Nonlinear Channel Estimation for the Radio over Fiber Uplink

After introducing the configuration and uplink model of the radio over fiber (RoF) system, an identification algorithm is proposed based on fractionally sampling the output of the RoF system. In the uplink, the dynamic linear multipath wireless channel is followed by the nonlinear memoryless RoF link Firstly, the impulse response identification of the linear part can be achieved based on subspace method. Secondly, the internal signal is restored using the identified wireless channel model. Finally, the nonlinear element of RoF system is identified by using the input signal and reconstructed internal signal. The effectiveness of the proposed algorithm is demonstrated by simulation.