Image and Video Transmission over Wireless Channels: A Subband Modulation Approach

A new approach of reliable image and video transmission over wireless channels is proposed. The subband modulation which combines source coding and channel modulation schemes achieves high compression efficiency and preferable quality. Further performance gain is obtained by multiresolution modulation and a bits re-mapping scheme that assigns efficient mapping from each source code word to channel modulation points. We show that bits re-mapping schemes perform nearly the same as the optimal mapping design scheme but with much lower complexity. The simulations are carried out on Additive White Gaussian Noise (AWGN) channels and slow Rayleigh fading channels

Subband Coded Image Transmitting over Noisy Channels Using Multicarrier Modulation

In this paper, we present a new loading algorithm for subband coded image transmission on multicarrier modulation systems. The image subbands are transmitted simultaneously, each occupying a number of subchannels. Different modulation rates and powers are assigned to the subchannels transmitting different subbands. Unlike the traditional loading algorithms, which flat the error performance of all the subchannels, the proposed loading algorithm assigns different error performances to the subchannels in order to provide unequal error protection for the subbands data. Numerical examples show that the proposed algorithm yields significant improvement over traditional loading algorithms, especially for spectral-shaped channels