Research And Analog Implementation Of High Interferece Cancellation GSM Receiver

GSM is a wireless cummunication system which has the largest number of usersand the number of users is still increasing.GSM has extremely low cost in voicecommunications,and it carries most of mobile voice services now.It can be expectedthat GSM will co-exist with other mobile communication systems for a long period oftime.In recent years as the number of users continues to grow,GSM graduallychanged from a noise-limited system to a interference limited system.Co-channelinterference within the system began to seriously affect the normal operation of theGSM system. So it becomes an very important research subject for major terminalchip manufacturers to look for a GSM terminal receiver which has a higher ability forthe co-channel interference elimination.Firstly this thesis introduces the development situation of the GSM system.GSMterminals are currently facing the serious problem of co-channel interference.To solvethis problem,the single antenna interference cancellation(SAIC) algorithm isproposed.And we introduce the research status of SAIC algorithm at home andabroad;Secondly This thesis analyses the adaptive MIC(Mono InterferenceCancellation) which is one of the most popular anti co-channel interference,and thelink simulation of this algorithm is done.Based on the analysis three defects of thealgorithm is summarized.After the simulation and analysis of existing algorithms thisthesis will propose three improved algorithms to settle deficiencies of the existingalgorithms.Simulation analysis proves that optimized MIC algorithms have betterperformance of the co-channel interference elimination and reduce the bit error rate ofthe entire GSM system in the case of equal complexity.After comparing simulationresults of the three improved algorithm, this thesis analyzes the pros and cons of eachalgorithm;Finally other major modules of GSM terminal receiver are studied.Combined with the improved co-channel interference cancellation algorithm,thisthesis realizes a GSM terminal receiver analog system based on the personalcomputer.The system can completely simulate the physical layer processing of theGSM full rate speech channel,including the symbol-level and bit-level processing.Through the data validation of actual GSM network,the analog system of the GSM terminal receiver which uses the optimized algorithms has better performancecompared with the GSM receiver without using the improved algorithms.The main innovations of this thesis are as follows:1、This thesis analyses the adaptive MIC(Mono Interference Cancellation) whichis one of the most popular anti co-channel interference algorithm,and numerous linksimulations of this algorithm are done.Based on the analysis three defects of thealgorithm is summarized.2、 In terms of the three defects of the existing co-channel interferencealgorithm,we propose three effective improved algorithms: variable step size MIC,two iterations MIC and normalized MIC.3、Based on the improved algorithms,this thesis realises a analog system of theGSM terminal receiver which has the high ability of co-channel interferenceelimination.