Study on RZ-4PAM downstream signals with duty cycles of 33% and 50% for optical access system applic

• 作 者: 陈福平 邵宇丰 陈烙 申世鲁 王安蓉 罗映祥 赵云杰
• 机 构: College of Electronic and Information Engineering,Chongqing Three Gorges University,
• 出 处: Optoelectronics Letters
• 发表日期: 2017年01期
• 关键词: downstream decoder restored downlink return transmitting deliver modulator custo

4-ary pulse amplitude modulation(4PAM) signals with 33% and 50% return-to-zero(RZ) clocks are generated for passive optical network(PON). We demonstrate that RZ-4PAM signals with duty cycles of 33% and 50% after transmission over 20-km-long single mode fiber(SMF) at 10 Gbit/s can be directly detected by using one photo detector,and the original data can also be restored by one M-ary threshold detector and one 4PAM sequence decoder. The optical spectra of 33% and 50% RZ-4PAM signals are measured,and their eye-diagrams before and after transmission are also analyzed. Simulation results show that 33% and 50% RZ-4PAM downlink signals can be received effectively,and the received power values are-15.1 d Bm and-13.8 d Bm when the bit error rate(BER) is 10~(-6). Moreover,33% RZ-4PAM optical signals have better reception performance than 50% RZ-4PAM optical signals.

4-ary pulse amplitude modulation (4PAM) signals with 33% and 50% return-to-zero (RZ) clocks are generated for passive optical network (PON). We demonstrate that RZ- 4PAM signals with duty cycles of 33% and 50 % after transmission over 20-km-long single mode fiber (SMF) at 10 Gbit / s can be directly detected by using one photo detector, and the original data can also be restored by one M-ary threshold detector and one 4 PAM sequence decoder . The optical spectra of 33% and 50% RZ-4 PAM signals are measured, and their eye-diagrams before and after transmission are also analyzed. the received power values ​​are -15.1 d Bm and -13.8 d Bm when the bit error rate (BER) is 10 ~ (-6). Moreover, 33% RZ-4 PAM optical signals have better reception performance than 50% RZ-4 PAM optical signals.