Abstract
In this paper, we examine the performance of two different phase modulation methods in coherent optical code-division multiple-access (OCDMA) systems. As optical spreading sequences, a recently introduced prime code family hereby referred to as double-padded modified prime code has been employed and analyzed. The OCDMA system operates under synchronous homodyne dual-balanced detection scheme. In this analysis, binary phase-shift keying format is deployed where the phase is modulated by either a Mach-Zehnder interferometer external phase-modulator or an injection-locking of distributed feedback laser diode's driving current. The performances of the two phase-modulation techniques in the presence of multiple-access interferences in a shot-noise limited regime are studied. Phase limitations and reasonable consequence associated with the limited phase excursion are also investigated.
| Original language | English |
|---|---|
| Pages (from-to) | 2840-2847 |
| Number of pages | 8 |
| Journal | Journal of Lightwave Technology |
| Volume | 26 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - 1 Aug 2008 |
Keywords
- Coherent balanced detection
- limited phase excursion
- multiple-access interference
- prime code family
- injection locking
- optical code-division multiple access