Radioengineering (Sep 2020)
Experimental Demonstration of the Potential 5G Based Multiplexed Radio Frequency Signals Transmission in Passive Optical Network
Abstract
Future passive optical network (PON) designs with 5G have been expected to provide simultaneous multiple wireless signals to the end-users. In this regard, this paper for the first time proposes and experimentally demonstrates the simultaneous transmission of baseband 4-pulse amplitude modulation (4-PAM), and radiofrequency (RF) filter bank multicarrier (FBMC), and universal filter orthogonal frequency division multiplexing (UF-OFDM) signals in a PON. A single optical wavelength from a laser source is used to demonstrate the signal transmission over a PON. The proposed system applies in one wavelength using one laser source for the PON. In contrast with conventional on-off keying (OOK) modulation format, 4-PAM modulation format can provide double bandwidth efficiency. Due to the property of high suppression for out of band emission, UF-OFDM and FBMC are considered as potential 5G modulation formats. In the optical line terminal (OLT), the composite signal consisting of 4-PAM, FBMC, and UF-OFDM is designed, generated, and transmitted using optical intensity modulation. The received signal is extracted in the optical network unit (ONU) and demodulated using digital signal processing techniques. Each of the above-mentioned modulation formats mentioned above is designed with a 2 Gbps data rate constituting a total of 6 Gbps aggregate data rate. The bit error rate (BER) and error vector magnitude (EVM) values have been measured after 25 km fiber length. Measurement results show EVM values below 12.5 % as a figure of merit as proposed by 3GPP LTE for 16 QAM modulation.
