摘要
本文对基带信号的成形和射频信号的多速率处理进行了研究。首先给出了成形滤波函数的数学模型，讨论了几种常用成形滤波函数的传输特性以及对传输系统信号误码率的影响。接着介绍了成形滤波器的几种实现方法，包括FIR算法、FFT-IFFT算法和码元滑动窗算法，并将遗传算法用于确定成形滤波器的系数。仿真结果表明，遗传算法在滤波器的设计中确实是有效的。然后介绍了数字成形滤波器多相结构的FPGA实现方法，运用查询系数ROM的方法可以省去实现滤波器的乘法器结构，并对此实现方法进行软件仿真和硬件电路板测试，测试结果达到了较理想的效果。最后讨论了多速率信号处理中两种重要的信号处理——内插和抽取，对它们的实现方法进行了软件仿真，同时给出了它们的FPGA实现。
This paper investigates the problems about the base-band signal shaping and the multi-rate signal processing of the radio-frequency signal. Firstly, the paper gives the mathematical model of the shaping-filter functions and discusses their transmission characteristics. Secondly, the methods to realize the shaping-filter are introduced, which include the FIR algorithm, the FFT-IFFT algorithm and the symbol sliding-window algorithm. The genetic algorithm (GA) is used to optimize the filter coefficients. Computer simulation shows the GA is effective in the filter's design. In addition, the paper presents filter multi-phase structure for the shaping-filter design and its FPGA implementation, where multipliers can be omitted by using the look-up table of the filter coefficients ROM . Test of the prototype circuit board shows the method is perfect. Finally, two important theories of the multi-rate signal processing, interpolation and decimation, are discussed. The paper also gives their computer simulation results and FPGA implementation.
引文
[1]B.P.Lathi,Modern Digital and Analog Communication System,California State University,CBS College Publishing,1983
[2]J.J.Dlklemba,Poles-zero Approximations for the Raised Cosine filter Family,Comsat Technical Review,1987,Vol.17,No.1,p18～25,
[3]K.Fether,Digital Communication Satellite-Microwave Application Prentice-hall,NJ,1981
[4]H.B.Voelcker,Generation of Digital Signaling Waveform,IEEE Trans.Com.Technical,Feb,1968,Vol.Com-16,No.1 p81～93.
[5]Altem公司用户数据手册，光盘版，2001
[6]杨小牛等编著，软件无线电原理与应用，电子工业出版社，2001．1
[7]沈振元，通信系统原理，西安电子科技大学出版社，1992．10
[8]数字通信工程，中国通信工程学会主编，人民邮电出版社，1996
[9]李强，白晓东，卫星广播数字电视信号基带成形特性的研究，卫星电视，1999．10，p48～67
[10]郑君里等，信号与系统(上册)，北京，高等教育出版社，1981，p．247～249
[11]曹志刚，钱亚生，现代通信原理，清华大学出版社，1992，p．228～234
[12]樊平毅，冯重熙，几种成形滤波器的抗时钟抖动性能分析，通信学报，1996，No．7，p．6975
[13]R.A.Hibby and J.W.Smith,Some Extensions of Nyquist's Telehraph Transmission Theory,BSTJ,Sep,1969,p.2425～2444
[14]王立宁等编著，Matlab与通信仿真，人民邮电出版社，1999．12
[15]胡广书，数字信号处理—理论、算法与实现，清华大学出版社，1995
[16]王世一，数字信号处理，北京理工大学出版社，1997，p．158～162
[17]杨贞斌，邬江兴，一种数字化基带成形实现的新方法：基于码元间隔的定长滑动窗法，通信学报，1999，Vol．20，No．6，p．40～44
[18]D.E.Golderg,Generic algorithm in search optizimation & machine learning,Addision-Weseley publishing company,Inc,1989
[19]David B.Forgel,An introduction to simulated evolutionary optimmion,IEEE Trans on netural networks,1994,Vol.5,No.1,p1～14
[20]陈国良，王煦法等，遗传算法及其应用，人民邮电出版社，1996
[21]陈根社，陈新海，遗传算法的研究与进展，信息和控制，1994，23(4)，p．215～222
[22]韩贞祥，文福拴，模拟进化优化方法及其应用—遗传算法，计算机科学，1995，Vol．22，No．2，47～56，
