Citation
Abstract
A deep-space optical communications channel is subject to fading losses due to pointing and tracking errors. Barron and Boroson [1] illustrated that these losses may be mitigated by introducing an interleaver that spreads a pointing-induced fade over many codewords of an error-correction code. Several approximations to determine the interleaver gain, which can be computationally prohibitive, are introduced in [1]. However, the methods are accurate only for a range of code rates and interleaver depths. We extend these methods, using a nonlinear fit to capacity, to allow the analysis of any code rate and fading depth. We also develop an efficient and accurate approximation of the finite-interleaving losses by an inversion of the Marcum Q-function, and provide expressions relating the interleaver memory to the finite-interleaver losses. The resulting expressions provide an accurate tool for a system engineer to size the interleaver memory as a function of the data rate and the allowable pointing loss.
Keywords
Details
- Volume
- 42-170
- Published
- August 15, 2007
- Pages
- 1–12
- File Size
- 162.8 KB