We present two key system technologies on the two ends of RF spectrum to support optical-wireless access using radio-over-fiber (RoF) based distributed antenna system (DAS) for in-building environments. The proposed technologies can enable protocol-independent, multi-carrier broadband connectivity to the end users' devices deployed in the in-door facilities by supporting existing and emerging wireless services with lower radio frequency carrier (from 500 MHz up to 3 GHz) as well as future-proof very high throughput (VHT) gigabit wireless services using 60 GHz mm-wave band. For low frequency wireless services, a broad spectrum band-shifting technique is experimentally demonstrated to simultaneously transmit multi-service multiple input multiple output (MIMO) radio signals over in-building active DAS. This approach facilitates easy upgrading of existing non-MIMO services to MIMO services or adding future MIMO services in a simple and cost-effective way. For wireless-VHT service, for the first time to our knowledge, we demonstrate simultaneous all-optical up-conversion of multiple, separate gigabit wireless services at 60 GHz and 64 GHz mm-wave band using one single lightwave transmitter. This scheme can be used to achieve seamless convergence of very high throughput wireless personal area network (VHT-WPAN) with more conventional low frequency distributed antenna based optical-wireless access system.
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