Comparison And Analysis On Technology Of Eliminating DC Offset Of The Zero-IF Receiver

This paper introduces the classification of the receiver,analyzing the advantages and disadvantages of various receiver,and thus the introduction of zero-IF receiver systems analysis principles and structure,pointed out the zero-IF architecture with the advantages and disadvantages.Then focus of this paper describes the zero-IF receiver,what are the deficiencies,and system analysis is how didi these shortcoming,the paper shows the main points in two areas of shortage:were I,Q mismatch and DC offset slip,and then analysis of DC offset is the main problem.The focus is on this part of the generation and elimination of DC offset,the first details of the main reasons for producing DC offset,DC offset,the paper summarizes the three major reasons,namely:"self-mixing"caused by DC offset,even order distortion caused by the DC offset,DC offset staggering.The paper also followed a systematic analysis of the DC offset the impact of the zero-IF receiver,based on the scope of this paper is given in turn to solve the five zero-IF receiver DC offset the method,the five methods are:the exchange coupling scheme,harmonic mixing scheme,nonlinear equalization program,the baseband digital signal processing programs,self-tuning program.This represents the five ways to eliminate DC offset current international mainstream,and analyzed according to their scope of application of the latter two methods of analysis is the firest mathematical derivation and experimental circuit diagram is given(or to improve the circuit),select the appropriate parameters,then Matlab simulation software,the final comclusing.It is the last part of the application of zero-IF receiver prospect.This paper focuses on the DC offset on the impact of zero-IF receiver,analyzes its way and the analysis is focused on the elimination of DC offset,particularly in the baseband digital signal processing technology and self-correction technology,the two method,analysis of the most comprehensive.The so-called base-band digital signal processing design expertise of the algorithm is DC offset single interference measurements and real-time dynamic compensatin of method,the firest of its operating mechanism,then circuit availabke in the market were reasonably optimized and gives circuit diagrm,through mathematical analysis and simulation of this circuit model obtained can indeed effectively eliminating the DC offset,and through analysis and found that the baseband digital signal processing solutions located in the vicinity of zero frequency IF signal processing is not very good.For this problem,the improvement measures are given by theoretical analysis with satisfactory results.As for self-correction program is to add correction circuit output circuit,the output signal to determine the method.Commonly used on the market since the correction circuit is also optimized and gives the blockdiagram of the circuit and,through mathematical analysis,findings and can effectively eliminate DC offset,but the prevalence of a common problem corrected too long,is not conducive to efficiency,then this correction circuit is added in the correct time to improve the speed circuit,by simulation,better improvement effect obtained.The paper analyzed why the need to improve the DC offset,and in to eliminate Dc offset descheme,the baseband digital signal processing technology of improving better,to a wider scope and better,on the correction technique in joined the acceleration module,and effectively improve their imaga quality.