Skip to main content
Log in

OTFS: A New Modulation Scheme for High-Mobility Use Cases

  • Review Article
  • Published:
Journal of the Indian Institute of Science Aims and scope

Abstract

Among the several emerging use case families in 5G, high-mobility use case family is a technologically challenging one. It is expected that there will be a growing demand for mobile services in vehicles, high-speed trains, and even aircraft. The degree of mobility support required (i.e., speed) will depend upon the specific use case (e.g., 500 km/h in bullet trains and 1000 km/h in airplanes). Mobility-on-demand, ranging from very high mobility to low or no mobility, need to be supported. The currently used waveforms fail to perform well in high-mobility scenarios where the Doppler shifts witnessed are quite high (e.g., several kHz of Doppler). Orthogonal time–frequency space (OTFS) is a recently proposed radio access technology waveform suited very well for high-mobility environments. It is a two-dimensional modulation scheme in which information symbols are multiplexed in the delay–Doppler domain. We present an overview of delay–Doppler representation of wireless channels and introduce OTFS modulation along with OTFS basis functions. We illustrate the slow variability and sparse nature of the delay–Doppler channel using an urban multi-lane scenario. Focusing on MIMO-OTFS systems, we present signal detection and channel estimation schemes and their performance. MIMO-OTFS is shown to achieve significantly better performance compared to MIMO-OFDM in high-Doppler environments operating in 4 GHz and 28 GHz frequency bands.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1:
Figure 2:
Figure 3:
Figure 4:
Figure 5:
Figure 6:
Figure 7:
Figure 8:
Figure 9:
Figure 10:
Figure 11:
Figure 12:
Figure 13:
Figure 14:
Figure 15:
Figure 16:
Figure 17:
Figure 18:
Figure 19:

Similar content being viewed by others

Notes

  1. Multicarrier modulation systems such as OFDM or filtered OFDM can constitute the inner core of OTFS modulation. For example, recently, it has been shown in 25 that OTFS can be implemented using a GFDM framework and that OTFS achieves better performance compared to GFDM.

  2. Design and performance of OTFS systems using practical pulse shapes have been discussed in 24. It has been shown in 24 that the OTFS modulation with practical pulse shapes like rectangular pulse and prolate spheroidal waveform shows better error performance compared to the conventional OFDM.

References

  1. Hattachi RE, Erfanian JJ (eds) (2015) 5G white paper. NGMN Alliance, Frankfurt a. M.

    Google Scholar 

  2. Jakes WC (1994) Microwave mobile communications. IEEE Press, New York

    Book  Google Scholar 

  3. Goldsmith A (2005) Wireless communications. Cambridge University Press, Cambridge

    Book  Google Scholar 

  4. Wang T, Proakis JG, Masry E, Zeidler JR (2006) Performance degradation of OFDM systems due to Doppler spreading. IEEE Trans Wireless Commun 5(6):1422–1432

    Article  Google Scholar 

  5. Strohmer T, Beaver S (2003) Optimal OFDM design for time-frequency dispersive channels. IEEE Trans Commun 51(7):1111–1122

    Article  Google Scholar 

  6. Han F-M, Zhang X-D (2007) Hexagonal multicarrier modulation: a robust transmission scheme for time-frequency dispersive channels. IEEE Trans Signal Process 55(5):1955–1961

    Article  Google Scholar 

  7. Han F-M, Zhang X-D (2009) Wireless multicarrier digital transmission via Weyl–Heisenberg frames over time-frequency dispersive channels. IEEE Trans Commun 57(6):1721–1733

    Article  Google Scholar 

  8. Sayeed AM, Aazhang B (1999) Joint multipath-Doppler diversity in mobile wireless communications. IEEE Trans Commun 47(1):123–132

    Article  Google Scholar 

  9. Bhashyam S, Sayeed AM, Aazhang B (2000) Time-selective signaling and reception for communication over multipath fading channels. IEEE Trans Commun 48(1):83–94

    Article  Google Scholar 

  10. Wornell GW (1996) Spread-response precoding for communication over fading channels. IEEE Trans Inform Theory 42:488–501

    Article  Google Scholar 

  11. Hadani R, Rakib S, Tsatsanis M, Monk A, Goldsmith AJ, Molisch AF, Calderbank R (2017) Orthogonal time frequency space modulation. In: Proc. IEEE WCNC’2017, pp 1–7

  12. Hadani R, Monk A (2018) OTFS: a new generation of modulation addressing the challenges of 5G. arXiv:1802.02623 ([cs.IT] 7 Feb 2018)

  13. Hadani R, Rakib S, Kons S, Tsatsanis M, Monk A, Ibars C, Delfeld J, Hebron Y, Goldsmith AJ, Molisch AF, Calderbank R (2018) Orthogonal time frequency space modulation. arXiv:1808.00519v1 ([cs.IT] 1 Aug 2018)

  14. Monk A, Hadani R, Tsatsanis M, Rakib S (2016) OTFS—orthogonal time frequency space: a novel modulation technique meeting 5G high mobility and massive MIMO challenges. arXiv:1608.02993 ([cs.IT] 9 Aug 2016)

  15. Hadani R, Rakib S, Molisch AF, Ibars C, Monk A, Tsatsanis M, Delfeld J, Goldsmith A, Calderbank R (Jun. 2017) Orthogonal time frequency space (OTFS) modulation for millimeter-wave communications systems. In: Proc. IEEE MTT-S Intl. Microwave Symp., pp 681–683

  16. Surabhi GD, Chockalingam A (2019) OTFS modulation with phase noise in mmWave communications. In: Proc. IEEE VTC’2019-Spring

