A flexible optical OFDMA-PON upstream scheme based on modulation format conversion technique

This paper introduces a novel architecture for next generation passive optical network (PON) upstream transmission based on the employment of optical orthogonal frequency division multiple access (OFDMA) and modulation format conversion technique. The upstream data could be allocated according to the time slot, subcarrier, and modulation format, which is more flexible to dynamically allocate the bandwidth among the ONUs. The feasibility of the proposed upstream scheme is verified in a 10 Gbps data rate, BPSK to QPSK conversion and a 20 Gbps data rate, QPSK to 16 QAM conversion experiments, respectively. The main advantages and issues of the proposed scheme that are under research are also discussed.