DSP在全数字BPSK解调器中的应用
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摘要
本文介绍了一种适合于用数字信号处理器(DSP)实现的全数字解调技术。该技术能方便、灵活地设计实现二进制相移键控(BPSK)解调器，而且使用该技术可以大大降低对接收机本身的振荡频率精度和稳定度的要求。目前，BPSK调制方式已广泛应用在数字卫星通信系统、移动卫星通信系统、遥测遥控系统中。这是因为这种调制体制不仅具有适中的频谱利用率，而且对于给定的信噪比，它具有很低的比特错误率。正是由于这些优点，使它在战斗弹遥测中起作越来越重要的作用。
卫星运动造成多普勒频率漂移，接收机一般都采用锁相环来跟踪接收信号频率，以便能正确解调信号。但是在实际上并非所有的解调器都容易设计和实现，尤其是当传输的数据速率很低时，则很难。
有关BPSK调制信号的解调方法很多，例如Castas环，平方环等，这些方法一般都是先提取载波，然后用提纯的载波去解调出传输的数据(大都在同一个环路内完成)，这些方法的优点是显而易见的，但是在某些条件下，这些方法的设计和实现却很困难。如在传输数据速率较低时，普通锁相环来跟踪接收信号频率则很困难。而我们这里就是准备用高速数字信号处理器，利用数字锁相环实现对载波的跟踪，从而实现调制信号的解调，它能有效克服其他解调方式所遇到的困难。
本文简要描述了数字信号处理器(DSP)的系统设计及DSP的发展过程，并运用DSP和用户现场可编程门阵列(FPGA)实现了全数字BPSK解调器的硬件及软件设计。
A full- digital demodulation technique is introduced in this paper, Which can make it easy and quick to design and achieve Binary Phase Shift Keying (BPSK) demodulator, and also can reduce the requirement of the oscillator frequency precision and the degree of stability of the receiver. At present, the way of BPSK demodulation is widely used in digital satellite communicating system, mobile satellite communicating system, telemetry system and telecontrol system. This is because this modulation system has a suitable spectrum availability and a low biterror rate for a given signal-to-noise ratio, which make it more and more important in telemetry system and telecontrol system.
The movement of the satellites causes doppler frequency to drift, the receiver usually tracks the signal frequency the receiver through phase locked loop, in order to can demodulate the signal. But in fact, not all the demodulator can easily be designed and achieved, especially when the data transporting speed is quite low.
There are many ways of modulating signal about BPSK such as Castas loop, square loop, etc. usually the carrier wave is put forward firstly, then the purified carrier wave is used to demodulate the output data( All these things are usually completed in the same loop). These methods have their strong points but at same times, it is difficult to design and achieve these ways. For example, when the speed of transporting is very low, it is very difficult to track the receiver signal frequency through the common phase locked loop. In this paper, we are going to use high speed digital signal processor ,track the carrier wave through the digital phase locked loop, and so to demodulate the modulating signal. It can overcome the difficult problems of the other ways.
The system design of the digital signal processor (DSP) and the development of DSP are briefly introduced in this paper. And designed of the hard ware and soft ware of full digital BPSK demodulator through DSP and FPGA.
卫星运动造成多普勒频率漂移，接收机一般都采用锁相环来跟踪接收信号频率，以便能正确解调信号。但是在实际上并非所有的解调器都容易设计和实现，尤其是当传输的数据速率很低时，则很难。
有关BPSK调制信号的解调方法很多，例如Castas环，平方环等，这些方法一般都是先提取载波，然后用提纯的载波去解调出传输的数据(大都在同一个环路内完成)，这些方法的优点是显而易见的，但是在某些条件下，这些方法的设计和实现却很困难。如在传输数据速率较低时，普通锁相环来跟踪接收信号频率则很困难。而我们这里就是准备用高速数字信号处理器，利用数字锁相环实现对载波的跟踪，从而实现调制信号的解调，它能有效克服其他解调方式所遇到的困难。
本文简要描述了数字信号处理器(DSP)的系统设计及DSP的发展过程，并运用DSP和用户现场可编程门阵列(FPGA)实现了全数字BPSK解调器的硬件及软件设计。
A full- digital demodulation technique is introduced in this paper, Which can make it easy and quick to design and achieve Binary Phase Shift Keying (BPSK) demodulator, and also can reduce the requirement of the oscillator frequency precision and the degree of stability of the receiver. At present, the way of BPSK demodulation is widely used in digital satellite communicating system, mobile satellite communicating system, telemetry system and telecontrol system. This is because this modulation system has a suitable spectrum availability and a low biterror rate for a given signal-to-noise ratio, which make it more and more important in telemetry system and telecontrol system.
