Performance Analysis of Raptor Codes in OFDM Systems

In wireless communication systems, intended to support broadcast services, it is not feasible to use an error control strategy such as automatic repeat request (ARQ) due to the heavy channel and transmitter load caused by all repeat-requests. An alternative error correcting strategy not suffering from the disadvantages of using ARQ is the introduction of a forward error correcting (FEC) code. In this paper, forward error correcting codes called Raptor codes (a class of Fountain codes) are applied for orthogonal frequency division multiplexing(OFDM) systems, which is a popular multi-carrier modulation technique in broadband communications and is currently being used in the IEEE 802.16e (Wi-Max) standard. The BER performance and burst-erasure correction capability of Raptor codes are compared with that of quasi-cyclic LDPC codes in AWGN channel.