Coexistence of OTFS Modulation With OFDM-based Communication Systems
- Resource Type
- Conference
- Authors
- Shafie, Akram; Yuan, Jinhong; Fang, Yuting; Fitzpatrick, Paul; Sakurai, Taka
- Source
- GLOBECOM 2023 - 2023 IEEE Global Communications Conference Global Communications Conference, GLOBECOM 2023 - 2023 IEEE. :4056-4061 Dec, 2023
- Subject
- Communication, Networking and Broadcast Technologies
Components, Circuits, Devices and Systems
Engineering Profession
General Topics for Engineers
Power, Energy and Industry Applications
Signal Processing and Analysis
Wireless communication
Time-frequency analysis
OFDM
Modulation
Channel estimation
Global communication
Signal detection
OTFS
CP-OTFS
Channel Estimation
- Language
- ISSN
- 2576-6813
This study examines the coexistence of orthogonal time-frequency space (OTFS) modulation with current fourth-and fifth-generation (4G/5G) wireless communication systems that primarily use orthogonal frequency-division multiplexing (OFDM) waveforms. We first derive the input-output-relation (IOR) of OTFS when it coexists with an OFDM system while considering the impact of unequal lengths of the cyclic prefixes (CPs) in the OTFS signal. We show analytically that the inclusion of multiple CPs to the OTFS signal results in the effective sampled delay-Doppler (DD) domain channel response to be less sparse. We also show that the effective DD domain channel coefficients for OTFS in coexisting systems are influenced by the unequal lengths of the CPs. Subsequently, we propose an embedded pilotaided channel estimation (CE) technique for OTFS in coexisting systems that leverages the derived IOR for accurate channel characterization. Using numerical results, we show that ignoring the impact of unequal lengths of the CPs during signal detection can degrade the bit error rate performance of OTFS in coexisting systems. We also show that the proposed CE technique for OTFS in coexisting systems outperforms the state-of-the-art threshold-based CE technique.