DVB-S2信道接收芯片载波恢复算法的研究与实现
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摘要
随着数字通信技术的飞速发展,卫星数字电视系统DVB-S逐渐的被新标准DVB-S2代替,由于国内的数字电视产业相对落后,所以跟踪最新的通信技术十分必要。
本论文详细的研究了第二代卫星数字电视系统DVB-S2的载波恢复技术。载波恢复是数字通信系统中解调模块里非常重要的一部分,用于纠正传输信道和接收系统所造成的信号的频偏、相偏和相位噪声。
由于载波恢复需要捕获较大的频偏范围、较短的收敛时间、较小的相位噪声和较低的硬件实现成本,所以本文从这四个方面考虑算法的选择。首先将载波恢复模块分成频率恢复环路和相位恢复环路,频率恢复环路用于纠正大的频偏,而相位恢复环路用于纠正剩余的频偏和相偏。分析了五种经典的频率检测器,由于四重相关器和频偏直接检测法能捕获的频偏范围小,而极大似然估计法和差分功率检测法的硬件实现复杂,所以选择了频率捕捉范围足够而且硬件实现方便的导频检测法作为频率检测器的算法。在分析了M阶科斯塔斯环、极型科斯塔斯环、直接判决法三种算法的原理和性能之后,选择了硬件实现简单、性能满足要求的极型科斯塔斯法作为相位检测器的算法,同时,锁定检测器采用了相偏累加法。然后用C语言对算法进行建模,仿真了环路捕获频偏范围、相位噪声、收敛速度等性能指标,仿真结果表明,能捕获至少20%的符号速率的频偏;在频偏为80KHz时,收敛时间是50us。然后根据仿真结果设定了环路滤波器的增益、锁定器的阈值等参数,最后给出了在不同信噪比下,整个环路的误码率,与理论值大约差了0.5dB。在浮点模型完成之后,进行了定点化和RTL代码实现,并对硬件结构进行了优化。最后在FPGA上进行综合,得到了硬件的最高可运行速度是85MHz,占用了硬件资源约为3000个LUT。
As the communication techniques improves, the satellite digital television system DVB-S will be replaced by the second generation standard DVB-S2. It is necessary to follow the newest communication techniques for the national digital television industry is behindhand.
This paper works on the carrier recovery techniques of DVB-S. Carrier recovery is an important part of the demodulator of digital communication systems, and it is used to correct the frequency offset, phase offset and the phase noise caused by the transmission channel and the demodulation.
Frequency offset, convergence time, phase noise and hardware cost are the most important factors for algorithm selecting. First, the carrier recovery loop is divided into two parts, frequency recovery loop and phase recovery loop. Frequency recovery loop is used to correct the initial frequency offset and phase recovery loop is used to correct the residual frequency offset and phase offset. Five classical algorithms are studied. Quadricorrector and Direct-Detector can capture small frequency offset range while Maximum-Likelihood and Differential-Power have complex hardware, so Pilot-aided detector is used in frequency recovery loop. And Polarity Costas Loop and Phase Offset Accumulation are adopted in phase recovery loop and lock detector respectively. C language is used to setup the float point model. Performance including frequency offset range, phase noise and convergence speed are simulated. It shows that at least 20 percents of symbol rate frequency offset can be captured, and the convergence speed is 50us when the frequency offset is 80kHz. The loop filter gain and the lock detector threshold are set according to the simulation result. The BER of the whole loop is also present. It’s about 0.5dB worse than the theory. Fixed point model and RTL code are finished, and the hardware structure is also optimized. Finally, the FPGA synthesis shows that hardware’s highest speed is 85MHz, while about 3000 LUTs are utilized.
