A cost-effective radio-over-fiber (RoF) system with novel source-free base station (BS) has been proposed and demonstrated for the first time, by employing polarization multiplexing (PolMUX). At a central station (CS), a downlink laser output is split into two orthogonal states of polarization (SOPs) and the two SOPs are used for an intermediate frequency (IF) signal and a local oscillation (LO), respectively. At a BS, we can obtain a 5 GHz IF signal for microwave access and a baseband signal for wireline access, as well as a 60 GHz LO for up/down conversions. A downlink 65 GHz wireless signal can be generated by mixing the 5 GHz IF signal with the 60 GHz LO and meanwhile an uplink baseband signal can be achieved by mixing the uplink 60 GHz signal with the 60 GHz LO which is generated at each BS. In this system, the uplink baseband signal is modulated onto the reused optical carrier while the 60 GHz LO used for up/down conversions is remotely delivered. Therefore, there are no optical or electric sources needed in each BS which could significantly reduce the system overall cost. The results successfully verify the feasibility of the proposed RoF system.