References

References

  1. W. Saad, M. Bennis, and M. Chen, A Vision of 6G Wireless Systems: Applications, Trends, Technologies, and Open Research Problems, IEEE Network, vol. 34, no. 3, pp. 134–142, 2020

    Influential vision paper outlining the key application drivers, technology trends, and open research challenges for 6G. Provides the high-level roadmap that motivates the technology deep-dives in this chapter, including AI-native design, sub-THz communications, and integrated sensing.

  2. E. Björnson and L. Sanguinetti, Power Scaling Laws and Near-Field Behaviors of Massive MIMO and Intelligent Reflecting Surfaces, IEEE Open Journal of the Communications Society, vol. 1, pp. 1306–1324, 2020

    Rigorous analysis of power scaling in the near field for large arrays and RIS, establishing the Rayleigh distance as the boundary between qualitatively different MIMO regimes. Foundation for the near-field beamfocusing analysis in Section 33.3.

  3. A. Sabharwal, P. Schniter, D. Guo, D. W. Bliss, S. Rangarajan, and R. Wichman, In-Band Full-Duplex Wireless: Challenges and Opportunities, IEEE Journal on Selected Areas in Communications, vol. 32, no. 9, pp. 1637–1652, 2014

    Comprehensive tutorial on in-band full-duplex wireless covering the three-stage self-interference cancellation architecture, transceiver design challenges, and rate gain analysis. The foundational reference for Section 33.4.

  4. B. Nazer and M. Gastpar, Computation Over Multiple-Access Channels, IEEE Transactions on Information Theory, vol. 53, no. 10, pp. 3498–3516, 2007

    The information-theoretic foundation for over-the-air computation, establishing that structured (lattice) codes can achieve the computation capacity of the Gaussian MAC. Motivates the AirComp framework in Section 33.5.

  5. M. Cui, Z. Wu, Y. Lu, X. Wei, and L. Dai, Near-Field MIMO Communications for 6G: Fundamentals, Challenges, Potentials, and Future Directions, IEEE Communications Surveys & Tutorials, vol. 25, no. 4, pp. 2461–2497, 2023

    Comprehensive tutorial on near-field MIMO covering spherical-wave channel models, beam focusing, spatial degrees of freedom analysis, polar-domain codebook design, and practical system considerations for XL-MIMO at 6G frequencies.

  6. A. Alkhateeb, S. Jiang, and G. Charan, Real-World Wireless Network Digital Twins: Opportunities, Challenges, and Best Practices, IEEE Communications Magazine, vol. 61, no. 10, pp. 148–153, 2023

    Overview of wireless digital twin architectures that combine ray tracing, ML calibration, and real-time network telemetry. Introduces the concept of site-specific digital twins as an operating framework for 6G networks, discussed in Section 33.6.

  7. F. Liu, Y. Cui, C. Masouros, J. Xu, T. X. Han, Y. C. Eldar, and S. Buzzi, Integrated Sensing and Communications: Toward Dual-Functional Wireless Networks for 6G and Beyond, IEEE Journal on Selected Areas in Communications, vol. 40, no. 6, pp. 1728–1767, 2022

    Comprehensive survey of ISAC covering joint waveform design, beamforming, the communication-sensing rate-CRLB trade-off, and practical system architectures. The primary reference for the ISAC discussion in Section 33.6.

  8. O-RAN Alliance, O-RAN Architecture Description, v9.0, O-RAN Alliance Technical Specification, 2023

    The O-RAN Alliance architecture specification defining the O-RU, O-DU, O-CU, near-RT RIC, and non-RT RIC functional splits and open interfaces (E2, A1, O1, fronthaul) discussed in Section 33.2.

  9. 3GPP, TR 38.821: Solutions for NR to Support Non-Terrestrial Networks (NTN), 3GPP Technical Report, Release 17, 2023

    Defines the 3GPP NTN architecture including timing advance compensation, Doppler pre-correction, and HARQ adaptations for LEO and GEO satellite links. Foundational for the NTN discussion in Section 33.2.

  10. K. Yang, T. Jiang, Y. Shi, and Z. Ding, Federated Learning via Over-the-Air Computation, IEEE Transactions on Wireless Communications, vol. 19, no. 3, pp. 2022–2035, 2020

    Develops the broadband AirComp framework for federated learning over OFDM channels, including power control, receive beamforming, and convergence analysis. Connects the AirComp signal processing of Section 33.5 with the FL application.

  11. E. Everett, A. Sahai, and A. Sabharwal, Passive Self-Interference Suppression for Full-Duplex Infrastructure Nodes, IEEE Transactions on Wireless Communications, vol. 13, no. 2, pp. 680–694, 2014

    Systematic characterisation of propagation-domain SI suppression techniques (antenna separation, cross-polarisation, absorptive shielding) and their interaction with multi-antenna spatial cancellation. Informs the full-duplex design discussion in Section 33.4.

  12. ITU-R, Recommendation ITU-R M.2160: IMT-2030 Framework, International Telecommunication Union, Geneva, 2023

    The ITU-R framework defining the 6G (IMT-2030) usage scenarios, KPI targets, and timeline. Provides the KPI comparison table in Section 33.1 and the overarching vision of 6G as a communication-computation-sensing platform.

Further Reading

For readers who want to go deeper into specific 6G research areas.

  • 6G vision and research landscape

    Dang et al., "What Should 6G Be?" Nature Electronics, vol. 3, pp. 20–29, 2020

    Accessible overview of the 6G vision published in Nature Electronics, covering use cases, technology candidates, and societal implications from a broad perspective.

  • Near-field MIMO channel modelling and beam focusing

    Lu and Dai, "Near-Field Channel Estimation for Extremely Large-Scale Antenna Arrays," IEEE JSAC, vol. 42, no. 4, 2024

    Develops polar-domain channel estimation algorithms for near-field XL-MIMO, addressing the increased pilot overhead when both range and angle must be estimated.

  • Full-duplex massive MIMO

    Shojaeifard et al., "Full-Duplex MIMO: A Survey on Antenna, Signal Processing, and System Design," IEEE Communications Surveys & Tutorials, vol. 25, no. 4, 2023

    Comprehensive survey covering full-duplex MIMO architectures, beamforming-aided SI cancellation, and system-level performance analysis with massive antenna arrays.

  • Over-the-air computation and federated edge learning

    Zhu et al., "Over-the-Air Computation for 6G — Turning Air into a Computer," IEEE Wireless Communications, vol. 30, no. 4, 2023

    Tutorial on AirComp for 6G covering MIMO extensions, RIS-assisted designs, asynchronous transmission, and privacy-preserving aggregation for federated learning.

  • ISAC waveform design and performance limits

    Xiong et al., "Fundamental Trade-offs in Monostatic ISAC: A Holistic Investigation Towards 6G," IEEE JSAC, vol. 42, no. 6, 2024

    Rigorous information-theoretic analysis of the fundamental trade-offs between communication rate and sensing estimation accuracy (CRLB) in monostatic ISAC systems.

  • Wireless digital twins and ray tracing

    He et al., "Channel Modeling for Reconfigurable Intelligent Surface Aided Multi-User MIMO: A Machine Learning Approach," IEEE Transactions on Communications, vol. 70, no. 12, 2022

    Demonstrates ML-calibrated ray tracing for channel prediction in complex environments, achieving path-loss RMSE below 4 dB and enabling the digital twin applications discussed in Section 33.6.

ExercisesCh 34 →