Contents 1. Introduction
Radio over Fiber (RoF) platforms are developing into a flexible and robust solution for the access network due to their potential for delivering broadband heterogeneous services over a wireless/wireline converged network infrastructure. Within this frame, sub-carrier multiplexing has been one of the main techniques for enabling multiple heterogeneous wireless signal delivery over a single optical channel [1]. In this respect, the Optical Frequency Multiplication (OFM) scheme has proved to be very efficient in generating multiple high-frequency subcarriers over a single wavelength [2] employing phase shift keying (PSK) modulation at a low-frequency microwave carrier and phase-to-intensity conversion with simultaneous microwave frequency multiplication by means of a Delayed Interferometer (DI) at the Central Office (CO). However, this approach has been utilized so far only for single microwave frequency multiplication [3], providing single-user data broadcasting only at multiples of the initial low - frequency microwave carrier.
