Multi-Color Laser Diode Heterodyned 28-GHz Millimeter-Wave Carrier Encoded With DMT for 5G Wireless Mobile Networks

By using a multi-color laser diode carrier with orthogonal polarization and single-carrier modulation, the long-reach single-mode fiber (SMF) passive optical network and millimeter-wave wireless access network (WAN) with carrying narrow-band and channelized discrete multitone (DMT) data format at >1 Gbit/s/channel are demonstrated for 5G wireless mobile applications. For fiber wireline transmission from central office to remote node, the multi-color laser diode is directly encoded by DMT with quadrature amplitude modulation (QAM) levels ranged from 64 to 1024, and the total raw data rate of the received DMT can maintain as high as 88 Gbit/s at a limit modulation bandwidth of 9.125 GHz. The allowable data band consisting of 0.07-6 GHz for 1024 QAM, 6-9 GHz for 512 QAM and 9-9.125 GHz for 256 QAM is achieved even after long-reach transmission in 75-km-long SMF spool. For wireless transmission from remote node to user end with 28-GHz millimeter-wave carrier after optical heterodyne, the wireless transmission distance can lengthen up to 10 meters with allowable data capacity optimized to 29.6 Gbit/s with a modulation bandwidth of 4.1 GHz in total. Consequently, the achievable bit-loaded data band is 256 QAM within 0.07-2.5 GHz and 64 QAM within 2.5-4.1 GHz for 5G mobile WAN transmission via horn antenna pair.