Wireless video has almost become an indispensable part of daily life. Conventional wireless video systems which contain separate source coding and channel coding are not suitable for broadcasting scenarios because of the rapid changes of channel status. The newly presented SoftCast is a jointly source-channel coding scheme which provides graceful quality transition but is not very efficient in important data protection due to operation over chunk. And the important data mainly exist in low frequency band. In this paper, we propose a Scalable Wireless video broadcast scheme based on Unequal Protection (SWUP) which allocates more bandwidth and power to important data for better accuracy. We use a method, named pseudo coset coding, to divide the important data into two parts by using the selected quantization step, where the coset index data are transmitted using conventional digital framework, while the residual codes utilizes SoftCast way. The simulation results show that our proposed scheme is about 3 ∼ 5dB and 2 ∼ 4dB better than 3D SoftCast and WaveCast in reconstruction quality respectively.
['Mengyang Lv', 'Yu Liu', 'Yumei Wang']
Scalable wireless video broadcast based on unequal protection