| 摘要(英) |
Satellite communications were originally developed for scientific and military researches. Nowadays, a number of nations have begun their plans to implement commercial Ka-band satellite systems in the world. These systems will offer multi-media and Internet communications services to individual and corporate customers around the world. ROCSAT-1 is Taiwan’s first scientific satellite. Because its success or failure will affect the future development of satellite technology, it is an object of great concern for the people of Taiwan.
For LEO satellites, systems at low elevation angle suffer not only large free space loss but also great physical attenuations. From the verifications, rain attenuation is the dominant propagation impairment in our experiment. The larger rain rate, the higher frequency or the lower elevation angle is, the larger rain attenuation value will become. Rain attenuation induced in the uplink direction (28.25GHz) are much larger than that induced in the downlink direction (18.45GHz) since the uplink utilizes a high frequency band.
For satellite communication experiments, it is very significant to establish a channel model as close as possible to the real situation. In the past two years, we have successively made some researches on channel characteristics and channel simulations of ROCSAT-1. In this thesis, we make many researches to improve the system performance by various FEC coding schemes: convolutional code, concatenated code, trellis coded modulation, turbo code, and turbo trellis coded modulation scheme. From the results, Turbo trellis coded modulation scheme has better performance, but its decoding structure demands more complexity and takes more time.
We discuss the specifications of ROCSAT-1 link need and how they vary through different paths. For this reason, we choose a real ROCSAT-1 pass as an example to make a complete description of the simulation procedure. Finally, we present the simulation process and give some suggestions from the simulation results. |
| 參考文獻 |
[1] Louis J. Ippolito Jr., “Radiowave Propagation in Satellite
Communications”.
[2] ITU Recommendation ITU-R RPN.618-4, 1996
[3] Asoka Dissanayake, Jeremy Allnutt, and Fatim Haidara, ” A prediction model that combines rain attenuation and other propagation impairment along earth-satellite paths ”, IEEE, Trans. on antenna and propagation, vol45, No 10,pp 1546-1558, 1997.
[4] Yen-Hsyang Chu and Shun-Peng Shih, “Ka Band Propagation Experiment for ROCSAT-1:Preliminary Results,” 中華衛星一號科學成果研討會大會手冊及論文摘要集, pp.111~112, 1999.
[5] Robert K. Crane, “Prediction of Attenuation by rain,” IEEE Trans. on Communications, Vol. Com-28, No. 9, pp1717~1733 Sept. 1980.
[6] Robert K. Crane, “A Global Model for Rain Attenuation Prediction,”EASCON’78 Record, IEEE Pub, 78CH 1354-4 AES, Arlington, VA, Sept. 1978.
[7] Crane, R. K., “Electromagnetic Wave Propagation Through Rain,”
Wiley, 1996.
[8] ITU-R Rec. 837-1, International Telecommunication Union.
[9] CCIR Rep.564-4
[10] Leon W., Digital and Analog Communication Systems.
[11] Rolf Johannesson, Kamil Sh. Zigangirov, ”Fundamentals of Convolutional Coding,” IEEE Press, 1999.
[12] G. D. Forney, Concatenated Codes, Cambridge, Mass.: MIT Press,
1967.
[13] Stephen B. Wicker, Vijay K. Bhargava, Reed-Solomon Codes and Their applications, Piscataway, pp. 25 ~ 38, NJ : IEEE Press, 1994.
[14] G. Ungerboeck and I. Csajka, “On improving data link performance by increasing the channel alphabet and introducing sequence coding,” in Proc., IEEE Int. Symp. On Inform. Theory, June 1976.
[15] G. Ungerboeck, “Channel Coding with Multilevel/Phase Signals”, IEEE Trans. Inform. Theory, vol. IT-28, no. 1, pp.55-67, Jan. 1982.
[16] Matthew C. Valenti, “Iteractive Detection and Decoding for Wireless Communication”, Viginia Polytechnic Institute and State University, July 8, 1999.
[17] J. Hagenauer, “Iterative decoding of binary block and convolutional codes,” IEEE Trans. Infrom. Theory, vol. 42, pp.429-445, Mar. 1996.
[18] Matthew C. Valenti, “Iteractive Detection and Decoding for Wireless Communication”, Viginia Polytechnic Institute and State University, July 8, 1999.
[19] B. Vucetic,”Iterative decoding algorithm,” in PIMRC’97, Helsinki, Finland, Sep. 1997, pp. 99-120.
[20] Branka Vucetic, Jinhong Yuan,” TURBO CODES Principles and Applications ”.
[21] P. Robertson and T. Woerz, “Bandwidth efficient turbo trellis-coded modulation using punctured component codes,” IEEE Journal on Selected Areas in Communications, vol. 16, no. 2, Feb. 1998, pp. 206-218.
[22] Gray D. Gordon and Walter L. Morgan, Principles of Communications Satellites, Jonh Wiley & Sons, Inc, 1993.
[23] Yi-Jeng Liau, “ Simulation & Preliminary Verification of Direct
Broadcast Experiments Via ROCSAT-1,” Master Thesis, National
Tsing-Hua University.
[24] Kuo-Wei Chao, “Noise Figure Modification and Simulation Results,”quarterly report to NSPO, September, 2000.
[25] Le-Gen Shi, “Channel Simulation of LEO ROCSAT-1 Using Ka-Band,” Master Thesis, National Tsing-Hua University.
[26] Pei-Kai Liau, “Channel Characteristics Analysis and ECP Experiment Planning for LEO ROCSAT-1 Using Ka-Band,” Master Thesis, National Tsing-Hua University, June 1999.
[27] Leo Wang, “System Performance Analysis and Simulation for ROCSAT-1 Direct Broadcast Experiment of Digital TV signals Using Ka-Band,” Master Thesis, National Center University. |
[Endnote RIS 格式]
[相關文章]
[文章引用]
[完整記錄]
[館藏目錄]
[檢視]
plurk
funp
live
udn
HD
myshare
netvibes
friend
youpush
delicious
baidu
Google bookmarks
del.icio.us
hemidemi
facebook
twitter
google
reddit