Hybrid digital-analog video transmission based on H.264/AVC and ParCast in MIMO-OFDM WLANs

Wireless video transmission is one of the main applications of wireless local area networks. And high-speed video transmission can be achieved with the application of MIMO-OFDM technologies. But the conventional digital video transmission in MIMO has to degrade performances of all the antennas to be the same as the antenna with the worst channel gain. Based on H.264/AVC and ParCast, a hybrid digital-analog scheme which transmits the residuals of H.264/AVC in MIMO to further improve video performance is proposed. With effective design of H.264/AVC compression ratio and FEC code rate, appropriate power is assigned to the digital part to guarantee the digital signal can be decoded accurately. Besides, the proposed power allocation algorithm balances the noise interferences of digital signal in different antennas, minimizes the analog errors and maximizes the analog gains. Simulations show that almost perfect video performance can be achieved when videos are transmitted over MIMO-OFDM channels with various SNRs, and our scheme outperforms the ParCast scheme by no less than 8dB.