The movement of the satellites causes doppler frequency to drift, the receiver usually tracks the signal frequency the receiver through phase locked loop, in order to can demodulate the signal. But in fact, not all the demodulator can easily be designed and achieved, especially when the data transporting speed is quite low.
There are many ways of modulating signal about BPSK such as Castas loop, square loop, etc. usually the carrier wave is put forward firstly, then the purified carrier wave is used to demodulate the output data( All these things are usually completed in the same loop). These methods have their strong points but at same times, it is difficult to design and achieve these ways. For example, when the speed of transporting is very low, it is very difficult to track the receiver signal frequency through the common phase locked loop. In this paper, we are going to use high speed digital signal processor ,track the carrier wave through the digital phase locked loop, and so to demodulate the modulating signal. It can overcome the difficult problems of the other ways.
The system design of the digital signal processor (DSP) and the development of DSP are briefly introduced in this paper. And designed of the hard ware and soft ware of full digital BPSK demodulator through DSP and FPGA.
引文
[1]程佩青．数字信号处理教程．清华大学出版社．1995
[2]苏涛，吴顺明，廖晓群．高性能数字信号处理器与高速实时信号处理，西安电子科技大学出版社，1999
[3]彭启琮、李玉柏．DSP技术．电子科技大学出版社
[4]软件无线电技术．电讯技术，2000年特刊，2000
[5]杨小牛，楼才义，徐建良．软件无线电原理与应用．电子工业出版社．2001
[6]张健，向敬成．软件无线电技术导论．成都电子科技大学出版社．2000
[7]陈世伟．锁相环路原理及应用．兵器工业出版社．1990
[8]张厥盛．锁相技术．西安电子科技大学出版社，1994
[9]郑继禹．锁相同步理论．重庆大学出版社，1991
[10]高宇．新型全数字化PCM同步解调器．遥测遥控，Vol．19，No．2，1998．3
[11]戴逸民．频率合成与锁相技术．中国科学技术大学出版社
[12]万心平．集成锁相环路的原理、特性、应用．人民邮电出版社，1995
[13]戴逸民．“频率合成器相位稳定原理”．电子测量技术，PE28-41，1979．6
[14]TMS320C32 DIGITAL SIGNAL PROCESSOR. TEXAS INSTRUMENTS
[15]Digital Signal Processing Applications With The TMS320 Family, Volumes 1,2 and 3. TEXAS INSTRUMENTS
[16]TMS320C3X Users Guide. TEXAS INSTRUMENTS
[17]WWW.ti.com
[18]WWW.altera.com
[19]赵雅兴．FPGA原理、设计与应用．天津大学出版社
[20]徐志军，徐光辉．CPLD／FPGA的开发与应用．电子工业出版社．2002
[21]ALTERA可编程逻辑器件及其应用．清华大学出版社
[22]FLEX 10K Embedded Programmble Logic Family Data Sheet. ALTERA.JUNE 1999,Ver.4.01
[23]Configuring APEX 20K, FLEX 10K & FLEX 6000 Devices(Application Note 116). ALTERA.December 1999,Ver. 1.02
[24]WWW.idt.com
[25]WWW. cypress.com
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[27]王立宁等．MATLAB与通信仿真．人民邮电出版社，1999
[28]MATLAB Help document. The Mathworks.Inc, 1999
[29]周金萍，王冉，吴斌．MATLAB 6实践与提高．中国电力出版社．2002
[30]范影乐，杨胜天，李轶．MATLAB仿真应用详解．2001
[31]徐志军，徐光辉．大规模可编程逻辑器件及其应用．成都电子科技大学出版社
[32]潘松．VHDL实用教程．成都电子科技大学出版社
[33]常晓明．Verilog-HDL实践与应用系统设计．北京航空航天大学出版社
[34]侯伯亭，顾新．VHDL硬件描述语言与数字逻辑电路设计．,1999
