Power Control for Radio-Over-Fiber Downlinks in Frequency Division Multiplexing Cellular Communication Systems

This paper, for the first time to our knowledge, introduces a power control technique for radio-over-fiber (RoF) downlinks in frequency division multiplexing (FDM) cellular communication systems. The power control technique, which has been widely used in traditional wireless systems, is to radiate sufficient power to establish an adequate service for a particular distance. Due to RoF link nonlinearities, RoF systems can be limited by nonlinear distortion that is dependent on the input RF power. The power control technique can manage the input power of RF signals to the RoF links, and thus nonlinear distortion and interchannel interference can be diminished. In this paper, we theoretically analyze the necessity of power control in FDM-RoF systems and then propose a simple power control algorithm. Finally, the proposed power control algorithm is verified in four-and nine-channel orthogonal frequency division multiplexing ultrawideband (OFDM UWB) wireless systems with RoF distribution.