Citation
Abstract
We consider a pulse-position-modulated (PPM) optical communications channel where photon arrival times are offset by a random jitter. This models jitter introduced by timing synchronization or detector delay, which is a significant degradation for very short slot widths. We derive the symbol likelihoods in the presence of inter-slot interference (ITI) as well as a number of practical approximations to the likelihoods. The impact on performance of a coded system is illustrated, where we show that using the proper likelihoods yields large gains over a conventional receiver that does not model the ITI. We show that, for large PPM orders and moderate jitter, inter-symbol interference (ISI) may be ignored in the receiver while incurring only small losses.
Keywords
Details
- Volume
- 42-171
- Published
- November 15, 2007
- Pages
- 1–13
- File Size
- 149.2 KB