Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Homodyne vs. Heterodyne Architectures in Sub-THz Transceivers: A Phase Noise Perspective

Didem Aydoğan, Korkut Kaan Tokgöz

Abstract

This letter examines the impact of oscillator phase noise on sub-terahertz OFDM transceiver architectures, with a focus on the comparison between homodyne and heterodyne designs. Using a Hexa-X compliant phase noise model, we analytically show that heterodyne architectures reduce the total accumulated phase noise variance by distributing frequency translation across lower-frequency oscillators under realistic phase-noise scaling laws, thereby shifting the dominant impairment from inter-carrier interference to common phase error. OFDM simulations at 70 GHz and 140 GHz demonstrate that while homodyne architectures remain competitive at mmWave frequencies, heterodyne designs provide improved robustness to phase noise at higher sub-THz carriers. These results highlight transceiver architecture as a key design lever for relaxing oscillator and phase-locked loop constraints in future sub-THz wireless systems.

Homodyne vs. Heterodyne Architectures in Sub-THz Transceivers: A Phase Noise Perspective

Abstract

This letter examines the impact of oscillator phase noise on sub-terahertz OFDM transceiver architectures, with a focus on the comparison between homodyne and heterodyne designs. Using a Hexa-X compliant phase noise model, we analytically show that heterodyne architectures reduce the total accumulated phase noise variance by distributing frequency translation across lower-frequency oscillators under realistic phase-noise scaling laws, thereby shifting the dominant impairment from inter-carrier interference to common phase error. OFDM simulations at 70 GHz and 140 GHz demonstrate that while homodyne architectures remain competitive at mmWave frequencies, heterodyne designs provide improved robustness to phase noise at higher sub-THz carriers. These results highlight transceiver architecture as a key design lever for relaxing oscillator and phase-locked loop constraints in future sub-THz wireless systems.
Paper Structure (13 sections, 16 equations, 7 figures, 1 table)

This paper contains 13 sections, 16 equations, 7 figures, 1 table.

Table of Contents

  1. Introduction
  2. Phase Noise Modeling and Architectural Impact
  3. Zero Pole Phase Noise Modeling and Carrier-Frequency Scaling
  4. Phase Noise Accumulation in OFDM
  5. Homodyne versus Heterodyne Architectures
  6. Architectural Phase Noise Impact and Design Guidelines
  7. Homodyne versus Heterodyne Phase Noise Accumulation
  8. Optimal IF Placement and Phase Noise Reduction
  9. Results and Discussion
  10. Simulation Parameters
  11. Phase Noise Injection and OFDM Processing
  12. Pilot-Aided CPE Correction
  13. Conclusion

Figures (7)

  • Figure 1: Heterodyne transmitter architecture.
  • Figure 2: Total phase noise variance vs. IF frequency for target RF of 70 GHz.
  • Figure 3: Total phase noise variance vs. IF frequency for target RF of 140 GHz (right).
  • Figure 4: BER at 70 GHz carrier frequency comparing heterodyne and homodyne systems under different CPE compensation strategies.
  • Figure 5: EVM at 70 GHz carrier frequency comparing heterodyne and homodyne systems under different CPE compensation strategies.
  • ...and 2 more figures