中频PCM/DPSK遥测信号全软化解调技术的研究
|
摘要
在遥测地面接收站中，过去通常采用磁带机来记录检前信号，随着高速数字采集和大容量磁盘阵列记录技术的发展，现在已可以采用直接中频采样和数字记录技术。数字记录有两个优点：一是可以避免磁带机模拟记录带来的信噪比损失；二是可以将数字记录的信号直接送PC机进行全软化事后解调。在这里，全软化解调实质上是在标准的PC机平台上全面采用软件来实现“接收机”的全部解调功能及视频信号解调功能，输出判决后的数据。
本文在说明了软件化解调优越性的基础上，研究了PCM/DPSK遥测信号的全软化解调原理，详细地介绍了软件解调过程，完成了算法的理论设计和具体的数学推导，并在此基础上进行软件设计，完成了包括数字下变频、级联数字滤波抽取、非反馈环定时误差提取、内插法码同步和差分判决等模块的全软件化实现，通过仿真测试和实验验证，获得了比较满意的结果，此研究工作为今后更深入地开展遥测系统的软件无线电研究，提高遥测系统的技术水平打下了良好的基础。
At ground receiving station, magnetic tape was generally used to record the undetectable signal. With the development of the technologies of high-speed sampling and large capacity disk array recording, sampling at intermediate frequency and digital recording can be adopted. There are two merits of digital recording: One is avoiding the lost of SNR when analog recording; the other is digital recorded signal can be directly sent to PC to be demodulated by software afterwards. In this paper, the software demodulation realizes the demodulation by software and outputs the code stream.
Based on the introduction of the software demodulation's advantage, the theory of PCM/DPSK telemetry signal's software demodulation is presented. The designation and the deduction of its arithmetic are accomplished. The realization of DDC, cascaded filter and decimation, timing-error decimation, bit synchronization and difference detection by software are all introduced in this paper. Satisfied result is achieved through computer simulation and experimentation. This research effort gives the preparation for going deeper into the research in future.
本文在说明了软件化解调优越性的基础上，研究了PCM/DPSK遥测信号的全软化解调原理，详细地介绍了软件解调过程，完成了算法的理论设计和具体的数学推导，并在此基础上进行软件设计，完成了包括数字下变频、级联数字滤波抽取、非反馈环定时误差提取、内插法码同步和差分判决等模块的全软件化实现，通过仿真测试和实验验证，获得了比较满意的结果，此研究工作为今后更深入地开展遥测系统的软件无线电研究，提高遥测系统的技术水平打下了良好的基础。
At ground receiving station, magnetic tape was generally used to record the undetectable signal. With the development of the technologies of high-speed sampling and large capacity disk array recording, sampling at intermediate frequency and digital recording can be adopted. There are two merits of digital recording: One is avoiding the lost of SNR when analog recording; the other is digital recorded signal can be directly sent to PC to be demodulated by software afterwards. In this paper, the software demodulation realizes the demodulation by software and outputs the code stream.
Based on the introduction of the software demodulation's advantage, the theory of PCM/DPSK telemetry signal's software demodulation is presented. The designation and the deduction of its arithmetic are accomplished. The realization of DDC, cascaded filter and decimation, timing-error decimation, bit synchronization and difference detection by software are all introduced in this paper. Satisfied result is achieved through computer simulation and experimentation. This research effort gives the preparation for going deeper into the research in future.
