A novel modulation scheme for short range polymer optical fiber communications

To make use of the spectrum of a step-index polymer optical fiber (SI-POF) channel, a hybrid modulation scheme is proposed combining discrete multi-tone modulation and M-ary position phase shift keying. The discrete line spectrum interference and sideband interference components of the new modulation scheme are analyzed. The waveform optimization factor and a new numerical symbol generating approach are introduced to strengthen the anti-interference capability of the system. Offline processing with an arbitrary waveform generator and digital storage oscilloscope is used to investigate the transmission performance. A transmission rate of 510.5 Mbps is achieved for a 50 m SI-POF in an intensity modulated direct detection system using eye-safe resonant cavity light-emitting diodes and a PIN diode at red 650 nm. The experimental verification demonstrates that, using the new methodology, an additional bit rate of 19.5 Mbps in the low signal-to-noise ratio region is obtained. Furthermore there 6 dB power is saved at a bit error rate (BER) of 1 x 10(-4), so better spectral efficiency can be achieved. It is demonstrated that the proposed scheme can offer better BER performance and make a better compromise between transmission rate, power consumption, spectral efficiency and BER.