PHY Layer Knowledge Base

5G NR Interactive PHY Simulator — Full DL/UL Chain

Interactive 5G NR PHY simulator — full DL/UL chain from DU TX through O-RAN fronthaul, O-RU TX, OTA channel, to UE/O-RU RX and DU RX. 100 MHz / 30 kHz SCS / 132 PRBs / 32TRX / 16 layers.

5G NR Beamforming — 3GPP Complete Reference

Full 3GPP beamforming reference — codebook design, CSI-RS, beam management, Type I/II, massive MIMO, analog/digital/hybrid beamforming in NR.

3GPP Antenna Element & Panel Beamforming — Deep-Dive

TS 38.901 antenna element pattern (AEH/AEV/3D), UPA panel structure (M×N), beam steering weights, array factor, grating lobe analysis — interactive simulator with live pattern and 2D cuts.

OFDM vs OTFS vs AFDM — L1 Waveform Deep-Dive

Deep-dive comparison of CP-OFDM, OTFS and AFDM waveforms for 5G NR and 6G — delay-Doppler channel theory, ISFFT, Heisenberg transform, DAFT chirp basis, BER, PAPR, complexity and 3GPP standardisation status.

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5G NR PHY — TS 38.211/212/213/214 Explained

Complete walkthrough of the core 5G NR PHY layer specs — physical channels, channel coding, control procedures, and data procedures.

5G Channel Models — TR 38.901 Explained

Deep dive into 3GPP TR 38.901 — CDL/TDL models, spatial consistency, massive MIMO channel modeling.

5G NR PHY Initial Power Control — Complete Reference

Complete reference for MSG1/MSG3/PUCCH power control — 3GPP TS 38.213/38.321.

OFDM Basics — DFT/FFT through 4G/5G/6G Waveforms

Interactive notebook covering OFDM fundamentals — 11 sections from DFT/FFT to modern 4G/5G/6G waveform design with 21 charts.

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PRACH — Physical Random Access Channel Deep Dive

PRACH preamble formats, ZC sequences, root index tables, timing advance estimation, and Msg1 power control.

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O-RAN Timing — Ta3/Ta4 and FH Timing Parameters

O-RAN WG4 CUS timing parameters — Ta3, Ta4, T1a, T2a windows and practical calibration for RU/DU deployments.

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PDCCH Blind Decoding — Search Space and CORESET

PDCCH blind decoding procedure, CORESET configuration, search space sets, and UE complexity limits per 3GPP TS 38.213.

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SSB Beam Sweeping and MIB Decoding

Synchronization Signal Block structure, beam sweeping patterns, MIB decoding, and initial cell search procedure.

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02

ML + PHY

Machine learning applied to physical layer problems — from channel estimation to AI-driven beam management.

3GPP AI/ML for 6G — Use Cases, Architecture & Standardization

Deep dive into 3GPP AI/ML standardization for 6G — air interface use cases, network architecture, and the path to AI-native wireless.

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Neural Channel Estimation — OFDM Pilot Interpolation

Deep learning for channel estimation in OFDM systems — from classical LS/MMSE to neural interpolation networks.

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Reinforcement Learning for Beam Management

RL-based beam selection and tracking for 5G mmWave — state spaces, reward design, and deployment challenges.

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End-to-End Learning for Physical Layer

Autoencoder-based end-to-end learning for joint TX/RX optimization — replacing modulation and coding with learned representations.

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Federated Learning for Wireless Networks

Distributed ML at the PHY/MAC boundary — gradient compression, over-the-air aggregation, and privacy in wireless FL.

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Semantic Communications — Beyond Shannon

Semantic and task-oriented communication — moving from bit accuracy to task completion as the optimization objective.

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Quantum + PHY

Quantum information theory meets wireless communications — post-classical PHY research directions.

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QKD for Wireless — Key Distribution Protocols

Quantum key distribution protocols (BB84, E91) adapted for wireless channels — fidelity, QBER, and range limitations.

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Entanglement-Assisted Communications

Super-dense coding and teleportation as communication primitives — capacity bounds with prior entanglement.

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Quantum Channel Models for Wireless

Modeling decoherence and noise in quantum wireless channels — amplitude damping, depolarizing, and erasure channels.

