International Journal of Wireless and Microwave Technologies (IJWMT)
IJWMT Vol. 16, No. 5, 8 Oct. 2026
Cover page and Table of Contents: PDF (size: 1052KB)
Performance Analysis of OTFS versus OFDM Waveforms for High-Mobility 6G Velocity Sensing
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Author(s)
Anamika Sharma
1,*
Jagrati Nagdiya
2
Om Prakash Pal
1
Arvind Pathak
3
Index Terms
6G wireless communication, Orthogonal Time Frequency Space (OTFS), Orthogonal Frequency Division Multiplexing (OFDM), joint communication and sensing (JCAS), integrated sensing and communication (ISAC), high-mobility velocity estimation, Doppler resilienc
Abstract
High-mobility 6G sensing places where strict requirements on waveform robustness are required because the large Doppler shifts can degrade velocity estimation. This paper presents a refined simulation-based comparison of Orthogonal Time Frequency Space (OTFS) and Orthogonal Frequency Division Multiplexing (OFDM) for monostatic velocity sensing at 28 GHz. The evaluation uses a three-way receiver design: the first is OTFS with a single delay–Doppler pilot. The second is a strong full-grid OFDM radar baseline with known time–frequency symbols and range–Doppler matched processing. Third is a communication-oriented sparse-pilot OFDM receiver that reflects practical joint communication and sensing (JCAS) pilot budgets. All branches share identical carrier frequency, subcarrier spacing, grid size, cyclic-prefix length, power normalization, and Monte Carlo settings (250 trials per point). Velocity accuracy is reported through root-mean-square error (RMSE), success rate within ±10 km/h, multipath ablations, a velocity sweep, and quantitative response-concentration metrics. The results show that OTFS with one delay–Doppler pilot achieves near-constant RMSE of about 0.43 m/s and 100% success rate across −10 dB to 25 dB SNR at 120 km/h. A full-grid OFDM radar baseline attains essentially the same accuracy, demonstrating that OFDM is not intrinsically incapable of high-mobility velocity estimation when dense known pilots are available. So sparse-pilot OFDM collapses under the same Doppler conditions (RMSE ≈ 79 m/s and zero success rate) while OTFS preserves compact energy concentration in the delay–Doppler plane. These findings justify OTFS for pilot-efficient high-mobility sensing and clarify that OFDM under-performance in high-mobility sensing can be primarily baseline- and overhead-dependent rather than an absolute waveform verdict.
Cite This Paper
Anamika Sharma, Jagrati Nagdiya, Om Prakash Pal, Arvind Pathak, "Performance Analysis of OTFS versus OFDM Waveforms for High-Mobility 6G Velocity Sensing", International Journal of Wireless and Microwave Technologies(IJWMT), Vol.16, No.5, pp. 365-376, 2026. DOI:10.5815/ijwmt.2026.05.22
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