本论文详细的研究了第二代卫星数字电视系统DVB-S2的载波恢复技术。载波恢复是数字通信系统中解调模块里非常重要的一部分,用于纠正传输信道和接收系统所造成的信号的频偏、相偏和相位噪声。
由于载波恢复需要捕获较大的频偏范围、较短的收敛时间、较小的相位噪声和较低的硬件实现成本,所以本文从这四个方面考虑算法的选择。首先将载波恢复模块分成频率恢复环路和相位恢复环路,频率恢复环路用于纠正大的频偏,而相位恢复环路用于纠正剩余的频偏和相偏。分析了五种经典的频率检测器,由于四重相关器和频偏直接检测法能捕获的频偏范围小,而极大似然估计法和差分功率检测法的硬件实现复杂,所以选择了频率捕捉范围足够而且硬件实现方便的导频检测法作为频率检测器的算法。在分析了M阶科斯塔斯环、极型科斯塔斯环、直接判决法三种算法的原理和性能之后,选择了硬件实现简单、性能满足要求的极型科斯塔斯法作为相位检测器的算法,同时,锁定检测器采用了相偏累加法。然后用C语言对算法进行建模,仿真了环路捕获频偏范围、相位噪声、收敛速度等性能指标,仿真结果表明,能捕获至少20%的符号速率的频偏;在频偏为80KHz时,收敛时间是50us。然后根据仿真结果设定了环路滤波器的增益、锁定器的阈值等参数,最后给出了在不同信噪比下,整个环路的误码率,与理论值大约差了0.5dB。在浮点模型完成之后,进行了定点化和RTL代码实现,并对硬件结构进行了优化。最后在FPGA上进行综合,得到了硬件的最高可运行速度是85MHz,占用了硬件资源约为3000个LUT。
As the communication techniques improves, the satellite digital television system DVB-S will be replaced by the second generation standard DVB-S2. It is necessary to follow the newest communication techniques for the national digital television industry is behindhand.
This paper works on the carrier recovery techniques of DVB-S. Carrier recovery is an important part of the demodulator of digital communication systems, and it is used to correct the frequency offset, phase offset and the phase noise caused by the transmission channel and the demodulation.
Frequency offset, convergence time, phase noise and hardware cost are the most important factors for algorithm selecting. First, the carrier recovery loop is divided into two parts, frequency recovery loop and phase recovery loop. Frequency recovery loop is used to correct the initial frequency offset and phase recovery loop is used to correct the residual frequency offset and phase offset. Five classical algorithms are studied. Quadricorrector and Direct-Detector can capture small frequency offset range while Maximum-Likelihood and Differential-Power have complex hardware, so Pilot-aided detector is used in frequency recovery loop. And Polarity Costas Loop and Phase Offset Accumulation are adopted in phase recovery loop and lock detector respectively. C language is used to setup the float point model. Performance including frequency offset range, phase noise and convergence speed are simulated. It shows that at least 20 percents of symbol rate frequency offset can be captured, and the convergence speed is 50us when the frequency offset is 80kHz. The loop filter gain and the lock detector threshold are set according to the simulation result. The BER of the whole loop is also present. It’s about 0.5dB worse than the theory. Fixed point model and RTL code are finished, and the hardware structure is also optimized. Finally, the FPGA synthesis shows that hardware’s highest speed is 85MHz, while about 3000 LUTs are utilized.
引文
1. 俞斯乐. 电视原理(第六版). 国防工业出版社. 2006,3
2. EN 300 421 V1.1.2(Digital Video Broadcasting; Framing Structure, Channel Coding and Modulation For 11/12GHz Satellite Services). 1997,8
3. ETSI EN 302 307V1.1.1(Digital Video Broadcasting; Second Generation Framing Structure, Channel Coding and Modulation Systems for Broadcasting, Interactive Services, News Gathering and Other Broadband Satellite Application). 2005,3
4. ETSI TR 102 376 V1.1.1(Digital Video Broadcasting User Guidelines for Second Generation System for Broadcasting, Interactive Services, News Gathering and Other Broadband Satellite Application ). 2005,2
5. Bernard Sklar. Digital Communications: Fundamentals and Applications, Second Edition. Prentice Hall PRT. 2001.
6. 王福昌,鲁昆生. 锁相技术. 华中科技大学出版社. 1997,5.
7. 匡锦瑜,姚力. 非线性电子线路基础. 北京师范大学出版社. 1999.
8. Aldo N.D’Andrea, Umberto Mengli. Design Of Quadricorrelators for Automatic Frequency Control Systems. Transactions On Communications. VOL. 41, NO 6. 1993,6.
9. Georges Karam, Isabelle Jeanclaude, Hikmet Sari. A Reduced-Complexity Frequency Detector Derived from the Maximum-Likelihood Principle. IEEE. 1995.
10. Hikmet Sari, Said Moridi. New phase and Frequency Detectors for Carrier Recovery in Psk and Qam Systems. IEEE Transactions on Communications. VOL. 36, NO 9. 1988,9.
11. E. Casini, R. De Gaudenzi, A. Ginesi. DVB-S2 Modem Algorithms Design and Performance over Typical Satellite Channels. Int. J. Satell. Commun. Network. 2004.
