A joint channel estimation and unequal error protection scheme for image transmission in wireless OFDM systems

Abmac-OrIhqonal Frequency Division Multiplexing (OFDM) modulatlon, adopted by the L%@tal Video Broadcasting (DVB-T) standard, has been remgniml for its good performance for high data rate wireless communications. Therelore, the study ofthe robust transmission of multimedia data over OFDM system bas attracted e d d v e research interests. In the past, channel eslimation, which is an important asp& in OFDM systems, has not been exploited for multimedia transmission. When using the block training based channel estimation, OFDM data blocks experience unequal decodii error rate due to the imprecision of channel ertimatian. We use this property l a provide unequal error prot&ion(UEP) for transmission of SPMT coded images. Compared with the systems using pilot training channel estimation schemes, which are " m e n d e d in the DVB-T standard, the proposed scheme improves the PSNR of reconstmcled images by up to MB.