摘要 |
<p>A technique for determining averaged Q-factor, Qavg , for an optical binary signal transmitted at a bit rate X, based on amplitude histogram evaluation and on asynchronous sampling. The technique is inexpensive since it uses sampling pulses, which have bit rate Y lower than X and are not synchronized with the optical signal. The technique proposes conducting N sampling sessions and constructing N respective amplitude histograms for the sessions, wherein an initial session is conducted at a randomly selected initial phase of the sampling pulses, and N-1 sessions are held at different phases shifted in respect of the initial phase. The technique then compares the obtained N amplitude histograms to select there-from the amplitude histogram having the minimal cumulative value of cross-point data. The averaged Q-factor is determined from the selected histogram, with accuracy comparable with that of synchronous methods.</p> |