12. Yang JianXiao, Wang kuang, Zou ZhiYong. DVB-S2 Inner Receiver Design for Broadcasting Mode. Journal of Zhejiang University Science A. 2007,8(1):28-35.
13. 黄智杰,易志强. 新一代卫星标准中解调算法的研究. 浙江大学学报(工学版). 2005,8.
14. Ki-Yun and Hyung-Jin Choi. Design Of Carrier Recovery Algorithm For High-Order Qam With Large Frequency Acquisition Range. IEEE. 2001.
15. 史晓锋,陈咏恩. DVB-C 接收机中的载波恢复电路设计. 电子技术应用. 2006.
16. 胡广书. 数字信号处理--理论、算法与实现. 清华大学出版社. 1997.
17. Ben Cohen. Component Design by Example. VhdlCohen Publishing. 2001.
18. Virtex-II Platform FPGAs: Introduction and Overview. http://www.xilinx.com/
19. Yuan Ouyang, Chin-Liang Wang. A New Carrier Recovery Loop for High-Order Quadrature Amplitude Modulation. IEEE. 2002.
20. Yair Linn. A Robust Phase Detection Structure for M-PSK: Theoretical Derivations, Simulation results, and System Identification Analysis. IEEE. 2005,5.
21. Steven P. Nicoloso. An Investigation of Carrier Recovery Techniques for PSK Modulated Signals in CDMA and Multipath Mobile Environments. Virginia Polytechnic Institute and State University. 1997.
22. Ivan B.Djordjevic, Mihajlo C. Stefanovic. Coherent Optical PSK Systems with Costas Loop in Multichannel Environment for Nonlinear PLL model. IEEE. 1999.
23. Neil K. Jablon. Joint blind equalization, Carrier Recovery and Timing Recovery for High-Order QAM Signal Constellations. IEEE Transactions on Signal Processing. VOL. 40, NO 6. 1992,6.
24. Y. Matsumoto, M.Morikura, S. Kato. A New Carrier Recovery Circuit for Mobile Satellite Communications. IEEE. 1992.
25. Marvin K. Simon, Eilliam C. Lindsey. Optimum Performance of Suppressed Carrier Receivers with Costas Loop Tracking. IEEE Transactions on Communications. VOL. COM-25, NO 2. 1977,2.
26. Aldo N. D’Andrea, U.Mengli. Performance of a Quadricorrelator Driven by Modulated Signals. IEEE Transactions on Communications. VOL. 38, NO 11. 1990,11.
27. Floyd M. Gardner. Properties of Frequency Difference Detectors. IEEE Transactions on Communications. VOL. COM-33, NO 2. 1985,2.
28. Robbert v.v. Wal, Leo Montreuil. QPSK and BPSK Demodulator Chip-Set for Satellite Applications. IEEE Transactions on Consumer Electronics. VOL. 41, NO 1. 1995,2.
29. Yair Linn, Nir Peleg. A Family of Self-Normalizing Carrier Lock Detectors and Es/N0 Estimators for M-PSK and Other Phase Modulation Schemes. IEEE Transactions on Wireless Communications. VOL. 3, NO 5. 2004,9.
30. A. Mileant, S. Hinedi. Lock Detection in Costas Loops. IEEE Transactions on Communications. VOL. 40, NO 3. 1992,5.
31. Amir H. Makarios, Patrick G. Farrell. Noise and False-Lock Performance of the PSK-Tanlock Loop. IEEE Transactions on Communications. VOL. COM-40, NO 10. 1982,10.
32. L. M. Robinson. Tanlock: A Phase Lock Loop of Extended Tracking Capabilities. In Proc, Nat. Conf. Military Electron. 1962,2.
33. M. L. Olson. False Lock Detection in Costas Demodulators. IEEE Transactions on AES, Vol AES-11. 1975,5.
34. F.M.Gardner. A BPSK/QPSK Timing-Error Detector for Sampled Receivers. IEEE Transactions on Communications. VOL COM-34,1986,5.
35. Thomas Alberty, Volker Hespelt. A New Pattern Jitter Free Frequency Error Detector. IEEE Transactions on Communications. VOL 37, NO. 2, 1989,2.
36. John F. Wakerly. Digital Design-Principles & Practices.(Third Edition). Prentice Hall. 2000.
37. John R. Barry, Edward A. Lee, David G. Messerschmitt. Digital communication. Kluwer Academic Publishers. 2004.
38. Charles R. Cahn. Improving Frequency Acquisition of a Costas Loop. IEEE Transactions on Communications. VOL COM-25,1977,11.
