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arxiv: 2604.22710 · v1 · submitted 2026-04-24 · 💻 cs.NI

Evaluation of the effects of 3GPP-specific beamforming and channel estimation on the 3D EIRP profile of a 5G gNB

Armed Tusha (a) , Joshua Roy Palathinkal (1) , Monisha Ghosh (1) ((1) Department of Electrical , Electronics Engineering , University of Notre Dame , IN , USA.) This is my paper

Pith reviewed 2026-05-08 09:39 UTC · model grok-4.3

classification 💻 cs.NI
keywords 5G NRbeamformingEIRP3GPP Release-18interferencebeam nullingchannel estimationAAS
0
0 comments X

The pith

3GPP-standard beamforming in 5G gNBs produces 3D EIRP profiles where side-lobes create interference in multiple directions beyond the main beam.

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

This paper evaluates the actual transmitted power in three dimensions from a 5G base station using the official 3GPP Release-18 specifications for frequency range 1. It finds that interference patterns depend on a range of beam directions due to side lobes, not just the strongest one. Antenna system design choices strongly affect the average power profile. The authors also propose two methods to null beams toward a target direction, reducing power by 11 dB but causing a noticeable drop in signal quality for users.

Core claim

Using 3GPP Release-18 codebooks for FR-1, the transmitted EIRP of a gNB in 3D space is analyzed, revealing that interference arises from various beamforming directions due to side-lobes, that AAS architecture and port configurations are crucial for average 3D EIRP, and that two introduced beam nulling methods achieve 11 dB power reduction toward a target with 3.5-4.5 dB SNR loss under ideal and practical channel estimation.

What carries the argument

The 3D EIRP profile calculation based on 3GPP beamforming codebooks and two proposed beam nulling methods applied to AAS configurations.

If this is right

  • Interference from a gNB depends on multiple beamforming directions due to side-lobes, not only the worst-case direction.
  • Advanced antenna systems architecture and antenna port configurations significantly influence the average 3D EIRP and are implementation dependent.
  • Beam nulling methods can reduce power by 11 dB toward a target direction.
  • These nulling methods incur 3.5-4.5 dB SNR loss at 10^{-4} BER across modulations, higher than theoretical predictions.
  • Channel estimation effects must be considered in practical evaluations of beam nulling performance.

Where Pith is reading between the lines

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

  • Regulators evaluating mid-band spectrum sharing with radar or satellites should account for realistic side-lobe interference rather than worst-case assumptions.
  • Network operators may need to optimize AAS configurations to balance coverage and interference mitigation.
  • Further real-world measurements could validate the simulated EIRP profiles for deployment decisions.
  • Extending these nulling techniques to other frequency bands or multi-user scenarios might improve coexistence.

Load-bearing premise

The 3GPP Release-18 codebook designs, antenna port setups, and channel estimation models used in the simulations match real-world hardware and deployment conditions at mid-band frequencies.

What would settle it

Conducting over-the-air measurements of a commercial 5G gNB's EIRP in 3D space and comparing the observed side-lobe levels and nulling performance against the simulation results.

Figures

Figures reproduced from arXiv: 2604.22710 by Armed Tusha (a), Electronics Engineering, IN, Joshua Roy Palathinkal (1), Monisha Ghosh (1) ((1) Department of Electrical, University of Notre Dame, USA.).

