Design Of Blind Equalizer And Multi-user Detection Based On Systolic Array

CDMA has become the air interface mainstream solution of the IMT-2000.With the booming of wireless communication market,it is expected in the CDMA engineering to improve the data transfer rate as well as the system capacity,But in the high-rate wireless access CDMA system,the intersymbol interference (ISI) can not be neglected as it often do in the low-rate CDMA system.The ISI with the multiple access interference (MAI) which arises from mutual interference among all the (nonorthogonal) active users of the system,constitutes the major impediment to the overall system performance.Without proper compensation for MAI and ISI, Bit Error Rate (BER) is generated highly.Blind equalization and multiuser detection,which are studied in this dissertation, can be used to solve the problem.Blind equalization is a self-adaptive equalization technology.It doesn't need referring to a training sequence to maintain normal work,only utilizes the prior information of transmitted signals to equalize the channel character.So in the digital communication system a training sequence isn't transmitted,which can raise the channel's efficiency.However blind equalization may get much better equalization ability at the same time.The super performance of blind equalization snakes it be noticed widely and be used in many fields.This paper systematically analyses and summarizes the basic theory of blind equalization such as algorithm form,performance parameter,B-G algorithm of Bussgang algorithms is the emphasis.Multiuser detection can eliminate MAI essentially and improve system performance,MUD is one of the key technologies in 3G mobile communication system.But due to the high complexity of MUD algorithm,it is very difficult to exploit this technology in pratical system,the main research work may focus on how to present a high performance,low complexity algorithm in recently years.In this paper ,we use a multiuser detection based on systolic array,this systolic architecture adaptively reconfigures the tap coefficient of the transversal filter,through comparing it with other detection,the conclusion is drawn that the detector has high performance.In this paper, a new algorithm which is named as blind equalization and multiuser detection based on systolic array is proposed,it can reduce the ISI and MAI together,and the effect of the detection in symbol error rate has been tested by means of computer simulations.With the combination of the detection and FPGA technology,a study of hardware realization of it is completed.