Performance analysis of OFDM-ROF system

The demand for high-speed mobile wireless communications is rapidly growing. Orthogonal Frequency Division Multiplexing (OFDM) technology promises to be a key technique for achieving the high data capacity and spectral efficiency requirements for wireless communication systems of the near future. The practical results will be more yielding when the OFDM is combined with Radio Over Fiber technology (ROF). This project presents an investigation of the performance of OFDM-ROF system based on papers [95] [96] [97] [98] in terms of peak power reduction capability and degradation of channel capacity. OFDM is an attractive technique for achieving high-bit-rate wireless data transmission. However, the potentially large peak-to-average power ratio (PAPR) of a multicarrier signal has limited its application. The analysis is based on three sections 1. Peak to average power ratio 2. Signal distortion and channel capacity 3. ROF transmission. This report is organized as follows. After the introduction in the second chapter, OFDM and its principles are studied. Thirdly, is a throughput on the basic ROF technology. The fourth chapter is based onthe OFDM-ROF system, its basic model and description. Fifth chapter is PAPR and instantaneous power analysis. The effect of the envelope clipping on the peak-to-average power ratio (PAPR) and then instantaneous power of the band-limited OFDM signal is studied. While doing the PAPR analysis, the different approaches for the reduction of PAPR by different authors are compared. The sixth chapter is about the Signal distortion and channel capacity over additive white Gaussian noise and Rayleigh fading channels. The capacity calculations shown are based on the assumption that the distortion terms caused by the clipping are Gaussian. In the seventh chapter the ROF transmission performance is based on split-step Fourier method and nonlinear Schrödinger equation. The transmission performance is discussed from the measurement values by incorporating the spectral distribution of a modulation signal into the calculation of composite triple beats. The dynamic range of OFDM-64QAM which is evaluated from the calculations of Desired to Undesired Signal Ratio (DUR) is also presented. Thus, this project evaluates the OFDM-ROF system as a candidate for the future (4G) wireless system design.