Citation
Abstract
Telemetry received from deep-space or near-Earth spacecraft often contains strong discrete spectral components extending far beyond the main lobe of the continuous spectrum. This is attributed to filtering of the data-modulated phase in the spacecraft transmitter, which generates discrete spectral components in the spectra of transmitted binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), and offset quadrature phase-shift keying (OQPSK) modulations. The theoretical development and simulations in this article focus on BPSK and OQPSK modulations, due to the underlying compatibility in the techniques used to mitigate discrete spectral components. The reasons for the appearance of spectral lines in BPSK and OQPSK modulations are examined, and methods designed to eliminate discrete spectral components are proposed and evaluated. Finally, the practical limits imposed by finite-phase modulator bandwidth is addressed, and its impact on achievable data rate examined.
Details
- Volume
- 42-208
- Published
- February 15, 2017
- Pages
- 1–25
- File Size
- 3.8 MB