引文
[1]．张健，向敬成．软件无线电技术导论．电子科技大学出版社．2001年6月．四川成都
[2]．杨小牛．软件无线电原理与应用．电子工业出版社．2001年1月．北京
[3]．钮心忻．软件无线电技术与应用．北京邮电大学出版社．2000年9月．北京
[4]．郭福成．数字下变频实现技术研究．湖南长沙国防科技大学电子工程学院404教研室 410073
[5]．郑君里．信号与系统．高等教育出版社．1981年7月．北京
[6]．王士林．现代数字调制技术．人民邮电出版社．1987年8月．北京
[7]．王世一．数字信号处理．北京理工大学出版社．1987年6月．北京
[8]．刘益成．信号处理与过抽样转换器．电子工业出版社．1997年9月．北京
[9]．骆聘．软件无线电数字前端的一种新实现方法．无线通信技术．2000,9(3)：1～5
[10]．刘东华．数字中频滤波技术及其在软件无线电中的应用．无线通信技术．2000,9(2)：24～28
[11]．姚玉强．基带数字滤波器的系数量化效应仿真．无线通信技术．2000,9(1)：48～49
[12]．仵国锋．一种高速FIR成型滤波器的设计和实现．无线通信技术，2001，10(2)：12～13
[13]．王小泉．软件无线电中的高效通用数字调制器．无线电通信技术．2001,27(3)：18～19
[14]．刘星成．软件无线电中的关键技术及平台构建初探．无线电通信技术．2000,26(1)：55～59
[15]．李静．用于软件无线电中的整数倍采样率转换技术．无线电通信技术．2000,26(3)：28～29
[16]．王方．多采样率数字滤波器的设计及实现．无线电通信技术．2000,26(4)：17～18
[17]．李纪武．用EDA软件实现电路的调制和解调．电子技术．1999(12)：32～34
[18]．樊平毅．全数字化接收机中插值滤波器的优化设计．电子学报．1996,24(10)：123～126
[19]．殷桂梁．窄带信号采样频率选取的改进方法．电子学报．1997,25(9)：125～127
[20]．曹志刚．现代通信原理．清华大学出版社．1992年8月．北京
[21]．洪福明．通信系统．西安电子科技大学出版社．1990年6月．西安
[22]．袁朝京．数字接收机设计．电讯技术．1998,38(3)：18～25
[23]．张睿．一种实用的软件无线电结构．电子学报．1999，27(11)增刊：38～41
[24]．张宜华．精通Matlab 5．清华大学出版社．1999．6．北京
[25]．林成森．数值计算方法．科学出版社．1998年3月北京
[26].Floyd M.Gardner, A BPSK/QPSK Timing-Error Detector for Sampled Receivers, IEEE Transactions on Communications, VOL.COM-34, NO.5, May 1986
[27].Floyd M.Gardner, Interpolation in Digital Modems-Part Ⅰ: Fundamentals, IEEE Transactions on Communications, VOL.41, NO.3, March 1993
[28].Lars Erup, Interpolation in Digital Modems-Part Ⅱ: Implementation and Performance, IEEE Transactions on Communications, VOL.41, NO.6, June 1993
[29].Jean Armstrong and David Strickland, Symbol Synchronization Using Signal Samples and Interpolation, IEEE Transactions on Communications, VOL.41, NO.2, February 1993
[30].B.Farhang-Boroujeny, Near Optimum Timing Recovery for Digitally Implemented Data Receivers, IEEE Transactions on Communications, VOL.38, NO.9, September 1990
[31].Rob Shepherd, Engineering the Embedded Software Radio, IEEE Communications Magazine, November 1999
[32].Alan Y. Kwentus, Application of Filter Sharpening to Cascaded Integrator-Comb Decimation Filters, IEEE Transactions on Signal Processing, VOL.45, NO 2, February 1997
[33].Shahriar Mirabbasi and Ken Martin, Classical and Moden Receiver Architectures, IEEE Communications Magazine, November 2000
[34].Alistair Munro, Mobile Middleware for the Reconfigurable Software Radio, IEEE Communications Magazine, August 2000
[35].Mark Cummings, FPGA in the Software Radio, IEEE Communication Magazine, February 1999
