Fast Prioritized Bit-Loading and Subcarriers Allocation for Multicarrier Systems

Unequal Error Protection (UEP) is the key to future multi-layer and scalable data and video transmission. This paper presents a novel bit-loading and channel adaptation technique to realize UEP properties in the physical transport using greedy and sub-optimal bit-loading algorithms. In this case, we exploited the power minimization approach developed by the greedy algorithm to allow for an arbitrary number of classes, arbitrary SNR margins between the classes, and arbitrary numbers of bits per class. We achieved a similar results using a fast sub-optimum power minimization bit-loading algorithm based on Campello´s algorithm. Our results show the suitability of this technique to realize UEP for a single user case using orthogonal frequency division multiplexing (OFDM). Additionally, we extended the results to demonstrate the performance of allocating resources to two users with different quality of service (QoS), each of which requires data of different priorities.