QAM调制解调技术研究及其FPGA实现
摘要
正交振幅调制(QAM)技术有着非常广泛的应用范围,不仅在移动通信领域应用,而且在有线电视传输、数字视频广播卫星通信(DVB-S)等领域也都得到广泛应用。QAM调制技术之所以得到如此广泛的应用,在于它具有很高的频带利用率,这在带宽资源不是很丰富的移动通信和卫星通信中更显现出该调制技术的优越性。
本文在对QAM调制解调的基本原理、调制端的基带成形理论和解调端的载波同步理论进行深入研究的基础上,通过Matlab软件的Simulink仿真平台实现了16QAM调制解调系统的建立及实验验证。之后利用Xilinx公司的ISE 9.li软件加载ModelSim6.1b作为软件开发环境,设计并实现了16QAM调制解调系统的伪随机序列发生器、星座映射、基带成形滤波器、载波信号发生器、载波恢复环路和星座逆映射等关键模块。其中基带成形滤波器选择平方根升余弦滤波器,采用分布式(DA)算法实现,可以有效的节约FPGA硬件资源；关于载波信号发生器的设计,本文采取数字坐标旋转(CORDIC)算法实时计算正余弦值的方法,替代传统DDS采用的正弦查表来实现DDS中相位幅度的转换,可以很好的克服DDS中使用ROM表时产生的相位截断误差,极大的提高了DDS的频率和相位分辨率,并显著地节省了FPGA的内部资源；载波恢复则采用通用科斯塔斯环法,这种环路结果简单且容易实现。
本文采用Verilog硬件描述语言对16QAM调制解调系统中的关键模块进行RTL级描述,完成了功能上的仿真验证,通过对比验证了设计的正确性,为下一步的硬件实现打下了很好的基础。
The modulation technology(QAM) is widely used, and it is used not only in the mobile communication field, but also in other fields, such as wire television transmission field, Digital Video Broadcasting-Satellite communication(DVB-S)field, etc...The reason why QAM modulation technology gets so extensive applicable lies in its high frequency band utilization ratio. This is the modulation technology superiority in the mobile communication and satellite communication fields, in which the bandwidth resources are not so abundant.
First of all, this paper introduce the basic principles of QAM modulation and demodulation, especially the base-band shaping theory of modulation and the carrier recovery theory of demodulation, then simulate the whole 16QAM modulation and demodulation system in the Matlab software's simulink toolbox. Beside research in theory, this thesis designs and built the key parts of 16QAM modulation and demodulation system based on FPGA with the simulation environment, which is constituted by the software of ISE9.1i and ModelSim6.1b. The key parts include the following modules:pseudo-random sequence generator, constellation mapping, base-band shaping filter, carrier signal generator, carrier recovery loop, constellation demapping. The srrc filter is used as base-band shaping filter,which is implemented by DA arithmetic,which achieveds the goal of total used resources redulation of the FPGA; we have adopted the use of CORDIC algorithm to replace the real-time computing sine look-up table in the DDS phase to achieve the conversion rate to overcome the use of DDS when ROM table phase truncation error; corrier recovery is implemented by costas loop,which is easy achieved.
This paper achieve the simulation of the key modules of 16QAM modulation and demodulation system by the language of Verilog HDL in the simulation environment. The result of simulation and synthesis proves the correctness of the design. It laid the foundation of the next hardware design.
