Study On Applying Neural Network To Suppress Wireless Communications Interference

Wireless communications is the fastest growing segment of the communications industry. With the plentifulness of the Internet resources,people request correspond by communication contents to continuously increase and this needs make the system capacity,transmittable velocity,communication quality and the safety of wireless communication become hot point in the study field of wireless wideband transmission today.Multi-carrier techniques,especially OFDM,is given more and more attention because of its various advantages in lessening the severe effects of frequency selective fading and high using frequency rate. Wireless Wave trainsmitting is special,there are always interference in signal transmitting, so Multi-carrier techniques are sensitive to inter sub-carriers interference(ICI) .People find many ways to suppress interferences.This paper proposed using neural network to suppress interference based on interference coefficients analysis.Simulation results demonstrate the way can obviously improve the bit error ration.In chapter 1, this paper given a brief introduction of wireless telecommunication. At the same time, the research background and significance were introduced. Finally, the main contents of the research were pointed out.In chapter 2, We listed some types of wireless modle, wireless modle, fading estimation of channel and the principles of OFDM .In chapter 3, neural network was introdued in brief. Based on it BP neural network, Hopfield neural network and wavelet neural network were listed. We studied how ICI was caused by carreries err and phase noise and how neural network suppressed ICI .OFDM receiver using neural network was given.At last, denoising process to baseband signals with WNN and detecting non-linear multier-user with neural network were discussed.In chapter 4, focused on the software design of the system. In this chapter, we specified how to design a simplified version of the IEEE802.11a by matlab. Methods given in chapter 3 were testified through it.At last, the summary of this thesis was made and review all works. The questions...