  17. Li L, Wei H, Huang Y, Yao Y, Ling W, Chen G, Li P, Cai Y (2017) A simple two-stage equalizer with simplified orthogonal time frequency space modulation over rapidly time-varying channels. arXiv:1709.02505v1 ([cs.IT] 8 Sep 2017)

  18. Raviteja P, Phan KT, Hong Y, Viterbo E (2018) Interference cancellation and iterative detection for orthogonal time frequency space modulation. IEEE Trans Wireless Commun 17(10):6501–6515

    Article  Google Scholar 

  19. Reyhani AR, Farhang A, Ji M, Chen R-R, Farhang-Boroujeny B (2018) Analysis of discrete-time MIMO OFDM-based orthogonal time frequency space modulation. In: Proc. IEEE ICC’18, pp 1–6

  20. Dean T, Chowdhury M, Goldsmith A (2017) A new modulation technique for Doppler compensation in frequency-dispersive channels. In: Proc. IEEE PIMRC’2017

  21. Farhang A, Reyhani AR, Doyle LE, Farhang-Boroujeny B (2018) Low complexity modem structure for OFDM-based orthogonal time frequency space modulation. IEEE Wireless Commun Lett 7(3):344–347

    Article  Google Scholar 

  22. Murali KR, Chockalingam A (2018) On OTFS modulation for high-Doppler fading channels. In: Proc. ITA’2018, San Diego

  23. Surabhi GD, Augustine RM, Chockalingam A (2019) On the diversity of uncoded OTFS modulation in doubly-dispersive channels. IEEE Trans Wireless Commun 18(6):3049–3063

    Article  Google Scholar 

  24. Raviteja P, Hong Y, Viterbo E, Biglieri E (2018) Practical pulse-shaping waveforms for reduced-cyclic-prefix OTFS. IEEE Trans Veh Tech 68(1):957–961

    Article  Google Scholar 

  25. Nimr A, Chafii M, Matthe M, Fettweis G (2018) Extended GFDM framework: OTFS and GFDM comparison. In: Proc. IEEE GLOBECOM’2018

  26. Ramachandran MK, Chockalingam A (2018) MIMO-OTFS in high-Doppler fading channels: signal detection and channel estimation. In: Proc. IEEE GLOBECOM’2018. Abu Dhabi

  27. Rakib S, Hadani R (2017) Multiple access in wireless telecommunications system for high-mobility applications, US Patent No. US9722741B1

  28. Khammammetti V, Mohammed SK (2019) OTFS based multiple-access in high Doppler and delay spread wireless channels. IEEE Trans Wireless Commun 8(2):528–531

    Article  Google Scholar 

  29. Surabhi GD, Augustine RM, Chockalingam A (2019) Multiple access in the delay-Doppler domain using OTFS modulation. arXiv:1902.03415v1 ([cs.IT] 9 Feb 2019)

  30. Augustine RM, Chockalingam A (2019) Interleaved time-frequency multiple access using OTFS modulation. In: Proc. IEEE VTC’2019-Fall

  31. Raviteja P, Phan KT, Hong Y (2019) Embedded pilot-aided channel estimation for OTFS in delay-Doppler channels. IEEE Trans Veh Tech 68(5):4906–4917

    Article  Google Scholar 

  32. Surabhi GD, Augustine RM, Chockalingam A (2019) Peak-to-average power of OTFS modulation. IEEE Commun Lett 23(6):999–1002

    Article  Google Scholar 

  33. Tiwari S, Das SS (2019) Circularly pulse shaped orthogonal time frequency space modulation. Electron Lett. arXiv:1910.10457 ([cs.IT] 23 Oct 2019)

  34. Augustine RM, Surabhi GD, Chockalingam A (2019) Space-time coded OTFS modulation in high-Doppler channels. In: Proc. IEEE VTC’2019-Spring

  35. Tiwari S, Das SS, Rangamgari V (2019) Low complexity LMMSE receiver for OTFS. IEEE Commun Lett. (preprint in IEEE Xplore)

  36. Surabhi GD, Chockalingam A (2019) Low-complexity linear equalization for OTFS modulation. IEEE Commun Lett. (preprint in IEEE Xplore)

  37. Samimi MK, Maccartney GR, Sun S, Rappaport TS (2016) 28 GHz millimeter-wave ultrawideband small-scale fading models in wireless channels. In: Proc. IEEE VTC’2016-Spring, pp 1–6

  38. Liu P, Springer A (2015) Space shift keying for LOS communication at mmWave frequencies. IEEE Wireless Commun Lett 4(2):121–124

    Article  Google Scholar 

  39. Bohagen F, Orten P, Oien G (2007) Design of optimal high-rank line-of-sight MIMO channels. IEEE Trans Wireless Commun 6(4):1420–1425

    Article  Google Scholar 

  40. Fish A, Gurevich S, Hadani R, Sayeed AM, Schwartz O (2013) Delay-Doppler channel estimation in almost linear complexity. IEEE Trans Inf Theory 59(11):7632–7644

    Article  Google Scholar 

  41. Hlawatsch F, Matz G (2011) Wireless communications over rapidly time-varying channels. Academic Press, New York

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. Chockalingam.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

This work in part has been presented in Information Theory and Applications Workshop, San Diego, February 2018, and in IEEE GLOBECOM’2018, Abu Dhabi, UAE, December 2018.

This work was supported in part by the J. C. Bose National Fellowship, Department of Science and Technology, Government of India, Tata Elxsi Limited, Bengaluru 560048, and the Intel India Faculty Excellence Program.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ramachandran, M.K., Surabhi, G.D. & Chockalingam, A. OTFS: A New Modulation Scheme for High-Mobility Use Cases. J Indian Inst Sci 100, 315–336 (2020). https://doi.org/10.1007/s41745-020-00167-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s41745-020-00167-4

Keywords

Navigation