本文在对QAM调制解调的基本原理、调制端的基带成形理论和解调端的载波同步理论进行深入研究的基础上,通过Matlab软件的Simulink仿真平台实现了16QAM调制解调系统的建立及实验验证。之后利用Xilinx公司的ISE 9.li软件加载ModelSim6.1b作为软件开发环境,设计并实现了16QAM调制解调系统的伪随机序列发生器、星座映射、基带成形滤波器、载波信号发生器、载波恢复环路和星座逆映射等关键模块。其中基带成形滤波器选择平方根升余弦滤波器,采用分布式(DA)算法实现,可以有效的节约FPGA硬件资源；关于载波信号发生器的设计,本文采取数字坐标旋转(CORDIC)算法实时计算正余弦值的方法,替代传统DDS采用的正弦查表来实现DDS中相位幅度的转换,可以很好的克服DDS中使用ROM表时产生的相位截断误差,极大的提高了DDS的频率和相位分辨率,并显著地节省了FPGA的内部资源；载波恢复则采用通用科斯塔斯环法,这种环路结果简单且容易实现。
本文采用Verilog硬件描述语言对16QAM调制解调系统中的关键模块进行RTL级描述,完成了功能上的仿真验证,通过对比验证了设计的正确性,为下一步的硬件实现打下了很好的基础。
The modulation technology(QAM) is widely used, and it is used not only in the mobile communication field, but also in other fields, such as wire television transmission field, Digital Video Broadcasting-Satellite communication(DVB-S)field, etc...The reason why QAM modulation technology gets so extensive applicable lies in its high frequency band utilization ratio. This is the modulation technology superiority in the mobile communication and satellite communication fields, in which the bandwidth resources are not so abundant.
First of all, this paper introduce the basic principles of QAM modulation and demodulation, especially the base-band shaping theory of modulation and the carrier recovery theory of demodulation, then simulate the whole 16QAM modulation and demodulation system in the Matlab software's simulink toolbox. Beside research in theory, this thesis designs and built the key parts of 16QAM modulation and demodulation system based on FPGA with the simulation environment, which is constituted by the software of ISE9.1i and ModelSim6.1b. The key parts include the following modules:pseudo-random sequence generator, constellation mapping, base-band shaping filter, carrier signal generator, carrier recovery loop, constellation demapping. The srrc filter is used as base-band shaping filter,which is implemented by DA arithmetic,which achieveds the goal of total used resources redulation of the FPGA; we have adopted the use of CORDIC algorithm to replace the real-time computing sine look-up table in the DDS phase to achieve the conversion rate to overcome the use of DDS when ROM table phase truncation error; corrier recovery is implemented by costas loop,which is easy achieved.
This paper achieve the simulation of the key modules of 16QAM modulation and demodulation system by the language of Verilog HDL in the simulation environment. The result of simulation and synthesis proves the correctness of the design. It laid the foundation of the next hardware design.
引文
[1]刘聪锋.高效数字调制技术及其应用.[M].北京：人民邮电出版社,2006.
[2]邓青.数字QAM基带解调技术研究与研究.[D].南京：东南大学,2007.
[3]樊昌信.通信原理(第5版).[M].北京：国防工业出版社,2001.
[4]西瑞克斯(北京)通信设备有限公司.无线通信的MATLAB和FPGA实现.[M].北京：人民邮电出版社,2009.
[5]田耘,徐文波,等.无线通信FPGA设计.[M].北京：电子工业出版社,2008.
[6]姜宇柏,黄志强,等.通信收发信机的Verilog实现与仿真.[M].北京：机械工业出版社,2007.
[7]段吉还,黄智伟.基于CPLD/FPGA的数字通信系统建模与设计.[M].北京：电子工业出版社,2004.
[8]吴伟陵,牛凯.无线通信原理.[M].北京：电子工业出版社,2005.
[9]马娅娜.基于FPGA的QAM调制解调技术研究.[D].西安：西安电子科技大学,2007.
[10]陈俊秀.基于软件无线电的调制解调系统关键技术研究.[D].成都：成都理工大学,2009.
[11]Zhang Weiliang, Pan Changyong, Guo Xingbo, Yang Zhixin. Design and FPGA Implementation of High-speed Square-root-raised-cosine FIR filters. [J]. IEEE 2002.
[12]杨霖.基于FPGA的EDSL系统QAM解调器的研究与实现.[D].南京：东南大学,2006.
