Power allocation and coding for image transmission over wireless channels

In this paper, joint optimization of power allocation and channel coding is proposed for image transmission over wireless channels. The proposed scheme works, iteratively to find the optimum combination of coding and power transmitted for individual bits to minimize the mean square error for better image quality. It is shown that bits of significant importance (most significant bits) should always be coded and allocated most of the power transmitted. However, other bits of less significance may be sent without coding and with less power. This is done while maintaining the average energy per bit at the same level. The combined approach shows a gain of about 3 dB compared to the case of coding alone. It also has better performance compared to the case of power allocation alone while reducing the peak-to-average ratio.