Scalable video SoftCast using magnitude shift

With the widespread popularity of mobile terminals, wireless video has become an indispensable part of daily life. The conventional wireless video transmission scheme which consists of separate digital source coding and digital channel coding is now unable to meet the broadcast and mobile scenarios owing to the dramatic changes in its channel conditions. However, a newly uncoded transmission scheme called SoftCast was presented to provide graceful quality transition. SoftCast performs power allocation over chunks to decrease the amount of Meta data. But the magnitudes vary dramatically in some chunks and SoftCast expends very large power to transmit some coefficients with large value. This paper introduces a scalable video SoftCast using Magnitude Shift to constraint the value of DCT coefficients. It only costs little power and bandwidth to transmit the overhead generated by Magnitude Shift. The experimental results show that the proposed scheme can improve the performance of the original SoftCast using 3D-DCT transform by 2-5dB.