Figure 1
Figure 1. Figure 1: Physical architecture of AAS panel. A. AAS Structure and Parameters The International Telecommunication Union (ITU) AAS array model is used to model the gNB’s AAS as illustrated in view at source ↗
Figure 2
Figure 2. Figure 2: Normalized radiation power pattern (relative EIRP) from AAS view at source ↗
Figure 3
Figure 3. Figure 3: Normalized radiation power pattern of a given SSB. view at source ↗
Figure 4
Figure 4. Figure 4: Average EIRP as a function of azimuth (ϕ) and elevation (θ) angles, evaluated over all possible PM-s for NL = 2 under two (N1, N2) configurations. Algorithm 2: HPBW-based PM Selection Input: Cpanel, Ccb, ε, θi , ϕi Output: result 1 Function SubsetPM(Cpanel, Ccb, ε, θi ,ϕi): 2 W ← getPMIType1SinglePanelCodebook(Ccb); 3 EIRP ← pattern(Cpanel, W); 4 (θp, ϕp) ← peak(EIRP); 5 θHP BW ∈ {−θHP BW 2 + θp, θHBBW 2 +… view at source ↗
Figure 6
Figure 6. Figure 6: Median level of normalized EIRP considering all PM-s and view at source ↗
Figure 5
Figure 5. Figure 5: CDF of the relative EIRP at (θ, ϕ) = (6◦, 5 ◦) considering the proposed beam nulling schemes for (N1, N2) = (4,4) and NL = 2. In view at source ↗
Figure 8
Figure 8. Figure 8: compares the BER performance of the SSB-PM and the proposed beam nulling-based precoding schemes (ε threshold and HPBW). Due to the reduced set of avail￾able PM-s by approximately 50%, discussed for direction (θi , ϕi) = (6◦ , 5 ◦ ) with reduced median EIRP by 11 dB, the proposed beam nulling approaches with 16QAM exhibit about 3.5 dB SNR degradation performance at 10−4 BER. Under the same BER, SNR degrada… view at source ↗
Figure 7
Figure 7. Figure 7: BER performance of PM vs SVD-based precoding considering view at source ↗
read the original abstract

Spatial domain exploitation through 3D beamforming serves as a critical technology enabler for performance enhancement in the Fifth Generation New Radio (5G NR) specification. This is realized at the gNodeB (gNB) through the integration of massive antenna element arrays that facilitates 3D spatial multiplexing. However, these systems with high-directional transmissions also represent a threat to incumbent services such as radar and satellites. These incumbents already operate in midband spectrum\textemdash{}including the 4.4-4.9 GHz and 7.125-7.4 GHz bands\textemdash{}that are currently being evaluated for future cellular deployments. Here, we present the first work that evaluates the transmitted Effective Isotropic Radiated Power (EIRP) of a gNB in 3D space, using the 3GPP Release-18 standard for FR-1 instead of theoretical analyses of beam nulling, which can be simplistic. We shed light on the problems requiring attention with the EIRP profile in 3D space for existing codebook designs predefined in 3GPP: i) interference from a gNB does not depend only on the worst-case beamforming direction, but on a variety of beamforming directions due to side-lobes; ii) advanced antenna systems (AAS) architecture and antenna port configurations play a crucial role in average 3D EIRP, which are implementation dependent, and iii) we introduce two beam nulling methods, which achieve a 11 dB power reduction toward a target direction, with 3.5-4.5 dB SNR loss in UE link performance at a 10^{-4} bit error rate (BER) across modulation schemes under ideal and practical channel estimation, a higher loss compared to predictions from theoretical analyses.

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

2 major / 0 minor

Summary. The manuscript evaluates the 3D Effective Isotropic Radiated Power (EIRP) profile of a 5G gNB using 3GPP Release-18 FR-1 beamforming and channel estimation models. It claims that gNB interference depends on multiple directions due to side-lobes rather than only worst-case beams, that AAS architecture and antenna port configurations critically affect average 3D EIRP in an implementation-dependent manner, and that two introduced beam nulling methods achieve an 11 dB power reduction toward a target direction with a 3.5-4.5 dB SNR loss at 10^{-4} BER across modulations under both ideal and practical channel estimation (higher than theoretical predictions). The work positions itself as the first to perform this evaluation with standardized 3GPP codebooks instead of simplified theoretical beam nulling analyses, in the context of mid-band spectrum sharing with incumbents.

Significance. If the simulation-based results are robust, the paper offers valuable quantitative insights into practical 3D EIRP behavior and nulling trade-offs for 5G mid-band deployments. The emphasis on side-lobe contributions and AAS/port sensitivity could guide interference management and regulatory considerations for coexistence with radar/satellite systems. The use of externally defined 3GPP standards avoids self-referential derivations and provides a reproducible baseline for comparing against future hardware measurements.

major comments (2)
  1. The central quantitative claims (11 dB reduction and 3.5-4.5 dB SNR loss at 10^{-4} BER) rest on simulations using 3GPP R18 codebooks and AAS models, yet the manuscript provides no cross-validation against over-the-air measurements or hardware-in-the-loop data from actual gNBs in the 4.4-4.9 GHz or 7.125-7.4 GHz bands. This is load-bearing for the interference and nulling conclusions, as unmodeled effects such as mutual coupling, calibration errors, or real propagation could change the reported side-lobe EIRP levels and the gap versus theoretical analyses.
  2. Abstract and results sections: the reported EIRP observations and BER performance lack error bars, confidence intervals, or exact simulation parameters (e.g., number of antenna elements, specific subcarrier spacing, or channel estimation filter details). Without these, it is difficult to assess whether the 11 dB reduction and SNR loss figures are statistically stable across the evaluated modulation schemes and practical channel estimation cases.