[23]Xiaofeng Qi,throretical analysis of evolutionary algofithms with an infinite population site in continuous space,Partl:Basic properties of selection and mutation,IEEE Trans on netuml networks,1994，Vol.5,No.1
[24]Xiaofeng Qi,Throretical analysis of evolufionary algorithms with an infinite population Site in continuous space,Part2:AnalysiS of the diversification role of crossover,,IEEE Trans on netural networks,1994,Vol.5,NO.1
[25]程佩清，数字信号处理教程，清华大学出版社，1995．8，p．337～340
[26]Z．米凯利维茨，演化程序——遗传算法和数据编码的结合，科学出版社，2000
[27]陈小平，于盛林，遗传算法在FIR滤波器设计—频率抽样中的应用，电子学报，2000，No．10，p．118～120
[28]Y.C.Lim,Frequency response masking approch for this synthesis of shaping linear phase digital filters,IEEE Trans.Circuit Syst,Apr,1986,Vol.CAS-44,p.457～464
[29]R.Yang,B.Liu,,Y.C.Lim,A new structure of sharp transition FIR filters using frequency-response masking,IEEE Trans.Circuit Syst,Apr.1988,Vol.CAS-45,p.955～966
[30]Y.Neuvo,C.Y.Dong,S.K.Mitra,Interpolated infinite impulse response filers,IEEE,Trans.Acoust,Speech,Signal Processing,June,1984,Vol.ASS,P-42,p.564～570
[31]Y.Neuvo,G.Rajan,S.K.Miltra,Desipn of narrow-bank FIR bandpass digital filters with reduced arithmetic compleXity,IEEE Trans.Circuit Syst,,Apr,1987,Vol.CAS-44,p.409～419
[32]J.W.Adams and A.N.Willsion,A new approch to FIR digital filters with fewer multipliers and reduced sensivty,IEEE Trans.Circuit SySt,May,1984,Vol.CAS-40,p.277～284
[33]G.F.Boudreaux,T.W.Parks,Thinning digital filers: A piecewise-exponential approximation approach,IEEE Trans.Acoust.Speech,Signal Processing,Feb,1984,Vol.ASSP-41,p.105～114
[34]M.R.Bateman B.Liu,An approch to programmable CTD filters using coefficient 0,+1,-1,IEEE Trans.Circuit Syst,,June,1980,Vol.CAS-27,p.451～456．
[35]Y.C.Lim,Predictive coding for FIR filter word-length reduction,IEEE Trans.Circuit Syst,Apr,1985,Vol,CAS-42,p.465～472
[36]王方，基带成形滤波器的设计，无线电通信技术，Vol26，p．65～75，2000
[37]沈兰荪等，调制解调的数字实现，电信科学，1994，Vol．9(6)，p．27～41
[38]张国雄等著，精密仪器电路，机械工业出版社， 北京，11，1988，p．55～126
[39]C.A.Siller,W.Debus,Spectral Shaping of M-State Data.Signal of Band-limited Communications,Proc.IEEE-ICC87,June,1987,p.1716～1724
[40]C.A.Siller,W.Debus,T.L/Osbrue,Spectral Shaping and Digital Synthesis of an M-ary time series,IEEE Communication Magazine,Feb,1989,Vol.27,p.15～24
[41]TI模数／数模转换器数据手册，武汉力源电子股份有限公司，4，1998
[42]16 AD公司放大器手册(上)，1992
[43)Floyd M.Gardner,Interpolation in Digital Modems—Part I:Fundamentals,IEEE Transactions on Communications,March,1993,Vol.41,No.3,p.501～507
[44]Lars Erup,Floyd M.Gardner,Robert A.Harris,Interpolation in Digital Modems-PartⅡImplementation and Performance,IEEE Transactions on Communications,June,1993,Vol.41,No.6,p.998～1008.
[45]Hong-wei,,Cheong-fat Chan,chiu-sing Choy,CMOS High Speed Interpolator on Parallel Architecture，IEEE Transactions on Consumer Electronics,MAY,2000,Vol.46,No.2,p.326～329
[46]Signal Processing,Sophocles J.Orfanidis,Prentice Hall,p.644～728,1998
[47]无线通信原理，蔡涛，李旭，杜振民译，电子工业出版社，北京，1999，p．146～214
[48]Matlab语言工具箱，施阳，西北工业大学出版社，西安，1999