The Performance Evaluation of OFDM/HL-16QAM System for Optimizing Image Transmission Quality in Wireless Fading

We have evaluated the performance of an OFDM/HL-16QAM system for achieving high quality image transmission. OFDM/HL-16QAM system has the capability of reliable high speed data service and simultaneous transmission of differentiated two quality of data streams in severe multipath fading channel. For application of image transmission, we have proposed the OFDM/HL-16QAM system adopting fixed length DCT based coding to achieve reasonable image compression rate and obtained the optimal hierarchical modulation parameter maximizing PSNR(Peak Signal to Noise power Ratio) of received still image. Then, it has been shown that the received image quality of the proposed system with optimized hierarchical modulation parameter is better than that of conventional OFDM/16QAM system. From the result, it is found that the proposed system is more effective for mobile multimedia services.