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Post-Quantum Cryptography in 5G/6G

NIST PQC standards and integration into 5G NAS/AS security — lattice and hash-based schemes in 3GPP.

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Quantum Internet Architecture — Physical Layer

Quantum repeaters, entanglement swapping, and the PHY challenges in building a global quantum network.

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04

NTN + PHY

Non-terrestrial network PHY challenges — large Doppler, long propagation delays, and 3GPP NTN standardization.

NTN + 5G/6G PHY — Complete Reference

Complete reference for NTN + 5G/6G PHY — 3GPP TR 38.811, TS 38.821, Rel-17 through IMT-2030. Orbital mechanics, Doppler analysis, timing advance, PRACH, OTFS/AFDM waveforms, link budget, HARQ, and architecture.

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NTN PHY Layer — 3GPP R17 and R18

3GPP NTN specifications — timing advance enhancements, Doppler pre-compensation, feeder link, and service link design.

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Doppler in LEO Satellite Systems

Doppler shift estimation and compensation for LEO satellites — frequency pre-correction, UE Doppler budget, and waveform impacts.

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LEO vs MEO vs GEO — PHY Tradeoffs

Comparative analysis of PHY layer parameters across LEO, MEO, and GEO orbits — path loss, delay, Doppler, and handover rates.

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OTFS for NTN — Delay-Doppler Waveforms

OTFS modulation in the delay-Doppler domain — advantages over OFDM for high-mobility NTN channels.

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Direct-to-Device NTN — PHY Considerations

Satellite-to-smartphone PHY design — link budget, reduced capability UEs, and NTN IoT standardization.

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ML + Quantum

Quantum machine learning for signal processing — variational algorithms and quantum advantage in wireless.

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Variational Quantum Circuits for PHY

VQC fundamentals — parameterized quantum gates, gradient estimation, and applications to wireless channel classification.

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Quantum Neural Networks for Signal Detection

QNN architectures for MIMO detection — amplitude encoding, measurement strategies, and NISQ-era feasibility.

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Quantum-Enhanced Channel Estimation

Quantum amplitude estimation applied to pilot-based channel estimation — theoretical speedup and practical barriers.

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Quantum Optimization for Resource Allocation

QAOA and quantum annealing for NP-hard wireless resource allocation — subcarrier assignment, power, beamforming.

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ISAC

Integrated Sensing and Communications — waveform design, joint PHY processing, and spectrum sharing.

ISAC OFDM Notebook v2 — Integrated Sensing & Communications

OFDM-based ISAC analysis — joint radar-comms waveform design, sensing-comms tradeoffs, PHY analysis.

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ISAC Waveform Design — DFRC and Dual Function

Dual-function radar-communications waveforms — spectral coexistence, clutter suppression, and sensing-rate tradeoffs.

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Sensing-Communications Tradeoff Analysis

Fundamental tradeoffs between sensing accuracy and communication capacity — Pareto front analysis and 6G ISAC targets.

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ISAC in 3GPP — 5G Advanced and 6G

3GPP standardization track for ISAC — sensing reference signals, use cases, and the NR sensing framework.

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Massive MIMO for ISAC — Spatial Degrees of Freedom

Leveraging massive MIMO spatial processing for simultaneous beamforming and radar sensing in dense networks.

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References & Standards

Key 3GPP and O-RAN specifications underlying the notebooks. External links to official portals.

3GPP · NR PHY

TS 38.211 / 38.212 / 38.213 / 38.214 — 5G NR Physical Layer

Physical channels, modulation, uplink/downlink control and data procedures.

3GPP · NR

TR 38.901 — 5G Channel Models for Frequencies 0.5–100 GHz

CDL / TDL channel models, spatial consistency, large-scale parameters for system simulations.

3GPP · NTN

TR 38.811 / TS 38.821 — NTN Study & Solutions

Rel-17 NTN architecture, Doppler, timing advance, and PRACH enhancements for satellite access.

3GPP · AI/ML

TR 38.843 — AI/ML for NR Air Interface

Study on AI/ML for beam management, CSI feedback compression, and positioning in NR Rel-18.