Energy efficiency improvement of OFDM-based Radio-over-fiber systems enabled with PAPR decrease method

In this paper we present the Peak-to-Average Power Ratio decrease method targeted at energy efficiency improvement of the Radio-over-fiber telecommunication systems based on the Orthogonal Frequency Division Multiplexing. The scheme for the proposed method that consists in the signal precoding with discrete function is discussed in details. The simulation results obtained for five different precoding functions: Discrete Hartley Transform, Discrete Cosine Transform, Discrete Sine Transform, Fast Walsh-Hadamard Transform, and Discrete Fourier Transform, show the peak-to-average power ratio decrease of the transmitted signal up to 7 dB without degradation in noise immunity. Such a gain in transmitted power reduction corresponds to energy efficiency improvement by 5.15 dB in the case of 16-position quadrature amplitude modulation. The experimental study confirms the simulation results, providing the 6.5 dB peak-to-average power ratio decrease for Discrete Fourier Transform function.