I. Introduction
Radio-over-fiber (rof) technology is very attractive for providing wireless services to fixed and mobile users in wireless and wireline convergent optical networks. Its well-known advantages compared to the traditional wireless communication techniques include low loss, large bandwidth, and high compatibility with electromagnetic environments [1]. This convergent network shares a homogenous infrastructure based on different types of access technologies, and paves the way to the future communication goal: a world where affordable communication is always available everywhere to everybody [2]. Therefore, a key issue in an access network is to design architecture with simple optical network units. Furthermore, the use of one single fiber for both upstream and downstream transmission is also expected to reduce network size and the connection complexity of the outside plant.