Optimal subcarrier allocation for H.264 based scalable video transmission in 4G OFDMA systems

In this paper, we present a novel scheme for optimal OFDMA subcarrier allocation towards video quality maximization employing the paradigm of H.264 based scalable video coding (SVC). We deduce the rate and quality model parameters for video characterization of the SVC extension of the H.264/AVC and propose an optimization framework for sum quality maximization of the transmitted video streams in unicast and multicast 4G scenarios. We derive the closed form solution for optimal quantizer selection towards net video quality maximization subject to rate constraints of the unicast/ multicast users, taking into account the different modulation and coding rates of the multicast groups in the 4G wireless system. This in turn yields the optimal OFDMA time/frequency resource allocation for video multiplexing. In the simulation results section, we specialize our proposed algorithm in the context of WiMAX based 4G video transmission and demonstrate that our algorithm provides significant improvement in video quality over the content agnostic non-scalable equal symbol rate allocation scheme for unicast and multicast scenarios.