The Research On Frequency Domain Equalization For Single-carrier Transmission System

In the new century, the access technology of broadcast wireless has been aninevitable trend of the development of communication technology, by the rapiddevelopment of mobile communication technology. Inter Symbol Interference(ISI) isthe major factor of performance influenced wireless communication, which is made ofmultipath effect, in the wireless communication. Therefore, treaty IEEE802.16hasproposed the standard of MAC layer and physical layer of broadcast wireless accesstechnology, in the frequency between2and11GHz. It also proposed OFDM andSC-FDE for the transmission plan of physical layer.As an effective transmission mode, single carrier frequency domainequalization (SC-FDE) technology has been seen as core technology of fourthgeneration mobile communication. And it has special superiority in the high speeddata transmission, like multi-media. The plan of traditional single carrier time domainequalization has a bigger complexity, and is hard to carry out. SC-FDE uses the signalprocessing method like OFDM, in which the FFT/IFFT block of the launch in OFDMis moved to the receiving terminal in SC-FDE, and then takes equalization infrequency domain. This method could tolerate the ISI from frequency selectivedecline effectively, in the meanwhile, it will not bring the question that PARA is toobig. When the complexity is invariant, SC-FDE also has a better performance.In this paper, it firstly analyzes the character of wireless communicationchannel, and describes the basic principle of SC-FDE, and the design of framestructure of transmission signal, and the produced method of pilot frequency signal.Secondly, it describes a classic algorithm—LMS algorithm, and it proposed animproved variable step algorithm which is based on normalization LMS. Thirdly, itdescribes DFE’s structure and performance, and proposed an improved plan forfeedback. At last, it simulated with Matlab, to check the performance of the contentabove.