39. Umberto Mengali, Aldo N.D’Andrea. Synchronization Techniques for Digital Receivers. Plenum Press. New York and London. 1997.
40. 周立丰. DVB-S 信道接收芯片载波恢复的研究及 ASIC 实现. 浙江大学硕士学位论文. 2005.
41. 沈丽丽,侯春萍. DVB-C 系统中载波恢复技术的比较. 电视技术. 2006.
42. 袁清升,刘文. 相位处理载波恢复算法研究. 信息与电子工程. 2003,6.
43. 袁清升,陈慧. 全数字接收机中的载波恢复算法研究. 哈尔滨工程大学学报. 2002,10.
44. 杨知行,刘奇佳. 全数字接收机中同步算法的定点设计. 中国空间科学学会空间探测专业委员会第十九次学术会议论文集(下册). 2006.
45. 董亚萍,金博. 基于扫描算法的 QPSK 载波恢复技术研究. 无线通信. 2006,7.
46. 崔恒亮,林涛. 基于 FPGA 的 DVB-S2 解调系统. 电视技术. 2005,7.
47. 桑林,郝建军,刘丹谱. 数字通信. 北京邮电大学出版社. 2002.
48. 谭浩强. C 程序设计(第二版). 清华大学出版社. 1999.
2. EN 300 421 V1.1.2(Digital Video Broadcasting; Framing Structure, Channel Coding and Modulation For 11/12GHz Satellite Services). 1997,8
3. ETSI EN 302 307V1.1.1(Digital Video Broadcasting; Second Generation Framing Structure, Channel Coding and Modulation Systems for Broadcasting, Interactive Services, News Gathering and Other Broadband Satellite Application). 2005,3
4. ETSI TR 102 376 V1.1.1(Digital Video Broadcasting User Guidelines for Second Generation System for Broadcasting, Interactive Services, News Gathering and Other Broadband Satellite Application ). 2005,2
5. Bernard Sklar. Digital Communications: Fundamentals and Applications, Second Edition. Prentice Hall PRT. 2001.
6. 王福昌,鲁昆生. 锁相技术. 华中科技大学出版社. 1997,5.
7. 匡锦瑜,姚力. 非线性电子线路基础. 北京师范大学出版社. 1999.
8. Aldo N.D’Andrea, Umberto Mengli. Design Of Quadricorrelators for Automatic Frequency Control Systems. Transactions On Communications. VOL. 41, NO 6. 1993,6.
9. Georges Karam, Isabelle Jeanclaude, Hikmet Sari. A Reduced-Complexity Frequency Detector Derived from the Maximum-Likelihood Principle. IEEE. 1995.
10. Hikmet Sari, Said Moridi. New phase and Frequency Detectors for Carrier Recovery in Psk and Qam Systems. IEEE Transactions on Communications. VOL. 36, NO 9. 1988,9.
11. E. Casini, R. De Gaudenzi, A. Ginesi. DVB-S2 Modem Algorithms Design and Performance over Typical Satellite Channels. Int. J. Satell. Commun. Network. 2004.
12. Yang JianXiao, Wang kuang, Zou ZhiYong. DVB-S2 Inner Receiver Design for Broadcasting Mode. Journal of Zhejiang University Science A. 2007,8(1):28-35.
13. 黄智杰,易志强. 新一代卫星标准中解调算法的研究. 浙江大学学报(工学版). 2005,8.
14. Ki-Yun and Hyung-Jin Choi. Design Of Carrier Recovery Algorithm For High-Order Qam With Large Frequency Acquisition Range. IEEE. 2001.
15. 史晓锋,陈咏恩. DVB-C 接收机中的载波恢复电路设计. 电子技术应用. 2006.
16. 胡广书. 数字信号处理--理论、算法与实现. 清华大学出版社. 1997.
17. Ben Cohen. Component Design by Example. VhdlCohen Publishing. 2001.
18. Virtex-II Platform FPGAs: Introduction and Overview. http://www.xilinx.com/
19. Yuan Ouyang, Chin-Liang Wang. A New Carrier Recovery Loop for High-Order Quadrature Amplitude Modulation. IEEE. 2002.
20. Yair Linn. A Robust Phase Detection Structure for M-PSK: Theoretical Derivations, Simulation results, and System Identification Analysis. IEEE. 2005,5.
21. Steven P. Nicoloso. An Investigation of Carrier Recovery Techniques for PSK Modulated Signals in CDMA and Multipath Mobile Environments. Virginia Polytechnic Institute and State University. 1997.
