Low Complexity Doped Wireless Broadcast for Multimedia Applications

We propose an efficient application layer coding scheme suitable for time-limited wireless broadcast framework of the MBMS standards. The scheme, referred to as doped broadcast, is based on Fountain codes, and uses feedback to implement and control the tradeoff between the reconstruction delay, broadcast overhead, and decoding time/complexity. As the standardized schemes, our doped broadcast operates in two phases consisting of the limited time broadcast followed by an individualized repair phase in order to ensure (possibly prioritized) quality of service (QoS) to most users. The goal of the scheme is not to improve on any particular performance metric where highly optimized standard recommendations already perform exceptionally well, but rather to enable flexible and transparent mechanisms to implement and control tradeoff between different performance metrics. Toward this goal, we develop an analytically tractable model for doped broadcast with Ideal Soliton based codes leading to a repair strategy parameter estimation. The impact that inactivation and doping mechanisms employed by the decoder have on the complexity and overhead metrics is quantified and discussed for the proposed model. Hence, our approach guides a practical design tradeoff, which is important in today´s highly heterogeneous environments requiring individualized QoS.