Optical wavelength division multiplexing for broadband trunking of RF channels to remote antennas

Advances in fiber optic technologies provide the capabilities to employ remote antenna links that improve the performance of RF communications systems in tactical and training scenarios. Such links support improved system flexibility, reduced radio frequency interference and improved personnel protection from anti-radiation ordnance. We discuss the application of commercial off-the-shelf (COTS) wavelength division multiplexing (WDM) and erbium doped fiber amplifier (EDFA) technologies to approaches for expansion of the transmission capacity of existing fiber optic links used for antenna remoting of RF channels. In a previous paper by Cleveland and Tamil (see MILCOM´96, IEEE Military Commun. Conf., p.42-46, 1996), they described the link performance achieved with an EDFA repeater for remoting of a supertrunk for SINCGARS SIP transceiver signals from the Operations Center at the National Training Center to remote antennas. This paper expands the performance analysis to include the addition of optical wavelength division multiplexing (WDM) for the transport of multiple RF supertrunks on a single fiber. The added supertrunk services could include EPLRS, video and cellular telephony links. Our discussion includes an analysis of the constraints imposed by EDFA and WDM components on the optimum link operating condition. We consider the balance between distortion, crosstalk, thermal noise, optical intensity noise, spontaneous emission-signal beat noise and the optical receiver sensitivity. We discuss these factors in terms of the limitations to the link dynamic range and the maximum signal-to-noise ratio