Simulated Author's Rebuttal

2 responses · 1 unresolved

We thank the referee for the constructive and detailed feedback. We address each major comment point-by-point below, indicating where revisions will be made to strengthen the manuscript while maintaining its focus on standardized 3GPP models.

read point-by-point responses

  1. Referee: The central quantitative claims (11 dB reduction and 3.5-4.5 dB SNR loss at 10^{-4} BER) rest on simulations using 3GPP R18 codebooks and AAS models, yet the manuscript provides no cross-validation against over-the-air measurements or hardware-in-the-loop data from actual gNBs in the 4.4-4.9 GHz or 7.125-7.4 GHz bands. This is load-bearing for the interference and nulling conclusions, as unmodeled effects such as mutual coupling, calibration errors, or real propagation could change the reported side-lobe EIRP levels and the gap versus theoretical analyses.

    Authors: We acknowledge that hardware validation would provide additional robustness. Our study deliberately employs the standardized 3GPP Release-18 FR-1 models and codebooks to ensure reproducibility and to establish a baseline free of proprietary hardware specifics, as noted in the referee's significance assessment. Real-world OTA measurements in the target bands are beyond the current scope due to access and resource constraints. We will revise the manuscript by adding an explicit limitations subsection that discusses potential discrepancies arising from unmodeled effects such as mutual coupling, calibration errors, and propagation, and how these might influence the reported EIRP profiles and nulling trade-offs relative to theoretical predictions. revision: partial

  2. Referee: Abstract and results sections: the reported EIRP observations and BER performance lack error bars, confidence intervals, or exact simulation parameters (e.g., number of antenna elements, specific subcarrier spacing, or channel estimation filter details). Without these, it is difficult to assess whether the 11 dB reduction and SNR loss figures are statistically stable across the evaluated modulation schemes and practical channel estimation cases.

    Authors: This observation is correct and will be addressed. We will update the abstract and all relevant results sections to explicitly state the simulation parameters, including the antenna array configuration (number of elements and ports), subcarrier spacing, channel estimation filter implementation details, and the number of Monte Carlo realizations used. We will also incorporate error bars or confidence intervals on the EIRP and BER plots to demonstrate statistical stability of the 11 dB reduction and 3.5-4.5 dB SNR loss figures across modulations and channel estimation scenarios. revision: yes

standing simulated objections not resolved
  • Cross-validation of the simulation results against over-the-air measurements or hardware-in-the-loop data from actual 5G gNBs in the specified mid-band frequencies

Circularity Check

0 steps flagged

Simulation of 3GPP R18 codebooks and AAS configurations shows no self-referential derivations or fitted predictions.

full rationale

The paper evaluates 3D EIRP using externally specified 3GPP Release-18 FR-1 codebooks, AAS port configurations, and channel models in simulation. No equations or results are shown to reduce by construction to parameters fitted from the paper's own outputs, self-citations that bear the central claim, or ansatzes smuggled from prior author work. Beam nulling methods are presented as new but operate within the standardized framework without redefining inputs as outputs. This is a standard simulation study whose claims rest on the fidelity of the 3GPP models rather than internal circularity.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

The central claims rest on 3GPP standard models and the introduction of two new nulling procedures; no free parameters are explicitly fitted to the paper's data.

axioms (1)
  • domain assumption 3GPP Release-18 beamforming codebooks and AAS port configurations accurately represent real gNB implementations for FR-1
    The entire EIRP evaluation and nulling performance claims are derived from these standard models.
invented entities (1)
  • Two beam nulling methods no independent evidence
    purpose: Reduce transmitted power toward a chosen direction while maintaining compatibility with 3GPP codebooks
    New procedures introduced in the paper that achieve 11 dB reduction.

pith-pipeline@v0.9.0 · 5673 in / 1680 out tokens · 62051 ms · 2026-05-08T09:39:45.303797+00:00 · methodology

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Reference graph

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