Abstract:

In order to realize the transparent bit rate and the tunable frequency of frequency shift keying (FSK) in the optical label switching (OLS) system, a new method is proposed and verified by simulation with 125Gbit/s FSK label which is generated by polarization modulation and 20Gbit/s amplitude shift keying (ASK) payload. The bit error rate (BER) performance of combined orthogonal FSK/ASK signal is also researched by simulation in the case of backtoback and the fiber transmission. Besides, the extinction ratio (ER) of ASK payload and the frequency spacing of FSK label have also been studied to obtain the better performance of this OLS system. It is indicated that larger frequency spacing of FSK label will deteriorate the ASK payload, but has little influence on FSK label; larger ER of ASK payload can improve the ASK payload, however, it will bring adverse impact on FSK label. As a result, the optimum ER of ASK payload and the most proper frequency spacing of FSK label are selected to be 4dB and 50GHz, respectively.

Key words: optical label switching, frequency shift keying, amplitude shift keying, orthogonal modulation, polarization modulation