Unequal block for low bandwidth adaption in wireless video broadcast

Abstract

With the development of information technology, people's demand for wireless video is improved. Recently, an uncoded video transmission scheme called SoftCast was proposed for wireless video communication which provided graceful transition quality. However, when channel bandwidth is low, we need to discard some packets before transmitting to meet the requirement of bandwidth. This will cause a sharp decline on receiver video quality. This paper proposed an unequal block method (UBCAST) based on the frequency of image. UBCAST divides the lowest frequency into the biggest block to protect low frequency information, and divides the highest frequency into the smallest block which can protect low frequency packets from being discarded. What's more we can increase high frequency block proportion to improve transmission quality. And we can also increase low frequency block proportion to increase discarding packets proportion to meet the bandwidth requirement of channel. The experimental results show that when transmitting video information completely, we can improve the performance of the original SoftCast using 8∗8 block up to 2dB. When the SNR of channel is 20dB, discarding packets, we can even get a 10dB gain.