Optimized Embedded Multicarrier Modulation for Efficientdelivery of Layered Video Data

DELIVERY OF LAYERED VIDEO DATA. S. Sandeep Pradhan and Kannan Ramchandran Beckman Institute and Department of ECE University of Illinois, Urbana, IL 61801 E-mail:[email protected] and [email protected] ABSTRACT We tackle the problem of e cient image transmission over Multi-Carrier Modulation (MCM) systems, proposing the use of a layered or multiresolution (MR) framework. In this work, we treat the source as being characterized by multiple layers of importance, and therefore deserving of multiple levels of noise immunity, i.e. having di erent BER requirements. We present the idea of Embedded Multi-Carrier Modulation (EMCM) as a very e ective way of achieving this, and introduce a fast table-lookup based power allocation algorithm that optimizes the multicarrier constellation design in terms of maximizing the deliverable throughput bitrates for the di erent resolution layers, subject to a total power constraint. Simulation results of our EMCM system reveal substantial gains (up to about 25 %) in deliverable bit rates over optimized TDM-based MCM designs. Further, in typical image transmission simulations using an embedded wavelet image coder, the EMCM approach yields almost 3 dB gains in delivered quality over conventional single-resolution MCM systems.