Research In Performance Results For WFRFT-OFDM Systems

The paper introduces single carrier and OFDM communication system, which are most commonly used in current communication technology. The system performance will drop significantly because of the traditional communication mode can be easily influenced by ICI and ISI. In recent years, as the demand of communication system is higher, communication environment becoming increasingly complex. How to resist the interference effectively attracted extensive attention. To solve the problems existing in the traditional communication system, we mainly studied the fractional Fourier transform which is a new time-frequency signal processing tools. WFRFT-OFDM system uses fractional Fourier transform module instead of Fourier transform in traditional OFDM system modulation module, which can effectively resist the influence of various interference and noises. Simulation results show that when carrier offset exists, the WFRFT system has superiority over both SC and OFDM systems after choosing an optimal fractional order by experiment.Fractional Fourier transform can be seen as a generalized form of Fourier transform. In the WFRFT-OFDM system, FFT/IFFT is replaced by WFRFT/IWFRFT. The WFRFT-OFDM system also can be seen as the generalized form of traditional OFDM system. This paper emphasised on the analysis of the main physical meaning of 4-WFRFT. We points out the digital communication system based on this form has the property of mixed carrier modulation.This paper try to use WFRFT module instead of FFT module in OFDM system. we analyzed the effects of carrier frequency offset for Weighted fractional Fourier transform (WFRFT) system under the time frequency fading channel. The expression of signal-to-interference ratio (SIR) due to intercarrier interference (ICI) and Inter Symbol Interference (ISI) is derived and the bit error rate (BER) performance of the BPSK modulation scheme are simulated for single-carrier (SC), OFDM and WFRFT-OFDM systems respectively. Simulation results show that when carrier offset exists, the WFRFT system has superiority over both SC and OFDM systems after choosing an optimal fractional order by experiment.