Smart RoF systems for spectrally efficient WLANs

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Ubiquitous communications today relies on the availability of two services: 1) a wireless connection to a network gateway, and 2) a wired (or fibered) backbone connecting the gateway to the Internet. By moving the RF processing of wireless links back through the fibered infrastructure to a centralized point, we can achieve the promise of advanced signal processing techniques to achieve tremendous bandwidth, quality of service and robustness. Video telephony, conferencing and multimedia services are some more obvious applications to benefit from such an infrastructure, but other more futuristic applications can also be imagined. A wearable computing device could access locally available high resolution displays wirelessly, Internet based collaborations would enjoy seamless access to all local information, equipment, facilities, etc.The wireless channel is inherently bandwidth limited and we must turn to sophisticated modulation formats, multiple and intelligent antenna systems, and exploitation of rich multipath returns. All this requires complex signal processing, and, more importantly, side information and coordination of access points across the physical propagation area. Only optical fiber provides the necessary bandwidth to transport the RF signals to a central processing center, hence this project makes the wireless and optical channels play together to provide an end-to-end cost-effective technological solution.Our research will examine the effect of the combined wireless and optical channel on the transmission of WiFi signals and propose new mitigation efforts to compensate for channel imperfections. We will propose routines that exploit fully the coordination of access points with multiple antennas for interference suppression, range enhancement and efficient multiplexing. Our efforts will yield networks with greater capacity in the number of users supported per unit area, and also in total throughput.