22. Ivan B.Djordjevic, Mihajlo C. Stefanovic. Coherent Optical PSK Systems with Costas Loop in Multichannel Environment for Nonlinear PLL model. IEEE. 1999.
23. Neil K. Jablon. Joint blind equalization, Carrier Recovery and Timing Recovery for High-Order QAM Signal Constellations. IEEE Transactions on Signal Processing. VOL. 40, NO 6. 1992,6.
24. Y. Matsumoto, M.Morikura, S. Kato. A New Carrier Recovery Circuit for Mobile Satellite Communications. IEEE. 1992.
25. Marvin K. Simon, Eilliam C. Lindsey. Optimum Performance of Suppressed Carrier Receivers with Costas Loop Tracking. IEEE Transactions on Communications. VOL. COM-25, NO 2. 1977,2.
26. Aldo N. D’Andrea, U.Mengli. Performance of a Quadricorrelator Driven by Modulated Signals. IEEE Transactions on Communications. VOL. 38, NO 11. 1990,11.
27. Floyd M. Gardner. Properties of Frequency Difference Detectors. IEEE Transactions on Communications. VOL. COM-33, NO 2. 1985,2.
28. Robbert v.v. Wal, Leo Montreuil. QPSK and BPSK Demodulator Chip-Set for Satellite Applications. IEEE Transactions on Consumer Electronics. VOL. 41, NO 1. 1995,2.
29. Yair Linn, Nir Peleg. A Family of Self-Normalizing Carrier Lock Detectors and Es/N0 Estimators for M-PSK and Other Phase Modulation Schemes. IEEE Transactions on Wireless Communications. VOL. 3, NO 5. 2004,9.
30. A. Mileant, S. Hinedi. Lock Detection in Costas Loops. IEEE Transactions on Communications. VOL. 40, NO 3. 1992,5.
31. Amir H. Makarios, Patrick G. Farrell. Noise and False-Lock Performance of the PSK-Tanlock Loop. IEEE Transactions on Communications. VOL. COM-40, NO 10. 1982,10.
32. L. M. Robinson. Tanlock: A Phase Lock Loop of Extended Tracking Capabilities. In Proc, Nat. Conf. Military Electron. 1962,2.
33. M. L. Olson. False Lock Detection in Costas Demodulators. IEEE Transactions on AES, Vol AES-11. 1975,5.
34. F.M.Gardner. A BPSK/QPSK Timing-Error Detector for Sampled Receivers. IEEE Transactions on Communications. VOL COM-34,1986,5.
35. Thomas Alberty, Volker Hespelt. A New Pattern Jitter Free Frequency Error Detector. IEEE Transactions on Communications. VOL 37, NO. 2, 1989,2.
36. John F. Wakerly. Digital Design-Principles & Practices.(Third Edition). Prentice Hall. 2000.
37. John R. Barry, Edward A. Lee, David G. Messerschmitt. Digital communication. Kluwer Academic Publishers. 2004.
38. Charles R. Cahn. Improving Frequency Acquisition of a Costas Loop. IEEE Transactions on Communications. VOL COM-25,1977,11.
39. Umberto Mengali, Aldo N.D’Andrea. Synchronization Techniques for Digital Receivers. Plenum Press. New York and London. 1997.
40. 周立丰. DVB-S 信道接收芯片载波恢复的研究及 ASIC 实现. 浙江大学硕士学位论文. 2005.
41. 沈丽丽,侯春萍. DVB-C 系统中载波恢复技术的比较. 电视技术. 2006.
42. 袁清升,刘文. 相位处理载波恢复算法研究. 信息与电子工程. 2003,6.
43. 袁清升,陈慧. 全数字接收机中的载波恢复算法研究. 哈尔滨工程大学学报. 2002,10.
44. 杨知行,刘奇佳. 全数字接收机中同步算法的定点设计. 中国空间科学学会空间探测专业委员会第十九次学术会议论文集(下册). 2006.
45. 董亚萍,金博. 基于扫描算法的 QPSK 载波恢复技术研究. 无线通信. 2006,7.
46. 崔恒亮,林涛. 基于 FPGA 的 DVB-S2 解调系统. 电视技术. 2005,7.
47. 桑林,郝建军,刘丹谱. 数字通信. 北京邮电大学出版社. 2002.
48. 谭浩强. C 程序设计(第二版). 清华大学出版社. 1999.