[13]Daekyo Shin, Ki Hyuk Park and Myung H. Sunwoo. A 64/256 QAM Receiver Chip for High-speed Communication. [J]. IEEE,2000.
[14]张辉,曹丽娜.现代通信原理与技术.[M].西安：西安电子科技大学出版社,2002.
[15]John GProakis.数字通信(第四版).[M].北京：电子工业出版社,2003.
[16]张公礼.全数字接收机理论与技术.[M].北京：科学出版社,2004
[17]姜宇柏,游思晴.软件无线电原理与工程应用.[M].北京：机械工业出版社,2006.
[18]楼顺天,刘小东,李博菡.基于MATLAB7.X的系统分析与设计—信 号处理.[M].西安：西安电子科技大学出版社.1998.240-250
[19]王沫然.Simulink4建模及动态仿真.[M].北京：电子工业出版社,2002.
[20]孙屹,李妍,等.Matlab通信仿真开发手册.[M].北京：国防工业出版社,2005.
[2l]任晓东,文博.CPLD/FPGA高级应用开发指南.[M].北京：电子工业出版社.2003
[22]夏宇闻,等.Verilog数字系统设计教程.[M].北京：北京航天航空大学出版社,2003.
[23]J.Bhasker著,孙海平等译,VERILOG HDL综合实用教程.[M].清华大学出版社,2004.
[24]徐欣,于红旗,易凡,卢启忠.基于FPGA的嵌入式系统设计.[M].北京：机械工业出版社,2004,9
[25]薛小刚,葛毅敏,Xilinx ISE9.X FPGA/CPLD设计指南.[M].人民邮电出版社,2007
[26]陈德峰,李欣.MQAM原理及其在EDSL系统中的应用.[J].铁路计算机应用,2000.：23 25
[27]陈德峰.EDSL系统中自适应MQAM调制器的研究及FPGA实现：[D].青岛：中国海洋大学,2007.
[28]史治国,洪少华,陈抗生.基于XILINX FPGA的OFDM通信系统基带设计.[M].杭州：浙江大学出版社,2009.
[29]张贤达.现代信号处理.[M].清华大学出版社,1995.1
[30]奥本海姆,离散时间信号处理.[M].黄建国,刘树棠译.科学出版社,1998.7
[31]胡广书.现代信号处理教程.[M].北京：清华大学出版社,2004.
[32]杨义先.最佳信号理论与设计.[M].人民邮电出版社,1996.12
[33]汤伟良,李建东,李维英.数控振荡器在FPGA上的实现.[J].微型机与应用2003,11：23-25
[34]王钿,卓兴旺.基于Verilog HDL的数字系统应用设计.[M].北京：国防工业出版社,2007.
[35]田骏骅.高速QAM解调器的算法及VLSI实现研究：[D].上海：复旦大学,2005.
[36]文安平.QAM接收机中定时恢复算法设计与实现：[D].武汉：武汉科技大学,2005.
[37]Joe Mitola, The software radio architecture. [J].IEEE Communications Magazine,1995(5):26-38
[38]文安平.QAM接收机中定时恢复算法设计与实现：[D].武汉：武汉科技大学,2005.
[39]田骏骅.高速QAM解调器的算法及VLSI实现研究：[D].上海：复旦大学,2005.
[40]张安安,杜勇,韩方景.全数字Costas环在FPGA上的设计与实现.[J].电子工程师,第32卷第1期,pp.18-20,2006.
[41]Zhang Weiliang, Pan Changyong, Guo Xingbo, Yang Zhixin. Design and FPGA Implementation of High-speed Square-root-raised-cosine FIR filters. [J].IEEE 2002.
[42]Yongbin Wu, YousefR. Shayan. Implementation of High-Speed Multi-level QAM Modems Based on FPGA. IEEE Tran. On Comm.2003.
