the system average E b N 0 (see (19) and ( 23)). The tightness of the derived bounds over a wide range of E b N 0 values is clearly demonstrated, as well as the superior performance of regular sparse NOMA compared to dense codedomain NOMA (which yields lower sum rates for all E b N 0 values).…”

Section: Numerical Resultsmentioning

confidence: 99%

“…For symmetric settings, we additionally rely on ( [38], Proposition 5; see also [39], Proposition 4) for the extreme-SNR characterization of the sum-rate bound in (14). Furthermore, note that the sum capacity (specifying the ultimate performance limit) is given by the sum-rate constraint in (13), which, when expressed as a function of snr av , boils down to…”

Section: Extreme-snr Characterizationmentioning

confidence: 99%

“…The difference between the offsets (68) and (69) specifies the horizontal gap (in logarithmic scale) between these lower and upper bounds on the achievable sum rate in the high-SNR regime. However, it is also insightful to compare L ub ∞ to the corresponding high-SNR power offset induced by the "symmetric construction" outer bound of Proposition 3 (see (14)). This offset is simply given by (62), while substituting β instead of β i , and reads…”

Section: Remark 2 As Indicated By (mentioning

confidence: 99%

See 4 more Smart Citations

Beyond Equal-Power Sparse NOMA: Two User Classes and Closed-Form Bounds on the Achievable Region

Zaidel

Shental

Shamai

2022

Entropy

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Non-orthogonal multiple access (NOMA) is a promising technology for future beyond-5G wireless networks, whose fundamental information-theoretic limits are yet to be fully explored. Considering regular sparse code-domain NOMA (with a fixed and finite number of orthogonal resources allocated to any designated user and vice versa), this paper extends previous results by the authors to a setting comprising two classes of users with different power constraints. Explicit rigorous closed-form analytical inner and outer bounds on the achievable rate (total class throughput) region in the large-system limit are derived and comparatively investigated in extreme-SNR regimes. The inner bound is based on the conditional vector entropy power inequality (EPI), while the outer bound relies on a recent strengthened version of the EPI. Valuable insights are provided into the potential performance gains of regular sparse NOMA in practically oriented settings, comprising, e.g., a combination of low-complexity devices and broadband users with higher transmit power capabilities, or combinations of cell-edge and cell-center users. The conditions for superior performance over dense code-domain NOMA (taking the form of randomly spread code-division multiple access), as well as a relatively small gap to the ultimate performance limits, are identified. The proposed bounds are also applicable for the analysis of interference networks, e.g., Wyner-type cellular models.

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“…The limit in (18) follows from Theorem 1. Combining (18) with (9) finally yields (14), which completes the proof.…”

Section: Alternative Outer Bound For Symmetric Loadingmentioning

confidence: 65%

Section: Proof See Appendix Dmentioning

confidence: 81%

Section: Numerical Resultsmentioning

confidence: 99%

Section: Extreme-snr Characterizationmentioning

confidence: 99%

Section: Remark 2 As Indicated By (mentioning

confidence: 99%

See 3 more Smart Citations

Beyond Equal-Power Sparse NOMA: Two User Classes and Closed-Form Bounds on the Achievable Region

Zaidel

Shental

Shamai

2022

Entropy

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Design of Incidence Matrices With Limited Constellation Expansion in Massive Connectivity NOMA Systems

2023

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Non-orthogonal multiple-access (NOMA) is designed to transmit massive amounts of user communications. The incidence matrix manages the relationship between users and resources. This study focused on increasing user supportability and complexity reduction using larger incidence matrices. Our approach to optimizing the incidence matrix to improve system capacity and reduce complexity is based on two critical mathematical concepts: Parallel classes in hypergraph theory and combinatorial designs allow us to explore and extend incidence matrices. Frame theory is used to estimate matrix structures. Then, we investigate applications utilizing our incidence matrix designs-Simple Orthogonal Multi-Arrays (SOMA). The characteristics of SOMA reflect the unique Latin Square pattern, allowing us to produce a highly flexible and fair resource allocation matrix. SOMA designs let us support overload factors over 500%. The theoretical performance analysis equations of our NOMA system were established to support dynamic adaptability and optimization. We implemented and evaluated security methods for eavesdroppers. The prototype of the user hierarchy allows a higher-priority group to have a lower error rate without significantly affecting the system's performance. Finally, the Monte Carlo simulation indicated that our NOMA systems allow higher degrees of freedom and lower complexity than other NOMA schemes while maintaining graceful error rates with a maximum 33% improvement.INDEX TERMS Incidence matrix, NOMA, combinatorial design, frame theory, SOMA.

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Delay-Doppler Domain Pulse Design for OTFS-NOMA

Kulhandjian,

Kurt

et al. 2024

2024 IEEE International Conference on Communications Workshops (ICC Workshops)

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Low-Density Spreading Design Based on an Algebraic Scheme for NOMA Systems

Cited by 4 publications

References 16 publications

Beyond Equal-Power Sparse NOMA: Two User Classes and Closed-Form Bounds on the Achievable Region

Beyond Equal-Power Sparse NOMA: Two User Classes and Closed-Form Bounds on the Achievable Region

Design of Incidence Matrices With Limited Constellation Expansion in Massive Connectivity NOMA Systems

Delay-Doppler Domain Pulse Design for OTFS-NOMA

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