Channel aware unequal error protection for image transmission over broadband wireless LAN
Orthogonal frequency division multiplexing (OFDM) has been adopted in many broadband wireless communication standards. In OFDM systems, channel estimation is a crucial module in coherent signal detection and receiver diversity combining. In this paper, we investigate the leakage effect of pilot-symbol-assisted channel estimation techniques and propose a channel-aware unequal error protection (UEP) scheme for multimedia communications in OFDM systems. The proposed method exploits the variations of (he bit error rate in different OFDM subchannels caused by the leakage effect, and provides UEP by transmitting the more important data through the subchannels experiencing lower channel estimation error. Compared with the systems that do not jointly consider the channel estimation in the transmission of multimedia data, the proposed scheme can improve the peak-signal-to-noise-ratio (PSNR) of reconstructed images by up to 3 dB.