In this work, we introduce the idea of adaptive sub-channel allocation based unequal error protection (ASCA-UEP) to a space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) system. In such a system, UEP is realized by adaptively allocating and transmitting high-priority and low-priority video data over high-quality and low-quality sub-channels, respectively. Further, we propose two ASCA-UEP schemes in a time division duplex (TDD) system: a receiver-based scheme and a transmitter-based scheme. Analysis and simulation results demonstrate that ASCA-UEP greatly enhances the quality of video reception, and the transmitter-based scheme is more robust to uplink channel noise than the receiver-based scheme, and is thus preferred when the receiver is power-constrained and the transmitter has sufficient power.published_or_final_versio