[2]．杨小牛．软件无线电原理与应用．电子工业出版社．2001年1月．北京
[3]．钮心忻．软件无线电技术与应用．北京邮电大学出版社．2000年9月．北京
[4]．郭福成．数字下变频实现技术研究．湖南长沙国防科技大学电子工程学院404教研室 410073
[5]．郑君里．信号与系统．高等教育出版社．1981年7月．北京
[6]．王士林．现代数字调制技术．人民邮电出版社．1987年8月．北京
[7]．王世一．数字信号处理．北京理工大学出版社．1987年6月．北京
[8]．刘益成．信号处理与过抽样转换器．电子工业出版社．1997年9月．北京
[9]．骆聘．软件无线电数字前端的一种新实现方法．无线通信技术．2000,9(3)：1～5
[10]．刘东华．数字中频滤波技术及其在软件无线电中的应用．无线通信技术．2000,9(2)：24～28
[11]．姚玉强．基带数字滤波器的系数量化效应仿真．无线通信技术．2000,9(1)：48～49
[12]．仵国锋．一种高速FIR成型滤波器的设计和实现．无线通信技术，2001，10(2)：12～13
[13]．王小泉．软件无线电中的高效通用数字调制器．无线电通信技术．2001,27(3)：18～19
[14]．刘星成．软件无线电中的关键技术及平台构建初探．无线电通信技术．2000,26(1)：55～59
[15]．李静．用于软件无线电中的整数倍采样率转换技术．无线电通信技术．2000,26(3)：28～29
[16]．王方．多采样率数字滤波器的设计及实现．无线电通信技术．2000,26(4)：17～18
[17]．李纪武．用EDA软件实现电路的调制和解调．电子技术．1999(12)：32～34
[18]．樊平毅．全数字化接收机中插值滤波器的优化设计．电子学报．1996,24(10)：123～126
[19]．殷桂梁．窄带信号采样频率选取的改进方法．电子学报．1997,25(9)：125～127
[20]．曹志刚．现代通信原理．清华大学出版社．1992年8月．北京
[21]．洪福明．通信系统．西安电子科技大学出版社．1990年6月．西安
[22]．袁朝京．数字接收机设计．电讯技术．1998,38(3)：18～25
[23]．张睿．一种实用的软件无线电结构．电子学报．1999，27(11)增刊：38～41
[24]．张宜华．精通Matlab 5．清华大学出版社．1999．6．北京
[25]．林成森．数值计算方法．科学出版社．1998年3月北京
[26].Floyd M.Gardner, A BPSK/QPSK Timing-Error Detector for Sampled Receivers, IEEE Transactions on Communications, VOL.COM-34, NO.5, May 1986
[27].Floyd M.Gardner, Interpolation in Digital Modems-Part Ⅰ: Fundamentals, IEEE Transactions on Communications, VOL.41, NO.3, March 1993
[28].Lars Erup, Interpolation in Digital Modems-Part Ⅱ: Implementation and Performance, IEEE Transactions on Communications, VOL.41, NO.6, June 1993
[29].Jean Armstrong and David Strickland, Symbol Synchronization Using Signal Samples and Interpolation, IEEE Transactions on Communications, VOL.41, NO.2, February 1993
[30].B.Farhang-Boroujeny, Near Optimum Timing Recovery for Digitally Implemented Data Receivers, IEEE Transactions on Communications, VOL.38, NO.9, September 1990
[31].Rob Shepherd, Engineering the Embedded Software Radio, IEEE Communications Magazine, November 1999
[32].Alan Y. Kwentus, Application of Filter Sharpening to Cascaded Integrator-Comb Decimation Filters, IEEE Transactions on Signal Processing, VOL.45, NO 2, February 1997
[33].Shahriar Mirabbasi and Ken Martin, Classical and Moden Receiver Architectures, IEEE Communications Magazine, November 2000
[34].Alistair Munro, Mobile Middleware for the Reconfigurable Software Radio, IEEE Communications Magazine, August 2000
[35].Mark Cummings, FPGA in the Software Radio, IEEE Communication Magazine, February 1999