Citation
Abstract
This article describes the motivation for, and development and initial testing of, a scaled-time telemetry test capability. The immediate need for this capability is to establish the sequential decoding performance of the data decoder assembly (DDA) for Helios and Pioneer, and the tests have been aimed at evaluating the suitability of the scaled phase-locked loop (PLL) for this task. The relevant parameters of limiter suppression, phase jitter variance, and phase jitter autocorrelation have been measured, and no discrepancy was found between the X16-scaled PLL and the 12-Hz loop of the DSN receiver. Comparative sequential decoding tests have also been performed for 128-bit/s data; no discrepancy was found between scaled and unscaled performance at any modulation index, either near-optimum or high (70 deg), where the carrier reference noise is dominant.
Details
- Volume
- XIX
- Published
- February 15, 1974
- Pages
- 144–151
- File Size
- 748.1 KB