Research On Multi-antenna HDA Video Transmission Scheme Based On Adaptive STBC

As a new cross-layer transmission technology,hybrid digital analog(HDA)video transmission can overcome the "cliff effect" caused by traditional digital transmission well,and has higher efficiency than analog transmission scheme.Multiple Input Multiple Output(MIMO)technology can further improve the transmission rate and efficiency of video through diversity gain and spatial multiplexing technology.Therefore,this paper studies the HDA scheme of MIMO system to improve the performance of wireless video transmission.The main work and innovation points of this paper include:Firstly,a multi-antenna HDA video transmission scheme based on adaptive STBC(space-time block coding)is proposed.First,each frame of video is organized into 64 packets,and the importance is arranged according to the energy of the packets.Then,OSTBC(Orthogonal Space-time Block Coding)and QSTBC(Quasi Orthogonal Space-time Block Coding)are selected according to the importance of the packets: OSTBC is used for transmitting the most important packets,QSTBC is used for transmitting the less important packets,and the other least important packets are discarded.Under the conditions of a given symbol rate and different channel signal-to-noise ratios,according to the best video restoration quality,a closed-form expression of transmission packet rearrangement is derived.The experimental results show that,in a 4×1 system,because STBC is selected adaptively according to the importance of packets,the proposed scheme achieves better quality than pure OSTBC or pure QSTBC,which reflects the advantages of the proposed scheme in bandwidth allocation.Secondly,a multi-antenna HDA video transmission power optimization scheme based on adaptive STBC is proposed.The expressions of analog signal distortion and analog signal power are derived on the premise that digital signal has no distortion,and the distortion of analog signal is reduced by optimizing the power distribution between digital signal and analog signal.The experimental results show that using power allocation optimization can further improve the quality of video reconstruction.