[43]John R. Treichler, Michael G Larimore and Jeffrey C. Harp, "Practical Blind Demodulators for High-Order QAM Signals."[J]. IEEE Proceedings, Vol.86, No.10,pp.1907-1926,Oct.1998.
[44]叶双应.QAM解调芯片中匹配插值滤波器的设计与实现.[D].南京：东南大学,2006.
[45]张欣.扩频通信数字基带信号处理算法及其VLSI实现.[M].北京：科学出版社,2004
[46]John G.Proakis. Digital Communication(Fouth edition). [M]. Beijing: Publishing house of electronics industry,2001,333-357
[47]Yuan Ouyang and Chin-Ling Wang. A New Carrier Recovery Loop for High-Order Quadrature Amplitude Modulation. [J].IEEE,2002.
[48]A.Mouaki Benani and F.Gagnon. Comparison of Carrier Recovery Techniques in M-QAM Degital Communication Systems. [J]. IEEE,2000.
[49]K.H.Muller and Muller. Timing recovery in digital synchronous data receivers. [J]. IEEE Transactions on Communication,pp:516-530,1976.
[50]王宏.MATLAB6.5及其在信号处理中的应用.[M].北京：清华大学出版社.2004
[51]莱昂斯(著),朱光明,程建远(译).数字信号处理.[M].北京：机械工业出版社,2006
[2]邓青.数字QAM基带解调技术研究与研究.[D].南京：东南大学,2007.
[3]樊昌信.通信原理(第5版).[M].北京：国防工业出版社,2001.
[4]西瑞克斯(北京)通信设备有限公司.无线通信的MATLAB和FPGA实现.[M].北京：人民邮电出版社,2009.
[5]田耘,徐文波,等.无线通信FPGA设计.[M].北京：电子工业出版社,2008.
[6]姜宇柏,黄志强,等.通信收发信机的Verilog实现与仿真.[M].北京：机械工业出版社,2007.
[7]段吉还,黄智伟.基于CPLD/FPGA的数字通信系统建模与设计.[M].北京：电子工业出版社,2004.
[8]吴伟陵,牛凯.无线通信原理.[M].北京：电子工业出版社,2005.
[9]马娅娜.基于FPGA的QAM调制解调技术研究.[D].西安：西安电子科技大学,2007.
[10]陈俊秀.基于软件无线电的调制解调系统关键技术研究.[D].成都：成都理工大学,2009.
[11]Zhang Weiliang, Pan Changyong, Guo Xingbo, Yang Zhixin. Design and FPGA Implementation of High-speed Square-root-raised-cosine FIR filters. [J]. IEEE 2002.
[12]杨霖.基于FPGA的EDSL系统QAM解调器的研究与实现.[D].南京：东南大学,2006.
[13]Daekyo Shin, Ki Hyuk Park and Myung H. Sunwoo. A 64/256 QAM Receiver Chip for High-speed Communication. [J]. IEEE,2000.
[14]张辉,曹丽娜.现代通信原理与技术.[M].西安：西安电子科技大学出版社,2002.
[15]John GProakis.数字通信(第四版).[M].北京：电子工业出版社,2003.
[16]张公礼.全数字接收机理论与技术.[M].北京：科学出版社,2004
[17]姜宇柏,游思晴.软件无线电原理与工程应用.[M].北京：机械工业出版社,2006.
[18]楼顺天,刘小东,李博菡.基于MATLAB7.X的系统分析与设计—信 号处理.[M].西安：西安电子科技大学出版社.1998.240-250
[19]王沫然.Simulink4建模及动态仿真.[M].北京：电子工业出版社,2002.
[20]孙屹,李妍,等.Matlab通信仿真开发手册.[M].北京：国防工业出版社,2005.
[2l]任晓东,文博.CPLD/FPGA高级应用开发指南.[M].北京：电子工业出版社.2003
[22]夏宇闻,等.Verilog数字系统设计教程.[M].北京：北京航天航空大学出版社,2003.
