comparison of convolutional and trellis coded ofdm for satellite channels
Anushruti Jaiswal,Bhavna Vyas,A.Karthikeyan
Published in International Journal of Advanced Research in Electrical and Electronics Engineering
ISSN: 2321-4775 Impact Factor:1.6 Volume:1 Issue:1 Year: 08 June,2013 Pages:1-5
Abstract
Orthogonal frequency-division multiplexing (OFDM) is a method of encoding digital data on multiple carrier frequencies. The data is divided into several parallel orthogonal sub-carriers. Each orthogonal sub- carrier signals are used to carry data and is modulated with a conventional modulation scheme (such as quadrature amplitude modulation or phase-shift keying) at a low symbol rate. In this paper, Convolutional and Trellis Coded Modulation is considered with OFDM for a Rician fading channel according to the specifications given by the Iridium system. Bit error rate (BER) performance is analyzed for both the coding techniques with different modulation schemes for L and Ka bands. Trellis coded OFDM gives the better performance compared to convolutional coded (CC) OFDM systems. Peak to average power ratio (PAPR) of the transmitted message is reduced by using partial transmit sequence technique (PTS).
Kewords
OFDM, PAPR, Convolutional & Trellis coding, PTS, satellite channel, Rician channel, Hard Viterbi Decoding
Reference
1.“Typical Channel Coding and Modulation Scheme for Satellite Communication Systems” by Liu Tianjun, Ding Wenrui in 2008. 2. “Suitability of Turbo coded OFDM for LEO Satellite Channels in Global Mobile Communications” by W.A.C. Fernando, R.M.A.P Rajatheva in 2001. 3. www.complextoreal.com 4. www.1-core.com
