Research On Wireless Video Soft Multicast Technology

Wireless video soft multicast scheme named SoftCast,because it can well adapt to the wireless transmission network user heterogeneity and has been widespread concern.At the same time,because the observed value of compression sensing is not structurally differentiated,this feature meets the requirements of wireless multicast.Therefore,this paper studies the SoftCast scheme combined with the compressed sensing theory,which mainly includes the following two parts:First,we propose a Distributed Compression Sensing Oriented Soft Video Transmission with 1D-DCT over Wireless(1D-DCS-Cast)base on Distributed Compressed Sensing-based multicast(DCS-Cast),and use the one-dimensional DCT transform to remove the correlation between the adjacent frame observations.At the encoder,we partition each frame apply block compressed sensing(BCS)to get a number of measurements,using interleaving package to package all the observations,since between observations with a very strong correlation in each packet,so we use the one-dimensional DCT transform to remove this correlation;In order to reduce the distortion energy,we further derive the optimal power allocation scheme for each packet,and transmit the optimized packets to the raw 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 SoftCast,DCS-cast and residual-based distributed compressed-sensing scheme for soft video multicast(RDCS-Cast).Second,we use NI USRP-2932 and Lab VIEW built a software radio system,to achieve the SoftCast encoded image in the real wireless channel transmission.This paper studies the synchronization algorithm and detection algorithm of the wireless communication system based on USRP and LabVIEW,and then build a SoftCast-based wireless image communication system,the superiority of SoftCast in wireless multicast is demonstrated by the real communication system.