Citation
Abstract
Telemetry systems supported by the DSN employ coherent detection of a bi-phase phase-shift keyed (PSK) waveform. The coherent reference for the detector is supplied by a bandpass limiter/phase-locked loop. Phase noise in this coherent reference is often a critical factor in establishing link performance. Lindsey has analyzed the performance of the DSN receivers under the extreme assumptions that (a, high-rate) the phase error of the coherent reference is constant over the symbol interval, and that (b, low-rate) the phase error of the coherent reference varies rapidly over the symbol interval. Blake/Lindsey and Tausworthe, subsequently developed techniques to approximate the DSN receiver performance between these extremes. Under close examination, however, it becomes apparent that with typical DSN parameters, the approximations used by Blake and Lindsey become suspect above 15-30 bits/s, and hence do not validly cover many of the interesting data rates. The interpolation proposed by Tausworthe depends upon approximating the log of the error probability by the first few terms of a Taylor series in the variational part of the decision variable. Again, there must be some ranges of defining parameters (not necessarily of practical interest) where his approximation becomes invalid. It is the intent of this article to develop a refined approximation to the performance of the DSN receivers with a (hopefully) wider validity range than previous techniques.
Details
- Volume
- XVII
- Published
- October 15, 1973
- Pages
- 83–88
- File Size
- 545.7 KB