Residual-based Distributed Compressed Sensing For Soft Video Multicasting Research

With the rapid development of wireless network and multimedia technology, video multicast transmission in wireless environment has received the widespread attention. However, it is still an enormous challenge that how to satisfy the needs of heterogeneous users. As the compressed-sensing deals with signals to obtain the observations which have no structural distinction.Thus, this paper try to apply the compressed-sensing feature mentioned above to video multicast transmission in wireless environment. The main works and innovations are as follows:Firstly, we propose an residual-based distributed compressed-sensing scheme for soft video multicast(RDCS-cast). At the encoder, we apply block compressed sensing(BCS) in each frame to get a number of measurements,according to the strong correlation in each video frame, for reference frames we transmit original measurements, but for the non-reference frames we transmit the residual values which derive by the reference and non-reference frames, and then all measurement data are packed; In order to reduce the distortion energy, we further derive the optimal power allocation scheme for the original measurements of reference frames and the residual measurements of non-reference frames measurements within each packet.And then transmitted over the OFDM channel. At the decoder side,the receivers with different channel characteristics obtain different numbers of packets and reconstruct videos with different quality. Experimental results show that our scheme has a greatly improved in performance at unicast and multicast than the Soft Cast and DCS-cast program, and CS shows a good robustness on the video multicast in wireless environment.Secondly, an adaptive distributed compressed sensing based video multicast(ARDCS-cast), is proposed in this paper. According to the different moving sequences have different correlations, we apply the RDCS-castscheme for the strong correlation sequences, and apply the ARDCS-cast scheme for the weak correlation sequences. At the encoder,we determine with the adaptive method if we use the residual technology on every block in non-reference frames. We first calculate the variance of their residual measurements and original measurements respectively; Then, we select the smaller variance between the residual and original measurements as the transmissive data. Meanwhile, we infer the formula of the power allocation again. The experimental results show that for an intense moving sequence, its performance has a great improvement.