Wireless image transmission based on adaptive OFDM system

This paper presents the image transmission system, that consists of the wavelet based image compression algorithm and the adaptive OFDM system. The wavelet based image compression algorithm searches the position information of the significant coefficients by the quad-tree information and computes the magnitude information using the EZW method. The adaptive OFDM system allocates the modulation bit of each subcarrier according to the channel condition by using the channel estimation algorithm. The proposed image transmission system progressively transmits the input image according to the compression bit rate and improves, up to 8 dB, the PSNR performance of the adaptive modulation in comparison with that of the fixed modulation (16QAM).