Performance analysis of optimized millimeter-wave fiber radio links

We present a comprehensive performance analysis of several optimized fiber radio distribution schemes for millimeter-wave radio services. The analysis includes the noise and nonlinear characteristics of the transmitter (Tx)-receiver (Rx) pair integrated with the analog optical link in the downlink transmission of a given wavelength without optical amplification. Investigations are focused on four configurations of optimized fiber radio links, which were derived by considering the best performing possible Tx-Rx configuration and specifications of commercially available devices to support multichannel subcarrier multiplexed transmission. It was found that the nonlinear characteristics of the Mach-Zehnder modulator are the major source of performance degradation of the fiber radio links. A comparison of RF-over-fiber and IF-over-fiber transport schemes also shows that RF-over-fiber can yield 3-dB improvement in performance compared to IF-over-fiber techniques.