Analysis of the performance improvement of fountain codes over puncturing schemes for OFDM system

The orthogonal frequency division multiplexing (OFDM) has become the most popular technique for wireless communication nowadays because of its high spectral efficiency and robustness against frequency selective fading. The rateless codes can provide better performance when the channel characteristics are time varying in nature. Fountain codes are class of rateless codes with forward error correction capability for erasure channels. It is widely used to compensate for high delay of retransmission protocol, high BER and high erasure probability. The channel associated with the space communication and internet produces erasure in addition to noise on the signal. In this paper novel crosscoding scheme of convolutional encoding and fountain coding is proposed for OFDM to improve the performance of fountain coded OFDM system in AWGN channel and to extent the system performance to a channel having both erasure and noise. The performance of the system is compared with punctured OFDM system. The simulation results show that the performance of the proposed system is superior to existing punctured OFDM system.