[35]王金明，杨吉斌．数字系统设计与Verilog HDL．电子工业出版社．2002
[36]宋万杰，罗丰，吴顺君．CPLD技术及其应用．西安电子科技大学出版社．1999
[37]TMS320C3X/C4X Assembly Language Tools. TEXAS INSTRUMENTS
[39]TMS320C32 Addendum To The TMS320C3X User's Guide. TEXAS INSTRUMENTS
[40]TMS320C3X General Purpose Applications Users Guide. TEXAS INSTRUMENTS
[41]TMS320C3X/C4X Optimizing C Compiler User's Guide. TEXAS INSTRUMENTS
[42]TMS320C3X C Source Debugger User's Guide. TEXAS INSTRUMENTS
[43]TMS320 Development Support Reference Guide. TEXAS INSTRUMENTS
[44]TMS320 Third-Party Support Reference Guide. TEXAS INSTRUMENTS
[45]TMS320C3X/C4X Code Generation Tools Getting Started Guide,TMS320 DSP Designer's Notebook. TEXAS INSTRUMENTS
[2]苏涛，吴顺明，廖晓群．高性能数字信号处理器与高速实时信号处理，西安电子科技大学出版社，1999
[3]彭启琮、李玉柏．DSP技术．电子科技大学出版社
[4]软件无线电技术．电讯技术，2000年特刊，2000
[5]杨小牛，楼才义，徐建良．软件无线电原理与应用．电子工业出版社．2001
[6]张健，向敬成．软件无线电技术导论．成都电子科技大学出版社．2000
[7]陈世伟．锁相环路原理及应用．兵器工业出版社．1990
[8]张厥盛．锁相技术．西安电子科技大学出版社，1994
[9]郑继禹．锁相同步理论．重庆大学出版社，1991
[10]高宇．新型全数字化PCM同步解调器．遥测遥控，Vol．19，No．2，1998．3
[11]戴逸民．频率合成与锁相技术．中国科学技术大学出版社
[12]万心平．集成锁相环路的原理、特性、应用．人民邮电出版社，1995
[13]戴逸民．“频率合成器相位稳定原理”．电子测量技术，PE28-41，1979．6
[14]TMS320C32 DIGITAL SIGNAL PROCESSOR. TEXAS INSTRUMENTS
[15]Digital Signal Processing Applications With The TMS320 Family, Volumes 1,2 and 3. TEXAS INSTRUMENTS
[16]TMS320C3X Users Guide. TEXAS INSTRUMENTS
[17]WWW.ti.com
[18]WWW.altera.com
[19]赵雅兴．FPGA原理、设计与应用．天津大学出版社
[20]徐志军，徐光辉．CPLD／FPGA的开发与应用．电子工业出版社．2002
[21]ALTERA可编程逻辑器件及其应用．清华大学出版社
[22]FLEX 10K Embedded Programmble Logic Family Data Sheet. ALTERA.JUNE 1999,Ver.4.01
[23]Configuring APEX 20K, FLEX 10K & FLEX 6000 Devices(Application Note 116). ALTERA.December 1999,Ver. 1.02
[24]WWW.idt.com
[25]WWW. cypress.com
[26]李人厚等．精通MATLAB综合辅导与指南．西安交通大学出版社，1997
[27]王立宁等．MATLAB与通信仿真．人民邮电出版社，1999
[28]MATLAB Help document. The Mathworks.Inc, 1999
[29]周金萍，王冉，吴斌．MATLAB 6实践与提高．中国电力出版社．2002
[30]范影乐，杨胜天，李轶．MATLAB仿真应用详解．2001
[31]徐志军，徐光辉．大规模可编程逻辑器件及其应用．成都电子科技大学出版社
[32]潘松．VHDL实用教程．成都电子科技大学出版社
[33]常晓明．Verilog-HDL实践与应用系统设计．北京航空航天大学出版社
[34]侯伯亭，顾新．VHDL硬件描述语言与数字逻辑电路设计．,1999
[35]王金明，杨吉斌．数字系统设计与Verilog HDL．电子工业出版社．2002
[36]宋万杰，罗丰，吴顺君．CPLD技术及其应用．西安电子科技大学出版社．1999
[37]TMS320C3X/C4X Assembly Language Tools. TEXAS INSTRUMENTS
[39]TMS320C32 Addendum To The TMS320C3X User's Guide. TEXAS INSTRUMENTS
[40]TMS320C3X General Purpose Applications Users Guide. TEXAS INSTRUMENTS
[41]TMS320C3X/C4X Optimizing C Compiler User's Guide. TEXAS INSTRUMENTS
[42]TMS320C3X C Source Debugger User's Guide. TEXAS INSTRUMENTS
[43]TMS320 Development Support Reference Guide. TEXAS INSTRUMENTS
[44]TMS320 Third-Party Support Reference Guide. TEXAS INSTRUMENTS
[45]TMS320C3X/C4X Code Generation Tools Getting Started Guide,TMS320 DSP Designer's Notebook. TEXAS INSTRUMENTS