Study And Simulation On Frequency Spreading-Filter Banks Based Multicarrier System

Orthogonal frequency division multiplexing(OFDM) system has a high sidelobe spectrum. In addition, due to the use of a long guard interval against multipath fading channel, the spectrum efficiency of OFDM system is greatly reduced. Unlike OFDM system, the sidelobe spectrum of the prototype filter in the FBMC system is very low. Therefore, FBMC system has a very low sidelobe spectrum congenitally. However, FBMC system cannot effectively overcome the influence of the multipath fading channel. Therefore, the receiver must use multitap equalizer which has high complexity.The frequency spreading-filter banks based multicarrier(FS-FBMC) was proposed to solve this problem later. FS-FBMC is also based on Inverse Fast Fourier Transform and Fast Fourier Transform architecture. It follows the principle of OFDM and doesn't need spectral separation between sub-channels. This scheme is optimal from the following several aspects. It can provide the perfect balance transmission channel and maximize the signal-to-noise ratio at the receiving end without producing additional delay. Unlike traditional FBMC, the dimension of IFFT/FFT is equal to the length of the filter in FS-FBMC system, significantly more than the subcarrier number. So FS-FBMC has stronger ability to resist multipath fading, thus simple single tap equalizer can be adopted.This paper focuses on the study of FS-FBMC system from the following aspects, the structure of the sender, the receiver structure, complexity analysis and the ability to resist multipath fading channel. The simulation results show that, compared to FBMC technique, FS-FBMC can get better performance under multipath channel.