The OFDM Baseband System’s Key Algorithm Research And Implementation That Is Based On The DSP

The broadband wireless communication not only can carry out broadband and theinformation communications anywhere by all means at any time, but also can providehigh mass, high reliability and high baud rate movement communication service in thefuture. Along with consumers’ movement communication of the request continuouslyraise, the advantage of broad bond wireless system (Broadband Wireless Access, BWA)come out gradually, and it is subjected to favor of the telecommunication craft andconsumers. Orthogonal Frequency Division Multiplexing is belonged to the multi-carrier technique. Its biggest characteristic is high-speed transmission, and it has thevery strong resistance to the intersymbol interference and the channel selective fading.Therefore, it is taken as the broadband wireless access system’s core technology.While this article deeply researchs OFDM technology and unifies the relevantdevelopment kit establishment system model, which is referred to the IEEE (Institute ofElectrical and Electronics Engineers)802.16e physics level standard. And it designs theplatform which is taken the OFDM baseband transmission system as the background. Italso realizes channel coding and Viterbi decoding algorithm based on DSP with it.First of all, this text introduces developing trend of the mobile communication inthe future and also introduces the history，developing，search worth，merit andshortcoming of OFDM technique. Then according to the OFDM mathematical models,it elaborates radical principle and key technique of the OFDM and it introduceshomologous IEEE802.16e physical layer standard. Then it studies the OFDM channelcoding and the decoding plan based on IEEE802.16e in the standard. The wirelesschannel is the existence stochastic noise and the burst noise compound channel.Therefore, it uses the stage unites code which has strong ability of correction randomerror and the burst error. Then it deeply researches performance of convolution codeand decoding algorithm. Then developing and designing communications platformwhich has the OFDM communication characteristic, Moreover it uses the highperformance stereo sound audio frequency to arrange decoding chip TLV320AIC23B torealize the simulated signal to digital signal which conforms to the DSP processing form,builds the hardware platform with DSP to realize the OFDM baseband processingsystem’s channel coding and the decoding function and transforms digital signalprocessed by the DSP to the simulated signal for output.