Citation
Abstract
Efficient use of a deep-space optical communications channel requires changes to the duty cycle of the modulation as the signal and noise powers change. This can be facilitated by modulating the signal with pulse-position-modulation (PPM), supporting multiple PPM orders. To implement iterative demodulation, which is required by certain error-correction-codes to obtain near-capacity performance, would nominally require a distinct hardware implementation for each PPM order. In this paper we describe a method to utilize a single hardware implementation of an iterative demodulator for any PPM order. The method may be applied to any coded modulation that utilizes iterative demodulation and maps to multiple modulation orders.
Details
- Volume
- 42-173
- Published
- May 15, 2008
- Pages
- 1–10
- File Size
- 256.4 KB