Adaptive Coded Modulation for OFDM System
محتوى المقالة الرئيسي
الملخص
This paper studies the adaptive coded modulation for coded OFDM system using punctured convolutional code, channel estimation, equalization and SNR estimation. The channel estimation based on block type pilot arrangement is performed by sending pilots at every sub carrier and using this estimation for a specific number of following symbols. Signal to noise ratio is estimated at receiver and then transmitted to the transmitter through feedback channel ,the transmitter according to the estimated SNR select appropriate modulation scheme and coding rate which maintain constant bit error rate
lower than the requested BER. Simulation results show that better performance is confirmed for target bit error rate (BER) of (10-3) as compared to conventional modulation schemes, the convolutional coded modulation offers a SNR gains of 5 dB compared to uncoded state at BER of 10-3. The proposed adaptive OFDM scheme maintains fixed BER under changing channel conditions.
تفاصيل المقالة
كيفية الاقتباس
تواريخ المنشور
المراجع
Buthaina Mosa Omran,“IMPROVEMENT TECHNIQUES FOR SATELLITE DIGITAL VIDEO BROADCASTING USING OFDM”, P.HD. Thesis, in electronic and communication engineering, University of Baghdad, 2007.
F.Y. Long and K.T. Lo ,“Measurements for performance degradation of adaptive modulation scheme caused by channel quality estimation error” IEE, Proceeding Communication Vol 150, No. 2, April 2003.
Fernando H. Gregorio,“802.11a - OFDM PHY Coding and Interleaving”, Helsinki University of Technology.
Hyung Suk Chu, Byung Su Park and Chong Koo An ,"Wireless Image Transmission based on Adaptive OFDM System",IEEE, 2007.
Nevio Benvenuto and Filippo Tosato, “On the selection Of Adaptive Modulation and Coding Modes Over OFDM”, IEEE Communications Society, 2004.
Seiichi Sampei and Hiroshi Harada, “System Design Issues and Performance Evaluations for Adaptive Modulation in New Wireless Access Systems”, Proceedings of the IEEE, Vol. 95, No. 12, December 2007.
Sinem Coleri, Mustafa Ergen, Anuj Puri, and Ahmad Bahai , “Channel Estimation Techniques Based on Pilot Arrangement in OFDM Systems”, IEEE Transactions On Broadcasting, VOL. 48, NO. 3, September 2002.