[23]J.Bhasker著,孙海平等译,VERILOG HDL综合实用教程.[M].清华大学出版社,2004.
[24]徐欣,于红旗,易凡,卢启忠.基于FPGA的嵌入式系统设计.[M].北京：机械工业出版社,2004,9
[25]薛小刚,葛毅敏,Xilinx ISE9.X FPGA/CPLD设计指南.[M].人民邮电出版社,2007
[26]陈德峰,李欣.MQAM原理及其在EDSL系统中的应用.[J].铁路计算机应用,2000.：23 25
[27]陈德峰.EDSL系统中自适应MQAM调制器的研究及FPGA实现：[D].青岛：中国海洋大学,2007.
[28]史治国,洪少华,陈抗生.基于XILINX FPGA的OFDM通信系统基带设计.[M].杭州：浙江大学出版社,2009.
[29]张贤达.现代信号处理.[M].清华大学出版社,1995.1
[30]奥本海姆,离散时间信号处理.[M].黄建国,刘树棠译.科学出版社,1998.7
[31]胡广书.现代信号处理教程.[M].北京：清华大学出版社,2004.
[32]杨义先.最佳信号理论与设计.[M].人民邮电出版社,1996.12
[33]汤伟良,李建东,李维英.数控振荡器在FPGA上的实现.[J].微型机与应用2003,11：23-25
[34]王钿,卓兴旺.基于Verilog HDL的数字系统应用设计.[M].北京：国防工业出版社,2007.
[35]田骏骅.高速QAM解调器的算法及VLSI实现研究：[D].上海：复旦大学,2005.
[36]文安平.QAM接收机中定时恢复算法设计与实现：[D].武汉：武汉科技大学,2005.
[37]Joe Mitola, The software radio architecture. [J].IEEE Communications Magazine,1995(5):26-38
[38]文安平.QAM接收机中定时恢复算法设计与实现：[D].武汉：武汉科技大学,2005.
[39]田骏骅.高速QAM解调器的算法及VLSI实现研究：[D].上海：复旦大学,2005.
[40]张安安,杜勇,韩方景.全数字Costas环在FPGA上的设计与实现.[J].电子工程师,第32卷第1期,pp.18-20,2006.
[41]Zhang Weiliang, Pan Changyong, Guo Xingbo, Yang Zhixin. Design and FPGA Implementation of High-speed Square-root-raised-cosine FIR filters. [J].IEEE 2002.
[42]Yongbin Wu, YousefR. Shayan. Implementation of High-Speed Multi-level QAM Modems Based on FPGA. IEEE Tran. On Comm.2003.
[43]John R. Treichler, Michael G Larimore and Jeffrey C. Harp, "Practical Blind Demodulators for High-Order QAM Signals."[J]. IEEE Proceedings, Vol.86, No.10,pp.1907-1926,Oct.1998.
[44]叶双应.QAM解调芯片中匹配插值滤波器的设计与实现.[D].南京：东南大学,2006.
[45]张欣.扩频通信数字基带信号处理算法及其VLSI实现.[M].北京：科学出版社,2004
[46]John G.Proakis. Digital Communication(Fouth edition). [M]. Beijing: Publishing house of electronics industry,2001,333-357
[47]Yuan Ouyang and Chin-Ling Wang. A New Carrier Recovery Loop for High-Order Quadrature Amplitude Modulation. [J].IEEE,2002.
[48]A.Mouaki Benani and F.Gagnon. Comparison of Carrier Recovery Techniques in M-QAM Degital Communication Systems. [J]. IEEE,2000.
[49]K.H.Muller and Muller. Timing recovery in digital synchronous data receivers. [J]. IEEE Transactions on Communication,pp:516-530,1976.
[50]王宏.MATLAB6.5及其在信号处理中的应用.[M].北京：清华大学出版社.2004
[51]莱昂斯(著),朱光明,程建远(译).数字信号处理.[M].北京：机械工业出版社,2006