Efficiently-mapped adaptive hierarchical QAM for reliable scalable video communication
This paper proposes an efficiently-mapped adaptive hierarchical QAM (AHQAM) scheme for unequal error protection (UEP) of embedded video bitstream. The coded bits of each frame are hierarchically partitioned into high priority (HP) and low priority (LP) substream, using two-staged partitioning strategy. Then pairs of stream blocks, one from each substream are selected judiciously to form symbols, which are modulated using HQAM with varying modulation parameter. The proposed scheme is generic in nature and can be applied to any scalable video bitstream. Simulations are performed with 16-AHQAM for AWGN channel and it is observed that the proposed scheme offers up to 7.2 dB improvement in quality of received video as compared to 16-HQAM.