1. LOGO The Principle of BeiDou Navigation System and Its Receiver Modification Course Code: GMAT9205 By LeShu Wu - Chinese Independent research and development of regional positioning system

2. 2011.5.24 LeShu Wu Contents Introduction 1 Positioning Principle 2 Compare with GPS 3 Receiver Modification 4 Conclusion 5 Reference 6

3. 2011.5.24 LeShu Wu 1.Introduction  1960s First Generation of Global navigation system based on Doppler principle  1970-1990 ， based on RNSS principle U.S. and U.S.S.R. started to establish new generation global navigation system  GPS – U.S.  GLONASS – U.S.S.R.

4. 2011.5.24 LeShu Wu Low cost & Short Circle - only 6 satellites can achieve Chinese region positioning Why China Choose Beidou? Communication – integrate positioning and communication on one platform which is important in disaster relief, search and rescue.

5. 2011.5.24 LeShu Wu 2.Positioning Principle BeiDou Navigation System (BDSS) “Double satellites positioning principle” GEOSTAR system “active satellite navigation and Communication system” 1970s American scientist G. K. Oneill

6. 2011.5.24 LeShu Wu Positioning Process and Principle Fig.1. Working Schematic Diagram of BDSS

7. 2011.5.24 LeShu Wu 1 st Time Delay Table.1. Signal Transport Part-1

8. 2011.5.24 LeShu Wu 2 nd Time Delay Table.2. Signal Transport Part-2

9. 2011.5.24 LeShu Wu Fig.2. Calculation Components 2(Ds1 + D1) ( D s1 + D1 + D s1 + D2 )

10. 2011.5.24 LeShu Wu 3. Compare with GPS

11. 2011.5.24 LeShu Wu

12. 2011.5.24 LeShu Wu Receiver Modification Fig.3. Overall Receiver System Schematic

13. 2011.5.24 LeShu Wu Modulation  OQPSK Modulation ： can avoid 180° phase shift I slip ： Sinusoidal modulation Q slip ： Cosine modulation Binary signal modulation ： NRZ“1 ， -1” Initial phase of “1” ： 0° Initial phase of “-1” ： 180°

14. 2011.5.24 LeShu Wu Fig.4. BDSS Signal modulation diagram

15. 2011.5.24 LeShu Wu 1 Encode signals I slip & Q slip Generator – 16kb/s NRZ bipolar signals 2 Multiply with 4.08Mb/s Short PN1 code (Kasami Sequence) 4.08Mb/s Long PN2 code (Gold Sequence) 3 Spread spectrum signal I slip delay half PN code period – Sin modulation Q slip – Cos modulation directly 4 I slip + Q slip send into the channel

16. 2011.5.24 LeShu Wu  Final transmit signals

17. 2011.5.24 LeShu Wu Demodulation Input Signal Q slip  Only demodulate I slip which includes satellite position and time. Q slip has nothing useful signals. I Slip Costas Central

18. 2011.5.24 LeShu Wu

19. 2011.5.24 LeShu Wu Control VOC output frequency Multiple I & Q Multiple with local PN code After Low-pass filter （ LPF ） I slip ： Q slip ：

20. 2011.5.24 LeShu Wu 5. Conclusion The Next Generation Of BDSS Same Principle as GPS More accurate on timing and positioning Combination with old system

21. 2011.5.24 LeShu Wu 6. Reference  [1]"The construction of BeiDou navigation system steps into important stage, "Three Steps" development guideline clear and certain" (China National Space Administration. 2010-05-19. http://www.BeiDou.gov.cn/2010/05/19/20100519101180c595f14a6d9938a42a2d796b 56.html. Retrieved 2010-05-19."The construction of BeiDou navigation system steps into important stage, "Three Steps" development guideline clear and certain" http://www.BeiDou.gov.cn/2010/05/19/20100519101180c595f14a6d9938a42a2d796b 56.html  [2]"Comparable with American and Russian in terms of performance, BeiDou-1 navigates for China" (in Chinese). China National Space Administration. 2003-05-30. http://www.cnsa.gov.cn/n615708/n620172/n677078/n751578/62676.html. Retrieved 2010-05-19."Comparable with American and Russian in terms of performance, BeiDou-1 navigates for China" http://www.cnsa.gov.cn/n615708/n620172/n677078/n751578/62676.html  [3]Pike, John. "BeiDou (Big Dipper)". Space. GlobalSecurity.org. http://www.globalsecurity.org/space/world/china/BeiDou.htm. Retrieved 2006-11- 09.[dead link]"BeiDou (Big Dipper)"GlobalSecurity.org http://www.globalsecurity.org/space/world/china/BeiDou.htmdead link  [4]Marks, Paul (2006-11-08). "China's satellite navigation plans threaten Galileo". NewScientist.com. http://www.newscientist.com/article/dn10472-chinas-satellite- navigation-plans-threaten-galileo.html. Retrieved 2006-11-09."China's satellite navigation plans threaten Galileo" NewScientist.comhttp://www.newscientist.com/article/dn10472-chinas-satellite- navigation-plans-threaten-galileo.html  [5]"China puts new navigation satellite into orbit".. 2007-02-03. http://english.gov.cn/2007-02/03/content_516638.htm. Retrieved 2010-05-20."China puts new navigation satellite into orbit" http://english.gov.cn/2007-02/03/content_516638.htm  [6]"BeiDou 1 Experimental Satellite Navigation System".. 2008-09-24. http://www.sinodefence.com/space/spacecraft/beidou1.asp. Retrieved 2010-05-20."BeiDou 1 Experimental Satellite Navigation System" http://www.sinodefence.com/space/spacecraft/beidou1.asp  [7]"60-day works in space -- Story of reparation of the BeiDou satellite" (in Chinese). Sohu. 2007-04-18. http://news.sohu.com/20070418/n249522961.shtml. Retrieved 2010-05-23."60-day works in space -- Story of reparation of the BeiDou satellite" Sohuhttp://news.sohu.com/20070418/n249522961.shtml  [8]"Compass due Next Year". Magazine article. Asian Surveying and Mapping. May 4, 2009. http://www.asmmag.com/news/compass-due-next-year. Retrieved 2009-05-05."Compass due Next Year"http://www.asmmag.com/news/compass-due-next-year  [9]"China successfully launched the third BeiDou satellite" (in Chinese). Sohu. 2010-01- 17. http://news.sohu.com/20100117/n269631862.shtml. Retrieved 2010-05-19."China successfully launched the third BeiDou satellite"http://news.sohu.com/20100117/n269631862.shtml  [10]"China sends Beidou navigation satellite to orbit".. 2010-06-02. http://www.spaceflightnow.com/news/n1006/02longmarch/. Retrieved 2010-06-04."China sends Beidou navigation satellite to orbit" http://www.spaceflightnow.com/news/n1006/02longmarch/  [11]"China successfully launches fifth satellite for its own global navigation network". Xinhuanet. 2010-08-01. http://news.xinhuanet.com/english2010/china/2010- 08/01/c_13424634.htm. Retrieved 2010-08-01."China successfully launches fifth satellite for its own global navigation network" Xinhuanethttp://news.xinhuanet.com/english2010/china/2010- 08/01/c_13424634.htm

22. LOGO Thanks for listening.