طراحي، تجزيه و تحليل يک سيستم مخابراتي براي ارسال امن سيگنال صحبت در كانال چندمسيري زير آب در خليج فارس
محورهای موضوعی : مهندسی برق و کامپیوترحميدرضا بخشي 1 * , حسين شهبازي 2
1 - دانشگاه شاهد
2 - پژوهشكده تحقيقات مهندسي
کلید واژه: تخمين كانالتداخل بين سمبليچندمسيري سيگنال صحبتيكسان‌ساز,
چکیده مقاله :
سيستمهاي مخابراتي بي‌سيم در زير آب داراي كاربرد‌هاي متعددي نظير كنترل از راه دور در عمليات حفاري چاه‌‌هاي نفت، جمع‌آوري اطلاعات ذخيره‌شده در پايگاه‌‌هاي اطلاعاتي در اعماق آب، ارسال اطلاعات سيگنال صحبت بين زيردريايي‌ها و غواص‌ها و عمليات اكتشاف و نقشه‌برداري از بستر اقيانوس‌ها هستند. در اين مقاله ضمن شبيه‌سازي كانال چندمسيره زير آب در خليج فارس، فرستنده و گيرند‌ه‌اي طراحي شده است كه براي ارسال امن سيگنال صحبت در پهناي باند كم مناسب هستند. در طراحي گيرنده از سه روش گيرنده RAKE، يكسان‌ساز خطي و يكسان‌ساز غير خطي استفاده شده و نتايج شبيه‌سازي نشان مي‌دهد که گيرنده با ساختار يكسان‌ساز غير خطی دارای بهترين عملکرد است.
One of the important applications of underwater communication is speech transmission between two divers or between divers and ship or submarine. This paper describes a project designed to investigate and demonstrate underwater communication system in Persian Gulf for speech transmission in a real channel. At first, transmitter is designed, then channel with real data is simulated by neural network and at last receiver is designed. Transmitted data is speech signal that for more secure transmission and low frequency bandwidth, a cryptography algorithm and speech coding algorithm is applied in transmitter. Quadrature phase shift keying (QPSK) signaling is employed to make efficient use of the available channel bandwidth. In the receiver, linear equalizer and decision feedback equalizer (DFE) are tested and the best scheme is applied. Also, ray tracing method is used for simulation of sound waves propagation in Persian Gulf underwater communication channel.
[1] M. Stojanovic, "Underwater acoustic communications," in Invited Paper, Proc. IEEE Electro Int. Conf., Boston, MA, pp. 435-440, Jun. 1995.
[2] F. Xiong, Digital Modulation Techniques, Artech House, Boston, US, 2000.
[3] A. S. Spanias, "Speech coding," Proceedings of the IEEE, vol. 82, no. 10, pp. 1541-1582, Oct. 1994.
[4] T. Painter and A. S. Spanias, "Perceptual coding of digital audio," Proceedings of the IEEE, vol. 88, no. 4, pp. 451-515, Apr. 2000. [5] M. Y. Rhee Internet Security, John Wiley & Sons Ltd, 2003.
[6] B. Stephen, Error Control Systems for Digital Communication and Storage, Upper Saddle River, N. J., Prentice Hall, 1995.
[7] M. C. Jeruchim, P. Balaban, and K. S. Shanmugan, Simulation of Communication Systems, Plenum Press, New York, 1992.
[8] A. Falahati, B. Woodward, and S. C. Bateman, "Underwater acoustic channel models for 4800 b/s QPSK signals," IEEE J. of Oceanic Engineering, vol. 16, no. 1, pp. 1-20, Jan. 1991.
[9] R. J. Urick, Principles of Underwater Sound, McGraw - Hill Book Company, 3rd Edition, 1983.
[10] C. Viala, C. Noel, and G. Lapieer, "Simulation of acoustic signal in time varying multipath underwater channel," Underwater Acoustics for Deep Sea Applications, 17 Jun. 2002, http://www.semantic-ts.fr/articles/publis/gr2a.doc.
[11] K. C. Hegewisch, N. R. Cerruti, and S. Tomsovic, "Ocean acoustic wave propagation and ray method correspondence: internal wave fine structure," the J. of the Acoustical Society of America, vol. 114, no. 4, p. 2428, Oct. 2003.
[12] ا. خداياري، ع. ولي‌نژاد و م. قاسميان، "مدل‌سازي انتشار امواج آكوستيكي در دريا و مدل‌سازي عملكرد سونار،" دوازدهمين كنفرانس برق ايران، جلد اول، صص. 331-337، مشهد، 1383.
[13] M. K. Simon and M. S. Alouini, Digital Communication Over Fading Channels, John Wiley & Sons Ltd, 2000.
[14] J. G. Proakis, Digital Communications, 3rd Ed. Boston, MA McGraw Hill, 1995.
[15] J. G. Proakis, M. Stojanovic, and J. Catipovic, "Phase coherent digital communications for underwater acoustic communications," IEEE J. Ocean. Eng., vol. 19, no. 1, pp. 100-111, Jan. 1994.
[16] M. Stojanovic, "Recent advances in high - speed underwater acoustic communications," IEEE J. of Oceanic Engineering, vol. 121, no. 2, pp. 125-136, Apr. 1996.
[17] J. P. Gomes and V. Barroso, SDR Underwater Acoustic Modem, Ph. D. Thesis, Instituto de Sistemas e Robotica, Lisboa, Portugal, Apr. 2005.